We are presenting new software for the measurement of reaction times (RTs) to simple visual and auditory stimuli. An earlier program had been developed to measure stress conditions in basketball players in order to avoid spontaneous traumas following overtraining. Its supposed theoretical background is that stress modifies RTs, but in a different way when acoustic or visual stimuli are used to elicit them. RTs are supposed to differ also when we can elicit them from either brain hemisphere.

The computer program ST-CON (STress-CONtrol), by R. Cocchi and C. Carli (1993), was prepared to check up RTs. These can be elicited by hand answers to simple visual stimuli, as a variation of a 200*150 mm rectangle from yellow to red. The same can be elicited to simple auditory stimuli as a beep lasting 55 msec. Every stimulus appears at random from between 1-15 seconds (start) from the beginning of the warning time. Stop is obtained by hitting the space bar. With some subjects (e.g. schizophrenics [1, 2]) the tester starts the warning time, otherwise the tested person can start it by himself. With this program we can measure RTs in msec, timing by functions that allow sequences of start-stop.

Four stimuli groups make up the test, carried out in a single session. This is the usual order: Visual stimuli - dominant hand; Visual stimuli - non-dominant hand; Auditory stimuli - dominant hand; Auditory stimuli - non-dominant hand. Each tested person has to do 15*4 or 30*4 valid trials, excluding Anticipations (< 80 msec for visual stimuli or < 70 msec for auditory stimuli) or Timeouts (> 279 msec). For each of the four groups the program gives the average RTs, the maximum, the minimum, the min-max differential, anticipations and timeouts figures. The program counts average, maximum, minimum and differential time only for the 15-30 trials considered as valid. In this way we can measure true RTs not biased by anticipations and timeouts. Immediate comparison is available with RTs range figures from a control group of normal people. Anticipations and timeout were considered a measure of impulsiveness or distraction, respectively. The program also allows the comparison between visual and auditory RTs and between left and right brain hemisphere RTs. Results on stress induced by alcohol challenge in disulfiram treated detoxified alcoholics [3] are presented.

References

1. Cocchi, R. (1993). A control study of left- and right-hand reaction times to visual or auditory stimuli in schizophrenics. Preliminary report. Ital. J. Intellect. Impair., 6, 155-162.
2. Cocchi, R. (1995). Left- and right-hand reaction times to simple visual or auditory stimuli in male and female schizophrenics. Ital. J. Intellect. Impair., 8, 43-52.
3. Cocchi, R. (1997). Left- and right-hand reaction times to simple visual or auditory stimuli in detoxified alcoholics. Ital. Intellect. Impair., 10, 151-155.