Confirmatory factor analysis of the adolescent self-report strengths and difficulties questionnaire

The Strengths and Difficulties Questionnaire (SDQ) is a widely used 25-item screening test for emotional and behavioral problems in children and adolescents. This study attempted to critically examine the factor structure of the adolescent self-report version. As part of an ongoing longitudinal cohort study, a total of 3,753 pupils completed the SDQ when aged 12. Both three- and five-factor exploratory factor analysis models were estimated. A number of deviations from the hypothesized SDQ structure were observed, including a lack of unidimensionality within particular subscales, cross-loadings, and items failing to load on any factor. Model fit of the confirmatory factor analysis model was modest, providing limited support for the hypothesized five-component structure. The analyses suggested a number of weaknesses within the component structure of the self-report SDQ, particularly in relation to the reverse-coded items.

Using time-to-contact information to assess potential collision modulates both visual and temporal prediction networks

Accurate estimates of the time-to-contact (TTC) of approaching objects are crucial for survival. We used an ecologically valid driving simulation to compare and contrast the neural substrates of egocentric (head-on approach) and allocentric (lateral approach) TTC tasks in a fully factorial, event-related fMRI design. Compared to colour control tasks, both egocentric and allocentric TTC tasks activated left ventral premotor cortex/frontal operculum and inferior parietal cortex, the same areas that have previously been implicated in temporal attentional orienting. Despite differences in visual and cognitive demands, both TTC and temporal orienting paradigms encourage the use of temporally predictive information to guide behaviour, suggesting these areas may form a core network for temporal prediction. We also demonstrated that the temporal derivative of the perceptual index tau (tau-dot) held predictive value for making collision judgements and varied inversely with activity in primary visual cortex (V1). Specifically, V1 activity increased with the increasing likelihood of reporting a collision, suggesting top-down attentional modulation of early visual processing areas as a function of subjective collision. Finally, egocentric viewpoints provoked a response bias for reporting collisions, rather than no-collisions, reflecting increased caution for head-on approaches. Associated increases in SMA activity suggest motor preparation mechanisms were engaged, despite the perceptual nature of the task.