Aging, dementia and Gibson Spiral Maze performance: a brief note

A comparison between normal and dementing subjects' performance on the Gibson Spiral Maze was carried out between two age groups (60-70 and 70-89 yr.). Analysis indicated that a differential pattern of impairment existed between early and late onset dementias (ns = 54 and 75), the latter characterized by poor accuracy, the former by abnormal slowing, when compared with their normal peers.     

A brief comment on Thurstone's note on a reanalysis of Davis' reading tests

A comparison of factorial analyses made by Thurstone and by the writer shows that they differ in three important respects. The results of the two analyses are compared with respect to their social utility, which is offered as a proper criterion for judging the merit of factorial analyses performed by different mathematical procedures.     

A note on the stability of team performance.

Yearly winning percentages of 23 professional basketball teams over a 10-year period were used to evaluate the stability of team performance. The intercorrelation matrix produced by these data is characterized by strong, positive correlations in adjacent time periods. As the number of intervening time periods increased, however, the observed correlations systematically decreased and ultimately became negative. Significant negative correlations of earlier performance with later performance are almost never observed with typical time-related performance data. Possible explanations and boundary conditions for these atypical results are discussed.     

Agentic extraversion moderates the effect of physical exercise on executive shifting performance

The present study investigated the impact of physical exercise on the executive shifting function in 24 participants low and 24 participants high in agentic extraversion and tested whether agentic extraversion moderated the exercise effect. Participants accomplished a shifting task and a control task that employed the same materials and response procedure as the shifting task but required less central-executive processing. Physical exercise was varied within subjects. The order of conditions was counterbalanced. After resting, the high agentic extraversion group showed higher cognitive flexibility than the low agentic extraversion group, whereas only the low agentic extraversion group improved after exercise. The results showed that agentic extraversion moderated the exercise effect on shifting performance. Implications concerning the hypothetical dopaminergic mediation were discussed.     

A methodological note on evaluating performance in a sustained-attention-to-response task

We evaluated the influence of speed–accuracy trade-offs on performance in the sustained attention to response task (SART), a task often used to evaluate the effectiveness of techniques designed to improve sustained attention. In the present study, we experimentally manipulated response delay in a variation of the SART and found that commission errors, which are commonly used as an index of lapses in sustained attention, were a systematic function of manipulated differences in response delay. Delaying responses to roughly 800 ms after stimulus onset reduced commission errors substantially. We suggest the possibility that any technique that affects response speed will indirectly alter error rates independently of improvements in sustained attention. Investigators therefore need to carefully explore, report, and correct for changes in response speed that accompany improvements in performance or, alternatively, to employ tasks that control for response speed.     

Sense of meaning and academic performance: A brief report

This study examined sense of meaning and academic performance among a sample of South African university students (n = 210, mean age = 19.49, SD = 1.99, female = 54.29%). Data on meaning were collected using the Purpose in Life Test. End of semester marks served as the academic attainment measure. Simple regression analysis with post-hoc independent-samples t-tests revealed that meaning predicts academic performance. No significant differences between genders emerged from the data. Sense of meaning is an important factor in supporting students to enhance their academic performance.     

Executive functions and extraversion

Executive functions and extraversion have been linked to similar neurological substrates. Participants were tested on a variety of tasks that assessed performance on three components of executive functioning (i.e., shifting, updating, and inhibition) and two measures of extraversion (Eysenck Personality Questionnaire-Revised and Carver and White’s BIS/BAS scales). More extraverted participants showed different patterns of executive function performance than the more introverted participants. Extraverts performed best on more difficult tasks and on updating tasks. Conversely, introverts performed best on set shifting tasks. These results suggest that executive functioning strengths differ based on degree of extraversion.