Frederick W. Obitz

Effect of alcohol and task on hemispheric asymmetry of visually evoked potentials in man

The study examined the effect of a dose of alcohol producing a mean blood alcohol content of 90 mg% on components of the scalp-recorded visually evoked potential (VEP) both with and without a visual discrimination task to control the level of attention, and the interaction of amplitudinal hemispheric asymmetry of the VEP with alcohol treatment and the discrimination task. Ingestion of ethyl alcohol producing a mean blood alcohol content of 90 mg% affected VEPs recorded from the central scalp by attenuating the overall amplitude of the later VEP components (60-200 msec) and by significantly reducing hemispheric asymmetry in the amplitude of these VEP components. Alcohol attenuates VEP components P90-N120 and N120-P180, and the task of counting flashes and attending to discriminate double flashes increased amplitude of VEP components N60-P90 and P90-N120 in control and placebo conditions. Several studies have reported that the VEP recorded from the right hemisphere of human beings is larger than the VEP recorded from the homologous location in the left hemisphere. Evoked potentials recorded under control and placebo conditions in this study also demonstrated a hemispheric asymmetry with right larger than left for component P90-N120. We also found a reliable alcohol by hemispheric asymmetry interaction. Alcohol selectively depressed the amplitude of the right hemisphere VEP (P90-N120) component to a significantly greater extent than the left hemisphere VEP was affected.

General and Specific Perceived Locus of Control in Alcoholics

50 alcoholics were administered the I-E scale and a specially constructed scale to determine the perceived locus of control for their drinking behavior. It was hypothesized and found that alcoholics perceive themselves in control of their behavior in general and of their drinking behavior in particular. Theoretical implications of these findings were discussed.

Change in General and Specific Perceived Locus of Control in Alcoholics as a Function of Treatment Exposure

Fifty alcoholics successfully completing a 2-month rehabilitation program were administered the I-E Scale and a drinking locus of control scale during their first week in treatment and again the week prior to discharge from treatment. A test--retest non-alcoholic control group was administered the I-E Scale at a 7-week interval. Alcoholics were significantly more internal with regard to their behavior in general and their drinking behavior in particular at the close of treatment than at the onset. The control group evidenced no change. It was suggested that the alcoholics perceived internality was a function of exposure to treatment rather than a predisposing personality dimension.

Varied Information Levels and Accuracy of Person Perception

200 Ss judged 4 stimulus persons in 20 experimental conditions with varying amounts and categories of information given them. The greatest judging accuracy was obtained when total information input of different amounts and categories was greatest. Adding more input did not result in greater accuracy of judgment with all stimulus persons, however, and actually reduced accuracy for some stimulus persons. Further, considering the disproportionate amount of input increase necessary in order to yield small amounts of increased predictive accuracy, a question was raised concerning whether it is practically profitable to attempt to maximize predictive accuracy.