Wednesday Evening
6:50 PM Opening Remarks - Mike Brown
7:00 PM Spatial Cognition I (Chair - Mike Brown)
7:00 PM Jody L. Lewis (University of Wisconsin –Stevens Point), Alan C. Kamil (University of Nebraska –Lincoln), & Kate Webbink (University of Nebraska -Lincoln)
Landmark cues are important for nutcracker spatial memory
Clark’s nutcrackers (Nucifraga Columbiana) are susceptible to proactive interference when remembering serial lists of locations.  We tested each bird’s memory for two serial lists in an open room.  During each list, they were shown a series of locations, given a 5 minute retention interval, and were then required to locate the seeds in the list using the cluster method.  Memory for locations was poorer for the second list.  We found that changing the landmark array between list 1 and list 2 decreased proactive interference, but changing the wall cues in the room did not.
7:14 PM Francis Bartlett and Fred Dyer (Michigan State University)
When do honey bees use snapshots during navigation?
Previous studies suggest that honey bees store an image of local landmarks near a rewarding goal location.  This memory is then used in a sequential image matching process to generate steering commands that lead to the goal upon their return.  Evidence for image matching during honey bee navigation comes from search distribution data collected when foragers were very near the goal location. Our experiments examined whether honey bees use a similar image matching strategy from more remote locations outside a familiar landmark array.  We found that honey bees prefer to use a single landmark as a beacon to get near a familiar landmark array even over very short distances.  Our results indicate that if bees use a snapshot to guide flight it is primarily during the final search in a small region surrounding the goal.
7:28 PM Jerome Cohen, Xue Han, Anca Mateir, & Varakini Parameswaran (University of Windsor)
Estimating Rats’ Working Memory Capacity for Objects in a Foraging Task
We developed a method for estimating the number of objects a rat can retain in its working memory as follows. After allowing a rat to obtain food under each object during a ‘study’ segment in foraging arena, we return it to the foraging arena for the ‘test’ segment to search for one or more new baited objects that replace one or more of the original objects. We analyzed the effects of varying the size of the patch (number of objects) on a trial and the proportion of new objects replacing original objects on rats’ accuracy in finding the new objects. We estimate each rat’s retention capacity by comparing its number of choices it made to find the new object(s) over many trials with hypothetical number of choices based on chance to perfect retention. We examine how our preparation addresses problems concerning measurement of memory in non-verbal organisms (e.g., Thorpe et al., 2004) and compare our estimates of rats’ working memory capacity for objects with that in verbal organisms (e.g. Olivers et al., 2006).
7:42 PM Michael F. Brown & Karen Doyle (Villanova University)
Social effects on spatial choice: Social stimuli and social memories produce different effects
We have recently reported several experiments in which pairs of rats made choices together in a radial arm maze. In those reports, the previous choices of another rat sometimes produced an increase in the probability of spatial choice and sometimes produced a decrease in the probability of spatial choice. Here we report more detailed analysis of the data which resolve the discrepancies. A consistent facilitation of spatial choice is found when a foraging partner is physically present in a maze location. However, working memory for the earlier choices of the other rat results in avoidance of those maze locations.
7:56 PM Ruey K. Cheng, Christopher J. MacDonald, Christina L. Williams, & Warren H. Meck (Duke University)
Organizational and activational effects of photoperiod on spatial and temporal memory in laboratory rats
Spatial and temporal memory were studied in adult Sprague-Dawley rats that were conceived and reared in either short day (SD–8:16 light/dark) or long day (LD–16:8 light/dark) photoperiods. Both male and female LD rats showed an increased capacity of spatial memory as indexed by a lower number of choices to criterion in a 12-arm radial maze task compared to the performance of SD rats. In contrast, when trained in the peak-interval procedure, SD rats displayed a distortion in the content of temporal memory by showing a proportional rightward shift in the 20 and 60s temporal criteria, a pattern that is consistent with reduced cholinergic function in normal rats. Taken together, our results suggest that both spatial and temporal memory processes are sensitive to photoperiod variation in laboratory rats in a manner similar to that previously observed for reproductive behavior.
8:03 PM Cassandra Gipson, Kelly DiGian, & Thomas Zentall (University of Kentucky)
Evidence for Retrospective and Prospective Spatial Coding by Pigeons may Result from Faulty Assumptions
In a radial maze task, when a delay is interpolated at different points in the trial (over trials), rats show evidence of both retrospective and prospective memory (Cook, Brown, & Riley, 1985).  This effect has been replicated in pigeons but it relies on the assumption that subtracting control-trial errors from delay-trial errors results in errors solely attributable to the delay.  In the present research, this assumption was avoided by including a binary choice involving one already visited and one not yet visited alternative following each point of delay interpolation and also pigeons were prevented from selecting the order of the stimuli chosen. We found that relative to control trial accuracy, on delay trials there was a constant error rate attributable to the delay (i.e., there was a general memory loss attributable to the delay). Thus, the findings from earlier research may have resulted from inappropriate assumptions.
8:15 PM Time, Number, and Sequence Learning (Chair - Bill Roberts)
8:15 PM Angelo Santi, Neil McMillan, & Patrick Van Rooyen (Wilfrid Laurier University)
Rats’ memory for event duration in delayed matching-to-sample with nonspatial comparison response alternatives.
Studies which have examined rats’ memory for event duration in delayed matching-to-sample have produced retention biases which are less consistent than those obtained with pigeons. Procedural factors which affect this variability will be reviewed. An experiment will be presented in which moving versus stationary levers are used as the nonspatial response alternatives. The results indicated that rats acquired the duration discrimination task faster than with previous methods, but they exhibited a choose-long bias, not a choose-short bias, when delay tested. Despite extensive training with variable delay intervals ranging from 1 – 4s, the rats continued to exhibit a tendency to time from onset of the signal until entry of levers into the chamber. Additional procedural modifications designed to discourage timing through the delay interval will be presented.
8:29 PM Joshua Beckmann & Michael Young (Southern Illinois University at Carbondale)
Effects of Stimulus Dynamics on Temporal Discrimination
The present study examined the functional relationship between stimulus dynamics and stimulus duration judgments in humans.  Stimulus dynamics were defined by how quickly a sphere rotated on its Y-axis. A bisection task was used to divide short stimulus durations (500 ms to 1700 ms) into two categories, short and long.  In Experiment 1, duration judgments were longer the faster the sphere was rotated.  In Experiment 2, the impact of contextual dynamics on temporal judgments was examined by accompanying one of the sphere rates with either two faster or two slower rates. The results indicate that stimulus dynamics influence the point of subjective equality and the sensitivity of the discrimination function.  The results are discussed within the context of a proposed “time as change” model.
8:36 PM Gin Morgan and Herbert S. Terrace (Columbia University)
A Comparison of Numerical Representation in Rhesus Macaques (Macaca mulatta) and Humans
Recent research on numerical representation in nonhuman primates has focused on possible mechanisms, their similarity to those used by humans, and their limits. We have conducted a series of experiments comparing performance of rhesus macaques (Macaca mulatta, n=2) and humans on a delayed, non-identical numerical matching-to-sample task.  The ranges of numerical values used were 1-9 and 1-15.  Results indicate that rhesus macaques use a parallel enumeration mechanism contrary to the iterative mechanism humans employ.  Due to the presence of a robust end effect on both ends of the stimulus continuum, but a lack of scalar variability in responses, rhesus macaques appear to use a single estimation mechanism for all stimuli that is influenced heavily by relative continuum position.  When humans are given limited time to complete the task, reaction times reflect a similar influence of continuum position.  Accuracy for human subjects appears to reflect an ability to subitize smaller values but response patterns for larger values appear similar to those
obtained from monkeys.  Thus, while human subjects may use more than one enumeration mechanism to complete the task, estimation appears to be similar in both species.  
8:43 PM Kazuhiro Goto (Keio University), Alan C. Kamil, & Alan B. Bond (University of Nebraska, Lincoln)
Interactions between associative and sequential priming
Facilitative effects of associative and sequential priming have often been reported in the literature, but little is known about their relationship.  In this study, we examined how these two types of priming might interact.  Blue jays were trained to search for two types of target among distractors.  At the beginning of each trial, either informative or uninformative prime was presented as a start key; pecks to the start key initiated the trial.  The four conditions tested were: 1) Only primes predicted target types (associative priming), 2) only trial sequence (i.e. AAA...BBB...) predicted target types (sequential priming), 3) both primes and trial sequence predicted target types (combinational priming) or 4) Neither primes nor sequence predicted target types (control).  The conditions 1) and 4) and the conditions 2) and 3) were paired and tested in alternative sessions to examine whether the effect of associative priming is conceivable when sequence priming is present/absent.
8:57 PM Stephen B. Fountain, Denise P. A. Smith, Amber M. Chenoweth (Kent State University), James D. Rowan (Wesleyan College), Melissa D. Muller (Mount Union College), Laura R. Glass, & Shannon M. Kundey (Kent State University)
Distinct Behavioral and Brain Processes Subserving Serial Pattern Learning
Our recent studies have shown that different aspects of serial pattern learning and performance can be disrupted by different drug and brain lesion manipulations.  We will summarize the differential effects of a) acute systemic administration of the drug, MK-801, an NMDA-receptor antagonist, b) dorsal hippocampal lesions, c) medial caudate-putamen lesions, d) acute administration of the muscarinic cholinergic antagonist drugs, atropine and scopolamine, and e) acute and chronic nicotinic cholinergic agonists and antagonists.  The differential effects of these neurobiological manipulations fit well with claims that serial pattern learning involves multiple concurrent psychological processes including stimulus-response learning, multiple item memory, counting or timing, chunking, and rule learning. Taken together, the results of the foregoing studies show that the serial pattern learning paradigm is an excellent model system
for examining the contribution of multiple cognitive and neural processes that contribute to performance in a single task.
9:11 PM Chuck Locurto (College of the Holy Cross)
Implicit Chaining in Cotton-Topped Tamarins
In human cognition implicit learning refers to procedures in which subjects learn a task that includes patterned information, although successful performance does not depend on mastery of the pattern. We studied a nonhuman analog of this procedure by arranging for cotton-topped tamarins (Saguinus oedipus) to observe a five-item patterned string that consisted of the same icon presented serially at different locations on a touchscreen. Tamarins had to touch the icon when it appeared to advance the pattern and receive reinforcement at the end of the string. Following training they were tested for their knowledge of the pattern using the same type of pair-wise item tests that are common in transitive inference and chaining experiments (e.g., B-D). The intent of the testing was to ask what the tamarins learned about the pattern when they didn’t have to learn anything. 
Implicit Chaining in Cotton-Topped Tamarins
In human cognition implicit learning refers to procedures in which subjects learn a task that includes patterned information, although successful performance does not depend on mastery of the pattern. We studied a nonhuman analog of this procedure by arranging for cotton-topped tamarins (Saguinus oedipus) to observe a five-item patterned string that consisted of the same icon presented serially at different locations on a touchscreen. Tamarins had to touch the icon when it appeared to advance the pattern and receive reinforcement at the end of the string. Following training they were tested for their knowledge of the pattern using the same type of pair-wise item tests that are common in transitive inference and chaining experiments (e.g., B-D). The intent of the testing was to ask what the tamarins learned about the pattern when they didn’t have to learn anything. 
9:30 PM Associative Learning (Chair - Aaron Blaisdell)
9:30 PM Heather T. Sissons, David Guez, and Ralph R. Miller (SUNY – Binghamton)
Blocking and Pseudoblocking: The Reply of Ratus norvegicus to Apis mellifera
Blaser, Couvillion, and Bitterman (2006), studying conditioned foraging by honeybees, reported pseudoblocking.  Pseudoblocking is a blocking-like effect in which, unlike conventional blocking treatment, the target (blocked) CS is omitted in Phase 2 of treatment, and a deficit in responding at test is observed relative to a control group that received presentations of the US alone in Phase 2.  The occurrence of pseudoblocking suggests that traditional accounts of blocking are incorrect.  In Experiment 1, we obtained conventional blocking but failed to observe pseudoblocking using a control procedure that was similar to our usual blocking control treatment. In Experiment 2, we obtained the pseudoblocking effect in rats using a fear conditioning preparation relative to Blaser et al.’s control treatment, but only when we modeled what Blaser et al. called the training context with a punctate stimulus. Our results are consistent with a simple account of pseudoblocking within the framework of conventional associative models.  Pseudoblocking does not challenge traditional accounts of blocking.
9:37 PM Gonzalo P. Urcelay and Ralph R. Miller (SUNY-Binghamton)
A Comparator View of the Overtraining Effect
In Pavlovian conditioning, an often unnoticed phenomenon is a loss of conditioned responding with extended reinforced training (e.g., Millenson & Hendry, 1967; Pavlov, 1927). We investigated a source of this effect in two experiments using rats as subjects in a fear conditioning preparation. In Experiment 1 four groups of rats received 5, 10, 20, or 50 reinforced trials. As reinforced training trials were increased, behavioral control decreased. We reasoned that the training context gains associative strength with extended training and competes at the time of testing with responding to the target cue. In Experiment 2 we trained rats with 5 or 50 reinforced trials and orthogonally extinguished or did not extinguish the training context. The groups that did not experience context extinction replicated those of Experiment 1. After context extinction the groups showed a recovery of conditioned responding, presumably because the training context no longer interfered with responding to the target cue. These results will be discussed in the framework of the comparator hypothesis and alternative
9:44 PM Singer, R. A. & Zentall, T. R. (University of Kentucky)
A Direct Test of Contrast and Delay Reduction Hypotheses to Account for Preference for Stimuli Following Relatively Aversive Events
Humans often prefer rewards that follow greater effort over rewards that follow less effort, a phenomenon known as justification of effort. Similar behavior, when seen in pigeons, has been interpreted as a form of contrast, within-trial contrast, in which the relative value of a reward depends on the value of the event immediately prior to the reward (Clement, Feltus, Kaiser, & Zentall, 2000). However, the delay reduction hypothesis (Fantino, 1969) which proposes that the value of a signal for food depends on the degree to which it is a better predictor of food than its absence can also account for many of these effects. The current experiments provided a direct test of the delay reduction and contrast hypotheses by manipulating the response requirement while holding trial duration constant. Consistent with the contrast hypothesis, pigeons showed a significant preference for the signal for food associated with their less preferred schedule.
9:51 PM Michelle Finn, Karl G. Lutterloh, & James C. Denniston (Appalachian State University)
Analysis of Mechanisms Underlying Renewal of Conditioned Responding
Two experiments using rats as subjects were designed to investigate mechanisms underlying the context specificity of extinction (i.e., the renewal effect).  Experiment 1 provided training in which each of three CSs (A, B, and C) were followed by a shock US in Context C.  These trials were interspersed with nonreinforced exposure in CS A in Context A and CS B in Context B.  At test, weak responding was observed to CS A in Context A, but not Context C, and weaker responding was observed to CS B in Context A than in Context C, thereby demonstrating occasion setting and transfer of occasion setting by context, respectively.  Experiment 2 was designed to examine mechanisms underlying the renewal effect.  In Experiment 2, training analogous to that of Experiment 1 was provided phasically (i.e., acquisition followed by extinction).  At test, equivalent renewal was observed to CS B when testing occurred in either another extinction context (A) or a neutral context.  This failure to observed transfer of control by context questions whether occasion setting is the
primary mechanism underlying the renewal effect.
Thursday Afternoon
12:30 PM Category and Concept Learning I (Chair - Jeff Katz)
12:30 PM Stephen E.G. Lea, Andy J. Wills & Catriona M.E. Ryan
Category Organisation in Free Classification by Pigeons: A Comparison with Human Subjects
In a free classification task using compound stimuli, humans will usually categorise exemplars according to a single dimension of the stimulus. Under certain conditions, however, they will sort according to the overall similarity of the exemplar to a prototype. The present experiment was designed to see if pigeons would behave in a similar way. Eight pigeons were trained to discriminate between two variants of each of four stimulus dimensions using a go-left-go-right procedure. When they had learned this they were switched to a new discrimination, where the stimuli consisted of triangular arrays of either the left-positive or the right-positive variants of three of the original dimensions. They were then given a series of test trials, in which one dimension in each array was exchanged for the one of the opposite type. All dimensions were found to have some control over the birds' responding, though one of them tended to predominate for four birds. Three more birds showed significant control by more than one dimension.  The results support the view that birds are 
more likely than humans to respond to variant stimuli in terms of overall similarity rather than a single dimension, which may reflect an associationistic rather than a rule-based determination of responding.
12:44 PM Jennifer M.B. Fugate (Emory University)
Categorical Perception of Emotional Expressions in Chimpanzees (Pan troglodytes)
Categorical perception reflects a process by which linear physical changes of a stimulus are perceived nonlinearly. Behavioral studies have shown that humans are better able to identify morphed facial expressions between categories of emotions compared to those within the same emotional category. The current experiments investigate if chimpanzees also perceive emotional expressions categorically. Experiment I used visual morphs of seven well-studied expressions in chimpanzees in a match-to-sample paradigm. Six chimpanzees first identified each of the morphs as one of the two expression endpoints, and then performed an ABX discrimination. Overall, the majority of subjects were better able to match morphed expressions within the same emotional category. Experiment II presented the same visual morphs for identification with the addition of the vocalization normally produced in concert with either of the two visual expression endpoints. Adding the congruent vocalization to visual morphs lowered the threshold at which each expression was
12:51 PM Carole Parron, Christine Deruelle, & Joël Fagot (CNRS, Marseille)
Processing of Biological Motion Point-Light Displays by Baboons (Papio papio)
Humans apply complex conceptual judgements to biological motion point-light displays (Johansson, 1973) but the comparative literature leaves uncertain how such displays are processed by animals (Blake, 1993;Dittrich et al., 1998). In this research, four baboons had to categorize several kinds of biological and non biological point-light displays in a conditional matching to sample task. Depending on the test condition, displays could be presented upright or inverted to assess processing strategies. Results of three experiments converge to demonstrate that our baboons failed to consider the biological content of the stimuli during the experiment, and solved the tasks by focusing their attention on the configural properties of stimulus’ sub-parts. Limits in perceptual grouping and restricted abilities in picture object-equivalence might explain why baboons did not map such degraded displays to what they represent.
1:05 PM Julie Martin-Malivel (Yerkes National Primate Research Center, Emory University) & Kazunori Okada (San Francisco State University)
Human and Chimpanzee Face Processing in Chimpanzees
The respective influences of exposure and inborn neural networks on conspecific face processing remain unclear. In the present study, we show that chimpanzees having a greater exposure to human than to chimpanzee faces are better at discriminating human than chimpanzee faces. A computational simulation was developed to evaluate the similarity among the stimuli of each category and to model subjects’ performance. It showed that the average similarities among human pictures and among chimpanzee pictures were comparable. Chimpanzees’ scores were significantly correlated with the computed similarity-coefficients. After taking into account the similarity-coefficients as covariate, the results show that performance with human pictures is still significantly higher than with chimpanzee pictures. The existence of categorical perception effects was tested using continua of morphed faces generated between chimpanzee or human individuals. A categorical perception effect emerged only for human faces, the category for which the chimpanzees had the highest level of expertise.
1:19 PM Darren Burke & Fiona Russell (Macquarie University)
Conditional Same-different Categorisation in the Short-beaked Echidna
Short-beaked echidnas, ant-eating monotremes, have surprisingly large brains with particularly well-developed frontal lobes, characteristics that are indicative of complex cognitive processing in Eutherian mammals. To see whether this sophisticated neurophysiology was correlated with cognitive sophistication, we examined the echidna’s ability to learn relational categorisation tasks. Using a t-maze, performance was significantly above chance (and above 75%) for a basic shape discrimination (triangle vs circle), a conditional shape discrimination (triangle on black, circle on white), a same-different discrimination (with 4 identical icons on each same stimulus), transfer to novel same–different exemplars, and on a conditional same-different discrimination (same on black, different on white). This level of discrimination performance has, to our knowledge, only previously been demonstrated in primates.
1:38 PM Discrimination Learning (Chair - Chuck Locurto)
1:38 PM Sheila Chase (Hunter College of the City University of New York)
Decision Processes in Pigeons
In our work together Eric G. Heinemann and I developed a computer model that provides a quantitative description of the choice behavior of pigeons. We have shown that the relationship between stimulus discriminability and the length of the presolution-period reflects an optimal procedure for detecting statistically significant differences in contingencies, that acquisition consists of gradual replacement of less precise information in long-term-memory with such information, that choices are based on optimal use of records of remembered contingencies. Our earlier work dealt with lights and sounds varying only in intensity and choices between two clearly distinguishable response manipulanda. Since then we have shown that the same basic mechanisms account for categorization of dot-matrix patterns, choice among multiple alternatives, and the limits on absolute identification. We called our model the Natural Intelligence Model in recognition of insights the study of living organisms brings to understanding of the evolution of intelligence. 
2:02 PM Emily D. Klein (Language Research Center, Georgia State University)
The Waiting is the Hardest Part: The Effect of Delay on Stimulus Preference
The present experiment investigated whether rhesus monkeys (Macaca mulatta) would prefer stimuli that followed a delay over those that followed no delay. Following presentation of a green square (No Delay Trial), two comparison stimuli (S+ND, S- ND) were immediately presented. Following presentation a red square (Delay Trial) the computer screen went white for 5-s before different comparison stimuli appeared (S+D, S-D). Monkeys were trained until they completed four consecutive blocks of 20 trials with at least 80% correct on each trial type. Following completion of training, probe test trials were randomly inserted into training blocks giving monkeys a choice between the two S+s and the two S-s. The training and testing procedure was repeated two different delays (5s and 10s) and 20 sets of unique stimuli. Overall results demonstrate that monkeys preferred the S+ that had been associated with delays during training.
2:09 PM Kenneth J. Leising, Michael Parenteau, Dennis Garlick, & Aaron P. Blaisdell (UCLA)
Development of an Automated Open Field for Examining Cognitive Processes in Pigeons
Last year we reported on the development of a wireless apparatus that automates open-field experiments. We now are reporting on the first set of behavioral studies using this Automated Remote Environmental Navigation Apparatus (ARENA). First, pigeons were successfully autoshaped to peck at either a lit or unlit module which was paired with grain reinforcement.  Second, pigeons learned a simultaneous discrimination task in which each of two ARENA modules was illuminated by a different color.  Pecks to one of the colors (S+) were reinforced while pecks to the other color (S-) were not. Pigeons learned to respond preferentially to the S+.  Third, pigeons were presented with a conditional discrimination task in which two ARENA units were simultaneously lit with one of eight colors on separate trials. Pecks to the unit in one location were reinforced for half of the colors, and pecks to the unit in the other location were reinforced for the remaining colors. Pigeons successfully learned to use the color to respond to the correct location.  ARENA provides a
three-dimensional format for behavioral experiments, and thus presents a more ecologically valid alternative to the touchscreen. 
2:16 PM Joseph Gaspard (University of Florida), Gordon  B. Bauer (New College of Florida), Roger Reep (University of Florida), Debborah Colbert, David Mann (University of South Florida), Kimberly Dziuk & Adrienne Cardwell (Sensory Biology and Behavior Program, Mote Marine Laboratory & Aquarium)
Detection of Hydrodynamic Stimuli by Florida Manatees, Trichechus manatus latirostris
Manatees have relatively poor visual acuity and neuroanatomy suggests that chemoreception is of limited importance. Although manatees have good hearing abilities, they do not echolocate. Thus, it is not clear how they navigate in the turbid waters they frequently inhabit. Anatomical investigation suggests that they might be able to use the vibrissae that cover their bodies to sense hydrodynamic stimuli. To test this hypothesis, two Florida manatees were tested in a go/no-go paradigm to assess their ability to detect water movements created by a sinusoidally oscillating sphere generating a dipole field. The subjects were stationed 10 cm from the sphere with the stimuli directed towards the facial region. Frequencies below the apparent functional hearing limit were presented (5 - 50 Hz). Preliminary results demonstrated the ability of
both subjects to detect the water movements. 
2:23 PM Kelly Caffery (University of Southern Mississippi)
Scent Discrimination in Lions and Tigers
Chemical communication has been intensely studied among smaller mammalian species; however few experiments have been conducted with larger mammals. In large felids, specifically lions and tigers where scent marking and flehmen behaviors are routinely observed, it is obvious that chemical communication serves some functionality in their life. The purpose of this study was to investigate the ability of these species to discriminate between various urine samples including inter and intraspecies urine, novel and familiar urine, self and other urine, kin and non-kin urine and urine scent versus no scent (the control). Overall differences in lion and tiger scent discrimination abilities were also compared. Results indicated that lions and tigers do discriminate various urine samples. Significant differences were shown between behaviors of lions and tigers and the results suggest that tigers are more likely to investigate urine scents than lions. 
2:35 PM Snack Break
3:25 PM Spatial Cognition II (Chair - Sara Shettleworth)
3:25 PM Brett M. Gibson (University of New Hampshire), Tyler J. Wilks, & Debbie M. Kelly (University of Saskatchewan)
Rats Encode the Shape of an Array of Discrete Objects
In order to navigate efficiently a traveler must establish a heading using a frame of reference.  A large body of evidence has indicated that humans and a variety of non-human animals utilize the geometry, or shape, of enclosed spaces as a frame of reference to determine their heading. An important and yet unresolved questions is whether the way shape information from arrays of discrete objects and enclosed environments are represented and utilized in the same way.  Here, rats were presented with a reference memory task in which they had to find water that was hidden in one of four discrete and unique objects placed at the vertices of a rectangle.  The results indicated that rats could utilize both feature and geometry cues to locate the hidden goal.  
Rats Encode the Shape of an Array of Discrete Objects
In order to navigate efficiently a traveler must establish a heading using a frame of reference.  A large body of evidence has indicated that humans and a variety of non-human animals utilize the geometry, or shape, of enclosed spaces as a frame of reference to determine their heading. An important and yet unresolved questions is whether the way shape information from arrays of discrete objects and enclosed environments are represented and utilized in the same way.  Here, rats were presented with a reference memory task in which they had to find water that was hidden in one of four discrete and unique objects placed at the vertices of a rectangle.  The results indicated that rats could utilize both feature and geometry cues to locate the hidden goal.  
3:39 PM Danielle Sulikowski & Darren Burke (Macquarie University)
Win-shift Learning is Sensitive to Food Type in the Noisy Miner Bird
The tendency of nectarivorous birds to better learn to avoid previously rewarding locations (to win-shift) than to return to them (win-stay), has been explained as an adaptation to the depleting nature of nectar. This interpretation relies on the previously untested assumption that the win-shift tendency is not associated with food types possessing a different distribution. To test this assumption we examined the specificity of this bias to different food types in an omnivorous honeyeater, the noisy miner (Manorina melanocephala). As predicted, we found that the win-shift bias was sensitive to foraging context, manifesting only in association with foraging for nectar, not with foraging for invertebrates.
3:46 PM Bradley R. Sturz (Auburn University), Debbie M. Kelly (University of Saskatchewan), & Jeffrey S. Katz (Auburn University)
Evidence against integration of spatial maps in humans: Generality across search tasks
In an open-field analogue of Blaisdell and Cook’s (2005) pigeon foraging task, human participants searched for a hidden goal located in one of 16 bins arranged in a 4 x 4 grid. In Phase 1, the goal was hidden between two landmarks (blue T and red L).  In Phase 2, the goal was hidden to the left and in front of a single landmark (blue T). Following training, goal-absent trials were conducted in which the red L from Phase 1 was presented alone. Bin choices during goal-absent trials assessed participants’ strategies: association (from Phase 1), generalization (from Phase 2), or integration (combination of Phase 1 and 2). Results were consistent with those found using a virtual environment by Sturz, Bodily, and Katz (2006). Specifically, participants used a generalization strategy followed by a shift in search behavior away from the test landmark, and these results were confirmed by a control condition.
3:53 PM Debbie M. Kelly & Dason V. Harker (University of Saskatchewan)
Encoding of Geometric Information by Clark’s Nutcrackers
Several experiments have shown that animals can use an environment’s shape to orient.  Two geometric properties that may be used for orientation within an environment are the relative length of the enclosure’s walls and the angle subtended when two walls join to form a corner.  We investigated the encoding of these two geometric properties by Clark’s nutcrackers.  Nutcrackers were trained to locate a hidden goal in one corner of a fully enclosed parallelogram-shaped enclosure.  Once the birds were accurately locating the goal they were presented with three sets of non-reinforced transformation tests.  Two sets of transformation tests were designed to examine whether the birds could use wall length ratios or angular information alone, whereas the third set of transformation tests were designed to examine how nutcrackers would weigh the two geometric properties when they provided conflicting information as to the correct search location.
4:00 PM Anna Wilkinson, Hui-Minn Chan, & Geoffrey Hall (University of York, UK)
A study of spatial learning in the tortoise (Geochelone carbonaria)
Mammals, birds and reptiles have all evolved from a common amniotic ancestor and it is likely that they share behavioural and morphological traits; few controlled experiments with reptiles have tested this assumption. The mammalian and avian hippocampus plays a critical role in navigation, but almost nothing is known about this ability in reptiles, who do not possess a hippocampus. Here we report the findings of an experiment examining spatial learning in the red-footed tortoise. The subject was trained to navigate an eight arm radial maze. He rapidly learnt the task, and by the second training session performed consistently above chance. Further tests confirmed that his performance was not based on the use of non-spatial cues.
4:07 PM Alisha A. Brown, Marcia L. Spetch & Peter L. Hurd (University of Alberta)
Growing in Circles: Rearing Environment Alters Spatial Navigation in Fish
Animals of many species use the geometric shape of an enclosed rectangular environment to re-orient, even in the presence of a more informative featural cue. Manipulating rearing environment affects performance on spatial tasks, but its effect on the use of geometric versus featural navigational cues is unknown. Our study varied the geometric information available in the rearing environment (circular vs. rectangular rearing tanks) of convict cichlids (Archocentrus nigrofasciatus) and tested their use of navigational cues. All fish used geometric information to navigate when no features were present. With features present, fish used geometric and featural information separately. When cues were in conflict, fish raised in a circular tank showed significantly less use of geometric information than fish raised in a rectangular tank. Thus, the ability to use geometry to navigate does not require exposure to angular geometric cues during rearing, though rearing environment affects the dominance of features and geometry.
4:19 PM Cognition and Metamemory (Chair - Jon Crystal)
4:19 PM Melinda R. Allen & Bennett L. Schwartz (Florida International University)
Self-Recognition in a Gorilla (G. gorilla gorilla)
Recognition of self is one of the first complex cognitive abilities to develop. Of the great apes only Bonobos, Chimpanzees and Orangutans have shown clear evidence of self-recognition. The data for Gorilla self-recognition has been insufficient to determine their abilities. Given that gorillas are in the same cognitive class as the other great apes and perform similarly in other cognitive tasks we argue that gorillas also show evidence of self-recognition. Using the mirror self-recognition task developed by Gallup (1970) we assed the ability of a captive raised gorilla (Otto) to identify himself in the mirror. We measured mark-directed behaviors, mirror directed behaviors, contingent movements, and mirror-guided behaviors. We saw evidence of self-recognition during the mark test, however few other mirror directed behaviors were seen. Our results suggest that gorillas are able to identify themselves without engaging in additional external behaviors.
4:26 PM Bill Roberts (University of Western Ontario)
Tests for Metamemory of Sample Information in Pigeons
In Experiment 1, pigeons were given a choice between seeing a sample stimulus before taking a memory test (choice between two comparison stimuli) or going immediately to the memory test.  In Experiment 2, pigeons were shown the sample stimulus for 1 or 5 s and then chose between seeing a 5-s sample reminder or going immediately to the memory test.  The question of interest is whether pigeons would choose to see the sample when they have no memory or only weak memory of the correct choice.  Data will be presented that answer this question about metamemory in the pigeon.
4:40 PM Jennifer E.  Sutton (University of Western Ontario) and Sara J. Shettleworth (University of Toronto)
Pigeons Still Don’t Have Metamemory
Metamemory, the ability to report on memory strength, is clearly established in rhesus macaques, with converging evidence from several paradigms and multiple tests within some of them.  Inman & Shettleworth (1999) found no conclusive evidence of metamemory in pigeons, however.  We report further experiments with pigeons in three paradigms, each of which afforded multiple tests of metamemory. Pigeons were presented with a safe alternative to completing a test of memory either before or concurrently with a test of memory in matching to sample. Choices of the safe option did not vary consistently with matching accuracy in the way predicted for an animal with metamemory nor change as predicted in tests with omitted samples. In other tests, “confidence ratings” following completion of the matching test also did not vary consistently as predicted by metamemory. The study of animal metamemory can be instructively compared with attempts to demonstrate episodic memory in animals.
4:54 PM Alexandra Rosati (Max Planck Institute for Evolutionary Anthropology), Jeffrey Stevens (Max Planck Institute for Human Development), Brian Hare (Max Planck Institute for Evolutionary Anthropology), & Marc Hauser (Harvard University)
The Evolutionary Origins of Human Patience
Although humans account for both the immediate and future consequences of behavior when making inter-temporal decisions, animals appear to ignore rewards that are delayed even a few seconds. However, this phylogenetic conclusion depends upon two untested assumptions: (1) great apes should make temporal decisions like other nonhumans, and (2) human patience should generalize to contexts beyond monetary rewards. Our results here lead us to reject both assumptions: bonobos and chimpanzees exhibit a degree of patience not seen in other animals, and humans are not only less patient for delayed food rewards than they are for money, but are also less patient for food than are chimpanzees. Therefore, a basic capacity for self-control and future-oriented decisions may have evolved before the human lineage diverged, suggesting that the extreme levels of patience that humans sometimes exhibit may be driven by fundamental 
differences between biological and abstract rewards.
8:00 PM Poster Session (8:00 - 10:00)
See Poster Abstracts Starting on Page 24
Poster Presenters: Please set up your posters between 7:30 and 8:00
Friday Afternoon
12:30 PM Category and Concept Learning II (Chair - Debbie Kelly)
12:30 PM Leyre Castro, Haley Kemp, & Edward A. Wasserman
Nonidentical items from the same category: Are they same or different?
Nonidentical items from the same category can be considered same, because of their similar categorical properties, or different, because of their dissimilar perceptual properties.  We investigated people’s discrimination of arrays containing identical items (Same), nonidentical items from the same category (Category), and nonidentical items from different categories (Different).  In Experiment 1, three groups were presented with two training arrays (Same vs. Category, Category vs. Different, Same vs. Different), and were tested with the remaining array.  In Experiment 2, a single group of participants was given a 3-choice task in which they had to discriminate all 3 types of arrays.  Overall, accuracy and confusion errors revealed that Category arrays are more similar to Same arrays than to Different arrays.  In contrast, reaction times revealed that it is especially difficult to discriminate Category from Different arrays.  Implications for same-different discrimination theories are discussed.
12:44 PM Andrea J. Frank & Edward A. Wasserman (University of Iowa)
Factors Affecting Pigeons’ Processing of Items and Relations in Multi-Element Visual Arrays.
Stimulus control can be either quite specific (e.g., particular items presented) or more general (e.g., relations between or among items).  Here, we gave pigeons icon set (Set 1 versus Set 2) or relation (Same versus Different) report keys after presenting them with a same or different display containing 12 visual icons.  This training method forced the pigeons to attend to both icon set and relation on every trial.  After the pigeons mastered this task, we tested them with displays containing 2, 4, 6, 8, 10, 12, 14, 16, 18, 20, and 22 icons.  Additionally, the icons in the displays could either be distributed (items shown randomly in 25 possible locations) or clustered (items grouped in the middle of the display).  Pigeons’ ability to flexibly report set or relation information strongly depended on the numbers of items, but was more weakly affected by item spacing.
12:51 PM Daniel I. Brooks & Edward A. Wasserman (University of Iowa)
A Connectionist Account of Item Set and Relation Discrimination in Multi-Element Arrays
Developing a model of Same/Different discrimination behavior will aid in understanding the interaction between memory for individual exemplars and the ability to detect interevent relations. A multilayer connectionist network was trained to report both the item set (Set 1 versus Set 2) or the relationship (Same versus Different) present in a multi-element array. This training was similar to how pigeons have been taught such a task. After the network met a similar discrimination criterion to that of pigeons, it was similarly tested with varying numbers of items in various spatial arrangements. Implications for the ability of such a network to learn this complex discrimination will be discussed.
12:58 PM Matthew S. Murphy & Robert G. Cook (Tufts University)
Investigation of Entropy in Auditory Sequence Same/Different Discrimination in Pigeons (Columba livia)
Discrimination of same/different sequences may be a gradated discrimination of varying levels of sameness and differentness (entropy) instead of a discrimination between two discrete categories. Three pigeons (Columba livia) were differentially reinforced in a go/no-go sequential auditory discrimination task based on pitch, timbre, or redundant cues, or using complex stimuli.  Sequences were composed of varying number of differing elements and transitions between differing elements in the sequence.  We found gradated discrimination that may be based on number of transitions and elements or on entropy. Further explanations will be discussed.
1:05 PM Olga F. Lazareva, John Doyle, and Edward A. Wasserman (University of Iowa)
Pigeons’ Perception of Similarity Among Different Basic-Level Categories
Certain cerebral pathologies in humans produce dissociated deficits in recognizing living and non-living objects. Some researchers have proposed that these categories may be represented in a qualitatively different manner; others have suggested that high between-category similarity for living objects and low between-category similarity for non-living objects accounts for this dissociation. We have explored how pigeons perceive similarity among different basic-level categories by using multiple go/no-go training. Birds were trained to respond to stimuli from one category (e.g., cars) and to refrain from responding to stimuli from other categories (e.g., chairs, flowers, and people). Error analysis revealed that pigeons perceived flowers and people as being more similar to each other than to either cars or chairs, whereas cars and chairs were perceived to be as different from each other as from flowers or people. Follow-up research replicated these findings using eight categories:  people, flowers, birds, frogs, cars, chairs, hats, and handbags.
1:19 PM Dana J. Gant, Dennis Garlick, & Aaron P. Blaisdell (UCLA)
Attributional versus Relational Processing in Pigeons in a Matching to Sample Task
Pigeons were trained to on a matching to sample task using stimuli composed of a pair of elements presented on a touch screen monitor. They were reinforced for selecting the comparison that matched the sample on both the color of the elements and the spatial relationship between the elements in the sample pair. After pigeons had learned to select the matching comparison, they received non-reinforced probe trials on which one of the comparisons matched only the color of the sample elements and the other comparison matched only the spatial relationship between the elements. Pigeons overwhelmingly preferred the color-match to the relational match. This suggests that pigeons attended more to attributional properties of the sample (e.g., color) than relational properties (e.g., spatial relationship between elements). 
Attributional versus Relational Processing in Pigeons in a Matching to Sample Task
Pigeons were trained to on a matching to sample task using stimuli composed of a pair of elements presented on a touch screen monitor. They were reinforced for selecting the comparison that matched the sample on both the color of the elements and the spatial relationship between the elements in the sample pair. After pigeons had learned to select the matching comparison, they received non-reinforced probe trials on which one of the comparisons matched only the color of the sample elements and the other comparison matched only the spatial relationship between the elements. Pigeons overwhelmingly preferred the color-match to the relational match. This suggests that pigeons attended more to attributional properties of the sample (e.g., color) than relational properties (e.g., spatial relationship between elements). 
1:31 PM Communication, Song, and Auditory Discrimination (Chair - Jerry Cohen)
1:31 PM Eduardo Mercado III (University at Buffalo, The State University of New York)
Learning to Localize in Auditory Space: The Origins of Vocal Imitation Abilities
Whales and dolphins use acoustic cues to determine the locations and identities of conspecifics and other environmental stimuli within their underwater habitats. Many of the cues that terrestrial mammals use to localize sounds in air are less well suited for localizing sounds underwater.  Nevertheless, cetaceans can localize sounds as well as or better than most terrestrial mammals. How do they do it? The mechanisms underlying sound localization traditionally have been assumed to involve real-time comparisons of differences in signals received at the two ears.  Recent evidence suggests, however, that auditory recognition of incoming sounds may be critical for accurate localization.  In light of this evidence, it is suggested that vocal learning and imitation capacities may have developed in various species to facilitate sound localization rather than as a result of sexual selection.
1:45 PM Laurie L. Bloomfield, Tara M. Farrell, & Christopher B. Sturdy (University of Alberta)
Species’ Discrimination of “Chick-a-dee” Calls by Cross-fostered Chickadees
We previously reported that black-capped and mountain chickadees treat each other’s “chick-a-dee” calls as belonging to separate open-ended categories, and that the terminal “dee” portion of the call appears to control species’ discrimination. Here we use a true-category/pseudo-category discrimination paradigm to test for species’ classification of chick-a-dee calls by normal black-capped and mountain chickadees and by black-capped chickadees cross-fostered with either black-capped or mountain chickadees. Preliminary findings revealed that (1) all birds learned the true-category discrimination faster than the pseudo-category discrimination, with no differences among the groups in their speed of acquisition, (2) there appeared to be no differences among the groups in the speed of acquisition of the pseudo-category discrimination, and (3) there appeared to be no rearing- or species-specific advantage to either discrimination. Further analyses will focus on the speed of acquisition on a stimulus by stimulus basis and the mechanisms by which the discriminations are performed.
1:52 PM Katherine A. Leighty, Joseph Soltis, Anne Savage (Disney’s Animal Kingdom), Kirsten Leong (Cornell University)
Elephant Vocal Communication Research at Disney’s Animal Kingdom
African elephants (Loxodonta africana) live in matrilineal societies and adult females produce “rumble” vocalizations to mediate social interactions.  Due to the infrasonic components of these rumbles, determination of the identity of the “rumbler” has been difficult in the wild. We have employed a unique collar system that allows us to document the vocal stream of each female in our herd at Disney’s Animal Kingdom. We will discuss the acoustic characteristics of these rumble vocalizations as well as briefly review our recent findings regarding the repertoire of African elephants, antiphonal calling among affiliated females, the impact of the reproductive cycle on vocal production, and the ontogeny of infant vocalizations. 
2:06 PM Henrike Hultsch (Freie Universität Berlin)
Stimulus primacy in the auditory song acquisition of the nightingale (Luscinia megarhynchos)
The clear temporal segregation of perceptual learning and motor performance makes song imitation by lab tutored birds an excellent paradigm to study how subsequent exposures to learning stimuli contribute to memory formation and retrieval. In an experiment with young nightingales subsequent exposures to song types were labeled by slightly different acoustic variants of the model patterns. Besides labeling ‘early’ versus ‘late’, I also tested for ‘few’ versus ‘many’ stimulus presentations. During later singing, subjects imitated more song-type versions from the early trials than from trials experienced later. Not only had males acquired the early variants in higher proportion, they also sung them more frequently than the later variants. Primacy of the first exposures occurred although subjects had heard the early song-type variants less often than those ones presented in the later trials. This experiment confirms that, in contrast with long held views, the role of stimuli in bird song learning is not confined to eliciting the performance of genetically inherited templates, that
of stimuli in bird song learning is not confined to eliciting the performance of genetically inherited templates, that memories from early exposures are not overwritten by stimuli experienced more frequently, and that performance as well as acquisition is affected by early experience.   
2:20 PM Helen Karpouzos (York University)
Great Ape Gestural Communication: An investigation of intentions
The notion of understanding intentions and mental states in others is argued to be a uniquely human capacity. Intriguing evidence from great ape studies however, has suggested otherwise.  This study then asks whether our great ape counterparts, namely orangutans and gorillas at the Toronto zoo, have the cognitive capacity to understand the intentions of others. By using the same behavioral criteria that human infancy researchers use to attribute this capacity to prelinguistic human infants, and controlling for possible methodological confounds of previous investigations of nonhumans, the aim is to more accurately test whether great apes understand the intentions of their conspecifics during communicative interactions. It is predicted that both orangutans and gorillas will behave analogously to prelinguistic human infants, indicating a capacity for intentionality. Second, it is predicted that intentional communication will be limited 
primarily to juveniles, adolescents and lower socially ranked adults who may be more highly motivated to use intentional communicative acts. 
2:27 PM Lauren Highfill, Stan Kuczaj (University of Southern Mississippi) & Harald Schwammer (Zoo Vienna)
Can sea lions understand communicative cues during an object-choice task?
Several species have demonstrated an ability to apprehend the attention of others, but the basis of such abilities is controversial. A relatively naďve South American sea lion was tested in an object choice task in which she had to use one of the following experimenter-given cues to target the correct object for a reward: (1) experimenter pointed and gazed at object, (2) experimenter pointed only at object, (3) experimenter gazed only at object, (4) experimenter placed a marker on object, (5) experimenter presented a replica of one of the objects. The sea lion was able to successfully use all five cues. The results indicated that relatively little experience with human trainers was necessary for the animal to perceive and act on attentional cues given by a human experimenter.
2:39 PM Choice (Chair - Brett Gibson)
2:39 PM Alex Kacelnik (University of Oxford)
State-dependent valuation learning: fitness, state, reinforcement and choice.
Behavioural ecologists model choice as a function of fitness gains, while associative learning researchers model learning as a function of reinforcement. While the former typically by-pass the issue of how the subject learns which option confers higher fitness gains, the latter typically ignore the functional implications of learning mechanisms, or even how associative strength translate into choice. I try to bridge this gap with models and experiments in starlings and locusts that assume that preference at the time of choice is a function of state improvement at the time of learning the properties of each option.
3:03 PM Marco Vasconcelos & Peter J. Urcuioli (Purdue University)
The Role of Initial Investment in the Sunk Cost Effect in Pigeons
We used a behavior-analytic analogue to study the maladaptive sunk cost effect in pigeons. In a mixed schedule procedure, a given fixed ratio (FR) was expected but, on some trials, the ratio was exceeded. Pigeons had the option of escaping the trial and start a new trial in which a smaller FR was again expected. Previous research shows that the greater the difference between the expected ratio given escape and the expected ratio given persistence, the less likely pigeons are to persist (i.e., the lower the probability of observing the sunk cost effect). However, greater differences in expected ratios were confounded with smaller FRs in the mixed schedule (particularly the first component). In this experiment, we kept the difference constant but varied the smaller FR and found evidence that the size of the initial investment mediates the effect.
3:10 PM Dennis Garlick & Aaron P. Blaisdell (UCLA)
Exploration by Pigeons on an N-Armed Bandit Problem
The n-armed bandit problem involves a choice between n-options or actions, where the probability of reward varies based on the option or action chosen. In a situation where the perceived distribution of probabilities is uncertain, an optimal strategy to maximize reward must both exploit existing knowledge of reward values to select the action that currently possesses the highest reward value, and also explore other options to increase knowledge of the probability distribution as a whole. Pigeons were presented with this task on a touch screen where 8 disks of different colors were associated with different probabilities of reward. The association between color and reward was consistent across trials within a single session, but was varied across sessions. It was found that the pigeons would neither systematically nor randomly explore all disks, and would instead perseverate to a limited number of disks. Various manipulations were made to examine whether exploration across the full complement of disks could be induced.
3:17 PM Holly Miller & Thomas Zentall (University of Kentucky)
Effects of Differential Biologically Neutral Outcomes Following Correct or Incorrect Comparison Choices in Delayed Matching to Sample
In matching-to-sample when different outcomes are associated each sample-correct comparison-response sequence, animals often learn faster and have improved retention over delays, effects known as the differential outcomes effect (DOE).   This effect has been explored primarily using outcomes that are differentially hedonic such as food versus no food.  Such differential outcomes may elicit different emotional states and the different emotional states may be used as cues for comparison choice. The question is can a differential outcomes effect be obtained when the differential outcomes have the same presumed value. Earlier research using non-hedonically different differential outcomes suggests that they can. The present experiment examined the differential outcomes effect using non-hedonic differences in outcome (a colored houselight vs. a tone).  Additionally, we examined the differential outcomes effect when the incorrect comparison choices were followed by differential non-hedonic outcomes.  A DOE was found on the retention test but only when the 
differential outcomes followed correct choices.
3:24 PM Walter T. Herbranson (Whitman College)
Pigeons perform optimally in a version of the "Monty Hall Dilemma"
The “Monty Hall dilemma” (MHD) is a well known probability puzzle in which a player tries to guess which of three doors contains a prize.  After an initial choice is made, one of the remaining doors is opened, revealing no prize.  The player is then given the option of staying with their initial guess or switching to the other unopened door.  Most people opt to stay with their initial guess, despite the fact that switching doubles the probability of winning.  Three experiments investigated if pigeons, like most humans, would fail to maximize their expected winnings in a version of the MHD.  Birds completed multiple trials of a standard MHD, with the three response keys in an operant chamber serving as the three doors, and access to mixed grain as the prize.  Across experiments, the probability of gaining reinforcement for switching and staying was manipulated.  Results indicate that unlike most humans, pigeons do perform optimally on the MHD by either switching from or staying with their initial choice, depending on whether switching or staying results in a higher likelihood 
of reinforcement.
3:45 PM Snack Break
4:50 PM In Honor of the Contributions of Ronald Weisman
4:50 PM Introduction - Chris Sturdy
4:55 PM Christopher B. Sturdy, Michael R.W. Dawson, Carly M. Nickerson, Laurie L. Bloomfield (University of Alberta) and Isabelle B. Charrier (Université Paris Sud)
Using artificial neural networks to understanding songbird perception
Here we report two series of studies in which we used artificial neural networks to understand songbirds’ perception of note-type categories. We first modeled empirical data obtained from black-capped chickadees by training perceptrons to discriminate between two call note types and then testing network generalization to novel notes that were shifted in their entirety either up or down in frequency. Perceptron results were highly similar to those obtained with birds trained in an analogous task. In a second study we trained perceptrons with notes in which individual acoustic features, both frequency and temporal, had been modified. Plots of network responses revealed that some acoustic features had significant effects on network responses, while others did not. Moreover, the context in which the network was trained determined network responses to test notes. The implications of using artificial neural networks for understanding empirical data and generating
testable hypotheses for songbird perception will be discussed.
5:10 PM Edward A. Wasserman, Olga F. Lazareva (University of Iowa), and Irving Biederman (University of Southern California)
Pigeons are more sensitive to nonaccidental than to metric changes in visual objects
Changes in nonaccidental properties (e.g., concave sides vs. straight sides) have been hypothesized to be critical for object classification (Biederman, 1987). In contrast, changes in metric properties (e.g., degree of concavity) are affected by rotation in depth, making them less reliable for object classification. We studied pigeons' sensitivity to metric and nonaccidental changes by using a three-alternative forced-choice task. The birds were trained to discriminate a target stimulus from a metrically-changed shape and a nonaccidentally-changed shape. The dependent measure was the percentage of total errors that the birds committed to the nonaccidentally-changed shape. All birds made more errors to the metrically-changed shape, suggesting that they perceived it to be more similar to the target stimulus than was the invariantly-changed shape.
5:25 PM Leslie Phillmore (Dalhousie University)
A Review of Discrimination Learning: From Behaviour to Brain
Discrimination is an important skill used daily by many organisms to make decisions about such problems as what food to ingest or which mate is the most desirable. Discrimination relies on an organism’s ability to differentiate stimuli using available features and make decisions based on this information that will lead to survival of the individual and, ultimately, the species. To determine what cues or features a particular organism may use to perform a discrimination task, researchers can set up contingencies based on discrimination of cues; it may then be inferred that an animal successful at earning reward or avoiding punishment can discriminate among stimuli distinguished by the specific features provided.  This presentation will review and compare the use of discrimination paradigms in organisms such as birds and mammals. Further, the review will include recent work that has begun to look at the neural systems involved in learning, examining what changes may occur in the brain as a result of performing discrimination tasks.
5:40 PM Robert Cook & Matthew Murphy (Tufts University)
Competitive Control by the Absolute and Relational Properties of Auditory Stimuli
A long-term focus of Ron Weisman's research has been on the contribution of absolute and relative factors in song perception and recognition by birds. We have recently focused on the contributions of these different factors in a non-songbird, the pigeon. Using a modified same/different task, our studies were designed to determine how absolute (pitch) and relational (same/different) properties spontaneously controlled responding in a sequential auditory discrimination. Both properties were found to be relevant and determined by the relative discriminability of each of these properties. Implications for stimulus control by these factors in several areas will be considered.
6:00 PM Master Lecture - Ronald Weisman (Queen's University)
Thinking Outside the Box: Advice to Young Scientists
This talk is my one opportunity to speak at length to our young colleagues about how they should conduct their careers. Other researchers may disagree but here I will share what I have learned about how to conduct our science. Research in Comparative Cognition tends to occur inside one box or another, often an operant conditioning chamber. Young researchers, especially, should think about conducting research about animal cognition outside that box. Also we need to know more about the real world tasks, outside the box, to which our research applies. This does not mean discarding your conditioning equipment. What I am suggesting is using your experiments to explain how animals think in the world in which they evolved.
7:30 PM Banquet
12:00 PM Business Meeting of the Comparative Cognition Society
All Invited to Attend - CCS Members May Vote on any Motions Made
1:10 PM (: Group Photo Shoot - SMILE :)
1:30 PM Perception and Attention (Chair - Angelo Santi)
1:30 PM Tomokazu USHITANI (Chiba Univ) & Masaki TOMONAGA (Kyoto Univ)
Object-based attention and visual organization in chimpanzees (Pan troglodytes)
Chimpanzees were investigated in a cuing task whether they possessed object-based attention. Chimpanzees were rewarded by touching a target after a brief presentation of a cue at one end of two rectangles arranged in parallel (Experiment 1). If object-based attention activating the cued rectangle as a unit works, chimpanzees’ reaction time would be shorter when the target appeared at the other end of the cued rectangle (WITHIN condition) than at one end in the other rectangle (BETWEEN condition), even though the distance from cued location to each target location was the same in both conditions. We could not find the evidence of such within-object benefit in Experiment 1. In Experiment 2, we arranged the rectangles horizontally in line to control the distance from the fixation stimulus to each target location; this time, we could find within-object benefit, suggesting that object-based attention process is shared by chimpanzees and humans.
1:44 PM Stephen E. G. Lea, Catriona M. E. Ryan, Catherine Bryant, and Andy J. Wills (University of Exeter)
Stopping rules in pigeons’ information acquisition in multidimensional discrimination
Pigeons are being trained in a go-left/go-right conditional discrimination task in which, on each trial, stimulus information is revealed gradually so long as the bird continues to peck at a central zone of a touchscreen.  Left and right choice response zones are available throughout the trial, and pecks made to them at any time during a trial halt the process of adding more information to the central zone.  The stimuli contain multiple equally valid cues, which are revealed in varying orders.  Earlier choice responses do not lead to more immediate reinforcement.  Humans in comparable situations tend show  “one-reason decision making”, withholding response until a particular type of information appears, and then responding immediately.  Initial indications are that pigeons make a more equal use of the different types of information, though they still tend to make a choice response before all information is available.
1:58 PM Caroline M. DeLong, Sarah A. Stamper, & James A. Simmons (Brown University)
Object Perception in Clutter by Echolocating Bats
In previous psychophysical experiments, big brown bats detected or discriminated objects (monopole and dipole targets comprised of 15 mm diameter cylinders) presented standing on smooth surfaces with little clutter. In this experiment, a two-alternative forced choice paradigm was used to train bats to discriminate between a two-cylinder dipole target presented within a clutter field and a clutter field with no target.  Different clutter fields were used, each with a different number of beads (4, 8, 12, or 16) presented at various aspect angles.  The bats' performance varied as a function of the number of beads.  The bats were able to detect the dipole even when the total energy of the echoes from the dipole plus clutter field was only 1.5 dB greater than the total energy of the echoes from the clutter field alone.  The results have implications for how bats isolate beetles against a backdrop of foliage.
2:12 PM Sarah A. Stamper, James, A. Simmons, & Caroline M. DeLong (Brown University)
Perception of Targets in Scenes by Echolocating Bats
Big brown bats (Eptesicus fuscus) are able to catch insects in open air and cluttered environments using sophisticated biosonar.   We have conducted a series of psychophysical experiments to examine the ability of these bats to detect and discriminate objects presented in simple and complex acoustic scenes.  Using a two-alternative forced choice paradigm, bats were trained to detect a two-cylinder dipole stimulus that was inserted into holes (14mm deep and 20mm in diameter) in foam pads (25mm thick).  The top of the dipoles' surfaces were positioned at 13, 5, or 2mm above or 1mm below the surface of the foam.  The bats' performance varied as a function of protruding height.  We found that for successful detection the target must protrude above the surface of the foam by 1-2mm, yielding an energy threshold difference between the target and clutter of approximately 2dB.
2:19 PM Martin J. Acerbo, Olga F. Lazareva, Andrea Frank, Amy Poremba, and Edward A. Wasserman (University of Iowa)
Metabolic Mapping of Brain Structures Involved in Figure-Ground Assignment in Pigeons
Recently, we found that figure-ground assignment in a nonmammalian species, pigeon, is analogous to primates, at least at the behavioral level (Lazareva et al., 2006). We used the same behavioral paradigm to pinpoint areas in the avian brain that are critically involved in figure-ground assignment. Using the same stimuli, three group of pigeons were trained to perform figure-ground discrimination, color discrimination, or shape discrimination. Once their discriminative performance reached the asymptote, the birds were injected with [C14] 2-deoxyglucose (2-DG) and required to perform discrimination for 45 minutes. The fourth, control group, was not required to perform any discrimination; instead, these birds were placed into dark operant chambers where they received food pellets according to VI schedule. We then compared metabolic levels in the tectum opticum, nucleus rotundus, and the entopallium in different groups to assess the neural correlates of 
figure-ground assignment.
2:33 PM Michael Lamport Commons & Patrice Marie Miller (Harvard Medical School)
What Animals Never Operantly Coordinate Actions with Sensory Input
In most developmental stage models, Stage 1 describes that organisms either act or sense, but do not coordinate the two.  Is there any empirical evidence for the existence of animals that never progress further than Stage 1 in any area?  Even very primitive animals differentially respond to stimuli, rejecting non-food items.  Animals change their behavior and learn to the extent to which consequences modify the control of behavior by stimuli.  The consequences lead to them to Stage 2 behavior where they coordinate action with sensory input.  But some very simple single-celled animals, e.g. zooplankton, may not operantly hunt for prey or forage.  Are such animals, and other simple multi-celled animals, coordinating actions with sensory input, or are their behaviors just directly elicited by only a specific stimulus in a manner independent of consequences?  This paper examines possible evidence for the existence of animals performing at Stage 1only.   
2:52 PM Social, Symbolic, and Cognitive Processes (Chair - Roger Thompson)
2:52 PM M.Kiley-Worthington (University of California, Berkeley & Centre d’Eco-Etho Recherche, Bezaudun sur Bine, France)
A multidisciplinary approach to assessing equine and elephant subjectivity.
The most difficult question of animal subjectivity is the  first personhood of individual experiences.  A multi disciplinary study involving anatomy , physiology, field and laboratory ethology, experimental psychology, philosophy of mind, and folk knowledge is the key to beginning to answer this question,  although there are large gaps in our knowledge. A brief summary of similarities and differences between the subjectivity of equines, elephants and a human is given.  The interesting questions are what do they know, what can they learn and what do they think? Many people here are of course attacking these problems, but  the result of some 15 years research,  produces evidence that the suggested multi disciplinary has an important part to play  in understanding another species cognition.
3:16 PM Emma Ware & Niko Troje (Queen’s University)
Pigeon courtship is sensitive to social contiguity but not social contingency
Joint action is behaviour that requires coordination between animals to achieve a desired goal. We investigated the perception of social feedback in mutual courtship of the pigeon, Columba livia, in a double closed-loop teleconferencing setup. Pigeons could interact in real time with the life-sized video image of the other bird. We manipulated social feedback in two ways; 1) by altering temporal contiguity by three delays of 1s, 3s and 10 s and 2) by altering social contingency, by playing back a video of the subject’s partner from a previous interaction.  Courtship intensity decreased in all three temporal delay conditions.  Courtship intensity did not differ between a zero-delay condition and the non-contingent playback condition. We conclude that pigeon courtship is sensitive to temporal contiguity in social feedback, implying visual coordination in joint action. Pigeons did not show social contingency perception, and may lack a representation of social causality.
3:23 PM Wendi Fellner, Barbara A. Losch  (The Seas, Epcot®), & Gordon B. Bauer (New College of Florida & Mote Marine Laboratory)
Synchronous Relationships among Four Male Bottlenose Dolphins
Synchronous movement is a frequently observed behavior among bottlenose dolphins. In addition to potentially providing hydrodynamic and predator-avoidance advantages, synchrony may have important implications in the formation and maintenance of pair bonds among male dolphins. For over 1 year, we observed synchrony characteristics in a population of 4 captive male dolphins in which 2 newcomers were introduced to 2 long-time residents. The amount of time spent in synchrony for the original 2 residents was 0% prior to the introduction of the new dolphins. Their post-introduction levels of synchrony changed from 5% in the early months to as high as 55% in the presence of one of the socially dominant newcomers. Synchrony may be an easily observable indicator of changing social relationships.
3:30 PM Annika Paukner, Matthew Novak & Stephen Suomi (National Institute of Child Health and Human Development)
Learning to inhibit: social environment and self-control in infant rhesus macaques
Inhibitory control processes are thought to play an important role in the organization and regulation of social groups. Furthermore, social status within a group appears to affect an individual’s ability to exhibit self-control. We evaluated the importance of social influences on self-control in a cohort of infant rhesus macaques raised in differential social environments. Each infant underwent multiple cognitive assessments, all thought to be a measure of self-control. Results indicate that the early social rearing environment may have a profound impact on self-control abilities. In addition, infants did not show consistent performance between tasks, suggesting that self-control is a multi-level construct.
3:37 PM Nicole R. Dorey, Stephen E. G. Lea (University of Exeter), & Vicky Melfi (Field Conservation and Research Department, Whitley Wildlife Conservation Trust, Paignton Zoo Environmental Park, UK)
Object movement imitation in Sulawesi black crested macaques (Macaca nigra)
After a 10 session baseline, we trained a demonstrator (adult male Sulawesi macaque) to perform five topographically different behaviours to an apparatus on a command.  The commands were directed only to the demonstrator; they were in the form of different coloured shapes which were associated with each behaviour.  A duplicate apparatus was set up 56cm away.  The other 10 macaques in the group (observers) had access to and could freely manipulate this second apparatus. Both the demonstrator’s and the observers’ behaviours were recorded.  For two of the observers, there was a non-significant increase in the likelihood of expressing at least one of the trained behaviours shortly after the demonstrator performed them. However, one observer performed three of the trained behaviours at significantly increased frequency shortly after the demonstrator had performed them.  These findings suggest that imitative learning occurred in some members of this 
group of macaques. 
3:44 PM Sylvain Fiset (Université de Moncton at Edmundston)
Spatial rotation of hidden objects in domestic dogs
The present study was aimed at investigating whether domestic dogs understand invisible displacement of objects in a spatial rotation task. The dogs faced a rotating platform. Two containers were placed at both ends of the platform and an attractive object was visibly put in one of the containers. Experiment 1 revealed that dogs did not understand spatial rotation of hidden objects when the two containers were opaque. In Experiment 2, dogs succeeded when the target container was transparent but failed when the target container was opaque. Additional testing sessions revealed that dogs gradually learned to find the target object hidden in the opaque container, suggesting that they might be able to understand some rudiments of spatial rotation of hidden objects.
4:03 PM Category and Concept Learning III (Chair - Gordon Bauer)
4:03 PM Heidi E. Harley (New College of Florida & The Seas, Epcot®), Wendi Fellner, & Kim Odell (The Seas, Epcot®)
Object-Photo/Photo-Object Matching by the Bottlenose Dolphin
Dolphins can accurately interpret two-dimensional video images and discriminate two-dimensional figures, but their ability to recognize an identity relation between three-dimensional objects and their static two-dimensional representations has not been documented.  In this study, two dolphins (Ranier & Toby) performed a 3-alternative matching-to-sample task with objects and photographs.  Ranier matched visually in three conditions: object to object (OO), photo to object (PO), and object to photo (OP).  Immediate transfer occurred to photographs.  Performance accuracy was comparable in all conditions within object sets of varying difficulty on five 3-alternative 18-trial sessions in each condition: Set 1, 97% OO, 94% PO, 97% OP; Set 2, 82% OO, 90%, PO, 89% OP; Set 3: 68% OO, 67% PO, 72% OP.  Toby matched photographs to echoic alternatives.  Performance accuracy with three different familiar object sets averaged 100%, 87%, 54%.  Apparently, dolphins can instantly recognize an identity relation between objects and their photographic representations.
4:17 PM Kristy Lindemann, Colleen Reichmuth, & Ronald J. Schusterman (University of California, Santa Cruz)
The Role of The Reinforcer in Equivalence Class Formation:  Evidence From Work With a California Sea Lion
Differential outcomes effect, or DOE, has been studied in various species and across a range of learning contexts.  The findings of these studies have illustrated that discrimination learning occurs more rapidly when responses to different stimuli produce different reinforcers.  There are a number of theories that have been proposed to explain DOE but no single theory or mechanism has been established.  We propose that Sidman’s (2000) theory of equivalence offers a possible explanation of DOE by including the reinforcer as a stimulus class member.   Our past and current work on equivalence classes with a California sea lion provides evidence that the differential reinforcement of two stimulus classes facilitates class formation but is not necessary for equivalence performances to emerge.  We hypothesize that the reinforcer is an equivalence class member and we discuss our current work which further investigates the relationship between the
reinforcer and the auditory and visual class members.  
4:24 PM Timothy M. Flemming (Georgia State University) and David A. Washburn (Georgia State University)
Focus!: Enhancement of Relational Matching in Rhesus Monkeys (Macaca mulatta) with Increased Attentional Demands
Compared to results from static presentations of a relational match-to-sample paradigm, presentations of moving stimuli in the same paradigm yielded higher rates of accuracy. In the static condition, one pair of identical or nonidentical stimuli was contacted with a cursor, subsequently presenting choice stimuli randomly in one of two corners of the computer screen. In the moving condition, stimuli were presented in pairs that moved together at a slow rate in random directions, with random starting locations around the computer screen. After contacting the first moving relational pair, two moving choice pairs appeared at random locations on the screen. Correct choices were made by contacting the moving pair that exemplified the same relation (identical/nonidentical) as the sample pair. Increased attentional demands on the composition of the moving pairs is likely responsible for the enhancement of relational matching.
4:31 PM Gabrielle Szafranski, Ketan Bakriwala, & Toru Shimizu (University of South Florida)
Conspecific Recognition Based on Biological Motion Cues in Pigeons
Humans have the ability to perceive the biological motion of other humans, even when most of the form information is absent.  Can highly visual animals, such as pigeons, also perceive the biological motion patterns of conspecifics when only limited form information is presented?  To address this issue, male pigeons were exposed to videotaped footage of female pigeons that were actively engaged in courtship.  By manipulating spatial frequency, the form information of the footage was either limited (i.e., blurred) or left intact.  Compared to the intact stimuli, the courtship response of male pigeons to the blurred stimuli was diminished, but still present, as long as the motion cues were presented.  However, the response was almost entirely absent when the stimuli were motionless blurred images.  The results suggest that when form information is limited, pigeons can use biological motion cues to recognize conspecifics.
4:38 PM Sue J. Chapman (University of Exeter)
Multi-dimensional Concept Discrimination in Non-human Mammals in an Ethologically Relevant Paradigm
Grey squirrels, Sciurus carolinensis, were trained to discriminate three dimensions, colour, shape and pattern, in their natural environment. 
The squirrels were first trained to discriminate between two prototype stimuli.  Biscuits were coloured either blue or orange, shaped into either stars or circles, and were piped with either dots or cross-hatched iced lines.  The negative training stimuli contained salt in both the icing and the dough. 20 biscuits, 10 negative and 10 positive, were placed in a computer generated random pattern in a tray beneath a mirror, and details of the squirrel subject in each trial was recorded photographically.
After reaching criterion, testing with both prototypes and stimuli resembling the prototypes (all unsalted) but with one of the dimensions changed took place, for example a blue star with dots prototype has three one-aways e.g. a blue circle with dots. All six possible one-aways were included in test trials. Video recordings were made to establish the order the stimuli
were taken in. The results of this discrimination will be compared to human studies of multi-dimensional selection.