Hypnosis, volition, and mind control
Is there actually an 'unconscious
mind' in some sense? And if so, does it explain certain kinds of response
to hypnotic suggestion?
First, it is very likely that
information is actually processed, at least under certain conditions, outside
of conscious awareness, and that it can influence behavior. A modern look
at this old topic can be found in Kihlstrom's 1987 Science article, "The
Cognitive Unconscious," 237,1445-1452. This is not to say that any particular
'subliminal learning' claims have support from this notion, only that it
is possible for perception of a sort to occur without apparent conscious
One study demonstrating a subliminal
influence on subsequent behavior was Borgeat & Goulet, 1983, "Psycho-physiological
changes following auditory subliminal suggestions for activation and deactivation,"
appearing in Perceptual & Motor Skills. 56(3):759-66, 1983 Jun.
This study was to measure eventual
psycho-physiological changes resulting from auditory subliminal activation
or deactivation suggestions. 18 subjects were alternately exposed to a
control situation and to 25-dB activating and deactivating suggestions
masked by a 40-dB white noise. Physiological measures (EMG, heart rate,
skin-conductance levels and responses, and skin temperature) were recorded
while subjects listened passively to the suggestions, during a stressing
task that followed and after that task. Multivariate analysis of variance
showed a significant effect of the activation subliminal suggestions during
and following the stressing task. This result is discussed as indicating
effects of consciously unrecognized perceptions on psycho-physiological
A hypnotic subject clearly
also takes an active and voluntary role in some sense as well when carrying
out suggestions, as pointed out by Spanos and the social-psychological
Perhaps the data showing this
contrast most strikingly is from the study of 'hypnotic blindness.' One
example is Bryant and McConkey's 1989 "Hypnotic Blindness: A Behavioral
and Experimental Analysis," Journal of Abnormal Psychology, 98, 71-77,
and also p. 443-447, "Hypnotic Blindness, Awareness, and Attribution."
Subjects given hypnotic suggestions for blindness behave in some ways as
if they were truly blind, and in other, often subtle and unexpected ways,
the information from their visual field influences their behavior.
It appears that some form of
neurological events involving more or less intelligent response to information
can occur, in or out of hypnosis, without our direct awareness of them.
One theory proposes that the brain has a simultaneous parallel capacity
for cognitive learning and for stimulus-response learning, independently
of each other and by different neural mechanisms. This has been proposed
by some as a partial explanation for automatisms and some hypnotic responses.
One version of this view may be found in the article by Mishkin, Malamut,
and Bachevalier, "Memories and Habits: Two Neural Systems," in The Neurobiology
of Learning and Behavior, edited by McGangh, Lynch, and Weinberger,
by Guilford Press.
It is important to recognize
that the detailed physiological mechanisms underlying the processing of
information in general are largely speculative, and that the gaps in our
understanding of hypnotic phenomena (or 'states of consciousness' in general)
complicate the situation. It has been contended that even some of the simpler
forms of learning and information processing consist of a number of different
processes, each with its own special properties.
One important distinction is
between explicit and implicit learning. Explicit learning is what we commonly
think of as doing as part of the conscious reasoning process when we try
to learn something deliberately. It generally involves reasoning and hypothesis
testing. Implicit learning is acquiring new information which either cannot
be verbalized, or which occurs apparently without conscious reasoning
and hypothesis testing. Kihlstrom, one investigator of hypnotic and unconscious
psychological processes, has shown that a particular variant of implicit
learning, involving certain non-novel information (such as word pairings),
can occur under medical anesthesia. The degree to which this can be considered
a form of learning in the more general non-technical sense is difficult
to say, and the precise neurobiological mechanism of anesthesia is likewise
somewhat elusive. But it has also been observed that implicitly learned
material has certain unique characteristics, as compared to explicitly
learned material, such as that implicit material is more often preserved
intact in cases of amnesia.
Some examples of research into
learning and perception which occurs outside of sensory (visual) attention:
- Mandler, Nakamura & Van
Zandt (1987). Nonspecific effects of exposure on stimuli that cannot
be recognized. J Exp Psych: Learning, Memory and Cognition, 13, 646-648.
- Miller (1987). Priming is
not necessary for selective-attention failures: Semantic effects of unattended,
unprimed letters. Perception and Psychophysics, 41, 419-431.
- Carlson & Dulany (1985).
Conscious attention and abstraction in concept learning. J Exp Psych:
Learning, Memory, and Cognition, 11, 45-58.
Some examples of research
into multiple foci of attention:
- Cohen, Ivry & Keele (1990).
Attention and structure in sequence learning. J Exp Psych: Learning,
Memory, and Cognition, 16, 17-30.
- Dienes, Broadbent, & Berry
(1991). Implicit and explicit knowledge bases in artificial grammar learning.
JEPLMC, 17, 875-887.
- Hayes & Broadbent (1988).
Two modes of learning for interactive tasks. Cognition, 28, 249-276.
On the concept of attention
- * Allport (1989) Visual
Attention. In M.I.Posner (Ed.) Foundations of Cognitive Science. (pp.
- Kahneman & Treisman (1984).
Changing views of attention and automaticity. In Parasuraman & Davies
(Eds.) Varieties of Attention.
- Navon (1985). Attention
division or attention sharing? In Posner and Marin(Eds) Attention and
- Neumann (1987). Beyond capacity:
A functional view of attention. In Heuer& Sanders (Eds.) Perspectives
on Perception and Action.