Psychophysiological reactions in dental phobic patients during video stimulation

Electromyography (EMG) reflecting forehead muscle tension, heart rate (I-IR ) and skin conductance (SC) were continuously recorded in dental phobic sub jects (n = 126) and controls (n = 25) during exposure of dental and neutral video scenes in order to explore the relationship between dental fear and psychophysiological responses. This relationship is far from well establish ed, and the present investigation was performed to contribute to the unders tanding of the psychophysiology of dental fear. Dental phobics had a mean a nxiety level of 17.3 as measured by Corah's Dental Anxiety Scale (DAS) and refused conventional dental treatment. Control subjects reported regular de ntal treatment and a DAS score below population average (DAS < 8). Psychoph ysiological data was reduced to level (mean) and reactivity (means of intra individual variations). Results showed that physiologic reactions to fear-r elevant conditions measured by HR and EMG reflected degree of dental fear, and that neutral conditions, n hcn presented for the second and third time, induced lower psychophysiologic reactions in phobics than in controls. Rec ordings of SC indicated that dental phobics may differ from individuals suf fering from other types of specific phobia by showing weakened autonomic re sponsiveness to threat.