The effect of dextroamphetamine on habituation of peripheral vascular response in children

The blood volume pulse (BVP) measured by a photoplethysmograph was recorded in 43 children with behavior and learning problems before and after either stimulant drug treatment or placebo. A series of twenty-four 750-cps tones was presented at 10-sec. intervals, with one trial having a doubled interval and one with a halved interval. A 1,000-cps tone was introduced following the 24th trial. As predicted, the drug-treated subjects showed significantly more rapid habituation to the tones. They also showed more variability of BVP following the longer intertriai interval, but showed less variability following the introduction of the high tone. The results are interpreted as showing that the stimulant has the effect of raising autonomie arousal level with consequently more rapid habituation of the orienting response.An earlier version of this article was presented to The Society for Psychophysiological Research, Monterey, California, October 1969. This research was supported by Grant No. MH14432 from the Psychopharmacology Section (National Institute of Mental Health) and Research Scientist Development Award No. K2MH7839 (National Institute of Mental Health).