Electromyographic reaction to strong auditory stimulation in psychiatric patients.

Abstract

MALMO, Shagass, and J. F. Davis found normal startle reflexes in the psychoneurotic patients they studied (5). This seems to contradict the ordinary clinical observation that "tense," apprehensive, anxious patients are easily startled ("jump at any sudden noise"). We shall see in a moment, however, that the contradiction is only apparent. The startle pattern has been beautifully detailed in the classic study of Landis and Hunt, who used a high-speed movie camera to record reactions to pistol shot. They found a latency up to about 0.2 seconds for the arm component of the startle pattern (3). It was this component which Malmo and his co-workers studied with strong auditory stimulation and electroznyographic techniques. The need for their work with psychiatric patients was clear: although Landis and Hunt had studied psychotics and other deviating individuals, they had not investigated the startle pattern in psychoneurotics. Malmo and his co-workers found no significant difference between patients and controls in the 0.2-second period of reflex startle. Curves for mean percentage change showed almost identical values for the first and second tenth-seconds. But beginning with the third tenth-second the control curve fell while the patients' curve continued to rise (5, p. 327). The period beginning after 0.2 second, in which patients and controls differed in reaction, was called the afterresponse period.We now see that the experimental data need not be considered contradictory to clinical observations (of "jumpiness" to sound). Without recording instruments it is impossible to gauge the precise latencies of reactions, and the clinician may be observing an exaggerated afterreaction in the patient, not an abnormally strong immediate reflex reaction. The possible theoretical implications of this distinction between

Electrodermal Activity

“…3.1.1.3). Habituation being slowed down or even missing in anxiety patients is a result consistently found not only for SCRs (Lader 1967(Lader , 1975Lader & Wing, 1964 but also for cardiovascular measures (Malmo & Smith, 1951;McGuinness, 1973), for EMG (Davis, Malmo, & Shagass, 1954), and for EEG parameters (Bond, James, & Lader, 1974;Ellingson, 1954). Hart (1974) provided an alternative interpretation of the failure of anxious patients to habituate as rapidly as normal individuals.…”

Anxiety and behavioral arousal.

“…Strong auditory stimulation served as another and very different kind of standard stimulating situation for comparing patients and controls. Two separate studies, the first one (30) with induced tension (produced by squeezing a rubber bulb), and the second (7) without induced tension and with a less intense stimulus, agreed in showing that the most reliable difference between anxious patients and controls was in "after-response" following the period of primary reflex-startle reaction.…”

Chronic Anxiety Treated by Feedback-Induced Muscle Relaxation

“…All ten successfully learned to sustain 25 Instructions to the patient were relatively brief. They were asked to relax with their eyes closed and to purposefully relax spe¬ cific individual muscle groups.…”