More than a matter of getting ‘unstuck’: flexible thinkers use more abstract representations than perseverators

Why do people perseverate, repeating prior behaviours that are no longer appropriate? Many accounts point to isolated deficits in processes such as inhibition or attention. We instead posit a fundamental difference in rule representations: flexible switchers use active representations that rely on later‐developing prefrontal cortical areas and are more abstract, whereas perseverators use latent representations that rely on earlier‐developing posterior cortical and subcortical areas and are more stimulus‐specific. Thus, although switchers and perseverators should apply the rules they use to familiar stimuli equally reliably, perseverators should show unique limitations in generalizing their rules to novel stimuli, a process that requires abstract representations. Two behavioural experiments confirmed this counterintuitive prediction early in development. Three‐year‐old children sorted cards by one rule, were asked to switch to another rule, and then were asked simply to continue their behaviour, with novel cards. Perseverators applied the rule they were using (the first rule) just as reliably as switchers applied the rule they were using (the second rule) with familiar cards; however, only switchers generalized their rule to novel cards. This finding supports an early link between active representations that support switching and abstract representations that support generalization. We interpret this synergy in terms of prefrontal cortical development.     

Two types of perseveration in the Dimension Change Card Sort task

In the Dimension Change Card Sort (DCCS) task, 3-year-olds can sort cards well by one dimension but have difficulty in switching to sort the same cards by another dimension when asked; that is, they perseverate on the first relevant information. What is the information that children perseverate on? Using a new version of the DCCS, the experiments in this article reveal that there are two types of perseverators: those who perseverate at the level of dimensions and those who perseverate at the level of values (stimulus features). This novel finding has implications for theories of perseveration.     

Why do children perseverate when they seem to know better: Graded working memory,or directed inhibition?

Children sometimes have trouble switching from one task to another, despite demonstrating an awareness of current task demands. This behavior could reflect problems either directly inhibiting previously relevant information or sufficiently activating graded working memory representations for the current task. We tested competing predictions from each account, using a computerized card-sorting task in which we assessed children’s task switching abilities and their response speed to simple questions about current task demands. All children answered these questions correctly, but children who successfully switched tasks responded more quickly to questions than did children who perseverated on previous tasks, even after factoring out processing speed and age. This reaction time difference supports graded working memory accounts, with stronger representations of current task demands aiding both task-switching and responses to questions. This result poses a challenge for directed inhibition accounts, because nothing needs to be inhibited to answer simple questions that lack conflicting information.     

When actions speak louder than words: improving children's flexibility in a card-sorting task

People often perseverate, or repeat habitual behaviors when they are no longer appropriate. For example, after sorting cards by one rule, children will reliably perseverate with this rule even when they are clearly and repeatedly instructed to switch to a new rule. Such perseveration may result from limitations in working memory abilities for holding instructions actively in mind. If so, children may switch more readily to a new rule following experiences that are less demanding on working memory, such as guided practice with the new rule. In a study testing this prediction, 3-year-old children received direct instructions to switch to a new rule, guided practice with the new rule, or both. Providing children with guided practice was much more effective than telling them what to do. These findings support theories of perseveration based on competing memory systems, challenge alternative theories, and suggest effective methods for countering prepotent behaviors.     

Task switching: on the origin of response congruency effects

When people frequently alternate between simple cognitive tasks, performance on stimuli which are assigned the same response in both tasks is typically faster and more accurate than on stimuli which require different responses for both tasks, thus indicating stimulus processing according to the stimulus-response (S-R) rules of the currently irrelevant task. It is currently under debate whether such response congruency effects are mediated by the activation of an abstract representation of the irrelevant task in working memory or by "direct" associations between specific stimuli and responses. We contrasted these views by manipulating concurrent memory load (Experiment 1) and the frequency of specific S-R associations (Experiment 2). While between-task response congruency effects were not affected by the amount of concurrent memory load, they were much stronger for stimuli that were processed frequently in the context of a competitor task. These findings are consistent with the idea that a large portion of the congruency effects stems from direct S-R associations and they do not support a sole mediation by task-set activation in working memory.     

When seeing is knowing: the role of visual cues in the dissociation between children's rule knowledge and rule use

The Dimensional Change Card Sort (DCCS) task requires children to switch from sorting cards based on shape or color to sorting based on the other dimension. Typically, 3-year-olds perseverate, whereas 4-year-olds flexibly sort by different dimensions. Zelazo and colleagues (1996, Cognitive Development, 11, 37-63) asked children questions about the postswitch rules and found an apparent dissociation between rule knowledge and rule use, namely that 3-year-olds demonstrate accurate knowledge of the postswitch rules despite sorting cards incorrectly. Here, we show that children's success with these questions is grounded in their use of available visual cues; children who fail sorting use the target cards to correctly answer questions, and when the cards are unavailable they guess. This suggests that there might not be a dissociation between children's rule knowledge and rule use in the DCCS.     

Task rules, working memory, and fluid intelligence

Many varieties of working memory have been linked to fluid intelligence. In Duncan et al. (Journal of Experimental Psychology:General 137:131-148, 2008), we described limited working memory for new task rules: When rules are complex, some may fail in their control of behavior, though they are often still available for explicit recall. Unlike other kinds of working memory, load is determined in this case not by real-time performance demands, but by the total complexity of the task instructions. Here, we show that the correlation with fluid intelligence is stronger for this aspect of working memory than for several other, more traditional varieties-including simple and complex spans and a test of visual short-term memory. Any task, we propose, requires construction of a mental control program that aids in segregating and assembling multiple task parts and their controlling rules. Fluid intelligence is linked closely to the efficiency of constructing such programs, especially when behavior is complex and novel.     

"Don't know" responding to answerable and unanswerable questions during misleading and hypnotic interviews

"Don't know" (DK) responses to interview questions are conceptually heterogeneous, and may represent uncertainty or clear statements about the contents of memory. A study examined the subjective intent of DK responses in relation to the objective status of information queried, in the context of memory distorting procedures. Participants viewed a video and responded to answerable and unanswerable questions phrased in misleading or nonmisleading formats, while hypnotized or not hypnotized. Subjective meanings of DK responses were queried, and a recognition measure assessed the contents of memory. Lower DK and accuracy rates were consistently associated with unanswerable and misleading questions. One-third of DK responses were statements that the information had no not presented. When these were recoded, accuracy estimates for answerable questions decreased and more so for hypnotized participants. These results demonstrate that DK responses convey different types of information, thus accuracy estimates in studies that permit DK responses may be misestimated. Robust risks associated with asking unanswerable questions and asking questions at all were observed. Implications for working with DK responses during interviews are discussed.     

The structure of working memory abilities across the adult life span

The present study addresses three questions regarding age differences in working memory: (1) whether performance on complex span tasks decreases as a function of age at a faster rate than performance on simple span tasks; (2) whether spatial working memory decreases at a faster rate than verbal working memory; and (3) whether the structure of working memory abilities is different for different age groups. Adults, ages 20-89 (n = 388), performed three simple and three complex verbal span tasks and three simple and three complex spatial memory tasks. Performance on the spatial tasks decreased at faster rates as a function of age than performance on the verbal tasks, but within each domain, performance on complex and simple span tasks decreased at the same rates. Confirmatory factor analyses revealed that domain-differentiated models yielded better fits than models involving domain-general constructs, providing further evidence of the need to distinguish verbal and spatial working memory abilities. Regardless of which domain-differentiated model was examined, and despite the faster rates of decrease in the spatial domain, age group comparisons revealed that the factor structure of working memory abilities was highly similar in younger and older adults and showed no evidence of age-related dedifferentiation.     

The Effects of Feedback on Perseverative Errors in Preschool Aged Children

Research using the Dimensional Change Card Sort (DCCS) showed that young children are usually able to sort accurately by an initial rule but are unable to switch to a new rule when the two rules conflict. In 2 experiments, the DCCS was modified to study the effects of feedback on 3- to 5-year-old children in a problem-solving task. In Experiment 1, half of the children in each of two age groups (36 to 44 months and 52 to 60 months) were administered the DCCS task using the standard (no feedback) procedure and the other half received feedback on their post-switch responses. Children who received feedback were able to categorize according to the new (correct) rule, whereas the children in the younger age group who did not receive feedback continued to perseverate. Experiment 2 with 3-year-olds replicated the results from Experiment 1 but found that children's successful performance with feedback on the card-sorting task did not lead to improved performance on the post-switch phase of a subsequent DCCS task. Successful performance under conditions of feedback in both studies implies that 3-year-olds are capable of shifting their response mode from one rule to an alternate rule under conditions that offer clear guidance. Poor performance on the standard version is interpreted to be a reflection of the inability to monitor their own task performance in the absence of clear contextual cues.     

Working memory and children's use of retrieval to solve addition problems

This study tested the hypothesis that children with high working memory capacities solve single-digit additions by direct retrieval of the answers from long-term memory more often than do children with low working memory capacities. Counting and reading letter span tasks were administered to groups of third-grade (mean age=107 months) and fourth-grade (mean age=118 months) children who were also asked to solve 40 single-digit additions. High working memory capacity was associated with more frequent use of retrieval and faster responses in solving additions. The effect of span on the use of retrieval increased with the size of the minimum addend. The relation between working memory measures and use and speed of retrieval did not depend on the numerical or verbal nature of the working memory task. Implications for developmental theories of cognitive arithmetic and theories of working memory are discussed.     

The influence of response conflict on voluntary task switching: a novel test of the conflict monitoring model

The conflict monitoring model of cognitive control posits that response conflict triggers a top-down enhancement of a task’s representation in working memory. In the present study, we conducted a novel test of the conflict monitoring model using a voluntary task switching paradigm. We predicted that a task’s representation would be enhanced following events associated with high response conflict (i.e., incongruent trials and incorrect responses), leading participants to voluntarily choose to repeat that task more often after these events than after events associated with low response conflict (i.e., congruent trials and correct responses). In two experiments, performance following incongruent trials was consistent with the conflict monitoring model. However, performance following incorrect trials did not fit with the model’s predictions. These findings provide novel support for the conflict monitoring model while revealing new effects of incorrect trials that the model cannot explain.     

The Cost of Accessing an Object's Feature Stored in Visual Working Memory

The effects of accessing or retrieving information held in working memory are poorly understood compared to what we know about the nature of information storage in this limited-capacity memory system. Previous studies of object-based attention have often relied upon memory-demanding tasks, and this work could indicate that accessing a piece of information in visual working memory may have deleterious effects upon the other representations being maintained. In the present study, we tested the hypothesis that accessing a feature of an object represented in visual working memory degrades the representations of the other stored objects' features. Our findings support this hypothesis and point to important new questions about the nature of effects resulting from accessing information stored in visual working memory.     

Mental reinstatement of context: A technique for interviewing child witnesses

The effectiveness of mental reinstatement of context as a technique for interviewing child witnesses was examined. Adult, 6-year-olds and 11 -year-olds viewed a film and were interviewed in one of three conditions; (1) free recall, (2) mental reinstatement of the context in which the film was viewed or (3) a series of specific questions about the film. In terms of correct information recalled, mental reinstatement of context and specific questions produced more correct responses than did free recall. In terms of errors of commission, specific questions produced more responses than either free recall or mental reinstatement of context. Age-related increases in both correct and incorrect responses were found supporting some previous findings. The implications of these results in terms of children's eyewitness memory were discussed, and future research directions were indicated.     

Job and home attitudes of undergraduate women and their mothers

Seventy-seven undergraduate women and their mothers participated in a study of job/home attitudes. All subjects rated 10 conflict elements and 8 conflict types: mothers also rated the conflict elements and types retrospectively, as young adults, and responded to related open-ended questions. Cohort effects were stronger than historical period or stage-of-life effects. Mothers' current and retrospective responses both indicated significantly more interest, confidence, and perceived external support for home-related than job-related activities, whereas daughters' responses reflected approximately equal interest, confidence, and support for home- and job-related activities.     

The effects of cumulative practice on mathematics problem solving

This study compared three different methods of teaching five basic algebra rules to college students. All methods used the same procedures to teach the rules and included four 50-question review sessions interspersed among the training of the individual rules. The differences among methods involved the kinds of practice provided during the four review sessions. Participants who received cumulative practice answered 50 questions covering a mix of the rules learned prior to each review session. Participants who received a simple review answered 50 questions on one previously trained rule. Participants who received extra practice answered 50 extra questions on the rule they had just learned. Tests administered after each review included new questions for applying each rule (application items) and problems that required novel combinations of the rules (problem-solving items). On the final test, the cumulative group outscored the other groups on application and problem-solving items. In addition, the cumulative group solved the problem-solving items significantly faster than the other groups. These results suggest that cumulative practice of component skills is an effective method of training problem solving.     

Aging, metamemory, and high-confidence errors: a misrecollection account

Two experiments showed that older adults were worse than younger adults at judging the accuracy of their responses on source identification (i.e., who said what) and cued-recall tests. It is important to note that this age-related metamonitoring impairment occurred even after older and younger adults were matched on overall source accuracy and cued-recall accuracy. By contrast, older and younger adults showed comparable metamonitoring capacities when assessing the likely accuracy of old-new recognition judgments and responses to questions about general knowledge. These experiments are consistent with the misrecollection account of cognitive aging, which suggests that age-related memory impairments are due to older adults' vulnerability to making high-confidence errors when answering questions that require memory for specific details about recently learned events.     

干扰任务对说谎影响的研究

摘要:本文将干扰任务对记忆的影响同测谎结合起来,试图运用这一方法来对求职者的真实学历和虚假学历进行区分。实验采用模拟面试的方式,对被试在有或无干扰任务条件下进行两次提问,结果发现,四种任务条件对被试真实经历和虚假经历都具有区分度,其中双双条件的区分度是最高的。并且,被试在双双任务条件下虚假经历的得分显著低于其他三种任务条件。     

The effects of memory trace strength on eyewitness recall in children with and without intellectual disabilities

Children with mild moderate intellectual disabilities (ID) were compared with typically developing peers of the same chronological age (CA) on an eyewitness memory task in which memory trace strength was manipulated to examine whether increased memory trace strength would benefit those with ID more than those without ID. No evidence was found for this claim or for the notion that different mechanisms are implicated in memory processes for children with ID versus CA controls. Fuzzy-trace theory was also used to contrast question types that probed verbatim memory versus gist memory. Manipulations of trace strength, when used with immediate recall (to reduce the impact of decay), were predicted to improve verbatim memory more than gist memory. The results broadly supported the predictions. Performance was not improved in the stronger trace strength condition on measures of recall that tapped gist memory (e.g., open-ended recall), whereas performance was significantly better in the stronger trace strength condition on two of the three measures of recall that tapped verbatim memory (i.e., closed misleading questions, open-ended specific questions). Differences in performance between the groups were quite marked on several question types, supporting previous findings that those with ID have certain vulnerabilities as potential witnesses compared with peers of the same CA.