Effects of modafinil and bromazepam on decision-making: a P300 analysis

Drug influence on the decision making process has been scarcely studied. Researchers have driven the hypothesis that drugs might cause interference on cortical circuits. The aim of the present study is to evaluate the electrophysiological and behavioral changes occurring in the P300 after ingestion of modafinil (200mg), bromazepam (6mg) and placebo in healthy subjects exposed to a sensorimotor task based on the oddball paradigm. The sample for this study consisted of 10 subjects of both sexes, with ages ranging between 20 and 45, who were submitted to a quantitative electroencephalography. The experimental procedure was carried out in three visits, before and after drug ingestion. The results demonstrated a significant increase in the P300 latency and amplitude for the target condition, when compared to the non-target condition, for all analyzed electrodes. No significant difference was found for group or moment. A statistically significant difference was found for the group variable in the behavioral analysis. Such results suggest that the P300 is a measure, which is not sensitive to drug ingestion. On the other hand, the measure presented certain level of sensitivity when the subjects faced two different conditions in the decision making process orientation.