On the waveform of the acoustic startle blink in the paradigm of prepulse inhibition - methodological and physiological aspects.
Recent studies suggest that the eye blink response to intense acoustic stimuli consists of two components that may occasionally result in waveforms with two peaks. In the present study, the prevalence, peak latencies, and peak magnitudes in responses exhibiting one or two peaks were investigated in healthy subjects in 25 pulse-alone and 25 prepulse-pulse trials using an interstimulus interval of 60 ms. Electromyographic activity was recorded simultaneously from the orbicularis oculi muscle (OOM) and from the sternocleidomastoid muscle (SCM) to explore the temporal relationship of the peaks to the generalized startle reaction. Responses in the OOM occurred with shorter onset and peak latencies than the responses in the SCM. In about 30% of pulse-alone trials, OOM responses exhibited two peaks that showed similar prepulse inhibition. These findings support the view that both components of the acoustically evoked OOM response exhibit similar plasticity in the paradigm of prepulse inhibition.
Meincke
Ulrich
U
Department of Psychiatry, University of California San Diego, La Jolla, USA. Meincke@Klinikum-Niederberg.de
Light
Gregory A
GA
Geyer
Mark A
MA
Braff
David L
DL
D000161:Acoustic Stimulation; D000328:Adult; D001767:Blinking / Q000502:physiology*; D004576:Electromyography; D005260:Female; D006801:Humans; D008297:Male; D009801:Oculomotor Muscles / Q000502:physiology*; D013216:Reflex, Startle / Q000502:physiology*