| Home | << 1 2 3 >> |
|
Urcuioli, P. J., & Zentall, T. R. (1986). Retrospective coding in pigeons' delayed matching-to-sample. J Exp Psychol Anim Behav Process, 12(1), 69–77.
Abstract: In this study we examined how coding processes in pigeons' delayed matching-to-sample were affected by the stimuli to be remembered. In Experiment 1, two groups of pigeons initially learned 0-delay matching-to-sample with identical comparison stimuli (vertical and horizontal lines) but with different sample stimuli (red and green hues or vertical and horizontal lines). Longer delays were then introduced between sample offset and comparison onset to assess whether pigeons were prospectively coding the same events (viz., the correct line comparisons) or retrospectively coding different events (viz., their respective sample stimuli). The hue-sample group matched more accurately and showed a slower rate of forgetting than the line-sample group. In Experiment 2, pigeons were trained with either hues or lines as both sample and comparison stimuli, or with hue samples and line comparisons or vice versa. Subsequent delay tests revealed that the hue-sample groups remembered more accurately and generally showed slower rates of forgetting than the line-sample groups. Comparison dimension had little or no effect on performance. Together, these data suggest that pigeons retrospectively code the samples in delayed matching-to-sample.
|
|
Shettleworth, S. J. (1985). Foraging, memory, and constraints on learning. Ann N Y Acad Sci, 443, 216–226.
|
|
Shettleworth, S. J., & Krebs, J. R. (1982). How marsh tits find their hoards: the roles of site preference and spatial memory. J Exp Psychol Anim Behav Process, 8(4), 354–375.
Abstract: Marsh tits (Parus palustris) store single food items in scattered locations and recover them hours or days later. Some properties of the spatial memory involved were analyzed in two laboratory experiments. In the first, marsh tits were offered 97 sites for storing 12 seeds. They recovered a median of 65% of them 2-3 hr later, making only two errors per seed while doing so. Over trials, they used some sites more often than others, but during recovery they were more likely to visit a site of any preference value if they had stored a seed there that day than if they had not. Recovery performance was much worse if the experimenters moved the seeds between storage and recovery. A fixed search strategy that had some of the same average properties as the tits' search behavior also did worse than the real birds. In Experiment 2, any tendency to visit the same sites on successive daily tests in the aviary was placed in opposition to memory for storage sites by allowing the tits to store more seeds 2 hr after storing a first batch. They tended to avoid individual storage sites holding seeds from the first batch. When the tits searched for all the seeds 2 hr later, they tended to recover more seeds from the second batch than from the first, i.e., there was a recency effect.
|
|
Vlasak, A. N. (2006). Global and local spatial landmarks: their role during foraging by Columbian ground squirrels (Spermophilus columbianus). Anim. Cogn., 9(1), 71–80.
Abstract: Locating food and refuge is essential for an animal's survival. However, little is known how mammals navigate under natural conditions and cope with given environmental constraints. In a series of six experiments, I investigated landmark-based navigation in free-ranging Columbian ground squirrels (Spermophilus columbianus). Squirrels were trained individually to find a baited platform within an array of nine identical platforms and artificial landmarks set up on their territories. After animals learned the location of the food platform in the array, the position of the latter with respect to local artificial, local natural, and global landmarks was manipulated, and the animal's ability to find the food platform was tested. When only positions of local artificial landmarks were changed, squirrels located food with high accuracy. When the location of the array relative to global landmarks was altered, food-finding accuracy decreased but remained significant. In the absence of known global landmarks, the presence of a familiar route and natural local landmarks resulted in significant but not highly accurate performance. Squirrels likely relied on multiple types of cues when orienting towards a food platform. Local landmarks were used only as a secondary mechanism of navigation, and were not attended to when a familiar route and known global landmarks were present. This study provided insights into landmark use by a wild mammal in a natural situation, and it demonstrated that an array of platforms can be employed to investigate landmark-based navigation under such conditions.
|
|
Ikeda, M., Patterson, K., Graham, K. S., Ralph, M. A. L., & Hodges, J. R. (2006). A horse of a different colour: do patients with semantic dementia recognise different versions of the same object as the same? Neuropsychologia, 44(4), 566–575.
Abstract: Ten patients with semantic dementia resulting from bilateral anterior temporal lobe atrophy, and 10 matched controls, were tested on an object recognition task in which they were invited to choose (from a four-item array) the picture representing “the same thing” as an object picture that they had just inspected and attempted to name. The target in the response array was never physically identical to the studied picture but differed from it – in the various conditions – in size, angle of view, colour or exemplar (e.g. a different breed of dog). In one test block for each patient, the response array was presented immediately after the studied picture was removed; in another block, a 2 min filled delay was inserted between study and test. The patients performed relatively well when the studied object and target response differed only in the size of the picture on the page, but were significantly impaired as a group in the other three type-of-change conditions, even with no delay between study and test. The five patients whose structural brain imaging revealed major right-temporal atrophy were more impaired overall, and also more affected by the 2 min delay, than the five patients with an asymmetric pattern characterised by predominant left-sided atrophy. These results are interpreted in terms of a hypothesis that successful classification of an object token as an object type is not a pre-semantic ability but rather results from interaction of perceptual and conceptual processing.
Keywords: Adult; Aged; Anomia/diagnosis/psychology; Atrophy; *Attention; Color Perception; Dementia/*diagnosis/psychology; *Discrimination Learning; Dominance, Cerebral; Female; Humans; Male; *Memory, Short-Term; Middle Aged; Neuropsychological Tests; Orientation; *Pattern Recognition, Visual; Reference Values; Retention (Psychology); Semantics; Size Perception; Temporal Lobe/pathology
|
|
Neiworth, J. J., Steinmark, E., Basile, B. M., Wonders, R., Steely, F., & DeHart, C. (2003). A test of object permanence in a new-world monkey species, cotton top tamarins (Saguinus oedipus). Anim. Cogn., 6(1), 27–37.
Abstract: Cotton top tamarins were tested in visible and invisible displacement tasks in a method similar to that used elsewhere to test squirrel monkeys and orangutans. All subjects performed at levels significantly above chance on visible ( n=8) and invisible ( n=7) displacements, wherein the tasks included tests of the perseverance error, tests of memory in double and triple displacements, and “catch” trials that tested for the use of the experimenter's hand as a cue for the correct cup. Performance on all nine tasks was significantly higher than chance level selection of cups, and tasks using visible displacements generated more accurate performance than tasks using invisible displacements. Performance was not accounted for by a practice effect based on exposure to successive tasks. Results suggest that tamarins possess stage 6 object permanence capabilities, and that in a situation involving brief exposure to tasks and foraging opportunities, tracking objects' movements and responding more flexibly are abilities expressed readily by the tamarins.
Keywords: Animals; Feeding Behavior; Female; Male; *Memory; *Saguinus; *Visual Perception
|
|
Schwartz, B. L., Colon, M. R., Sanchez, I. C., Rodriguez, I. A., & Evans, S. (2002). Single-trial learning of “what” and “who” information in a gorilla (Gorilla gorilla gorilla): implications for episodic memory. Anim. Cogn., 5(2), 85–90.
Abstract: Single-trial learning and long-term memory of “what” and “who” information were examined in an adult gorilla (Gorilla gorilla gorilla). We presented the gorilla with a to-be-remembered food item at the time of study. In Experiment 1, following a retention interval of either approximately 7 min or 24 h, the gorilla responded with one of five cards, each corresponding to a particular food. The gorilla was accurate on 70% of the short retention-interval trials and on 82% of the long retention-interval trials. In Experiment 2, the food stimulus was provided by one of two experimenters, each of whom was represented by a card. The gorilla identified the food (55% of the time) and the experimenter (82% of the time) on the short retention-interval trials. On the long retention-interval trials, the gorilla was accurate for the food (73%) and for the person (87%). The results are interpreted in light of theories of episodic memory.
Keywords: Animals; Cognition; Gorilla gorilla/*psychology; *Learning; Male; *Memory; Perception; Reinforcement Schedule
|
|
Treichler, F. R., & Van Tilburg, D. (2002). Premise-pair training for valid tests of serial list organization in macaques. Anim. Cogn., 5(2), 97–105.
Abstract: This study evaluated the role of several different training procedures on (1) efficiency of acquisition and (2) organizational characteristics of memory for lists that could be serially ordered. Five macaque monkeys were trained via two-choice object discriminations in a formboard apparatus on several five-item-series tasks that provided different levels of intrasession conditionality. Although ease of acquisition differed for subsets of the constituent pairs, concurrent inclusion of the four premise pairs that defined a list required equivalent amounts of training on every task. All training procedures yielded similar retention-test performances and showed common organizational properties (on both error and latency measures) consistent with the view that lists were retained as internally represented ordered series. Test outcomes emphasized the need for integrated exposition of all concurrent conditional relationships to allow appropriate tests of serial organization. However, if given such training, the monkeys revealed integrated serial memory even though they had never seen many of the possible novel combinations of list items. In overview, their performances offered further definition of the procedures required for valid assessment of inferential properties in comparative cognition.
Keywords: Animals; *Discrimination Learning; Female; Macaca/*psychology; *Memory
|
|
Devenport, J. A., Patterson, M. R., & Devenport, L. D. (2005). Dynamic averaging and foraging decisions in horses (Equus callabus). J. Comp. Psychol., 119(3), 352–358.
Abstract: The variability of most environments taxes foraging decisions by increasing the uncertainty of the information available. One solution to the problem is to use dynamic averaging, as do some granivores and carnivores. Arguably, the same strategy could be useful for grazing herbivores, even though their food renews and is more homogeneously distributed. Horses (Equus callabus) were given choices between variable patches after short or long delays. When patch information was current, horses returned to the patch that was recently best, whereas those without current information matched choices to the long-term average values of the patches. These results demonstrate that a grazing species uses dynamic averaging and indicate that, like granivores and carnivores, they can use temporal weighting to optimize foraging decisions.
|
|
Zentall, T. R. (2005). Timing, memory for intervals, and memory for untimed stimuli: the role of instructional ambiguity. Behav. Process., 70(3), 209–222.
Abstract: Theories of animal timing have had to account for findings that the memory for the duration of a timed interval appears to be dramatically shorted within a short time of its termination. This finding has led to the subjective shortening hypothesis and it has been proposed to account for the poor memory that animals appear to have for the initial portion of a timed interval when a gap is inserted in the to-be-timed signal. It has also been proposed to account for the poor memory for a relatively long interval that has been discriminated from a shorter interval. I suggest here a simpler account in which ambiguity between the gap or retention interval and the intertrial interval results in resetting the clock, rather than forgetting the interval. The ambiguity hypothesis, together with a signal salience mechanism that determines how quickly the clock is reset at the start of the intertrial interval can account for the results of the reported timing experiments that have used the peak procedure. Furthermore, instructional ambiguity rather than memory loss may account for the results of many animal memory experiments that do not involve memory for time.
|