Impact of stimulus signal-to-noise ratio on prepulse inhibition of acoustic startle.
Prepulse inhibition (PPI) of the human acoustic startle response is reduced in the presence of background noise of a sufficient intensity, possibly due to a reduction in signal-to-noise ratio (prepulse intensity relative to background noise). We examined this hypothesis by varying prepulse intensity and background noise intensity in order to hold three different signal-to-noise ratios constant (5, 15, and 25 dB(A) above background noise intensity). The results showed that signal-to-noise ratio proved to be a more important factor than absolute stimulus intensity in determining the degree of PPI of startle eyeblink response magnitude. Therefore, the effectiveness of a prepulse is determined by prepulse salience, not intensity, and this effectiveness is equivalent across a range of physical intensities.
Franklin
Joseph C
JC
Department of Psychology, Wake Forest University, Winston-Salem, North Carolina 27109, USA.
Moretti
Nicole A
NA
Blumenthal
Terry D
TD
D000161:Acoustic Stimulation; D000293:Adolescent; D000328:Adult; D001767:Blinking / Q000502:physiology; D004576:Electromyography; D005260:Female; D006801:Humans; D008297:Male; D013216:Reflex, Startle / Q000502:physiology*