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The present study attempted to determine the role of instructions and feedback on alpha activity. Thirty‐six normal subjects were instructed to enhance or to suppress alpha activity or were given ambiguous instructions. Subjects were randomly assigned to three croups of 12 subjects earn. One‐half of the subjects in each group received feedback for increasing alpha activity, while the other half received feedback for suppression. Active and dummy electrodes were attached to each subject. Subjects were instructed to keep their eyes closed (luring the session. The session consisted of a 10‐min adaptation period, an instruction period, another 5‐min adaptation and then a series of 5 lest trials with feedback separated by 2‐min rest periods without feedback. Alpha enhancement was associated with instructions hut was independent of feedback. However, accurate instructions and feedback were associated with alpha activity suppression. Alpha activity was greatest during rest periods or when the subject was unaware of the significance of the feedback cue. which indicates the importance of monitoring basal levels of alpha activity in evaluating changes in alpha activity.

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After 56 days on a light-dark cycle, male Sprague-Dawley rats, 90 to 120 days old, received either ECS or sham ECS 4 or 24 h prior to training during the light or the dark phase of the cycle in one-way active avoidance. These variables interacted significantly to affect both errors and trials to criterion; however.principal consideration is given the errors data. The EC8-4-Dark group had significantly greater mean errors than all other groups (15.5 error p < .005), except the Sham-ECS-24 -Light group, and the ECS-24·Dark group had significantly fewer mean errors than five of the other seven groups (6.2 errors; p <.005). The findings were interpreted in terms of the evidence that ECS and light-dark cycles affect brain acetylcholine and Deutsch's hypothesis (1971) that too much or too little ACh activity may impair retention; this has been shown by Davis (1972) to be applicable to acquisition of one-way avoidance.

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