BEHAVIORAL ANALYSIS OF AUDITORY FUNCTIONING IN PRIMATES.
Final rept. 1 Feb 67-31 Jan 68,
NEW MEXICO STATE UNIV UNIVERSITY PARK
Pagination or Media Count:
An experiment was performed for the purpose of evaluating the usefulness of the technique of conditioned suppression of auditory threshold determination in rhesus monkeys. Nine rhesus Macaca mulatta monkeys were shaped to the lever in an operant conditioning experiment and trained until a stable rate of response on a variable interval 90 schedule was attained. At this point training in conditioned suppression was undertaken. The criterion of suppression used was a 90 percent or better ratio for 3 consecutive days. When criterion was reached, threshold testing was begun and continued until a range of dB levels which surrounded the 50 percent suppression ratio level was reached and maintained more or less stable for 3 days of testing. Stimuli in the region of the threshold were separated by 2 dB increments, and trials at each intensity level were presented several times in a non-systematic fashion. Threshold was defined as the dB level at which the line connecting the suppression ratios to the 2 dB apart stimuli crossed the 50 percent suppression ratio. The technique yields results which are remarkably stable over time and which are achieved with minimum difficulty. No other technique yet devised seems to be superior to conditioned suppression in any particular degree if ease of accomplishment and intra-organismic temporal stability are desired. Author
- Anatomy and Physiology