Methylphenidate effects on task-switching performance in attention-deficit/hyperactivity disorder.
OBJECTIVE
To examine the specificity of methylphenidate effects on the processes that support the ability to rapidly and accurately coordinate the performance of multiple tasks in children with attention-deficit hyperactivity disorder (ADHD).


METHODS
Twenty children with ADHD performed the task-switching paradigm while on and off medication. The paradigm involves switching between two different tasks, discriminating the value of a number presented on a computer screen and deciding how many numbers were present on the screen. The children also performed single-task control conditions.


RESULTS
Analyses of variance indicated the medication selectively enhanced the children's ability to rapidly and accurately switch between tasks and to focus attention on the currently relevant response set.


CONCLUSIONS
This study helps to elucidate the nature of methylphenidate effects on the cognitive processes which support the ability to coordinate the performance of multiple tasks. Medication appears to selectively enhance inhibitory processes which support task-switching.
Kramer
A F
AF
Beckman Institute and Department of Psychology, University of Illinois at Urbana-Champaign, 61801, USA. akramer@s.psych.uiuc.edu
Cepeda
N J
NJ
Cepeda
M L
ML
D000293:Adolescent; D001288:Attention / Q000187:drug effects*; D001289:Attention Deficit Disorder with Hyperactivity / Q000175:diagnosis / Q000188:drug therapy* / Q000523:psychology; D002648:Child; D003657:Decision Making / Q000187:drug effects*; D005260:Female; D006801:Humans; D007266:Inhibition, Psychological; D008297:Male; D008774:Methylphenidate / Q000627:therapeutic use*; D011340:Problem Solving / Q000187:drug effects; D011597:Psychomotor Performance / Q000187:drug effects; D011930:Reaction Time / Q000187:drug effects*
D008774:Methylphenidate