The Effects of Practice on Choice Reaction Time and Critical Flicker Fusion Threshold.

The use of psychometrics in psychopharmacology assumes that subjects are 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 scores reached a ‘plateau’ after three trials. There was no effect of time on CFF on either day 1 or 5. There was a significant interaction between day, time and CFF thresholds (F = 3 · 71, p < 0·006) which was probably 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 results show performance ‘plateaus’ on CFF and CRT tests are reached after three trials and four sessions of 20 trials respectively. © 1997 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]