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Effects of stimulus intensity, risetime, and duration on autonomic and behavioral responding: Implications for the differentiation of orienting, startle, and defense responses
Author(s) -
Turpin Graham,
Schaefer Florian,
Boucsein Wolfram
Publication year - 1999
Publication title -
psychophysiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.661
H-Index - 156
eISSN - 1469-8986
pISSN - 0048-5772
DOI - 10.1111/1469-8986.3640453
Subject(s) - psychology , orienting response , stimulus (psychology) , audiology , moro reflex , heart rate , skin conductance , habituation , reflex , perception , startle reaction , developmental psychology , neuroscience , cognitive psychology , blood pressure , medicine , biomedical engineering
The effects of stimulus intensity, duration, and risetime on the autonomic and behavioral components of orienting, startle, and defense responses were investigated. Six groups of 10 students were presented with 15 white noise stimuli at either 60 or 100 dB, with controlled risetimes of either 5 or 200 ms, and at stimulus durations of 1 or 5 s (1 s only in the case of the 60‐dB groups). A dishabituation stimulus consisting of a 1000 Hz tone was also presented. Measures consisted of skin conductance and heart rate, together with ratings of facial expressions and upper torso movement obtained using video recording. Increased intensity resulted in greater amplitudes and frequencies of electrodermal and behavioral responses, and a change from cardiac deceleration to acceleration. Faster risetimes elicited larger electrodermal responses, greater frequencies of eye‐blinks, head and body movements, and larger cardiac accelerations. The effects of duration for the 100‐dB stimuli were less clear‐cut. Overall, the results are discussed in relation to the differentiation of orienting, startle, and defense responses.