Secobarbital and information processing.

The Sternberg fixed-set memory-search paradigm was used to assess the relative vulnerability of hypothetical stages of information processing to an oral dose of secobarbital (2.9 mg/kg). D-amphetamine (15 mg, oral dose) was intended to serve as an active placebo. However, since the amphetamine produced a slight, non-significant reduction in choice reaction time (RT), the principal analysis of secobarbital effects was conducted between drug and baseline conditions. Secobarbital showed choice RT by 60 msec. and did not increase errors significantly. The results, as interpreted within Sternberg's model, suggest that input processes, e.g., stimulus preprocessing-encoding, are particularly sensitive to the effects of the barbiturate. There was no evidence of a drug effect on cognitive processes associated with serial comparison, binary decision, or translation-response organization (response selection). In contrast, earlier studies have indicated that another CNS depressant, alcohol, interferes with both speed and accuracy of output processes, viz, the response selection stage.