Modafinil improves rapid shifts of attention.
BACKGROUND
The majority of studies investigating the cognitive effects of modafinil, a wake-promoting compound, demonstrate some improvements in attention. The potential of the drug to selectively benefit distinct components of attention has yet to be fully explored in healthy adults.


OBJECTIVE
The present study was conducted to investigate modafinil's effect on specific cognitive tasks that tax components of attention switching. One required the rapid switching of attention between stimuli, and another contained an embedded working memory component on top of the attentional shift requirements. Additionally, prospective memory was examined, which requires the interruption of an ongoing activity to retrieve and act upon a previously formed intention.


METHODS
Healthy non-smoking volunteers, matched on age, intelligence, and baseline cognitive ability, received either a capsule that contained 200 mg modafinil or placebo. Subjective measures of mood and physiological response were taken throughout the experimental session, and the tasks were completed between 2 and 3 h post-dosing.


RESULTS
Two hundred milligrams modafinil improved accuracy without a reaction time trade-off, in both conditions of the attention-shifting task, but only when resources were most challenged. In contrast, the drug afforded no improvement in prospective remembering or in the ongoing task that was interrupted.


CONCLUSIONS
Modafinil appears to promote rapid switching of attention in conditions that are most demanding, whilst it offers no benefits in a task that requires unpredictable and infrequent disengagement of attention from an ongoing task in order to act upon an alternative task.
Marchant
Natalie L
NL
Department of Psychology, Sussex University, Brighton, East Sussex BNI9QG, UK. n.l.marchant@sussex.ac.uk
Kamel
Faddy
F
Echlin
Kezia
K
Grice
John
J
Lewis
Mark
M
Rusted
Jennifer M
JM
D000339:Affect / Q000187:drug effects; D001288:Attention / Q000187:drug effects*; D001559:Benzhydryl Compounds / Q000494:pharmacology*; D000697:Central Nervous System Stimulants / Q000494:pharmacology*; D003657:Decision Making / Q000187:drug effects; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D008297:Male; D008568:Memory / Q000187:drug effects; D011939:Mental Recall / Q000187:drug effects; D000077408:Modafinil; D009483:Neuropsychological Tests; D011597:Psychomotor Performance / Q000187:drug effects; D011932:Reading; D055815:Young Adult
D001559:Benzhydryl Compounds; D000697:Central Nervous System Stimulants; D000077408:Modafinil