Latent inhibition in ADHD adults on and off medication: a preliminary study.
OBJECTIVE
To determine the effects of stimulant medication on performance of ADHD adults on a selective attention task that assesses the processing of irrelevant stimuli.


METHODS
ADHD patients and matched controls were given two sessions of a two-stage visual search-latent inhibition (LI) task. In stage-1, they detected the location of a unique shape presented with homogeneous distractors. In stage- 2, target detection response time was examined as a function of the stage-1 experience with the target or distractor, or both, providing a within-subject measure of LI. In Session-1, the ADHD subjects were off their customary stimulant medication. In Session-2, they were on medication.


RESULTS
Off-medicated ADHD subjects exhibited similar LI to that of controls; medicated ADHD subjects exhibited less LI than controls. Group differences in LI were mediated by RTs to the previously task-irrelevant distractor stimulus.


CONCLUSIONS
The attenuated LI of the on-medication ADHD group is attributable to drug action that reduces attentional resources allocated to distractors.
Tel Aviv University, Ramat Aviv, Israel lubow@freud.tau.ac.il.
R E
RE
Lubow
College of Management, Rishon Le Zion, Israel.
Oren
O
Kaplan
Geha Mental Health Center, Petah Tikva, Israel.
Iris
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Manor
D000328:Adult; D001289:Attention Deficit Disorder with Hyperactivity / Q000188:drug therapy* / Q000523:psychology*; D016022:Case-Control Studies; D000697:Central Nervous System Stimulants / Q000627:therapeutic use; D005260:Female; D006801:Humans; D007266:Inhibition, Psychological; D008297:Male; D011930:Reaction Time; D013647:Task Performance and Analysis; D016896:Treatment Outcome
D000697:Central Nervous System Stimulants