Mt. Schmolesky et al., THE EFFECT OF ACOUSTIC PULSE INTENSITY UPON THE ELECTRICALLY ELICITEDBLINK REFLEX AT POSITIVE AND NEGATIVE STIMULUS ONSET ASYNCHRONIES, Biological psychology, 44(2), 1996, pp. 69-84
The present study examined the effects of acoustic pulse intensity and
stimulus onset asynchrony (SOA) on the electrically elicited startle
reflex response. Subjects were presented with 165 startle eliciting st
imuli; 15 control trials with no acoustic pulse, and 5 trials at each
pulse intensity (50, 70, and 90 dB) for each SOA (-80, -60, -40, -20,
0, 20, 40, 60, 80, and 100 ms). The results demonstrated R2 magnitude
facilitation at negative, simultaneous, and short positive SOAs. R2 fa
cilitation was greatest in the 90 dB condition and least in the 50 dB
condition. R1 facilitation at short positive SOAs was greater for more
intense acoustic pulses. These data support the notion that R2 facili
tation at near-zero SOAs may be the result of a combination of pulse i
nduced potentiation of the electrically elicited startle response and
temporal summation of the effects of electrical and acoustic stimuli a
t the facial motor nucleus.