Central executive involvement in children's spatial memory

Previous research with adults found that spatial short-term and working memory tasks impose similar demands on executive resources. We administered spatial short-term and working memory tasks to 8- and 11-year-olds in three separate experiments. In Experiments 1 and 2 an executive suppression task (random number generation) was found to impair performances on a short-term memory task (Corsi blocks), a working memory task (letter rotation), and a spatial visualisation task (paper folding). In Experiment 3 an articulatory suppression task only impaired performance on the working memory task. These results suggest that short-term and working memory performances are dependent on executive resources. The degree to which the short-term memory task was dependent on executive resources was expected to be related to the amount of experience children have had with such tasks. Yet we found no significant age-related suppression effects. This was attributed to differences in employment of cognitive strategies by the older children.     

Using memories to motivate future behaviour: An experimental exercise intervention

This study tested a novel memory-based experimental intervention to increase exercise activity. Undergraduate students completed a two-part online survey ostensibly regarding college activity choices. At Time 1, they completed questionnaires that included assessments of exercise-related attitudes, motivation and self-reported behaviours. Next, they described a memory of a positive or negative experience that would increase their motivation to exercise; students in a control condition did not receive a memory prompt. Finally, they rated their intentions to exercise in the future. Eight days following Time 1, students received a Time 2 survey that included an assessment of their self-reported exercise during the prior week. Students in the positive memory condition reported higher levels of subsequent exercise than those in the control condition; students in the negative memory condition reported intermediate levels of exercise. Activating a positive motivational memory had a significant effect on students' self-reported exercise activity even after controlling for prior attitudes, motivation and exercise activity.     

Facilitation and analogical transfer in the THOG task

This study was concerned with Wason's THOG task, a hypothetico-deductive reasoning problem for which performance is typically very poor (<20% correct). Recently, however, Needham and Amado (1995) and Koenig and Griggs (2004) have observed both facilitation and spontaneous analogical transfer effects for the Pythagoras version of this task. Based on their findings, Koenig and Griggs concluded that in addition to the separation of the data (the properties of the designated THOG) from the hypotheses that need to be generated (the possible combinations of properties written down), an explicit request to generate these hypotheses is necessary to obtain significant analogical transfer. In the present study we extended the generalisability of this conclusion in three experiments with 214 undergraduate participants using O'Brien et al.'s (1990) Blackboard version of the task. We discuss the relationship of the results to dual process theories of reasoning and propose that analogical transfer may be a better criterion than task facilitation for judging participants' task understanding.     

Executive functions in decision making: An individual differences approach

This individual differences study examined the relationships between three executive functions (updating, shifting, and inhibition), measured as latent variables, and performance on two cognitively demanding subtests of the Adult Decision Making Competence battery: Applying Decision Rules and Consistency in Risk Perception. Structural equation modelling showed that executive functions contribute differentially to performance in these two tasks, with Applying Decision Rules being mainly related to inhibition and Consistency in Risk Perception mainly associated to shifting. The results suggest that the successful application of decision rules requires the capacity to selectively focus attention and inhibit irrelevant (or no more relevant) stimuli. They also suggest that consistency in risk perception depends on the ability to shift between judgement contexts.     

Age-Related Differences in Memory Illusions: Revelation Effect

Older adults are often more susceptible to various illusions and distortions of memory than young adults. In the experiments reported here, we explored the question of whether normal aging was associated with a larger revelation effect, an illusion of memory in which items that are revealed gradually during a recognition test are more likely to be called old than unrevealed items that are shown in their entirety. Contrary to expectations, older adults were not susceptible to this memory illusion. A revelation effect occurred for young but not older adults, even when older adults were similar to young adults on measures of recognition and repetition priming. When data across experiments were combined, there was evidence for a negative revelation effect in older adults in which revealed items were less likely called old than unrevealed items. These results place boundary conditions on the claim that older adults are more susceptible than young adults to memory illusions, and imply that one or more mechanisms underlying the revelation effect are age sensitive.     

Executive Dysfunctions Across Adulthood: Measurement Properties and Correlates of the DEX Self-Report Questionnaire

ABSTRACT

Difficulties in executive processes can disturb daily life functioning. Using data obtained from two independent community-dwelling samples (n ₁?=?468, n ₂?=?669, 18–97 years), we examined the factor structure of the Dysexecutive Functioning Questionnaire (DEX) and explored the frequencies and potential correlates of self-reported executive difficulties. Our results revealed that executive problems are parsimoniously described with one underlying factor. Everyday executive dysfunctions were moderately frequent throughout adulthood. Reports of executive problems were associated with individual difference characteristics including age, subjective health, personality, affect, and cognition. We also found that, although executive functions are known to decline with advancing adult age, younger age groups reported more problems than older groups, an effect that was partially mediated by a negative affect factor. We discuss implications for the validity of the instrument as well as directions for future research on executive functioning difficulties in everyday life.     

Construction and validation of an ecological version of the Wisconsin Card Sorting Test applied to an elderly population

ABSTRACT

The goal of this project was to construct and validate an ecological version of the Wisconsin Card Sorting Test (WCST) aimed at the elderly. This was accomplished by replacing the geometric stimuli of the traditional version with stimuli belonging to the semantic category of transport vehicles, and by elimination of the color yellow. The results showed the ecological WCST version was preferred over the traditional version and older people felt less tired during test performance. In the two independent normal elderly groups, all pairs of scores that can be derived from the WCST correlated significantly with each other. Six of 11 outcome measures of the traditional WCST-128 (long) version were significantly influenced by age. By contrast, in the WCST-64 (short) version and in the ecological WCST-54 version only one measure was affected by the age variable. No significant effect of education level or gender emerged from the results in any WCST version. Again, the subjects with cognitive deterioration had lower performance in the ecological WCST-54 version than in the two traditional WCST versions. It seems reasonable to assume that the ecological version of WCST is more discriminating and has more advantages than the traditional versions. Further research on individual differences in the performance on this task will increase understanding of the components of the test, and of the variety of factors and possible deficits that could lead to an impaired performance of the test.     

Childhood Aggression and Unconventionality: Impact on Later Academic Achievement,Drug Use,and Workforce Involvement

The interrelation of childhood aggression, unconventionality, academic orientation, work involvement, and drug use was explored. Data were obtained for the research participants when they were 5 to 10 years old. Follow-up interviews were conducted when the participants were 15 to 20 years old and again at 21 to 26 years old. Latent variable causal analysis was used, and the findings reveal long-term relations between early childhood aggression and adolescent problem behavior in the academic and occupational areas. The findings also indicate that adolescent drug use generates an early involvement with adult role behaviors, such as work at the expense of further education. Implications of the findings for prevention are discussed.     

Revisiting Mednick's Model on Creativity‐Related Differences in Associative Hierarchies. Evidence for a Common Path to Uncommon Thought

Fifty years ago, Mednick [Psychological Review, 69 (1962) 220] proposed an elaborate model that aimed to explain how creative ideas are generated and why creative people are more likely to have creative ideas. The model assumes that creative people have flatter associative hierarchies and as a consequence can more fluently retrieve remote associative elements, which can be combined to form creative ideas. This study aimed at revisiting Mednick's model and providing an extensive test of its hypotheses. A continuous free association task was employed and association performance was compared between groups high and low in creativity, as defined by divergent thinking ability and self‐report measures. We found that associative hierarchies do not differ between low and high creative people, but creative people showed higher associative fluency and more uncommon responses. This suggests that creativity may not be related to a special organization of associative memory, but rather to a more effective way of accessing its contents. The findings add to the evidence associating creativity with highly adaptive executive functioning.     

Dichotic listening,executive functions and grey matter cortical volume in patients with schizophrenia and healthy controls

Schizophrenia is characterized by cognitive impairment, especially in relation to executive functions. Brain structural abnormalities are also often seen in schizophrenia although little is known of the relationship between cognitive impairment and structural brain changes. Our aim was therefore to investigate this relationship further using MRI and a dichotic listening (DL) task with simple speech sounds and with instructions to focus attention and report only from the left or right ear stimulus. When instructed to focus attention on the left ear syllable a cognitive conflict is induced requiring the allocation of executive resources to be resolved. Grey matter (GM) volume was measured with MRI from four volumes of interests (VOIs), left and right frontal and temporal cortex, respectively, and correlated with DL performance. The results showed significant differences between the groups in their ability to focus attention on and report the left ear stimulus, which was accompanied by reduced GM volume in the left frontal and right temporal lobe VOIs. There was also a significant positive correlation between left frontal GM volume and performance on the DL task, for the groups combined. The results did not support a conclusion that an impairment in cognitive function in schizophrenia was driven by an corresponding impairment in brain structure, since there were no significant correlations when the groups were analyzed separately. It is however concluded that patients with schizophrenia are impaired in executive functions and that they also show reduced GM volumes in left frontal and right temporal lobe areas, compared to healthy controls.