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44
DONALD
R.
ROBERTS
Hypnosis
is
a
graduated condition; in
this
paper the term “general
hypnosis” refers
to
the relatively stable condition of
full
trance effected
by skilled hypnotists. The main behavioral components of the trance
state are considered
to
be loss of voluntary control (automatism)
;
loss
of current sequential memory (amnesia)
;
lack of response to fear-
and anger-producing stimuli (apathy)
;
loss of sensory definition, anes-
thesias, and similar dysfunctions
;
suggestibility; and capacity for motor
and ideational (symbolic) responses.
Pavlov (1941) defined hypnosis
as
a
“partial sleep”; he stated that
sleep is “identical in process” with inhibition; thus, in Pavlov’s view,
the cortex in hypnosis is in a state of partial inhibition. Hypnosis was
defined by Kubie and Margolin
(1944)
as a
focus
of
central excitation
with surrounding areas of inhibition
(or
non-excitation)
;
by Weitsen-
hoffer (p.
254)
on
the basis of behavioral studies,
as
a
“dissociation
of
awareness
from the majority of sensory and even strictly neural events
that are taking place.”
Hypothesis
The view presently advanced
is
that the central area of excitation
may be identified with the central integrating system of the brain stem
concerned with waking, consciousness, activation and response. The
anatomic existence of such a system was intimated by
Morison
and
Dempsey’s definition (1942) of a nonspecific thalamic projection rela-
tively independent of the specific-sensoryafferent projection.
An
ascend-
ing activating formation in the lower brain stem, distinct from the
classical sensory pathways and connected with waking consciousness
and electrocortical activity, was identified by Moruzzi and Magoun
(1949)
;
a thalamic reticular formation mediating the activity of the
diffuse thalamocortical projection was identified by Jasper (1949). The
unitary action of these two
systems
has been posited by Penfield (19528)
in his “centrencephalic” theory
of
consciousness. The excitation of this
central system-with the possible exception
of
the diffuse projection-
in
hypnosis is indicated by the presence of normal
waking
electrocortical
rhythm
in
hypnotized
subjeds
(Dynes,
1947).
The area of
surrounding
inhibition
is
to be d e h e d
aa
the primary-
sensory and (secondary) parasensory areas of the cortex, together with
a
paramotor
area
and certain anterior regions
of
the cortex t o be
dis-
cussed below.
It
is
the inhibition
of
interaction between
these regions of
the cortex
and
the central integrating system that may condition gen-
eral hypnosis.
The symptoms of hypnotic trance (general hypnosis) are consonant
with the following:conditions in the electrical activity of the brain:
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