Neuroelectric correlates of response production and inhibition in individuals at risk to develop alcoholism.

P300 recordings were made from males at high risk (HR) for alcoholism and low-risk (LR) controls, participating in a visual go/no go reaction time paradigm. The go (button press) and no go (inhibit response) stimuli were large and small forms of the same letters. The LR group had significantly larger go than no go P300 amplitudes in the central, parietal, and temporal regions; the HR group manifested no response differences in any region. In the LR group compared to the HR group, both go and no go response amplitudes were larger over the entire head; no group differences in latencies were observed in any region. Surface energy magnitudes paralleled P300 amplitudes and were also larger in the LR group during both go and no go trials. Our findings indicate that HR individuals manifest widespread P300 amplitude deficits while performing a simple information-processing paradigm. These deficits, which may reflect genetic influences, preceded the onset of alcoholism and may function as a phenotypic marker for its development.