Touch screen assays of behavioural flexibility and error characteristics in Eastern grey squirrels (<Emphasis Type="Italic">Sciurus carolinensis</Emphasis>)

Behavioural flexibility allows animals to adjust their behaviours according to changing environmental demands. Such flexibility is frequently assessed by the discrimination–reversal learning task. We examined grey squirrels’ behavioural flexibility, using a simultaneous colour discrimination–reversal learning task on a touch screen. Squirrels were trained to select their non-preferred colour in the discrimination phase, and their preferred colour was rewarded in a subsequent reversal phase. We used error rates to divide learning in each phase into three stages (perseveration, chance level and ‘learned’) and examined response inhibition and head-switching during each stage. We found consistent behavioural patterns were associated with each learning stage: in the perseveration stage, at the beginning of each training phase, squirrels showed comparable response latencies to correct and incorrect stimuli, along with a low level of head-switching. They quickly overcame perseveration, typically in one to three training blocks. In the chance-level stage, response latencies to both stimuli were low, but during initial discrimination squirrels showed more head-switches than in the previous stage. This suggests that squirrels were learning the current reward contingency by responding rapidly to a stimulus, but with increased attention to both stimuli. In the learned stage, response latencies to the correct stimulus and the number of head-switches were at their highest, whereas incorrect response latencies were at their lowest, and differed significantly from correct response latencies. These results suggest increased response inhibition and attention allowed the squirrels to minimise errors. They also suggest that errors in the ‘learned’ stage were related to impulsive emission of the pre-potent or previously learned responses.     

Working memory and intrusions of irrelevant information in a group of specific poor problem solvers

An important body of evidence has shown that reading comprehension ability is related to working memory and, in particular, to the success in Daneman and Carpenter's (1980) reading and listening span test. This research tested a similar hypothesis for arithmetic word problems, since, in order to maintain and process the information, they require working memory processes. A group of children possessing average vocabulary but poor arithmetic problem-solving skills was compared with a group of good problem solvers, matched for vocabulary, age, and socioeconomic status. Poor problem solvers presented lower recall and a greater number of intrusion errors in a series of tasks testing working memory and memory for problems. The results obtained over a series of six experimental phases, conducted during a 2-school-year period, offer evidence in favor of the hypotheses that groups of poor problem solvers may have poor performance in a working memory test requiring inhibition of irrelevant information (Hypothesis 1), but not in other short-term memory tests (Hypothesis 2), that this difficulty is related to poor recall of critical information and greater recall of to-be-inhibited information (Hypothesis 3), that poor problem solvers also have difficulty in remembering only relevant information included in arithmetic word problems (Hypothesis 4) despite the fact that they are able to identify relevant information (Hypothesis 5). The results show that problem-solving ability is related to the ability of reducing the memory accessibility of nontarget and irrelevant information.     

Young children's knowledge of their memory span: effects of task and experience

This study investigated the hypothesis that young children have knowledge about their memory that they may be unable to articulate, but are able to reflect on and use in problem-solving. Forty-eight kindergarteners made one of two types of judgments about their memory span for words. Half of the children made prospective verbal predictions about the number of words they thought they could recall from a list of 10. The other half made concurrent, nonverbal predictions by listening to words on a tape and manually stopping the tape when they heard as many words as they thought they could recall. Children's actual recall for words was then assessed. All children participated in multiple trials to assess the effect of task experience on their predictions. Analyses revealed that predictions made in the concurrent task were significantly more accurate than those made in the prospective task. All children lowered their predictions across trials, although only in the concurrent task were children's final-trial predictions not significantly greater than their actual recall. No meaningful effects or interactions were associated with actual recall scores. These results revealed that young children manifested greater memory knowledge when this knowledge was assessed through their concurrent problem-solving behavior rather than through their prospective verbal predictions.     

Ask and ye shall receive: behavioural specificity in the accuracy of subjective memory complaints

A cross‐sectional sample of adults completed an extensive set of cognitive tasks and a set of questionnaires measuring depressive affect, memory complaint, and other variables. During an interview about their prescribed medications, the participants also reported whether they were having problems remembering to take the medication as prescribed (an everyday prospective memory problem). Their medication adherence at home was then monitored for one month using pill bottles which microelectronic caps. Cognitive tasks correlated with memory complaints, as measured by the Memory Functioning Questionnaire, but not with problems in remembering to take medications. The highest correlations were with a free recall task. Conversely, reported problems with medication adherence during the interview had good predictive validity for subsequent adherence problems, but not for cognitive tasks, including a measure of prospective memory. Depressive affect was related to both the questionnaire and the interview complaints about medication adherence, but a structural equation model showed that the relationships of cognition and medication adherence to the different memory complaints were independent of depressive affect. The results are interpreted in terms of a behavioural specificity hypothesis, which states that adults' self‐reports of memory problems are valid when they focus directly on specific memory‐related behaviours in everyday contexts. Copyright © 2000 John Wiley & Sons, Ltd.     

Ontogenetic effects on gazing behaviour: a case study of kennel dogs (Labrador Retrievers) in the impossible task paradigm

Life experiences and living conditions can influence the problem-solving strategies and the communicative abilities of dogs with humans. The goals of this study were to determine any behavioural differences between Labrador Retrievers living in a kennel and those living in a house as pets and to assess whether kennel dogs show preferences in social behaviours for their caretaker relative to a stranger when they are faced with an unsolvable task. Nine Labrador Retrievers living in a kennel from birth and ten Labrador Retrievers living in a family as pets were tested. The experimental procedure consisted of three “solvable” tasks in which the dogs could easily retrieve food from a container followed by an “unsolvable” task in which the container was hermetically locked. Dogs of both groups spent the same amount of time interacting with the experimental apparatus. Kennel dogs gazed towards people for less time and with higher latency than pet dogs; however, there were no significant preferences in gazing towards the stranger versus the caretaker in both groups. These findings demonstrated that kennel dogs are less prone to use human-directed gazing behaviour when they are faced with an unsolvable problem, taking the humans into account to solve a task less than do the pet dogs.     

Audience effects on food caching in grey squirrels (<Emphasis Type="Italic">Sciurus carolinensis</Emphasis>): evidence for pilferage avoidance strategies

If food pilferage has been a reliable selection pressure on food caching animals, those animals should have evolved the ability to protect their caches from pilferers. Evidence that animals protect their caches would support the argument that pilferage has been an important adaptive challenge. We observed naturally caching Eastern grey squirrels (Sciurus carolinensis) in order to determine whether they used any evasive tactics in order to deter conspecific and heterospecific pilferage. We found that grey squirrels used evasive tactics when they had a conspecific audience, but not when they had a heterospecific (corvid) audience. When other squirrels were present, grey squirrels spaced their caches farther apart and preferentially cached when oriented with their backs to other squirrels, but no such effect was found when birds were present. Our data provide the first evidence that caching mammals are sensitive to the risk of pilferage posed by an audience of conspecifics, and that they utilise evasive tactics that should help to minimise cache loss. We discuss our results in relation to recent theory of reciprocal pilferage and compare them to behaviours shown by caching birds.     

Specialization effect and its influence on memory and problem solving in expert chess players

Expert chess players, specialized in different openings, recalled positions and solved problems within and outside their area of specialization. While their general expertise was at a similar level, players performed better with stimuli from their area of specialization. The effect of specialization on both recall and problem solving was strong enough to override general expertise—players remembering positions and solving problems from their area of specialization performed at around the level of players 1 standard deviation (SD) above them in general skill. Their problem-solving strategy also changed depending on whether the problem was within their area of specialization. When it was, they searched more in depth and less in breadth; with problems outside their area of specialization, the reverse. The knowledge that comes from familiarity with a problem area is more important than general purpose strategies in determining how an expert will tackle it. These results demonstrate the link in experts between problem solving and memory of specific experiences and indicate that the search for context-independent general purpose problem-solving strategies to teach to future experts is unlikely to be successful.     

Grey squirrels (Sciurus carolinensis) show a feature-negative effect specific to social learning

Previous laboratory studies on social learning suggest that some animals can learn more readily if they first observe a conspecific demonstrator perform the task unsuccessfully and so fail to obtain a food reward than if they observe a successful demonstrator that obtains the food. This effect may indicate a difference in how easily animals are able to associate different outcomes with the conspecific or could simply be the result of having food present in only some of the demonstrations. To investigate we tested a scatter-hoarding mammal, the eastern grey squirrel, on its ability to learn to choose between two pots of food after watching a conspecific remove a nut from one of them on every trial. Squirrels that were rewarded for choosing the opposite pot to the conspecific chose correctly more frequently than squirrels rewarded for choosing the same pot (a feature-negative effect). Another group of squirrels was tested on their ability to choose between the two pots when the rewarded option was indicated by a piece of card. This time, squirrels showed no significant difference in their ability to learn to choose the same or the opposite pot. The results add to anecdotal reports that grey squirrels can learn by observing a conspecific and suggest that even when all subjects are provided with demonstrations with the same content, not all learning occurs equally. Prior experience or expectations of the association between a cue (a conspecific) and food influences what can be learned through observation whilst previously unfamiliar cues (the card) can be associated more readily with any outcome.     

Enhancing memory and imagination improves problem solving among individuals with depression

Recent work has revealed links between memory, imagination, and problem solving, and suggests that increasing access to detailed memories can lead to improved imagination and problem-solving performance. Depression is often associated with overgeneral memory and imagination, along with problem-solving deficits. In this study, we tested the hypothesis that an interview designed to elicit detailed recollections would enhance imagination and problem solving among both depressed and nondepressed participants. In a within-subjects design, participants completed a control interview or an episodic specificity induction prior to completing memory, imagination, and problem-solving tasks. Results revealed that compared to the control interview, the episodic specificity induction fostered increased detail generation in memory and imagination and more relevant steps on the problem-solving task among depressed and nondepressed participants. This study builds on previous work by demonstrating that a brief interview can enhance problem solving among individuals with depression and supports the notion that episodic memory plays a key role in problem solving. It should be noted, however, that the results of the interview are relatively short-lived.     

Young children's spontaneous utterances of mental terms and the accuracy of their memory behaviors: a different methodological approach

The purpose of this study was to determine whether young children's spontaneous utterances of mental terms would be congruent with the accuracy of their memory behaviours, and whether the use of an incidental memory task would yield similar developmental patterns as other methodologies. It was hypothesized that if children realize that internal mental activities influence behavioural actions, then the children's behavioural actions (recall) would be congruent with their utterances. A total of 27 three‐ and five‐year‐old children spontaneously used cognitive verbs such as knowing, forgetting, remembering, thinking, guessing and betting during a recall task. The results revealed that 39% of the 3‐year‐old children's behavioural responses and 67% of the 5‐year‐old children were congruent with their spontaneous utterances. These and other findings were consistent with studies that utilized different methodologies. Copyright © 2002 John Wiley & Sons, Ltd.     

A brighter side to memory illusions: false memories prime children's and adults' insight-based problem solving

Can false memories have a positive consequence on human cognition? In two experiments, we investigated whether false memories could prime insight problem-solving tasks. Children and adults were asked to solve compound remote associate task (CRAT) problems, half of which had been primed by the presentation of Deese/Roediger-McDermott (DRM) lists whose critical lures were also the solutions to the problems. In Experiment 1, the results showed that regardless of age, when the critical lure was falsely recalled, CRAT problems were solved more often and significantly faster than problems that were not primed by a DRM list. When the critical lure was not falsely recalled, CRAT problem solution rates and times were no different from when there was no DRM priming. In Experiment 2, without an intervening recall test, children and adults still exhibited higher solution rates and faster solution times to CRAT problems that were primed than to those that were not primed. This latter result shows that priming occurred as a result of false memory generation at encoding and not at retrieval during the recall test. Together, these findings demonstrate that when false memories are generated at encoding, they can prime solutions to insight-based problems in both children and adults.     

Influence of recorder affect on the content of behavioural diaries and the recall of behaviours

Two experiments are described. In Experiment 1, supervisors (N = 4) kept daily performance diaries for each of four subordinates over an eight‐week period. In Experiment 2, students (N = 48) kept behavioural diaries for their instructor over a three‐week period. Daily measures of positive and negative affect were used to predict the favourability, person‐typicality and behavioural specificity of diary entries. Diary‐keepers tended to record behaviours that were consistent with their affect levels. Analyses of the variability of the favourability and person‐typicality ratings further suggested that high negative affect induced diary‐keepers to make fine discriminations among events, while high positive affect induced diary‐keepers to perceive events as similar. Diary‐keeper affect and the three diary content variables were used to predict memory for the diary entries. Diary‐keepers in Experiment 1 reported higher recall for negative behaviours than for positive behaviours, particularly if the behaviours were typical of others. This same negativity effect in recall emerged in Experiment 2, but only when there was low consistency in the positive affect experienced by diary‐keepers at encoding and recall. Copyright © 2001 John Wiley & Sons, Ltd.     

The functional equivalence of problem solving skills

The tower of Hanoi problem is used to show that, even in simple problem environments, numerous distinct solution strategies are available, and different subjects may learn different strategies. Four major classes of solution strategies are described for the problem. Different strategies have different degrees of transferability, place different burdens on short-term memory and on perception, and require different learning processes for their acquisition. The analysis underscores the importance of subject-by-subject analysis of “what is learned” in understanding human behavior in problem-solving situations, and provides a technique for describing subjects' task performance programs in detail.     

The role of sound intensity and stop-consonant voicing on McGurk fusions and combinations

The present paper argues that generalisation is conservative. Our goal was to experimentally study the links between knowledge generalisation and the storage of contextual elements. The knowledge domain, very simple chess configurations, allowed subjects, novices in chess, to acquire micro-expertise based on the analysis of a single source problem. In the first experimental phase, subjects had to analyse a source problem. We induced two modes of source-problem encoding: In the first group, subjects were given explanations focused on the sequence of elementary solving steps; in the other group they were given the general principle relevant to the category of problems in question. Subjects had then to solve different tests (solving isomorphic problems, recall tests, similarity tests) designed to answer two questions: The first question was to test whether the experimental manipulation in the two groups had in fact generated knowledge that varied in abstractness; the second question was to determine whether generalisation is accompanied by storage of surface features of the source problem. Results show that the knowledge generalisation is conservative. Subjects who generalise their knowledge have a better memory retention of context-dependent elements than the other subjects.     

The development of memory efficiency and value-directed remembering across the life span: a cross-sectional study of memory and selectivity

Although attentional control and memory change considerably across the life span, no research has examined how the ability to strategically remember important information (i.e., value-directed remembering) changes from childhood to old age. The present study examined this in different age groups across the life span (N = 320, 5-96 years old). A selectivity task was used in which participants were asked to study and recall items worth different point values in order to maximize their point score. This procedure allowed for measures of memory quantity/capacity (number of words recalled) and memory efficiency/selectivity (the recall of high-value items relative to low-value items). Age-related differences were found for memory capacity, as young adults recalled more words than the other groups. However, in terms of selectivity, younger and older adults were more selective than adolescents and children. The dissociation between these measures across the life span illustrates important age-related differences in terms of memory capacity and the ability to selectively remember high-value information.     

Autobiographical memory specificity predicts social problem-solving ability in old and young adults

Based on recent research with young, depressed adults, age-related cognitive declines and decreased autobiographical specificity were hypothesized to predict poorer social problem-solving ability in older than in younger healthy adults. Priming autobiographical memory (ABM) was hypothesized to improve social problem-solving performance for older adults. Subsequent to cognitive tests, old and young participants' specific ABMs were tested using a cued recall task, followed by a social problem-solving task. The order of the tasks was counterbalanced to test for a priming effect. Autobiographical specificity was related to cognitive ability and predicted social problem-solving ability for both age groups. However, priming of ABM did not improve social problem-solving ability for older or younger adults. This study provides support for the hypothesis that autobiographical memory serves a directive function across the life-span.     

Scent-evoked nostalgia

Declarative and non-declarative memories are thought be supported by two distinct memory systems that are often posited not to interact. However, Wagner, Maril, and Schacter (2000a) reported that at the time priming was assessed, greater behavioural and neural priming was associated with lower levels of subsequent recognition memory, demonstrating an interaction between declarative and non-declarative memory. We examined this finding using a similar paradigm, in which participants made the same or different semantic word judgements following a short or long lag and subsequent memory test. We found a similar overall pattern of results, with greater behavioural priming associated with a decrease in recognition and recall performance. However, neither various within-participant nor various between-participant analyses revealed significant correlations between priming and subsequent memory performance. These data suggest that both lag and task have effects on priming and declarative memory performance, but that they are largely independent and occur in parallel.     

Does the presence of priming hinder subsequent recognition or recall performance?

Declarative and non-declarative memories are thought be supported by two distinct memory systems that are often posited not to interact. However, Wagner, Maril, and Schacter (2000a) reported that at the time priming was assessed, greater behavioural and neural priming was associated with lower levels of subsequent recognition memory, demonstrating an interaction between declarative and non-declarative memory. We examined this finding using a similar paradigm, in which participants made the same or different semantic word judgements following a short or long lag and subsequent memory test. We found a similar overall pattern of results, with greater behavioural priming associated with a decrease in recognition and recall performance. However, neither various within-participant nor various between-participant analyses revealed significant correlations between priming and subsequent memory performance. These data suggest that both lag and task have effects on priming and declarative memory performance, but that they are largely independent and occur in parallel.     

Autobiographical memory specificity predicts social problem-solving ability in old and young adults

Based on recent research with young, depressed adults, age-related cognitive declines and decreased autobiographical specificity were hypothesized to predict poorer social problem-solving ability in older than in younger healthy adults. Priming autobiographical memory (ABM) was hypothesized to improve social problem-solving performance for older adults. Subsequent to cognitive tests, old and young participants' specific ABMs were tested using a cued recall task, followed by a social problem-solving task. The order of the tasks was counterbalanced to test for a priming effect. Autobiographical specificity was related to cognitive ability and predicted social problem-solving ability for both age groups. However, priming of ABM did not improve social problem-solving ability for older or younger adults. This study provides support for the hypothesis that autobiographical memory serves a directive function across the life-span.     

Notational strategies for problem solving in 5- to 7-year-olds

The study focuses on the production and use of notations as a means to solve a memory problem. It reports results from two experiments. In the first, a memory task, 5- to 7-year-old children were asked to notate the contents of three identical boxes in order to later determine the identity and number of the objects inside the boxes once they had been closed and moved to a different position. Statistical analysis of the data revealed developmental trends in subjects' notational performance: prior to age seven their notations were generally ineffective in helping them to later determine the exact contents of the boxes. In order to rule out the possibility that their low performance on the memory task was due to their inability to represent information by means of a notation, we designed a second experiment, a representation task, in which subjects produced a notation to represent the same set of objects as in experiment 1. Results comparing performance on the two experiments (the memory and representation tasks) showed no differences at age five, statistical differences for identity at age six, and only marginal statistical differences for quantity at age seven, mainly due to the statistically significant age-trend in performance. Seven-year-olds' performance improved in both conditions, weakening the differences between the two conditions. These results suggest a metacognitive hypothesis that it is not until age seven that children begin to make the prospective analysis needed to solve the memory task.