Stimulant medication improves recognition memory in children diagnosed with attention-deficit/hyperactivity disorder.

Abstract

The effect of stimulant medication on recognition memory was examined in 18 children with attention-deficit/hyperactivity disorder (ADHD). Recognition memory was assessed using a delayed matching-to-sample task at 6 delays ranging from 1 to 32 s. Each child was tested on 2 separate occasions, once 60 to 90 min after taking stimulant medication and the other at least 18 hr after taking medication. Children performed significantly better on medication than off. Stimulant administration significantly increased accuracy and the number of nickel reinforcers earned. Decreases in observing response latency and correct choice response latency occurred after taking stimulant medication. The results indicate that stimulant medication improved recognition memory for children with ADHD.

The Use of Operant Tasks to Assess Cognition in Persons with Alzheimer’s Disease

“…This is not particularly surprising given that this battery is derived from work with nonhuman primates that often rely on highly sensitive measures to detect drug effects. Similar to this study, we have found the OTB to detect drug effects in small samples of monkeys (see for example Buffalo et al, 1994;Frederick et al, 1995) and to detect treatment effects in small samples of children with ADHD (see for example Chelonis et al, 2002).…”

Acute effects of cocaine on the neurobiology of cognitive control

“…While the beneficial effects of stimulant medications such as methylphenidate to enhance cognitive performance in both children and adults have been demonstrated (Chelonis et al 2002;Aron et al 2003;Bedard et al 2003Bedard et al , 2004, these benefits appear to vary by dose, with more unfavourable behaviours appearing at higher doses . Similar inverted U-shaped function curves for behaviour are observed in studies of chronic cocaine users (Johnson et al 1998).…”

Methylphenidate restores visual memory, but not working memory function in attention deficit-hyperkinetic disorder

“…Whilst deficits on "true" working memory tasks, with substantial executive demands, have been accepted as part of the pathophysiology of AD-HKD, relatively little attention has been paid to the possibility that these children, many of whom are, by definition, disorganised and forgetful, may also demonstrate specific performance deficits on non-working memory tasks which place much lower demands on executive functioning. Studies have reported that children with AD-HKD demonstrate deficits on free recall (Borcherding et al 1988;Loge et al 1990), paired associates learning (Conte et al 1986;Chang et al 1999), spatial recognition (Kempton et al 1999) and delayed matching-to-sample (Chelonis et al 2002;Kempton et al 1999) tasks (DMtS); however, negative findings have also been reported particularly on memory tasks in which stimuli are clustered or recall strategies are presented (August 1987;Benezra and Douglas 1988;Voelker et al 1989), and also on a patternrecognition task (Kempton et al 1999), suggesting that when executive demands are reduced, the tasks become manageable. Unfortunately, much of this work has been hampered by a range of methodological concerns, including the failure to use clearly defined, specific, sensitive measures, small sample sizes, the use of rating scales rather than clinical interviews in the assessment of subjects and the inclusion of children with AD-HKD who were either currently taking stimulant medication or who had been recently withdrawn from stimulant medication.…”