involved. Subjects who score high on tests of hypnotic
susceptibility are generally more suggestible than
those who are not very susceptible to hypnosis.
Hypnotically susceptible individuals have also been
found to have greater capacity for sustained atten-
tional focus; they process information more rapidly
and more easily, and they have a more active imagina-
tion and a more active fantasy life. It appears that the
experiential system is particularly active in individu-
als who are highly susceptible to hypnosis. Subjects
who are high in susceptibility to hypnosis appear to be
particularly prone to accept misleading information,
especially when the hypnotic interview is conducted
by a trained hypnotist. Disturbingly, this is the situa-
tion where the greatest inflation of the subject’s confi-
dence in the accuracy of his or her memory is likely to
occur also.
Subjects who are highly susceptible to hypnosis can
be easily led to construct vivid and detailed false mem-
ories of childhood experiences in situations that are
analogs to the clinical interview when various memory-
enhancing techniques are used, including hypnosis,
guided mnemonic restructuring, and visualization
instructions. These kinds of results are particularly rel-
evant to the courtroom battles based on repressed mem-
ories of childhood sexual abuse. Studies of hypnotic
age regression show that hypnosis and other memory-
enhancing techniques can produce fantastic memories
of fictional events, such as vivid and detailed memories
of the hospital environment the day after birth. Michael
Nash and his colleagues were able to hypnotically age
regress hypnotically susceptible subjects back to an
event that allegedly occurred when they were 3 years
old. The instructions that were used produced memo-
ries in the majority of subjects of a transitional object,
such as a teddy bear, which when checked against the
memory of the mother often turned out to be false.
Subjects continued to believe in these false memories
when they were questioned about them subsequently in
a normal waking state. Thus, vivid and detailed memo-
ries of childhood events that never actually occurred
can be produced with hypnotic age regression; how-
ever, Nash found that it does not appear that hypnotized
subjects in these studies are transformed to a childlike
state of mind.
The degree to which sexual trauma during childhood
interferes with the victim’s memory of the event or
series of events is not a question that lends itself to
experimental analysis. Even with the more general
question of the effects of arousal on the memory of awitness, there are limits to the degree of stress that the
subjects in our experiments may be exposed to. When
staged events are used to examine the effect of high lev-
els of arousal on a witness’s memory of the perpetrator
of a crime, it is generally found that arousal has a debil-
itating effect. During emotional events, the attention of
the witness is often focused on those aspects of the envi-
ronment that have the greatest significance for his or her
well-being, such as a weapon used by the perpetrator in
the commission of a crime. The evidence suggests that
due to poorer encoding of target features during these
kinds of events, the witness’s ability to recognize the tar-
get in a subsequent lineup will be impaired.
When hypnosis is used to refresh a witness’s mem-
ory of an emotional event, pressure is placed on the
witness to remember aspects of the event that were not
initially processed very well, if at all. Research has
found that hypnotized witnesses do not perform any
better on photographic lineups than witnesses who
have not been hypnotized. Instead, the hypnotized
witness may become particularly susceptible to cues
that direct attentional focus to a particular individual
in the lineup, leading in some cases to misidentifica-
tion of an innocent suspect. Staged-event studies have
also revealed that the level of anxiety experienced by
a witness during a staged event is negatively corre-
lated with the degree of confidence subsequently
expressed by the witness in a decision he or she has
made about the presence of the perpetrator in a lineup.
This finding has important implications regarding the
cohesiveness of memories of highly emotional inci-
dents. Regardless of the actual accuracy of a witness’s
recollection of a stressful event, if he or she is less
confident about it, then there is an increase in the
probability that misinformation will be incorporated
into the witness’s recollection of the event when he or
she is questioned about it. Several studies on the
effects of hypnosis on memory have produced results
consistent with this hypothesis. After exposure to
emotionally arousing stimuli, subjects with high lev-
els of hypnotic susceptibility showed an increased
tendency to fill in the gaps in their memories while
under hypnosis, taking information suggested by the
hypnotist or confabulating on their own.Robert K. BothwellSee also Cognitive Interview; Eyewitness Memory; Postevent
Information and Eyewitness Memory; Reconstructive
Memory; Repressed and Recovered Memories362 ———Hypnosis and Eyewitness MemoryH-Cutler (Encyc)-45463.qxd 11/18/2007 12:43 PM Page 362