Basic HTML Version
376
PAMELA SADLER AND ERIK Z. WOODY
investigates the nature of underlying mental activity during hypno-
sis by using heart rate as a way of measuring actual, underlying
effort.
Hypnosis and Imagery
Sturgis and Coe (1990) studied heart-rate change in high and low
hypnotizable participants in response to ten items from the Stanford
Hypnotic Susceptibility Scale, Form C (SHSS:C; Weitzenhoffer &
Hilgard, 1962). Although highs and lows did not differ in heart-rate
change for most of the items, highs showed significantly greater
heart-rate increases on four items. Unfortunately, these differences
were very difficult to interpret because of the confound that the
highs tended to pass the items and the lows did not; thus, the two
groups were engaged in frankly different behavior. For example,
two of the items on which there was a significant difference critically
involved motor activity; as the researchers pointed out, this alone
may account for the difference in heart-rate change. Another impor-
tant confound is that passing some of the more dramatic items—for
instance, age regression, on which there was also a significant heart-
rate difference—can evoke an emotional response that is simply
irrelevant for those who fail such items. This difference in reactions
likely elicited changes in heart rate irrespective of the amount of
cognitive effort highs and lows were expending to try to enact the
suggestion.
To avoid these kinds of confounds in the present research, we
studied the generation of relatively neutral imagery in hypnosis.
Compared to their low hypnotizable counterparts, high hypnotiz-
able individuals produce imagery that is not only experienced as
more effortless (P. Bowers, 1978, 1982) but also as more vivid and
absorbing (Hilgard, 1979; Hughes, 1988; Monteiro, MacDonald, &
Hilgard, 1980; Sutcliffe, Perry, & Sheehan, 1970; Tellegen & Atkinson,
1974; Wagman & Stewart, 1974). In addition, because imagery is an
activity that lows as well as highs can do and because it does not
evoke differences in overt (e.g., motor) behavior, it avoids the con-
found of highs and lows being engaged in noncomparable behav-
iors. Although some imagery, such as fearful imagery, can evoke an
emotional response that could affect heart rate irrespective of
cognitive effort (e.g., Bauer & Craighead, 1979; Carroll, Baker, &
Preston, 1979; Jones & Johnson, 1980), restricting the suggestions
for imagery to neutral subjects readily overcomes this possible
confound.
Possible Effects of Suggestion Wording in the Experience of Effortlessness
The effortless experiencing of imagery is a striking phenomenon in
those who are high hypnotizable (P. Bowers, 1978, 1982). However, it
Downloaded by [University of Macedonia] at 02:14 29 March 2012