Date of Award


Document Type


Degree Name

Master of Science (MS)


An investigation was conducted to study the effects of interstimulus interval upon the startle response of eighteen male subjects. Four treatments were used, each consisting of a pre-startle sound and a startle eliciting sound, with an interstimulus interval of 0, 40, 120, or 1000 milliseconds. A treatment consisting of only the startle eliciting stimulus was used as a control.

Electromyography and pulse rate were monitored to record the response to the stimuli. Each subject was tested twice over a two week period, with a week separating the two tests.

Analysis of the electromyogram indicates that a significant difference (F= 21.82) does exist between the muscle response elicited by the treatments and the control response. While not significantly different from the other treatment responses, the treatment with an interstimulus internal of 120 milliseconds appeared to have exhibited the greatest amount of response inhibition. Analysis of pulse rate (F= 0.41) indicates that none of the treatments used elicited a significant change in pulse rate.


iv, 45 leaves : ill., photographs ; 28 cm.


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