Hypnotic Susceptibility and the Endogenous Eyeblink: A Brief Communication

Abstract

This study investigated the relationship between hypnotic susceptibility, hypnotic state, and the endogenous eyeblink with 36 undergraduates, who were assigned to four independent groups (waking-low, hypnotized-low, waking-high, and hypnotized-high susceptibles) on the basis of combined cutoff scores on both the Creative Imagination Scale and the Stanford Hypnotic Clinical Scale for Adults. The auditory vigilance task required subjects to discriminate between 200 ms and 300 ms tones over a 35-minute period. Hypnotic depth was controlled across trials using the Long Stanford Scale of Hypnotic Depth. As predicted, high-susceptible subjects had a significantly lower blink rate than low-susceptible subjects. The predicted interaction between susceptibility and hypnotic state was also confirmed. High-susceptible subjects showed a significant decrease in blinking for the hypnotized condition, whereas low-susceptible subjects did not. The need for replication with more adequate measures of susceptibility is discussed.

Hypnotizability and Blink Rate:A Test of the Dopamine Hypothesis

“…Lindsay, Kurtz, and Stern (1993) investigated specifically the blink rate before as well as during hypnosis and, contrary to our expectations, found an increased rate for low hypnotizables. However, the method that they employed to assess blink rate was to have the subjects "maintain their gaze on a dimly lighted box .…”

“…On the contrary, we found a negative correlation between hypnotizability and blink rate, accounted for primarily by the higher blink rates at rest in medium as compared to high hypnotizables. These findings are different from those of Lindsay, Kurtz, and Stern (1993). Employing auditory and visual tasks, they found that high hypnotizables blink less than low hypnotizables.…”

“…Different studies have employed different methods; no standardization exists. Subjects have been engaged in conversation (Kimber & Thompson, 2000;Tulen et al, 1999), made to stare at objects (Deuschl & Goddemeier, 1998) or lights (Lindsay et al, 1993), listened to electronic sounds or to music (Chen, Lam, Chen, & Nguyen, 1996) or simply been told to relax (Nakamori, Odawara, Nakajima, Mizutani, & Tsubota, 1997). A sound methodology, then, will incorporate different conditions during which the spontaneous blink rate will be measured.…”

Revisiting the association between hypnotisability and blink rate

“…studies of functions classically considered as "dopaminergic" (Kohl et al 2013;Colzato et al 2009) have provided inconsistent results. In fact, reduced pre-pulse inhibition has been found associated with high hypnotisability (Lichtenberg et al 2008b), but blink rate (BR) has been found lower in highs than in medium hypnotizable individuals (mediums) (Lichtenberg et al 2008a) and lows (Lindsay et al 1993).…”

The Existence of a Hypnotic State Revealed by Eye Movements

“…It is a glazed look in the eyes accompanied by a highly reduced eye-blinking rate [20]–[22]. Weitzenhoffer [18] has described this phenomenon flowingly:…”