Changes in GSR and heart rate during listening to tones, words, and nonsense syllables.

In order to compare the habituation of orienting responses to tones, words, and nonsense syllables, GSR and heart rate were recorded following mass (habituation) and discrete presentations of the stimuli. Each of 36 10-yr.-old boys and 36 male undergraduates listened to two presentations of a tone (word and nonsense syllable in a random order) under discrete condition in contrast to 40 presentations under mass condition. Immediately following 2 or 40 presentations, habituation of orienting response was measured while five instances of the stimulus were slowly presented. Results indicated (i) habituation of GSR but not of heart rate, (ii) nonsense syllables evoked the strongest GSRs and heart-rate changes among the three stimuli, and (iii) children showed stronger reactions than the adults in some measure of GSR and heart rate. These results were discussed in terms of the theory of Sokolov.