Developmental differences in error-related ERPs in middle- to late-adolescent males

Although there are some studies documenting structural brain changes during late adolescence, there are few showing functional brain changes over this period in humans. Of special interest would be functional changes in the medial frontal cortex that reflect response monitoring. In order to examine such age-related differences, the authors analyzed event-related potentials following errors in a visual flanker task and a go/no-go task in adolescent males, 15-16 and 18-20 years old. Response times and accuracy were comparable between groups on each task, but the younger group made more go/no-go errors, suggesting this task was more difficult. Error-related negativity, thought to be generated in the anterior cingulate cortex (ACC), had greater amplitude for the older adolescents on both tasks; thus the increased errors are not simply due to performance level differences. Results from this study suggest that the ACC, which supports response monitoring, is late to mature due to age-related structural or neurochemical changes.     

Psychometric analysis of the Stunkard-Messick Eating Questionnaire (SMEQ) and Comparison with the dutch Eating Behavior Questionnaire (DEBQ)

The factor structure of the Stunkard-Messick Eating Questionnaire (SMEQ) differs from that of the Dutch Eating Behavior Questionnaire (DEBQ). Using students and members of a weight watchers club, we factor-analyzed responses to the SMEQ and produced a solution which was different from that obtained by Stunkard and Messick, but which had some similarities to the factor structure of the DEBQ. “External” taste items and “internal” hunger items loaded on the same factor, a finding inconsistent with externality theory but consistent with the common sense notion of appetite strength. Although our finding suggests factor instability of the SMEQ, the stability of the DEBQ appears to be the consequence of a restricted range of DEBQ items compared with SMEQ items. Financial support for this research was given by Lilly Industries.     

The empirical violation of conservation laws and its relation to structural change

Concrete operational Ss were provided empirical evidence of nonconservation of discontinuous quantity and weight. The findings were that few Ss accepted this evidence. This was interpreted as supporting the organismic-developmental claim that lower forms of reasoning are transformed into structurally more advanced forms. It was also found that (1) probing provides a more accurate assessment of Ss' operational levels, (2) one can empirically distinguish between logicomathematical and physical knowledge, and (3) the former is understood by Ss to be nomically necessary and the latter, in the case of weight, may not be.     

The relationship between binocular brightness matches and luminance difference discriminability of successively presented light flashes1

Measurements of monocular ΔI and PSE as a function of the ISI between two 2-deg foveal fields successively presented to the same retinal area were obtained for two Standard durations, using the method of constant stimuli. Binocular brightness matches of the stimuli revealed that detection of a difference occurred whenever a constant difference (in log mL) in matching luminance existed. The implication of the results was that ΔI is related to the rate of change of brightness with changes in test-field luminance.