Executive functions in kindergarteners with high levels of disruptive behaviours

Executive function (EF) deficits have yet to be demonstrated convincingly in children with disruptive behaviour disorders (DBD), as only a few studies have reported these. The presence of EF weaknesses in children with DBD has often been contested on account of the high comorbidity between DBD and attention‐deficit/hyperactivity disorder (ADHD) and of methodological shortcomings regarding EF measures. Against this background, the link between EF and disruptive behaviours in kindergarteners was investigated using a carefully selected battery of EF measures. Three groups of kindergarteners were compared: (1) a group combining high levels of disruptive behaviours and ADHD symptoms (COMB); (2) a group presenting high levels of disruptive/aggressive behaviours and low levels of ADHD symptoms (AGG); and (3) a normative group (NOR). Children in the COMB and AGG groups presented weaker inhibition capacities compared with normative peers. Also, only the COMB group showed weaker working memory capacities compared with the NOR group. Results support the idea that preschool children with DBD have weaker inhibition capacities and that this weakness could be common to both ADHD and DBD.     

A study of the effect of structural information and familiarity in form perception

Two experiments were carried out to investigate the influence of structural information and familiarity on the processing of visual forms. Pairs of “well” structured and nameable and “poorly” structured and non-nameable fragmented forms were employed as stimuli. The effects of structure and familiarity were assessed by manipulating the visual hemifield of presentation and the task. In Experiment 1 stimuli were judged as being either in the same orientation or mirror-reversed, a task that does not require high-level semantic information to be processed. Experiment 2 required physically identical forms to be matched, which may use either physical or name information. In Experiment 1 “same” judgements were equivalent for both types of stimuli, and “different' judgements were longer for the “poorly” structured (non-nameable) forms. In Experiment 2 there was little overall difference between “well” and “poorly” structured forms, though response times to “well” structured (nameable) forms were slowed for right-visual-field presentations. It is suggested that familiarity may not be sufficient to provide a perceptual advantage for nameable forms, as the advantage for nameable stimuli was confined to “same” judgements in Experiment 1 and response times were shorter for non-nameable stimuli in Experiment 2. Rather, performance depends upon factors such as the computation of global shape (due to structural properties of collinearity and closure) and on the use of different kinds or representations (physical versus name) in matching.