Stimulus rise time, intensity and the elicitation of unconditioned cardiac and electrodermal responses

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Abstract

In recent discussions on the differentiation of orienting, startle and defense responses, the importance of stimulus rise time for the elicitation of different cardiac response patterns was re-emphasized. Especially, it has been claimed that phasic accelarative heart rate (HR) responses-interpreted as indicators of startle-might not only be evoked by auditory stimuli with instantaneous rise times and high intensities, but also by low to moderate stimulus intensities with sudden onsets. The present study examined this question by manipulating rise time (instantaneous vs. 50 ms) and intensity (60 vs. 95 dB). Subjects (N = 120) were randomly assigned to one of the four independent groups. They performed a habituation experiment in which 12 tones of 1000 Hz with a constant interstimulus interval of 90 s were presented. On trial 13, a change in rise time was introduced by reversing the rise time condition in each group (i.e., from instantaneous to 50 ms and vice versa). Examination of HR changes across 4 poststimulus seconds, of maximal HR deceleration and acceleration, as well as examination of magnitude of skin conductance responses (SCRs) indicated clear intensity effects. Rise time, on the other hand, had no effects on HR and SC that could be interpreted as indicative of startle. Thus, it could neither be observed that instantaneous rise time led to stronger accelerative HR responses nor that the combination of instantaneous rise time and high intensity elicited anything but a dominant accelerative response pattern. These findings were also obtained when the first four trials were analyzed separately. As a consequence of stimulus change, larger SCRs as well as larger decelerative HR responses were observed without, however, being affected by the direction of the change in rise time. In sum, the present study suggests that the role attributed to rise time with respect to eliciting qualitatively different cardiac response patterns has been exaggerated. The consequences for the differentiation of different unconditioned responses are briefly addressed.

References (26)

  • F.K. Graham

    Habituation and dishabituation of responses innervated by the autonomic nervous system

  • G. Turpin et al.

    Cardiac and forearm plethysmographic responses to high intensity auditory stimulation

    Biol. Psychol.

    (1978)
  • R.J. Barry

    Novelty and significance effects in the fractionation of phasic OR measures: A synthesis with traditional OR theory

    Psychophysiology

    (1982)
  • R.J. Barry

    Preliminary processes in orienting response elicitation

  • R.J. Barry et al.

    Heart rate deceleration is not an orienting reflex; heart rate acceleration is not a defensive reflex

    Pavlovian J. Biol. Sci.

    (1985)
  • W.K. Berg et al.

    Tone intensity and rise-decay time effects on cardiac responses during sleep

    Psychophysiology

    (1975)
  • T.D. Blumenthal

    The startle response to acoustic stimuli near startle threshold: Effects of stimulus rise and fall time, duration, and intensity

    Psychophysiology

    (1988)
  • T.D. Blumenthal et al.

    Stimulus rise time, intensity, and bandwidth effects on acoustic startle amplitude and probability

    Psychophysiology

    (1986)
  • P.J. Dallos et al.

    Integration of energy at threshold with gradual rise-fall tone pips

    J. Acoust. Soc. Am.

    (1964)
  • P. Ekman et al.

    Is the startle reaction an emotion?

    Journal of Personality and Social Psychology

    (1985)
  • D.C. Fowles et al.

    Publication recommendations for electrodermal measurements

    Psychophysiology

    (1981)
  • F.K. Graham

    Distinguishing among orienting, defense, and startle reflexes

  • H.M. Hatton et al.

    Effects of acoustic rise time on heart rate response

    Psychonom. Sci.

    (1970)
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