Basic HTML Version
ROLE OF COGNITIVE EFFORT
383
In contrast, the pattern of results is clearly inconsistent with our compet-
ing prediction derived from the social-cognitive and dissociated-experi-
ence theories (Prediction 3a). Rather than being greater, heart-rate increases
were nonsignificantly smaller for highs than for lows in both suggestion-
wording conditions. Thus, the highs do not appear to exert greater under-
lying cognitive effort than the lows, unlike what these theories argue.
Correlations Among the Dependent Variables
Although we had formulated no predictions about the within-group
correlations among the dependent variables, these correlations were
quite interesting. Table 1 shows the correlations among the four subjec-
tive measures for high versus low hypnotizable participants in condi-
tions of effortful versus effortless suggestion wording. Note first that the
pattern for vividness, absorption, and subjective effort is quite consistent
across the four conditions, with vividness positively related to absorp-
tion, and subjective effort negatively related to vividness and absorp-
tion. In contrast, the correlations for subjective control are strikingly
different across the conditions. Focusing first on the effortful suggestion
wording, control is negatively related to vividness and absorption for
low hypnotizable participants, but positively related to these variables
for highs. Further, control is strongly positively related to subjective
effort for lows, but entirely unrelated to effort for highs. All three pairs
of correlations involving control are significantly different between lows
and highs. Focusing next on the effortless suggestion wording, the corre-
lations involving control are somewhat less distinct between lows and
highs, with the major exception of the correlation with subjective effort,
which is again strongly positive for lows but negligible for highs.
This pattern of results is consistent with the concept of effortless
control in high hypnotizables, as advanced by dissociated-control theory
(K. Bowers, 1992; Miller & Bowers, 1993), in which control becomes dis-
sociated from executive effort. In particular, whereas subjective control
and subjective effort were strongly related for low hypnotizables, they
were unrelated for highs. In addition, whereas for lows control was neg-
atively related to imagery quality (vividness and absorption), for highs it
was positively related (under effortful suggestion wording) or unrelated
(under effortless suggestion wording) to imagery quality. These findings
support the hypothesis that differences in the nature of control processes
are what distinguish highs from lows.
Also of interest was the relation of heart-rate change to the four sub-
jective-experience measures. None of these correlations, within the
four conditions of high versus low hypnotizable participants with
effortful versus effortless suggestion wording, was statistically signifi-
cant. In particular, within-group correlations between adjusted heart-rate
increase, our objective measure of cognitive effort, and subjective effort
ranged from
−
.26 to .09. Although such within-group correlations
Downloaded by [University of Macedonia] at 02:14 29 March 2012