THE EFFECTS OF PRACTICE ON CHOICE-REACTION TIME AND CRITICAL FLICKER FUSION THRESHOLD

The use of psychometrics in psychopharmacology assumes that subjects a re trained to 'plateau' performance levels prior to experimental data being collected. Fourteen healthy, naive volunteers were tested on CFF and CRT over a 5-day period. On days 1 and 5 subjects carried out the tests six times, with intervals of 10 min between the trials. On days 2, 3 and 4, the subjects were tested once on both CFF and CRT. CFF sc ores reached a 'plateau' after three trials. There was no effect of ti me on CFF on either day 1 or 5. There was a significant interaction be tween day, time and CFF thresholds (F = 3.71, p < 0.006) which was pro bably a result of the method of limits technique used in this CFF task , but there were no significant differences in CFF thresholds between test days. The CRT scores reached a 'plateau' after six trials on day 1 and this 'plateau' was maintained over the following days. The resul ts show performance 'plateaus' on CFF and CRT tests are reached after three trials and four sessions of 20 trials respectively.