Startle Reaction: Modification by Background Acoustic Stimulation

Science  06 Sep 1963:
Vol. 141, Issue 3584, pp. 928-930
DOI: 10.1126/science.141.3584.928


Six rats were exposed to a sequence of gunshot-like acoustical bursts during silence, during steady noise, and during pulsed noise. Assessment of their startle reactions to the bursts revealed that a background of steady noise enhanced the response, whereas a background of pulsed noise produced suppression of response. It is hypothesized that pulsed noise causes a relative refractory state in the mechanisms responsible for startle and that steady noise may enhance startle by masking uncontrolled punctiform acoustic stimuli.