Dissociation of the effects of alcohol and amphetamine on inert gas narcosis using reaction time and P300 latency.
Alcohol exacerbates and amphetamine ameliorates the slowing of reaction time (RT) produced by inert gas narcosis. The event-related brain potential P300 was used to determine whether these drug effects involve stimulus- or response-related processes, since P300 largely reflects the time to evaluate a stimulus while RT reflects this time plus the time to select and execute a response. Subjects breathed nitrous oxide (N2O) alone and in combination with ethyl alcohol or dextroamphetamine while responding to visually presented names that differed in probability (the oddball paradigm). N2O slowed P300, but this measure was comparatively insensitive to the exacerbation and amelioration that were indexed by RT. Relative to N2O alone, an RT-P300 difference was found for amphetamine + N2O but not for alcohol + N2O. We conclude that exacerbation involves both stimulus- and response-related processes but amelioration involves only the latter. This pattern of results can be explained by a model in which the drugs modulate slowing via the two energetical dimensions of arousal and activation, which influence stimulus- and response-related processes, respectively.
Fowler
B
B
Graduate Programme in Exercise and Health Science, York Centre for Health Studies, York University, Ontario, Canada.
Adams
J
J
D000200:Action Potentials / Q000187:drug effects; D000328:Adult; D000428:Alcohol Drinking / Q000009:adverse effects*; D001143:Arousal / Q000187:drug effects; D003913:Dextroamphetamine / Q000494:pharmacology*; D004242:Diving / Q000009:adverse effects; D004305:Dose-Response Relationship, Drug; D004347:Drug Interactions; D004566:Electrodes; D004569:Electroencephalography; D004585:Electrooculography; D005260:Female; D006801:Humans; D007222:Inert Gas Narcosis / Q000150:complications / Q000503:physiopathology*; D008297:Male; D008606:Mental Processes / Q000187:drug effects*; D008956:Models, Chemical; D011930:Reaction Time / Q000187:drug effects*; D013997:Time Factors
D003913:Dextroamphetamine