TONIC PHYSIOLOGICAL-RESPONSES TO REPEATED PRESENTATIONS OF PHOBIC STIMULI

Questionnaire, electrodermal and cardiac responses to phobic and neutral stimuli were assessed both within and across three daily test sessions. Each session consisted of 5 phobic and 5 neutral trials. Questionnaire responses in the first session showed some initial sensitization followed by habituation across the rest of the sessions. Cardiac response patterns differentiated phobic and neutral stimuli in the first two sessions. Electrodermal spontaneous fluctuation levels and habituation patterns differentiated the two stimulus types. Skin conductance levels showed sensitization across phobic trials and habituated across sessions, but showed habituation or asymptotic response levels to the neutral stimulus. The experiment raises methodological points suggesting that conflicting and unexpected results in the literature may be due to the use of phasic instead of tonic physiological responses and the use of stimuli which are not subject-specific. Results are also discussed in relation to proposals that psychiatric patients are those who are unable to cope with repeated life stresses. © 1979.