Flexible learning and use of multiple-landmark information by pigeons (Columba livia) in a touch screen-based goal searching task.

Three touch screen-based experiments were conducted to investigate whether pigeons would learn to use configural information about a goal's location in relation to a multiple-landmark array. In Experiment 1, 4 pigeons (Columba livia) were trained to peck a computer monitor at a location that constituted the third vertex of a hypothetical triangle defined by 2 different landmarks. The landmarks appeared in 3 orientations during the training, and the pigeons' goal-searching ability easily transferred to the landmarks presented in 3 novel orientations. Each landmark was asymmetric, so we next examined whether the pigeons used (a) the small-scale, local orientation information that could be inferred from each landmark individually, or (b) the large-scale, configural information that could be inferred from the spatial arrangement of multiple landmarks taken as a whole. Even when each single landmark appeared by itself, the pigeons were able to locate the goal accurately, suggesting that the large-scale, configural information was not essential. However, when 1 landmark locally pointed to a location that was consistent with the triangular configuration and the other landmark locally pointed to a different location, the pigeons predominantly pecked at the configurally array-consistent location. These results suggest that the pigeons redundantly learned both the large-scale, configural strategy and the local, single-landmark strategy, but they mainly used the latter information, and used the former information solely to disambiguate conflicts when the 2 landmarks pointed toward different targets. Such flexible learning and use of redundant information may reflect the pigeons' adaptation to unstable wild environments during their evolutionary history. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Transfer of self-control in black (Eulemur macaco) and brown (Eulemur fulvus) lemurs: Choice of a less preferred food item under a reverse-reward contingency.

When presented a choice between two food-type arrays of equivalent size under a reverse-reward contingency, black (Eulemur macaco) and brown (Eulemur fulvus) lemurs transposed their self-control abilities, acquired in a previous experiment, to significantly select the less-desired food item in order to gain access to the more desired one. However, when presented with the choice between two different food-type arrays in which the amount of the less desired food array was larger than the more desired one, large individual differences were revealed: Some subjects established a consistent rule favoring quality or quantity, whereas others exhibited various point of trade-off. These results show that lemurs seem to manage the task considering not only food quantity but also food quality. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Chimpanzee (Pan troglodytes) anticipation of food return: Coping with waiting time in an exchange task.

Despite controversial expectations that animals achieve reciprocal altruism, it is unclear if nonhuman species possess the necessary cognitive abilities. For reciprocal altruism, individuals must anticipate the loss of a commodity and accept a delay before some return. The authors investigated the abilities of 5 chimpanzees (Pan troglodytes) to cope with increasing waiting duration in exchange tasks. Subjects had to keep a small cookie before returning it to a human partner to obtain a larger piece. For a piece 2, 4, or 8 times the size of the small piece, 3 of the 5 subjects waited for up to 4 min. For a piece 40 times larger, 4 of the 5 subjects waited up to 8 min. At long time lag, renouncement to wait occurred earlier than predicted by subjects' general waiting capacity, suggesting that the decision to wait was based on a trade-off between reward quantity and expected costs of the waiting duration. Chimpanzees could anticipate a delayed reward at a time scale of several minutes. If this reflects a cognitive limit in chimpanzees' anticipation capacity, reciprocal altruism by keeping track of costs and benefits over extended periods may be unlikely in chimpanzees. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

How the great apes (Pan troglodytes, Pongo pygmaeus, Pan paniscus, and Gorilla gorilla) perform on the reversed contingency task: The effects of food quantity and food visibility.

S. T. Boysen and G. G. Berntson (1995) found that chimpanzees performed poorly on a reversed contingency task in which they had to point to the smaller of 2 food quantities to acquire the larger quantity. The authors compared the performance of 4 great ape species (Pan troglodytes, Pongo pygmaeus, Pan paniscus, and Gorilla gorilla) on the reversed contingency task while manipulating food quantity (0-4 or 1-4) and food visibility (visible pairs or covered pairs). Results showed no systematic species differences but large individual differences. Some individuals of each species were able to solve the reversed contingency task. Both quantity and visibility of the food items had a significant effect on performance. Subjects performed better when the disparity between quantities was smaller and the quantities were not directly visible. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

How the great apes (Pan troglodytes, Pongo pygmaeus, Pan paniscus, Gorilla gorilla) perform on the reversed reward contingency task II: Transfer to new quantities, long-term retention, and the impact of quantity ratios.

We tested 6 chimpanzees (Pan troglodytes), 3 orangutans (Pongo pygmaeus), 4 bonobos (Pan paniscus), and 2 gorillas (Gorilla gorilla) in the reversed reward contingency task. Individuals were presented with pairs of quantities ranging between 0 and 6 food items. Prior to testing, some experienced apes had solved this task using 2 quantities while others were totally na?ve. Experienced apes transferred their ability to multiple-novel pairs after 6 to 19 months had elapsed since their initial testing. Two out of 6 na?ve apes (1 chimpanzee, 1 bonobo) solved the task--a proportion comparable to that of a previous study using 2 pairs of quantities. Their acquisition speed was also comparable to the successful subjects from that study. The ratio between quantities explained a large portion of the variance but affected na?ve and experienced individuals differently. For smaller ratios, na?ve individuals were well below 50% correct and experienced ones were well above 50%, yet both groups tended to converge toward 50% for larger ratios. Thus, some apes require no procedural modifications to overcome their strong bias for selecting the larger of 2 quantities. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Comparative assessment of handedness for a coordinated bimanual task in chimpanzees (Pan troglodytes), gorillas (Gorilla gorilla) and orangutans (Pongo pygmaeus).

Hand preferences for a coordinated bimanual task were assessed in a sample of 31 captive gorillas (Gorilla gorilla) and 19 captive orangutans (Pongo pygmaeus) and were compared with chimpanzee (Pan Troglodytes) hand preferences in subjects that were matched on the basis of age, sex, and rearing history. The task required that the apes remove food from the inside edges of a symmetrical polyvinyl chloride pipe presented to them in their home cages. The results indicate significant species differences with chimpanzees showing population-level right-handedness and orangutans showing population-level left-handedness. The gorillas showed a nonsignificant trend toward right-handedness. The results are discussed in terms of possible ecological or biomechanical factors that may influence hand preferences in different ape species. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Evidence of a Time-Dependent Long-Term Stage of Memory for a Spatial Learning Task in the Chick (Callus gallus).

The generalizability of temporal parameters of memory formation previously observed for a passive avoidance task was investigated in a spatial task with day-old chicks (Callus gallus). The percentage improvement in completion time over 2 separate trials was measured, and chicks were found to complete the second trial faster at all times tested up to 2 hr, except at 55 min posttraining. In addition, retention at 120 min, but not at 30 min, posttraining was found to be impaired by protein synthesis inhibition. These findings are consistent with the timing of a long-term stage of memory formation following passive avoidance training, implying that there may be some hardwiring to the temporal characteristics of memory formation in this species. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Grip morphology and hand use in chimpanzees (Pan troglodytes): Evidence of a left hemisphere specialization in motor skill.

Three experiments on grip morphology and hand use were conducted in a sample of chimpanzees. In Experiment 1, grip morphology when grasping food items was recorded, and it was found that subjects who adopted a precision grip were more right-handed than chimpanzees using other grips. In Experiment 2, the effect of food type on grasping was assessed. Smaller food items elicited significantly more precision grips for the right hand. In Experiment 3, error rates in grasping foods were compared between the left and right hands. Significantly more errors were made for the left compared with the right hand. The cumulative results indicate that chimpanzees show a left-hemisphere asymmetry in motor skill that is associated with the use of precision grips. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Inhibitory Control and Response Selection in Problem Solving: How Cotton-Top Tamarins (Saguinus oedipus) Overcome a Bias for Selecting the Larger Quantity of Food.

When presented with a choice between 1 and 3 pieces of food in a type of reversed contingency task, 4 cotton-top tamarins (Saguinus oedipus) consistently chose the 3 pieces of food and received nothing, even though the choice of 1 piece would have yielded 3. However, in a task in which the tamarins received the 1 piece of food when they chose it, all subjects learned to select 1 over 3. Thus, the tamarins' prior failure on the reversed contingency task did not result entirely from an inherent inability to suppress the prepotent response of reaching to the larger of 2 quantities of food. After the experience of selecting the smaller quantity and receiving it, all of the tamarins solved the version of the reversed contingency task that they failed initially. These results suggest that the tamarins' initial failure may have reflected a difficulty with selecting an alternative response option. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Searching in the Center: Pigeons (Columba livid) Encode Relative Distance From Walls of an Enclosure.

Pigeons (Columba livia) searched for food hidden in the center of a square enclosure. On occasional tests without food, the enclosure was (a) unchanged from training (control tests), (b) moved to different corners of the testing room (corner tests), or (c) doubled in size (expansion tests). The birds showed localized search in the center of the enclosure on control and corner tests. On expansion tests, some birds searched near the center of the enclosure, suggesting relative-distance encoding. Other birds searched at locations that maintained the training distance from walls, suggesting absolute-distance encoding. These results are consistent with previous studies on chicks (Gallus gallus) in similar enclosures and contrast with previous results on pigeons' responses to expansions of discrete landmark arrays. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The use of bouts and frequencies in the evaluation of hand preferences for a coordinated bimanual task in chimpanzees (Pan troglodytes): An empirical study comparing two different indices of laterality.

Hand preferences for a coordinated bimanual task were assessed in 109 chimpanzees (Pan troglodytes). Hand preference was evaluated for 4 test sessions using bouts and frequencies of hand use to compare the sensitivity of each level of analysis in evaluating individual variation in handedness. Overall, significant population-level right-handedness was found using several different measures of hand use. Handedness indices based on bouts and frequencies were highly and significantly correlated. Moreover, hand preferences were consistent across tests despite efforts to situationally bias preference during each test. Taken together, these data do not support the view that bouts are a better level of analysis for evaluating hand preference. The results further suggest that hand preferences for coordinated bimanual actions are not influenced by situational factors and may reflect an inherent specialization of the left hemisphere for motor skill. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Pigeons (Columba livia) associate time intervals with symbols in a touch screen task: Evidence for ordinality but not summation.

The present experiments examined whether pigeons can sum symbols that are associated with various temporal consequences in a touch screen apparatus. Pigeons were trained to discriminate between two visual symbols that were associated with 0, 1, 2, 3, 4, or 5 s either of delay to 4 s of hopper access (delay group) or duration of hopper access (reward group). In Experiment 1, the pigeons in both groups learned to select the symbol associated with the more favorable outcome, and they successfully transferred this discrimination to novel symbol pairs. However, when tested with 2 pairs of symbols associated with different summed durations, they responded on the basis of a simple response rule rather than the sum of the symbol pair. In Experiment 2, the reward group was presented with four symbols at once and was allowed to successively choose one symbol at a time. All pigeons chose the symbols in order from largest to smallest. This indicates that pigeons formed an ordered representation of symbols associated with different time intervals, even though they did not sum the symbols. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Distinguishing logic from association in the solution of an invisible displacement task by children (Homo sapiens) and dogs (Canis familiaris): Using negation of disjunction.

Prior research on the ability to solve the Piagetian invisible displacement task has focused on prerequisite representational capacity. This study examines the additional prerequisite of deduction. As in other tasks (e.g., conservation and transitivity), it is difficult to distinguish between behavior that reflects logical inference from behavior that reflects associative generalization. Using the role of negation in logic whereby negative feedback about one belief increases the certainty of another (e.g., a disjunctive syllogism), task-naive dogs (Canis familiaris; n?=?19) and 4- to 6-year-old children (Homo sapiens; n?=?24) were given a task wherein a desirable object was shown to have disappeared from a container after it had passed behind 3 separate screens. As predicted, children (as per logic of negated disjunction) tended to increase their speed of checking the 3rd screen after failing to find the object behind the first 2 screens, whereas dogs (as per associative extinction) tended to significantly decrease their speed of checking the 3rd screen after failing to find the object behind the first 2 screens. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The relationship between problem solving and inhibitory control: Cotton-top tamarins ( Saguinus oedipus ) performance on a reversed contingency task.

To explore the relationship between problem solving and inhibitory control, the authors present 4 experiments on cotton-top tamarins (Saguinus oedipus) using a reverse-reward contingency task. In Experiment 1, 1 group of tamarins was given a choice between a small and a large quantity of food. Whichever quantity the tamarins reached for first, they received the alternative. The tamarins consistently picked the larger quantity, thereby receiving the smaller. A 2nd group of tamarins was given the same task, except that if they reached for the larger quantity of food, they received nothing. The tamarins continued to pick the larger quantity, even though this resulted in no food. In addition, most of the tamarins continued to pick the larger quantity even when the food payoff for choosing the smaller quantity was increased (Experiment 2) or when the visual salience of the food was reduced (Experiment 3). Experiment 4 was based on the finding that chimpanzees (Pan troglodytes) that have been trained on the concept of number can solve the reversed contingency task if the food is replaced by Arabic numerals. With the help of a color association, and a higher cost incurred by picking the color associated with 3 food items, the tamarins learned to pick the color associated with... (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Hand preferences for a coordinated bimanual task in 110 chimpanzees (Pan troglodytes): Cross-sectional analysis.

Hand preference for a coordinated bimanual task was assessed in a sample of 110 chimpanzees (Pan troglodytes). Subjects were presented with opaque tubes, the inside of which was coated with peanut butter. The hand and finger used to extract the peanut butter was recorded in 2 test sessions. A population right-hand bias was found. Juvenile and adolescent subjects were less lateralized than adults. All subjects primarily used their index finger to extract peanut butter. Use of the index finger was higher in adults and adolescents compared with juveniles. The results suggest that coordinated bimanual tasks (a) elicit strong hand preferences at the individual level and (b) elicit population level right-handedness. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Spatial memory of domestic dogs (Canis familiaris) for hidden objects in a detour task.

Spatial memory of domestic dogs (Canis familiaris) for hidden objects was investigated via a visible displacement problem of object permanence with a detour paradigm. Experiment 1 showed that dogs were able to spontaneously locate a disappearing object in a detour situation. In Experiments 2 and 3, dead reckoning and allocentric spatial information were put in conflict. Results revealed that dogs simultaneously encoded both sources of information when they had to bypass an obstacle to locate a hidden object. Experiment 3 also revealed that, over the course of testing, dogs gradually learned to rely predominantly on allocentric cues when the detour involved several reorientations. The current study reveals that spatial memory of dogs for hidden objects in a detour task was guided by flexibility in processing spatial information. Dogs could simultaneously encode dead reckoning and allocentric information to locate a disappearing object and used them hierarchically according to the complexity of the detour they encountered in the environment. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Learning and generalization of tool use by tufted capuchin monkeys (Cebus apella) in tasks involving three factors: Reward, tool, and hindrance.

We tested 4 captive tufted capuchin monkeys (Cebus apella) for their understanding of physical causality in variations of a 2-choice tool use task, 1 alternative of which allowed the monkeys easier access to food. Our monkeys, who had been adept at this task involving 2 items, that is, tool and food, quickly learned 3-term problems involving food, tool, and 1 type of hindrance (an obstacle or a trap, which could prevent success). All of the monkeys generalized their performance to new problems with the other type of hindrance and those with another familiar tool. These results suggest flexibility of their abilities to process complex physical information comprising 3 items in the environment, that is food–tool–hindrance spatial relationships. Such flexibility also implies that capuchin monkeys may possess rudimentary understanding of causal relationships involved in tool use. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Lateralized scratching in chimpanzees (Pan troglodytes): Evidence of a functional asymmetry during arousal.

This study evaluated laterality in scratching by chimpanzees (n = 89) during socially arousing circumstances. Hand use and the side of the body scratched was recorded during a baseline and experimental condition. In the experimental condition, chimpanzees were shown a video of other conspecifics sharing, fighting over, and consuming a watermelon. Self-touches were categorized as either rubs or scratches. The chimpanzees showed a significant right hand bias for rubbing and also significantly directed the rubs to the right side of the body. For scratching, the chimpanzees showed no hand preference but a significant bias for scratching on the left side of the body. These results support the view that the right hemisphere regulates the autonomic nervous system during arousal. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

"The role of ventral and orbital prefrontal cortex in conditional visuomotor learning and strategy use in rhesus monkeys (Macaca mulatto)": Correction to Bussey et al (2001).

Reports an error in "The role of ventral and orbital prefrontal cortex in conditional visuomotor learning and strategy use in rhesus monkeys (Macaca mulatta)." by Timothy J. Bussey, Steven P. Wise and Elisabeth A. Murray (Behavioral Neuroscience, 2001[Oct], Vol 115[5], 971-982). In Figure 1 (p. 974), the extent of the intended lesions in the sections 32 and 28 mm from the interaural plane was misprinted. The correctly printed figure is shown in the erratum. (The following abstract of the original article appeared in record 2001-18882-001.) Four rhesus monkeys (Macaca mulatta) were trained to learn novel sets of visuomotor associations in 50 trials or less, within single test sessions. After bilateral ablation of the orbital and ventral prefrontal cortex, the monkeys lost the ability to learn these associations within a session, although they could learn them when given several daily sessions. Thus, relatively slow, across-session visuomotor learning depends on neither the ventral nor orbital prefrontal cortex, but rapid, within-session learning does. The ablations also eliminated at least 2 response strategies, repeat-stay and lose-shift, which might account, in part, for the deficit in rapid learning. The deficit is unlikely to result from a failure of visual discriminative ability or working memory: The monkeys could discriminate similar stimulus material within a session, and reducing the working memory load did not improve within-session learning. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Long-Term Memory for Spatial Locations in a Food-Storing Bird (Poecile atricapilla) Requires Activation of NMDA Receptors in the Hippocampal Formation During Learning.

Food-storing birds use a form of long-term memory to recover their hidden food caches that depends on the hippocampal formation (HF). The authors assessed whether food-storing birds' long-term memory for spatial locations requires N-methyl-D-aspartate receptor (NMDA-R)-dependent synaptic plasticity. Black-capped chickadees (Poecile atricapilla) were given bilateral infusions of the NMDA-R antagonist AP5 into the hippocampus, and their memory on a spatial reference memory task was assessed. NMDA-R inactivation during learning prevented formation of long-term spatial memories but did not affect short-term memory and retrieval processes. NMDA-R inactivation immediately following learning did not disrupt long-term memory formation. NMDA-R inactivation disrupted the learning of multiple serially encoded reward locations when a 180-min delay separated successive learning episodes, suggesting that NMDA-R activity has a role in the incorporation of new information into existing long-term memory, as well as in forming unitary long-term memories. (PsycINFO Database Record (c) 2010 APA, all rights reserved)