An actual or apparent exaltation of the perceptive faculties,
or superacuity of the normal senses, characteristic of the hypnotic
state. It has been observed frequently in hysterics. They
may feel a piece of wire on their hands as heavy as a bar of iron.
The smallest suggestionwhether given by word, look, gesture,
or even breathing or unconscious movementis instantly
seized upon and interpreted by the entranced subject, who for
this reason is often called sensitive.
The phenomenon of hyperesthesia, observed but wrongly
interpreted by the early magnetists and mesmerists, was largely
responsible for the so-called clairvoyance, thought reading,
community of sensation, and other kindred phenomena. In its
manifestation, hyperesthesia is often difficult to distinguish
from telepathy or clairvoyance. Theoretically the dividing line
is that hyperesthesia is a peripheral perception. Telepathy or
clairvoyance is a central perception that does not reach us
through the sensory organs. In practice it is difficult to decide
whether the perception takes place through the sensory organs
The realization of a relationship between suggestion and hyperesthesia
by Alexandre Bertrand and James Braid brought
hypnotism into the domain of scientific fact. The significance
of hyperesthesia in connection with every form of psychic phenomena
can hardly be overestimated. Nor is it found only in
the trance state. It enters into the normal existence to an extent
that is but imperfectly understood. Dreams, for instance, frequently
reproduce impressions that have been recorded in
some obscure stratum of consciousness, while much that we call
intuition is made up of inferences subconsciously drawn from
indications too subtle to reach the normal consciousness.
Hyperesthesia has been defined as an actual or apparent exaltation
of the preceptive faculties, modern scientists being
unsure whether the senses are actually sharpened or not. Most
probably the hyperesthetic perception is merely a normal perception
that, through cerebral dissociation, operates in a free
field. Very slight sense impressions may be recorded in the
brain during normal consciousness but other impressions may
inhibit them from reaching the conscious mind.
Gilbert Murray conducted telepathic experiments by placing
himself in a different room from the sensitive and having
a sentence spoken to him in a very low voice. The sensitive in
the other room reproduced the sentence. The British Society
for Psychical Research considered this a case of telepathy.
Charles Richet considered it exceptional auditory hyperesthesia.
Similarly, the sudden movements that save people from
falling objects in the street may be attributed to subconscious
hearing of an almost inaudible sound that generates and sends
an urgent impulse to the motor centers.
Hyena Encyclopedia of Occultism & Parapsychology 5th Ed.
Emile Boirac recorded interesting cases of tactile and visual
hyperesthesia. His subject read with his fingertips in complete
darkness. Being bandaged, his back turned to Boirac, but holding
his elbow, he could also read if Boirac passed his own fingertips
along the lines of a newspaper. It did not make the least
difference if Boirac closed his eyes. (See also Eyeless Sight.)
Another subject could tell the time from a watch wrapped up
in a handkerchief. A Mme. M., before the Medical Society of
Tamboff, told the colors of 30 flasks wrapped in paper and
placed under a thick cloth. Further complicating the issue,
Mme. M. could also taste by the sense of touch.
James Braid found the olfactory sense so acute in some hypnotic
patients that by the smell of a glove they could unhesitatingly
and unerringly detect its owner in a large company. It is
questionable whether auditory hyperesthesia could explain the
astounding phonic imitations he observed, such as patients repeating
accurately what was spoken in any language, or singing
correctly in a language they had never heard before. Braid
A patient of mine who, when awake, knew not the grammar
even of her own language, and who had very little knowledge
of music, was enabled to follow Mlle. Jenny Lind correctly in
songs in different languages, giving both words and music so
correctly and simultaneously with Jenny Lind, that two parties
in the room could not for some time imagine that there were
two voices, so perfectly did they accord, both in musical tone
and vocal pronunciation of Swiss, German, and Italian songs.