| Males with a family history of alcoholism (Family History Positive: FHP) have been found to differ from males without such a history (Family History Negative: FHN) on a number of psychophysiological and electrophysiological measures. A frequently reported result is that FHP males show an attenuated amplitude of the P300 component of the EEG event-related potential (ERP) (e.g., Begleiter, Porjesz, Bihari, & Kissin, 1984). The purpose of the present study was to explore the influence of motivational factors on the amplitude of the P300 displayed by FHP Ss in response to a visual discrimination task. The ERPs of 20 FHP and 20 FHN males were recorded under two conditions: a no incentive (Neutral) and a reward/loss of reward (Incentive) condition. The FHP Ss displayed the expected attenuation of P300 amplitude regardless of the stimulus type (Target, Non-Target, or Novel), perhaps reflecting a general cognitive difference between the two subject groups. The FHN Ss showed the predicted effect of an increased P300 amplitude in response to incentive. Conversely, the FHP Ss did not display greater P300s in the Incentive condition. Analyses suggest that group differences in response to incentive are due, at least in part, to the variables of sensation seeking and behavioral undercontrol. However, these variables could not explain Ss' mean P300 amplitude, averaged across stimulus type and incentive condition. |
