Object permanence and working memory in cats (Felis catus).

Cats (Felis catus) find an object when it is visibly moved behind a succession of screens. However, when the object is moved behind a container and is invisibly transferred from the container to the back of a screen, cats try to find the object at or near the container rather than at the true hiding place. Four experiments were conducted to study search behavior and working memory in visible and invisible displacement tests of object permanence. Exp 1 compared performance in single and in double visible displacement trials. Exp 2 analyzed search behavior in invisible displacement tests and in analogs using a transparent container. Exps 3 and 4 tested predictions made from Exps 1 and 2 in a new situation of object permanence. Results showed that only the position changes that cats have directly perceived are encoded and activated in working memory because they are unable to represent or infer invisible movements. (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)     

Association, inhibition, and object permanence in dogs' (Canis familiaris) spatial search.

The relative role of associative processes and the use of explicit cues about object location in search behavior in dogs (Canis familiaris) was assessed by using a spatial binary discrimination reversal paradigm in which reversal conditions featured: (1) a previously rewarded location and a novel location, (2) a previously nonrewarded location and a novel location, or (3) a previously rewarded location and a previously nonrewarded location. Rule mediated learning predicts a similar performance in these different reversal conditions whereas associative learning predicts the worst performance in Condition 3. Evidence for an associative control of search emerged when no explicit cues about food location were provided (Experiment 1) but also when dogs witnessed the hiding of food in the reversal trials (Experiment 2) and when they did so in both the prereversal and the reversal trials (Experiment 3). Nevertheless, dogs performed better in the prereversal phase of Experiment 3 indicating that their search could be informed by the knowledge of the food location. Experiment 4 confirmed the results of Experiments 1 and 2, under a different arrangement of search locations. We conclude that knowledge about object location guides search behavior in dogs but it cannot override associative processes. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Finding hidden food: Behavior on visible displacement tasks by mynahs (Gracula religiosa) and pigeons (Columba livia).

Four visible displacement tasks showed that pigeons can learn to find hidden food but revealed little evidence of spontaneous retrieval. In Experiment 1, given a choice between 2 screens, 1 of which concealed food, pigeons performed at chance level. In Experiment 2, when shown a moving cart of grain that disappeared into a tunnel and reemerged, they spontaneously followed the cart if the tunnel was clear but not if it was opaque. After learning to follow the cart, they would follow it when it was filled with grit. In Experiment 3, pigeons were rewarded for pecking at a key when a horizontally moving figure disappeared behind an occluder. Performance was characterized by a time-waiting rule. Experiment 4 describes a species comparison in finding food hidden in 1 of 4 compartments: As predicted from ecological considerations, mynahs performed better than pigeons. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Evidence of location memory in 8-month-old infants in a nonsearch AB task.

Recent studies have shown that when an object is hidden in a location A and then in a location B, 8-month-old infants tend to search in A if forced to wait 3 s before retrieving the object, and to search randomly in A or B if forced to wait 6 s before retrieving the object (e.g., Diamond, 1985). A non-search method was devised to examine 8-month-olds' ability to remember the location of a hidden object. The infants saw an object standing on one of two placemats located on either side of the midline. Next, screens were pushed in front of the placemats, hiding the object from view. After 15 s, a hand reached behind one of the screens and reappeared holding the object. The infants looked reliably longer when the hand retrieved the object from behind the "wrong" as opposed to the "right" screen (where the object was actually hidden). This result suggests that the infants (a) remembered the object's location during the 15-s delay and (b) were surprised to see the object retrieved from behind the right (left) screen when they had last seen it on the left (right) placemat. These results indicate that 8-month-old infants' ability to remember the location of a hidden object is far better than their performance in the AB search task suggests. As such, the present results cast serious doubts on accounts that attribute infants' perseverative and/or random search errors to limited memory mechanisms. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Dolphins (Tursiops truncatus) comprehend the referential character of the human pointing gesture.

The authors tested a dolphin's (Tursiops truncatus) understanding of human manual pointing gestures to 3 distal objects located to the left of, to the right of, or behind the dolphin. The human referred to an object through a direct point (Pd), a cross-body point (Px), or a familiar symbolic gesture (S). In Experiment 1, the dolphin responded correctly to 80% of Pds toward laterally placed objects but to only 40% of Pds to the object behind. Responding to objects behind improved to 88% in Experiment 2 after exaggerated pointing was briefly instituted. Spontaneous comprehension of Pxs also was demonstrated. In Experiment 3, the human produced a sequence of 2 Pds, 2 Pxs, 2 Ss, or all 2-way combinations of these 3 to direct the dolphin to take the object referenced second to the object referenced first. Accuracy ranged from 68% to 77% correct (chance?=?17%). These results established that the dolphin understood the referential character of the human manual pointing gesture. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The development of perceptual completion abilities: infants' perception of stationary, partially occluded objects

We explored infants' ability to perceive stationary, partially occluded objects as connected units (Experiments 1 and 2) with specific appearances (Experiment 3). In each experiment, the infants saw 2 test events involving what appeared to adults to be a tall rectangular object whose middle portion was hidden behind a narrow screen. During the test events, the screen alternately uncovered and covered the object. In Experiments 1 and 2, removal of the screen revealed either a single, connected rectangle (complete object event) or an interrupted rectangle with a gap where the screen had been (broken object event). In Experiment 3, removal of the screen revealed either a rectangle (rectangle event) or a cross-shaped object (cross-shape event). The pattern of infants' looking times at these events suggest that they perceive the unity of the partially occluded object by 6.5 months of age but did not perceive the form of the hidden part of the object until 8 months. The results of baseline control conditions support this interpretation.     

Object permanence in rhesus monkeys (Macaca mulatta).

We evaluated the performance of 6 adult rhesus monkeys (Macaca mulatta) on object permanence tasks. In Experiment 1, monkeys received search tasks that correspond to Stages 4, 5, and 6 of object permanence. Subjects were successful on tasks of visible displacements (Stages 4 and 5) but failed to find the object in invisible displacements (Stage 6). The monkeys adopted a search strategy of investigating a specific hiding location. In Experiment 2, monkeys were given a second opportunity to find the object if they investigated a location that was part of the displacement on their first search. Subjects relied on the same search strategy identified in Experiment 1. In Experiment 3, the experimenter hid the object in her hand rather than a container. The monkeys failed to recover the object, and individual differences were found in the strategies used. These results suggest that the upper limit of object permanence in rhesus monkeys is Stage 5. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Motivational influences underlying prolactin-induced feeding in doves (Streptopelia risoria).

Prolactin (Prl) increases food consumption in ring doves (Streptopelia risoria) and may promote the hyperphagia exhibited by parent doves when provisioning young. These experiments tested whether Prl also enhances appetitive aspects of feeding behavior. Prl elevated pecking rates in food-restricted doves on a variable-interval (VI) reinforcement schedule and supported continued responding when doves were returned to ad-lib feeding. Prl-treated doves learned the key-pecking response when food intake was clamped at ad-lib levels exhibited before Prl treatment but not when given free access to food. Median break points on a progressive ratio schedule were 2–3 times greater in food-restricted doves than Prl-treated, food-clamped doves even though response rates were similar on VI schedules. These results indicate that Prl enhances appetitive aspects of feeding, although food restriction at the level imposed in this study was more effective in this regard. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A Comparative Study of the Use of Visual Communicative Signals in Interactions Between Dogs (Canis familiaris) and Humans and Cats (Felis catus) and Humans.

Dogs' (Canis familiaris) and cats' (Felis catus) interspecific communicative behavior toward humans was investigated. In Experiment 1, the ability of dogs and cats to use human pointing gestures in an object-choice task was compared using 4 types of pointing cues differing in distance between the signaled object and the end of the fingertip and in visibility duration of the given signal. Using these gestures, both dogs and cats were able to find the hidden food; there was no significant difference in their performance. In Experiment 2, the hidden food was made inaccessible to the subjects to determine whether they could indicate the place of the hidden food to a naive owner. Cats lacked some components of attention-getting behavior compared with dogs. The results suggest that individual familiarization with pointing gestures ensures high-level performance in the presence of such gestures; however, species-specific differences could cause differences in signaling toward the human. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Object permanence in cats (Felis catus): An ecological approach to the study of invisible displacements.

A single invisible displacement object permanence task was administered to 19 cats. In this task, cats watched a target object from behind a transparent panel. However, cats had to walk around an opaque panel to reach the object. While cats were behind the opaque panel, the object was hidden behind 1 of 2 screens. As cats did not perceive the disappearance of the object behind the target screen, the object was invisibly hidden. Results showed that cats solved this task with great flexibility, which markedly contrasts with what has been observed in previous research. The discussion emphasizes the difference between the typical Piagetian task in which the information necessary to succeed must be dealt with in a retrospective way, whereas in this task cats had to anticipate a new position of the object. The ecological relevance of this new task is also discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The relation between hiding skill and judgment of eye direction in preschool children.

This study examines J. H. Flavell, S. G. Shipstead, and K. Croft's (1978) finding that 2 1/2-year-old children can hide an object behind a screen but cannot achieve the same result by placing the screen in front of the object. Experiment 1 replicated this finding alongside a task in which children judged what a person in a picture was looking at. Performance on the move-object task approached ceiling; performances on the move-screen and looking-where tasks were highly correlated even after age and control task performance were partialed out (r=.54, pengagement, a precursor to a mature understanding of attention. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Viewing another person's eye movements improves identification of pulmonary nodules in chest x-ray inspection.

Double reading of chest x-rays is often used to ensure that fewer abnormalities are missed, but very little is known about how the search behavior of others affects observer performance. A series of experiments investigated whether radiographers benefit from knowing where another person looked for pulmonary nodules, and whether the expertise of the model providing the search behavior was a contributing factor. Experiment 1 compared the diagnostic performance of novice and experienced radiographers examining chest x-rays and found that both groups performed better when shown the search behavior of either a novice radiographer or an expert radiologist. Experiment 2 established that benefits in performance only arose when the eye movements shown were related to the search for nodules; however, only the novices' diagnostic performance consistently improved when shown the expert's search behavior. Experiment 3 reexamined the contribution of task, image, and the expertise of the model underlying this benefit. Consistent with Experiment 1, novice radiographers were better at identifying nodules when shown either a na?ve's search behavior or an expert radiologist's search behavior, but they demonstrated no improvement when shown a na?ve model not searching for nodules. Our results suggest that although the benefits of this form of attentional guidance may be short-lived, novices can scaffold their decisions based on the search behavior of others. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Conditional copying fidelity in capuchin monkeys (Cebus apella).

In the last two decades, it became largely accepted that monkeys show little, if any, copying fidelity. However, some recent studies have begun to challenge this notion. To explore reasons for such contrary findings, we designed a foraging apparatus so that in each of two experiments with capuchin monkeys (Cebus apella), a model would demonstrate one of two alternative methods to obtain food. The apparatus had a V-shaped track on which a panel could be slid up left or right from the center to reveal food. In Experiment 1, food was located in a cup directly behind the center panel. In Experiment 2, sliding the panel left or right revealed food either in left or right ends of the V-track. Since this sliding movement led directly to one food location exclusive of the other, we predicted capuchins would show greater copying fidelity in this second Experiment. Instead, subjects were significantly more faithful to the model’s method in Experiment 1, which provided strong evidence of capuchins copying what they had observed. We suggest that the contrasting results of Experiment 1 may have occurred because capuchins prioritize exploratory behavior when alternative foraging locations are accessible. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Information integration about object–object relationships by chimpanzees (Pan troglodytes).

Three experiments tested the ability to integrate information about object–object relationships in 2 chimpanzees. In Experiment 1, the subjects were trained to match 1 part of a 2-part object to its other part, match a tool to its assembled object, match a container to its tool, and match a tool to its container. In Experiment 2, the subjects were trained to match a picture of the sample. One subject learned this type of matching task and was then tested on whether she could choose the pictures of related items in Experiment 1. Although the subject was reinforced irrespective of her choices, she chose pictures of items related to the sample when there was no picture of the sample. Experiment 3 showed that the subject was able to match a picture of the item among related items. The results suggest that the subject might integrate information about relationships acquired in Experiment 1 and organize it to make networks of related items. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Does consistent scene context facilitate object perception?

The conclusion that scene knowledge interacts with object perception depends on evidence that object detection is facilitated by consistent scene context. Experiment 1 replicated the I. Biederman, R. J. Mezzanotte, and J. C. Rabinowitz (1982) object-detection paradigm. Detection performance was higher for semantically consistent versus inconsistent objects. However, when the paradigm was modified to control for response bias (Experiments 2 and 3) or when response bias was eliminated by means of a forced-choice procedure (Experiment 4), no such advantage obtained. When an additional source of biasing information was eliminated by presenting the object label after the scene (Experiments 3 and 4), there was either no effect of consistency (Experiment 4) or an inconsistent object advantage (Experiment 3). These results suggest that object perception is not facilitated by consistent scene context.     

Dimensional comparisons: An experimental approach to the internal/external frame of reference model.

According to the internal/external frame of reference model (H. W. Marsh, 1986, 1990a), students not only use social comparisons to evaluate their performance (external frame of reference) but they also use dimensional comparisons (internal frame of reference), comparing their own achievement in one subject with that in other subjects. Three experimental studies were conducted to investigate the psychological processes underlying the effects of achievement in one domain on self-perceived competence in another. In Study 1 (N?=?36), high achievement in one domain led to lower self-perceived competence in the other domain. Study 2 (N?=?45) showed inverse effects on self-perceived competence when achievement feedback included explicit dimensional comparison information about students' achievement in both tasks. In Study 3 (N?=?90), dimensional comparison effects were shown even when additional social comparison information was presented. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Metacognitive regulation of text learning: On screen versus on paper.

Despite immense technological advances, learners still prefer studying text from printed hardcopy rather than from computer screens. Subjective and objective differences between on-screen and on-paper learning were examined in terms of a set of cognitive and metacognitive components, comprising a Metacognitive Learning Regulation Profile (MLRP) for each study media. Participants studied expository texts of 1000–1200 words in one of the two media and for each text they provided metacognitive prediction-of-performance judgments with respect to a subsequent multiple-choice test. Under fixed study time (Experiment 1), test performance did not differ between the two media, but when study time was self-regulated (Experiment 2) worse performance was observed on screen than on paper. The results suggest that the primary differences between the two study media are not cognitive but rather metacognitive—less accurate prediction of performance and more erratic study-time regulation on screen than on paper. More generally, this study highlights the contribution of metacognitive regulatory processes to learning and demonstrates the potential of the MLRP methodology for revealing the source of subjective and objective differences in study performance among study conditions. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Looking and search measures of object knowledge in preschool children.

The same preschoolers were tested on an observation task and a search task involving the invisible displacement of an object. In the observation task, children watched an object roll behind a screen from which protruded the top of a solid wall. Analyses revealed significantly longer looking to impossible than to possible outcomes in all children. In search, the child was allowed to retrieve the rolled object. Most 3-year-olds but significantly fewer 2.5-year-olds completed the search successfully. An unexpected sex difference was found, with boys outperforming girls. Search performance was not associated with observation measures. The findings indicate that children visually discriminate violations of solidity but that this sensitivity is not associated with successful search performance. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Some affective consequences of social comparison and reflection processes: The pain and pleasure of being close.

A self-evaluation maintenance (SEM) model of social behavior was described. According to the comparison process, when another outperforms the self on a task high in relevance to the self, the closer the other the greater the threat to self-evaluation. According to the reflection process, when another outperforms the self on a task low in relevance to the self, the closer the other the greater the promise of augmentation to self-evaluation. Affect was assumed to reflect threats and promises to self-evaluation. In 3 studies, Ss were given feedback about own performance and the performance of a close (friend) and distant (stranger) other on tasks that were either low in self-relevance (Study 2) or that varied in self-relevance (Studies 1 and 3). In Study 1 (N?=?31), being outperformed by a close other resulted in greater arousal than being outperformed by a distant other. In Study 2 (N?=?30), results indicate that when relevance was low, more positive affect was associated with a friend's outperforming the self than either a friend's performing at a level equal to the self or being outperformed by a stranger. In Study 3 (N?=?31), pleasantness of expression was an interactive function of relevance of task, relative performance, and closeness of comparison other. All 3 studies are interpreted as being generally consistent with the SEM model. (PsycINFO Database Record (c) 2010 APA, all rights reserved)