Impulsivity and inhibitory control in normal development and childhood psychopathology.

Abstract

Two experiments investigated the development and pathology of inhibitory control in children. Inhibitory control was investigated with the stop-signal paradigm, which is based on a formal theory of inhibition and directly measures the mechanism of inhibition. The ability to inhibit developed little after Grade 2, but subjects with attention deficit disorder with hyperactivity (ADDH) showed deficient inhibitory control. Their deficient inhibitory control was attributable to the subgroup of ADDH subjects with pervasive hyperactivity who had a more severe inhibitory deficit than did the situational hyperactive subgroup, the normal group, and the pathological controls. These studies reflect the utility of the stop-signal paradigm as a measure of inhibitory control.

Methylphenidate and cognitive flexibility: Dissociated dose effects in hyperactive children

“…This is important, because one of the most robust effects of MPH is to reduce the variability of response times (Coons, Klorman, & Borgstedt, 1987;Peloquin & Klorman, 1986), which in turn might enhance the observed probability of inhibiting ongoing responses (Logan, 1994;, despite any concomitant adverse effects of the medication on the efficiency of the inhibitory processes. The theoretical assumptions and predictions of the model have been validated empirically in numerous studies of adults (e.g., De Jong et al, 1990;, Osman et al, 1990 and more recently have also been validated in children (Schachar & Logan, 1990;Schachar et al, in press). …”

“…The "checked swing" phenomenon in baseball or cricket provides a useful analogy for this inhibitory action (De Jong, Coles, Logan, & Gratton, 1990;Osman, Kornblum, & Meyer, 1990). Of relevance here are the findings that children with ADHD exhibit deficits in response inhibition (Pliszka & Borcherding, 1994;Schachar & Logan, 1990;Schachar, Tannock, Marriott, & Logan, in press), so that any further impairment in this cognitive process as a result of stimulant treatment would be of great concern. We found that stimulants enhanced the response inhibition processes (Tannock et al, 1989a).…”

“…In a previous dose-response study (Tannock, Schachar, Carr, Chajczyk, & Logan, 1989a), we used a stop signal paradigm that is a well-established and theoretically derived method for studying the central regulation of the ability to inhibit a planned action or thought Schachar & Logan, 1990). The "checked swing" phenomenon in baseball or cricket provides a useful analogy for this inhibitory action (De Jong, Coles, Logan, & Gratton, 1990;Osman, Kornblum, & Meyer, 1990).…”

Prefrontal cortical α2A-adrenoceptors and a possible primate model of attention deficit and hyperactivity disorder

“…Perhaps the most fundamental deficit in ADHD is the lack of response inhibition [52] . In laboratory studies of tasks that measure inhibitory control, children with ADHD often perform more poorly than both normal controls and children with other psychiatric disorders [59,60] .…”

“…Perhaps the most fundamental deficit in ADHD is the lack of response inhibition [52] . In laboratory studies of tasks that measure inhibitory control, children with ADHD often perform more poorly than both normal controls and children with other psychiatric disorders [59,60] .Schulz et al reported that response inhibition in adolescents diagnosed with ADHD is primarily mediated by fronto-striatal circuitry [61,62] . …”