Phantom Limb Research
(updated
11/25/09 --» What’s
new?)
Thank
you for your interest in our research on phantom limbs. In
September 2007, we conducted several experiments with a subject (M.G.)
who presented phantom limb sensations of the absent fingers of her left
hand. In August 2009, we conducted additional experiments. This
page contains a summary of our experiments and the results.
More detailed results are available on
request.
Contents
Comments on our work are welcome!
Please feel free to comment on our Discussion
Group on the Self-Conscious Mind.
Robert
and Suzanne Mays
What’s
new?
- 11/25/09 - expanded page
on Phantom
Limb Pain and Therapeutic Touch
- 11/17/09 - added information
about apparent involvement of peripheral nerves in phantom pain and
sensations of movement; split off cases of Therapeutic Touch use in
treating phantom
pain to a separate
page
- 11/08/09 - added
information
about Therapeutic Touch which apparently can be felt in the
phantom (like M.G.) and appears to alleviate phantom limb
pain; added note
to use galvanic skin response in conjunction with M.G. tests of “touch”
of an object.
- 10/03/09 - added
note to use a door or similar barrier in further double blind
experiments with M.G.
- 09/27/09 - clarified
subject’s reaction
to “touch” with
dizziness and headache, based on subsequent interview with subject
- 09/09/09 - reorganized page; added
summary research results from 2009 sessions; split off details of 2007
research
to a separate page
- 04/19/09 - set up page for public
access; added highlights of 2007 phantom limb research
sessions; restricted access to detailed experimental results page
- 04/07/08 -
earlier version
of page
Theoretical
motivation
In earlier work (Mays and Mays, 2008), we postulated that the self-conscious mind*
or simply mind
is an autonomous non-material entity, a
“field of consciousness”. Ordinarily, the
self-conscious
mind is
united with and operates through the mediation of the brain, but can
separate temporarily from the body in the near-death experience (NDE).
This view is supported by evidence from NDEs and from various
neurological phenomena. The NDE phenomena suggest that the
“field of
consciousness” separates from the body as an objective
independent
entity in the NDE and can engage in apparent subtle
interactions with physical processes (light, sound, surfaces),
including interactions with “in-body” persons. The
ability
to have subtle physical interactions
suggests that the non-material self-conscious mind is able to
interact in some
physical way with brain neurons.
A phantom limb is the vivid subjective experience of the presence of a
limb that is absent congenitally or through amputation. Since the
self-conscious mind,
in our view, is a spatially extended field, coextensive with the
physical body, then in the absence of a physical limb, a part of
the self-conscious mind will still project beyond the stump as
a
kind of “mind
limb” which is experienced subjectively as a phantom limb.
The spatial region of the phantom/mind-limb then should exhibit some of
the properties of the
“mind body” in
the NDE
out-of-body experience. In particular:
- Since the near-death experiencer (NDEr)
“body” appears to have subtle interactions with
physical objects causing a
subtle
feeling of resistance,
we would expect a subtle interaction when a physical object enters the
spatial region of the phantom, possibly causing physical sensations
within the body.
- Since the NDEr “body” can
sometimes interact with an “in-body” person (the
NDEr can touch another person and cause sneezing and can
“merge” with another person’s brain and
experience
what they are sensing and thinking), we would
expect a
subtle interaction of the phantom limb with another person’s
physical body, which could be felt by the other person.
- Since the NDEr can sometimes
“see” her own out-of-body form with luminous
limbs, can
“see” fellow NDErs, and can
be
“seen” by dogs,
we would expect that there might be a faint glowing of the phantom in
the dark. Interestingly, one phantom limb subject (A.Z.), a 44-year-old
university-educated woman born without forearms and without legs
(congenital tetramelia), stated, “In darkness, I have noted a
faint glowing of my phantom body parts” (Brugger, Kollias,
Müri, Crelier, Hepp-Reymond, and Regard, 2000).
Thus we would expect:
- Subtle interactions when a physical
object enters the spatial region of the phantom, possibly causing
physical sensations in the body, that, is, the ability to
“feel” an object;
- Subtle interactions of the
phantom limb with another person’s physical body, which could
be felt
by the other person, that is, the
ability to “touch” another person;
- A
faint
glowing of the phantom in the
dark, similar to reports by some NDErs of seeing their own
out-of-body
form.; and
- Since the self-conscious mind interacts
with neurons in some physical way, there will be some
physically detectable interaction of the phantom limb with physical
processes that could influence neural electrical activity.
To our knowledge, none of these types of interactions has been reported
in the phantom limb literature.
We have had the opportunity to work with subject M.G.,
a college educated woman born in 1952 with congenital unilateral
adactylia
(missing
five fingers of the left hand). In many respects, M.G. experiences her
phantom fingers in the same way other phantom limb subjects
do: M.G.
experiences proprioceptive sensations of them, subjectively they have a
normal shape but are “frozen”, they appear -- they
“light up” -- when they are thought
about, they
disappear when M.G. is not paying attention or is using her physical
left hand, and they sometimes feel “telescoped”
into the
upper arm near the shoulder. However, M.G. also appears to
exhibit three of the four expected properties:
- M.G. reports physical sensations in her finger
buds, palm and arm (tingling, warmth, pressure) when her phantom
fingers are “touched” by an object, by another person or by
her right hand. When her phantom hand is “massaged”
by a therapist passing her hand over the phantom hand during a massage,
M.G. feels the “touch” as tickling and she giggles.
- When “touched” on the head by M.G., other
people report feeling warmth and pressure, and seeing inner visual
images (e.g., a dark circle with a white ring of light) which are
reminiscent of visual sensations evoked by electrical brain
stimulation.
- M.G. reported in 2009 that she
has begun sometimes to “see” her phantom fingers as a faint
whitish or bluish light when held up against a dark background.
To date, we have not detected any evidence of purely physical
interactions
between her phantom fingers and a physical process.
In 2009, we learned that similar research on phantom limbs was first
proposed by Rupert Sheldrake
in his 1995 book Seven
Experiments that Could Change the World (1995,
2002). His proposed experiment #5, to test phantom limbs as a
phenomenon of the “extended mind”, is motivated
along very similar
lines as our own reasoning. For Sheldrake, the phantom limb is the
“morphic field” of the missing limb which generates the
form of the physical limb during embryonic development (and is thus
“morphogenetic”) and which holds the form during
the person’s life. If
the physical limb is amputated or was congenitally absent, the phantom
morphic field persists and is located where the person feels it to be.
The morphic field is physical (having detectable physical effects) but
is not material (made of matter).
To support his hypothesis that
phantom limbs have an objective reality, Sheldrake cites the phenomenon
of out of body experiences (OBEs). This is similar to our reasoning but
Sheldrake does not consider more detailed aspects of the phenomenon of
OBEs during NDEs. Also, Sheldrake’s primary experimental
approach is to
have a “sensitive” detect the presence of the
phantom by
“feeling” its
presence when the phantom is projected through an opaque surface such
as a door. Sheldrake proposes several other possible phantom limb
experiments including: the interaction of the phantom field with
various physical processes (as we have tested), seeing whether the limb
deficient person can feel the touch of someone else or an object (as we
have tested), having the phantom “touch”
other people
(as we are
testing) or “touch” a sleeping
animal, seeing whether
the phantom
can influence germinating seeds or the development of microorganisms,
and seeing whether the phantom can produce a Kirlian photograph.
* Our conception of the “self-conscious mind” is
different from that of
Karl Popper and John Eccles (1977) who also used the term in a dualist
interactionist theory of mind.
Research
summary
M.G.’s
phantom
fingers appear
to be a structured, dynamic but diffuse “field of
sensation” in the region
beyond her finger buds, where her fingers normally would have been. The
phantom limb field is experienced as a “streaming
out” from the finger
buds and has two regions of sensing: an outer arc about
14-18" beyond
the finger buds where weak physical sensations begin to be felt, and a
more definite finger
region a little beyond where her fingers would ordinarily
be, where M.G. feels the “ends” of her fingers are.
There are three apparent states
of M.G.’s phantom fingers:
- Retracted
or telescoped:
usually occurring during physical use of her left hand, where the
phantom fingers either are not sensed at all or are only felt vaguely.
The phantoms appear to retract or telescope in, perhaps as far as the
upper left arm, near the shoulder.
- Activated
or “lit up”:
usually occurring when M.G. focuses attention on the phantom fingers
but may happen spontaneously when the lower arm is in contact with an
arm rest. M.G. can also cause her phantoms to “light
up”
when she
begins to “touch” them with her right hand or when
she
tries to “touch” something with her phantoms. When
the
fingers are “lit up”
there is a sense of streaming out from the finger buds but there is no
definition of the finger “ends”.
- Focused:
usually occurring when M.G. “locates” or
“finds” the fingers by
touching and pulsing with the fingers of the right hand. M.G. appears
to find the streaming column of a specific phantom finger and pulses
it, following it down to where she feels the “end”.
This process is
done by following the sensations felt both in that finger’s
bud and
in the right-hand finger pad. There can also be accompanying sensations
going up the left arm, in particular “channels”,
and also a strong
feeling in a 2-3 sq. cm. area of the outer side of the upper left arm.
Once the finger(s) are focused, they can more readily
“touch” another
person or an object, or be “touched”.
In our
exploratory experiments with subject M.G. in September
2007 and August 2009, we found:
- M.G. can sense
the presence of
her left phantom fingers through interaction with the fingers of her
other hand, with another person’s body or with an
object’s surface. She
senses the presence through physical sensations such as warmth,
pressure or tingling in her left finger buds, palm, wrist, arm
or
other areas of her body. After M.G. has been using her phantom fingers
for a time in such “feeling” situations, her hand
usually shows increased skin color and
her finger
buds at times show observable twitching.
- M.G. can “touch” another
person (e.g., subject S.M.) and that person can generally sense the
interaction,
particularly if he/she is attending to the area being
“touched”. The
sensations experienced by the other subject can be warmth, a white
light, a shadow or
darkness, or a particular light pattern such as a dark circular disk
surrounded by
a white ring. The inner visual images are reminiscent of visual
sensations evoked by electrical brain stimulation as reported by Wilder
Penfield and others in the 1950s and 1960s (e.g., a brilliant ball, a
streak, a shadow, a light, etc. reported by Penfield and Rasmussen in The cerebral cortex in man,
1950;
colored spots, oblique lines and annuli or rings reported by Marg and
Dierssen in Confinia
Neurologica, 26:57-75,
1965).
- Subject S.M.’s responses when M.G.
“touched” the same
points on the back of the head in 2007 versus 2009 were somewhat
similar (in two cases S.M. gave very close to the same wording).
However, the points appeared weaker with fewer visual
sensations,
which was probably due to not having M.G. follow a fixed
procedure to “prepare” her phantom
fingers. Also as M.G. grew
tired during a long session, her phantom fingers appeared to weaken,
both subjectively to M.G. and objectively in the sensations felt by the
other subject..
- Two out of six subjects in addition to
S.M.
reported similar responses to
S.M.’s visual responses, with
striking
and sometimes complex visual experiences. Visual sensations are
generally enhanced when the subjects eyes are closed. Where we tried to
repeat “touching” the same point more than once,
the subject reported
similar responses in each instance.
- Different subjects report different physical
reactions, generally characteristic of the subject, including strong
sensations of warmth or a sensation of water cascading over the head, a
few cases of sharp, almost painful sensations, a sense of the head
being pushed to one side, the eyelid twitching, the ear
“popping”, and
the stomach “growling” as a response. The
responses for
different subjects appear to have different latencies of responding,
ranging from about 4 seconds to sometimes longer than 30
seconds. Frequently, strong
sensations were reported lingering for several minutes after the trial
ended. One subject
reported experiencing
a strong headache starting right after the session,
that appeared related to dizziness felt during the session. Subject
took ibuprofen and had a nap in the afternoon but still felt headachy
and went to bed early. Headache was resolved in the morning. It is not
entirely clear if the headache was causally
connected to the“touch” interaction, since
subject had only 3-4 hours’ sleep the night before.
- We tried two preliminary blinded trials of
randomized “touch” and “no
touch” cases,
providing immediate feedback to the
subject (n=6 and n=7). The two subjects got nearly perfect scores
detecting a phantom finger touch versus a control (a leather mitten
held on a yard stick). The subjects’ perceived strength of
sensation
also corresponded well with M.G.’s perceptions of the
strength of the
“touch”. In both of these cases, the strength of
the
sensations was
generally weak to strong. The sensations were not visual but rather a
tingling or pressure or a sense of the head being rotated. Further work
needs to be done to validate a proper control for the “no
touch” case,
such as the glove held at a distance, that does not result in false
positives.
- M.G. had numerous reactions and sensations
while
“touching” other subjects, including a strong sense
of
warmth or light
when working on what she felt were “strong” points
on the
other subject
and twice heard a tone. M.G. noted many times that what the
other
subject reported corresponded or correlated to her own specific
experiences. In some cases, M.G. felt that she had
“touched” and “felt”
the other person’s brain within their skull. We also noted
that M.G.
frequently had nasal congestion after a particularly
“strong”
“touching” trial and
had to blow her nose.
- We have tested possible physical interactions
three ways so far, all with negative results:
- Interaction
with fog
generated from dry ice and warm water. This experiment was motivated by
the story of an NDE involving apparent interaction of the
NDEr’s
“body”
with fog
on a cold night. The NDEr jumped up and down and the “jumping
fog” was
seen by another man. M.G.
activated her phantom fingers as usual and placed her
hand in the dry ice vapor. There was no effect at all. The situation in
the
NDE was somewhat different in that the NDEr’s
“movements” were
involved and M.G. is not able to move her phantom fingers, which are
“frozen” in position.
- Interaction
with light
in an interferometer.There was no perceptible change in the
interference pattern when M.G. placed her phantom thumb within the
laser light of either leg of the interferometer or when
she “touched” the
laser spot on the splitting mirror.
- Interaction
with a physical object:
We arranged an interferometer with one of the mirrors suspended from
two threads such that any slight movement would cause the laser light
to go out of phase. There was also no perceptible change in the
interference pattern when M.G. “pushed” her thumb
and other fingers
against the mirror.
- To
the
level of precision and care that we were able to accomplish with this
apparatus, we detected no effect of interaction of the phantom finger
regions with laser light or with a physical object. It is very possible
that measurable effects could be detected with more precise equipment
or a better constructed arrangement.
Conclusions: The
phenomena
studied to date strongly suggest that M.G.’s phantom fingers
have an
objective reality and act as a field beyond her physical palm and
finger buds. M.G. reports that she can “feel” an
object
when it “touches” her phantom fingers. Other
subjects
report unusual sensations
when their head is “touched” by M.G.’s
phantom
fingers.
M.G. reports
that she can sometimes “see” her phantom
fingers when she looks at them
against a dark background. Preliminary blinded trials of
“touch” and “no touch” have
yielded results
that are promising.
Note: all subjects
in these experiments gave informed
written consent
to participate in the experiments. All subjects were 18 years or older,
except one subject, age 17, whose parent gave written consent.
Research
results
PLEASE NOTE:
The
videos and photographs on this page are copyrighted and are presented
here to assist
other researchers to analyze our research and provide comments. The
videos and photographs are not to be copied, saved or republished
without express written permission of the authors.
Research
results page
- Physiological
condition of M.G.’s left hand adactylia (2007)
- Locating
and
mapping phantom finger “ends” through right finger
“touching” (2007)
- Preliminary
tests of M.G.’s
sensations when
“touched” by an object (2007)
- Preliminary
tests of
M.G.’s interactions with different areas of another
subject’s
face (2007)
- Tests
of
M.G.’s interactions with different points on the back of the
head (2007)
- Tests
of
M.G.’s interactions with a different subject (2007)
- Comparison
of interactions
with S.M. on the same points, 2007 versus 2009
- Different
subjects also reported complex
visual experiences (2009)
- Subjects
had a wide range of sensations and
physical reactions (2009)
- Preliminary
blinded trials of randomized
“touch” and “no touch” cases
(2009)
- M.G.’s
own sensations and physical
reactions
during the tests (2009)
- Tests
of possible physical interactions with
M.G.’s phantom fingers (2009)
Access
to
detailed research results
For privacy
considerations for M.G.
and the other subjects, we wish to
provide access to the more extensive, detailed experimental results only to those people with a
legitimate research interest. If
you are in this category, please contact
us for access details. We also welcome your comments and can
provide further details upon request.
Discussion
In our experiments with M.G., we found preliminary evidence supporting
both the phenomenon of “feeling” and the
phenomenon
of “touch”. M.G. reports physical
sensations when her
phantom fingers are “touched” and presents observed
physiological reactions. Other people report subtle but definite
physiological sensations when “touched”, as well as
distinct inner visual images. The phenomena of M.G.’s phantom
fingers
suggest that they are a “field of sensation” that
can both experience “feeling” a touch and can
itself
“touch”.
Apparent
objective reality: M.G.’s subjectively
experienced phantom limb has an apparent objective reality: (1)
“touching” physical objects evokes physical
sensations in the finger buds, in the left palm and along the left arm,
and presents objective physiological reactions (increased skin color,
twitching of the finger buds); (2) “touching”
another person evokes subtle but definite physiological sensations
(warmth, pressure in the head and sinuses) and distinct, unusual inner
visual images, the effects of which can linger for several minutes.
M.G. also reports
that she can sometimes “see” her phantom fingers
when she looks at them
against a dark background.
Additional
evidence: Additional phenomenal evidence supports the view
that the phantom limb has objective spatial reality extending beyond
the physical body.
1. Similarity of
“touch” with electrical brain
stimulation: The inner visual images evoked by
“touch” by M.G. are reminiscent of visual sensations evoked
by electrical brain stimulation as reported by Wilder Penfield and
others in the 1950s and 1960s: for example, a brilliant ball, a streak,
a shadow, a light, etc. reported by Penfield and Rasmussen (1950);
colored spots, oblique lines and annuli or rings reported by Marg and
Dierssen (1965). We observed that the visual imagery appeared to occur
only when the “touch” was directed (even
inadvertently) toward the second subject’s brain. This
suggests
that the imagery results from an interaction between
the phantom finger and the second subject’s
brain.
2. Reported visual perception of
phantoms: M.G. reports she can sometimes
“see”
her phantom fingers as a faint
whitish or bluish light when held up against a dark background, when
she is focusing (pulsing) her phantom fingers with a finger of her
right hand. Phantom limb subject (A.Z.),
a 44-year-old university educated woman born without forearms and
without legs (congenital tetramelia),
also stated, “In darkness, I have noted a faint glowing of my
phantom body parts”
(Brugger, Kollias, Müri, Crelier, Hepp-Reymond, and Regard,
2000). Such apparent direct
“perceptions” suggest an objective reality but
could also be explained as “suggestibility” or
“wishful thinking”.
3. Apparent
involvement of peripheral nerves in phantom pain and in sensations of
movement: M.G.
reports physical sensations in her left finger
buds and palm and up her left arm (tingling, warmth, pressure)
when her phantom
fingers are “touched” by an object, by another
person or by
her right hand. These sensations suggest direct involvement of afferent
nerves in the physical hand and arm. Stephen Klein and colleagues
(2004) reported that a female double leg amputee normally experienced
constant bilateral phantom sensations of her feet, accompanied by
sharp, stabbing, and throbbing pain at a 6 on a verbal 0-10 pain scale.
The patient underwent a procedure to drain an abscess on the right leg
stump and received a sciatic anesthetic nerve block. The sciatic nerve
was located with a nerve stimulator medially from where the stimulator
elicted a hamstring motor response. Upon stimulation of the sciatic
nerve, the patient reported movement of her phantom foot which appeared
to flex in coordination with the 2-hertz stimulator signal. Nine
minutes after the anesthetic block was administered, the patient
reported reported, “There ’s
no
pain and my foot is numb”. About 24 hours after the block, the
sensation returned in her phantom foot as well as the usual phantom
pain. Both the motor and proprioceptive sensations (movement, pain
reduction and numbness) accompanying the sciatic nerve stimulation and
nerve block strongly suggest peripheral nerve involvement in
phantom limb sensations.
Nikolajsen and Jensen (2001) reported more general
observations that (1) phantom limb sensations
can be modulated by stump manipulations, temporarily abolished by local
stump anesthesia, or altered by changes in stump blood flow, (2)
injection of gallamine (which increases neural sodium conductance) near
a neuroma produces phantom pain whereas a sodium channel blocker
injection blocks phantom pain, (3) stump revisions that remove
tender neuromas often reduce phantom pain at least transiently, (4)
phantom pain is significantly more frequent with long-term stump pain
and (5) altered cutaneous sensibility in the stump is a very common
feature associated with phantom pain.
It is interesting that while this case and these observations suggest
peripheral nerve
involvement in phantom limb pain, ablation or transsection of the
relevant nerves in the stump, spinal cord, thalamus or cortex
generally do not
result in elimination of the phantom limb pain. Such procedures for the
most part have been abandoned (Nikolajsen and Jensen, 2001).
4.
Therapeutic Touch (TT) treatment apparently can be felt in the phantom
and
appears to alleviate phantom limb pain: M.G. reports that
when
her phantom fingers are massaged
by a therapist passing her hand over the fingers,
M.G. feels the “touch”
as tickling and she giggles. There are
numerous reports by amputees that they can “feel”
the touch of a therapist in their phantom limb during Therapeutic Touch
and that the “sweeping”
movements of TT over the phantom limb area relieves their phantom limb
pain. More details of these reports are given in Phantom Limb
Pain and Therapeutic Touch.
5. Tactile sensations follow
subjectively felt movement of phantom
hand: One reported subject (F.A.) had his right arm
amputated 8 cm below the elbow after a boating
accident. F.A. showed a striking ability to move his phantom at will.
He experienced a referral
of sensation on the face and at two different arm locations, on the
stump and the biceps, which formed
two complete “maps” of his phantom hand. When F.A.
subjectively rotated (pronated) his phantom
hand to the left, the touch sensation of the biceps map shifted 1.5 cm
to the left (toward the
body) and shifted back on return to the original hand position. As a
demonstration of this, if a drop of
water was placed, say, on the pinkie finger region on the arm, when
F.A. rotated the phantom hand, he felt
the water moving from the pinkie to the ring finger
(Ramachandran, 1993a, p. 10419; 1993b, p.
65). The movement of the phantom hand maps with pronation and the
movement of the sensation of the water
drop from one phantom finger to the adjacent one suggest that the
“field”
of phantom sensation has a direct, objective mapping to the arm,
consistent with an objective spatial reality.
6. Use of functional prosthetic
devices reduces phantom limb pain: The
active use of functional prostheses, such as myoelectric or Sauerbruch
prostheses, has been
found to be positively correlated with reduced
“reorganization” and reduced phantom
limb pain (Lotze, Grodd, Birbaumer, Erb, Huse, and Flor, 1999; Karl,
Mühlnickel, Kurth, and Flor, 2004;
Weiss, Miltner, Adler, Bruckner, and Taub, 1999). The use of a cosmetic
prosthesis did not result in reduced
phantom limb pain. Reduced cortical
“reorganization” and pain with the use of
a functional prosthesis suggest that the active use of the prosthesis
“focuses” the objective phantom limb
back to its correct location, relative to the physical body. If this
interpretation is correct, then phantom limb pain would
at least in part be due to an “unfocused” or
“deformed”
post-amputation phantom.
7. Mirror therapy for phantom
limbs reduces phantom limb pain:
Ramachandran and Diane Rogers-Ramachandran (1996) described a novel
treatment for phantom pain
using a “virtual reality” mirror box, in which a
mirror image of the intact limb is superposed on
the phantom limb. The patient makes mirror symmetric movements with
both hands and generally
experiences vivid sensations of movement in the muscles and joints of
the phantom. When the eyes are
closed or the mirror is removed, the patient’s phantom arm
remains frozen as before. The
visual feedback of movement in response to volitional motor commands
restores phantom limb movement and
sensations. If the phantom hand has been clenched or frozen, it can be
unclenched and the related
pain is relieved. In general, the phantom pain is reduced or eliminated
following a number of short
mirror-box sessions and in some cases the phantom recedes completely
(Ramachandran and
Rogers-Ramachandran, 1996; Chan, Witt, Charrow, Magee, Howard,
Pasquina, Heilman, and Tsao, 2007).
With training in these movements, a dramatic increase in motor cortex
(M1) activation was
detected in some subjects, with a corresponding decrease in pain.
Subjects not showing the increase in
motor cortical activation had little or no pain relief. The effect of
the phantom limb
“movement” in conjunction with a mirror or
computer-generated image in reducing pain is consistent with a
“refocusing” of the objective phantom limb to its
correct location.
8. Delays in sensation/latency
imply unusual involvement of neurons:
The referred sensations in phantoms are not exactly like normal touch
or temperature sensations,
because there is a 2-3 second latency before the sensation is felt in
the phantom hand, and when the
stimulus is removed, an “echo” of the sensation
persists for 8-10 seconds afterward in the phantom.
The sensory latency and echo, of course, do not occur in the direct
touch sensations from the direct
stimulus to the face or arm (Ramachandran, 1993a). These phenomena
suggest that adjacent pathways,
which are neurally close together to the hand at points along the path,
for example in the
thalamus (cf. Ramachandran, 1993a, p. 10418; Grüsser, Winter,
Mühlnickel, Denke,
Karl, Villringer, and Flor, 2001, p. 270), are involved in an unusual
“crossover” or
“induction” of neural impulses. Since the referred
sensations appear within hours or days of the amputation, they are
unlikely to be due to
new neural synaptic growth. One possible mechanism that could drive
such crossover of
impulses would be a “mind body” which works through
the neurons, which then must reorganize when the
normal neural pathways no longer function, and “take
over” other pathways.
The alternate pathways end in other parts of the physical body. If the
actual cross-over involves physiologically
adjacent neurons, then the phantom/mind-limb will “refer
to” regions that are
cortically adjacent, such as the stump and the face, in the case of an
arm amputation.
Alternate
Explanations
From
our view of the autonomous self-conscious mind,
wereason as follows. Since the self-conscious mind is
a spatially extended field, coextensive with the physical body, then in
the
absence of a physical limb, a part of the self-conscious mind will
still project beyond
the
stump as a kind of “mind-limb” which is experienced
subjectively as a
phantom
limb. The spatial region of the phantom/mind-limb then should exhibit
some of
the properties of the self-conscious mind “body” in
the NDE out-of-body experience,
such as subtle interactions when a physical object enters the spatial
region of
the phantom, possibly causing physical sensationsin the body,
and subtle
interactions of the phantom limb with another person’s
physical body,
which
could be felt by the other person.
In
our experiments with M.G.,
we found preliminary evidence supporting both of these properties:
- M.G.
reports physical sensations in her
finger buds, in her left palm, along the left arm and in a specific
spot in her
upper left arm, when her phantom fingers are
“touched”, and presents
objective physiological reactions (increased skin color, twitching of
the
finger buds).
- Other
people reported subtle but definite physiological
sensations (warmth, pressure in the head and sinuses, unusual inner
visual
images) when “touched” on the face or back of the
head by
M.G.’s
phantom fingers. The visual images include shadows, light, dark circle
with
white ring, gradually progressing oblique white lines forming a
sword-like
shape, gradually forming channel rising from abdomen up and ending with
bright
white light in the head, and arcs of colored light rising up with
changing
colors.
The phenomena of subject
M.G.’s
phantom fingers suggest that there is a “field of
sensation” that can
both experience “touch” and can itself
“touch”. However, there are
alternate explanations for these phenomena that should be examined.
The
physiological sensations M.G. feels
The
physiological sensations M.G. feels could be due to (1) suggestibility/imagination
(the power
of suggestion generates thought associations that prompt imagined
states that
are experienced); (2) proprioceptive or other neural interaction
between the right-hand fingers and the left-hand finger
buds; (3) sensations evoked by
focus
of attention (e.g. sensations of streaming,
“touching”); (4) body
image projections from the brain
generate the “fields” that are sensed; (5) cortical
reorganization: sensory pathways from the missing limb are
taken over by
cortically adjacent neurons; (6) “psychic
impressions” or images received through other
means.
These
alternate explanations do
not fully explain how an object entering a region well beyond the
physical
body, out of the subject’s sight, can elicit subjective
sensations and objective
physiological changes, when the subject’s reactions have none
of the character
of “psychic impressions” or images. However, to
achieve consistent results,
future “touch” experiments will require more
rigorous controls and
double-blinding.
The
sensations of other subjects who are “touched”
The
sensations that other subjects who are “touched”
appear to feel could be due to: (1) researcher
bias since the subjects were the researchers themselves who
may have had
unconscious expectations or biases; (2) focus
of attention on a specific area evokes the sensations; (3) single-blind experimenter bias where
the experimenter subconsciously influenced the outcome; (4) suggestibility/imagination
(thought
associations prompt imagined states appearing as
“experiences”); (5) subjects
are in a meditative state where
such
visual experiences can occur; (6) “healing
energy” sent from M.G. causes the images; (7) some other faculty in M.G.
is causing the reactions, not her phantom fingers.
The
first three explanations can
be addressed by more rigorous control of the experiment, with
additional
subjects and double blind controls. Additional subjects have now been
tested and show similar sensations as reported by S.M. and R.M. In
addition, the sensations have been shown to be generally repeatable
when the same point is “touched”
during a session. Subjects
are told
in
general terms what sorts of sensations or experiences might occur.
Otherwise,sensations that are actually experienced may be
overlooked or
dismissed as irrelevant. The subjects do not appear to have been
influenced by the instructions, in that they reported a wide variety of
sensations including those which were not mentioned as possibilities.
The next three alternate explanations do not
fully
explain the fact that (1) all of the inner visual images that were
experienced
in these experiments were completely unexpected and novel; (2) the
images could
not be self-evoked later (e.g. in meditation); (3) some of the
sensations were very
strongly felt, such that there was no doubt that the sensation
occurred; (4)
M.G. felt no sense of “sending”, only of
“touching”.
The last explanation requires more testing: what is experienced when
M.G. simply stands behind the subject, what is experienced when M.G.
uses her right
hand to “touch”
the subject, and what is experienced when another person tries to
“touch”
the subject in the way M.G. does? This explanation does not square with
the observed fact that the reactions appear to be causally linked to
M.G.’s left hand, with the response
sometimes coming very quickly (1-3 sec) after the start of
“touching”.
If the effects are coming from some unusual power to evoke visual and
other strong physiological sensations in a person, one would expect
other people to exhibit this ability without a missing limb. We are not
aware of any report of this sort of paranormal power.
Papers
on phantom limb research
Poster presentation
at Toward
a Science of Consciousness conference
(Tucson
2008)
Phantom limb
“touch” suggests that a
“mind-limb” extends beyond
the physical body
Robert Mays,
Suzanne Mays (Chapel Hill,
NC)
Abstract:A
phantom limb is the vivid subjective experience of
the presence of a limb that is absent congenitally or through
amputation.
The phenomenon of phantom limb “touch” has not been
reported to our
knowledge. We have completed exploratory experiments with subject M.G.,
a
56-year-old, college educated woman with congenital unilateral
adactylia
(missing five
fingers of the left hand). In many respects, M.G. experiences her
phantom
fingers in the same way as other phantom limb subjects. However, she
also reports
physical sensations in her finger buds, palm and arm (tingling, warmth,
pressure) when her phantom fingers are “touched” by
an object or by
her right hand. When “touched” on the head by M.G.,
other people
report feeling warmth and pressure, and seeing inner visual images
(e.g., a
dark circle with a white ring of light) which are reminiscent of visual
sensations evoked by electrical brain stimulation,
In earlier
work (Mays and Mays, 2008), we postulated
that the self-conscious mind is an autonomous “field
of
consciousness” which ordinarily is united with and operates
through the
mediation of the brain, but which separates from the body in the
near-death
experience (NDE). This view is supported by evidence from NDEs and from
various
neurological phenomena. NDE phenomena include apparent subtle
interactions with
physical processes (light, sound, surfaces), including interactions
with “in-body”
persons, suggesting that the non-material self-conscious
mind is
able to interact in
some physical way with brain neurons.
Since the
self-conscious mind in this view is
a spatially extended field, coextensive with the physical body, then in
the
absence of a physical limb, a part of the self-conscious mind will
still project beyond
the
stump as a kind of “mind-limb” which is experienced
as a phantom
limb. The spatial region of the phantom/mind-limb then should exhibit
some of
the properties of the self-conscious mind “body” in
the NDE out-of-body experience,
such as subtle interactions when a physical object enters the spatial
region of
the phantom, possibly causing physical sensations in the body,
and subtle
interactions of the phantom limb with another person’s
physical body,
which
could be felt by the other person.
In our experiments with M.G.,
we found preliminary evidence supporting both of these properties. M.G. reports physical
sensations in her
finger buds, in her left palm, along the left arm and in a specific
spot in her
upper left arm, when her phantom fingers are
“touched”, and presents
objective physiological reactions (increased skin color, twitching of
the
finger buds). Other people reported subtle but definite physiological
sensations (warmth, pressure in the head and sinuses, unusual inner
visual
images) when “touched” on the face or back of the
head by
M.G.’s
phantom fingers. The visual images include shadows, light, dark circle
with
white ring, gradually progressing oblique white lines forming a
sword-like
shape, gradually forming channel rising from abdomen up and ending with
bright
white light in the head, and arcs of colored light rising up with
changing
colors.
In this
paper, we present the
detailed phenomenology of phantom limb “touch” and
address alternate
explanations.
Keywords: phantom
limb; mind-limb; dualistic interaction; tactile
sensation; brain stimulation
The poster paper is located
at http://selfconsciousmind.com/papers.html
as
a PDF file (3.3MB, 12 pages).
Further
investigations
- Run mirror box with M.G. to see whether she can
come to “move” her phantom fingers
- Test
“touch” of objects by using a palm down
orientation to “anchor” the phantom fingers plus
randomized double-blind
testing of “touching” an object. Include galvanic skin response test on
left hand (e.g. back of hand and palm or wrist) during these tests.
- Repeat
key “touching” experiments from earlier sessions
(subject S.M. and others)
- Validate
that the
sensations felt are from M.G.’s phantom fingers and not an
effect from
M.G.’s standing next to the subject or using her right hand.
- Run double-blinded
“touch”/“no touch” tests with
several subjects
- Videotape
possible interactions with sleeping animals (suggested by Sheldrake
(2002))
- Encourage
other
researchers to test other phantom
limb subjects experiencing this phenomenon
- Enhance our
model phantom limb phenomena as the
result of the interaction of the self-conscious mind with the brain and
body
Further
changes:
- We
need to screen potential subjects for health problems, in particular
neurological problems, to avoid any potential problems that interaction
with phantom limbs and the head might cause.
- We need to give better instructions as to how
to
score the strength of the sensations for a trial point: it is the
strength of the most prominent sensation experienced; sensations
include all modalities: warmth, pressure, tingling, visual sensations,
etc.
- We should set up double blind conditions which
include a “barrier”
such as a closed door between M.G. and the other subject, which will
eliminate or significantly reduce ordinary sensory cues (sound,
peripheral vision, sense of M.G.’s
presence). There will probably need to be a window (glass or other
material) in the door so M.G. can see what she is doing. (We are
grateful to Rupert Sheldrake for this suggestion.)
- When we run double blind experiments, part of
the set
up will be to adjust the timing of the steps of the procedure to give
enough time for the latency of the sensations,as observed in the
preliminary tests
. In some subjects, the latency is <10 sec but in others it can
be
>30 sec. If we don’t allow for sufficient latency,
there will be
false negatives or very weak sensations felt.
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