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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:
  1. 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;
  2. 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;
  3. A faint glowing of the phantom in the dark, similar to reports by some NDErs of seeing their own out-of-body form.; and
  4. 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:
  1. 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.
  2. 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.
  3. 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
  1. Physiological condition of M.G.’s left hand adactylia (2007)
  2. Locating and mapping phantom finger “ends” through right finger “touching” (2007)
  3. Preliminary tests of M.G.’s sensations when “touched” by an object (2007)
  4. Preliminary tests of M.G.’s interactions with different areas of another subject’s face (2007)
  5. Tests of M.G.’s interactions with different points on the back of the head (2007)
  6. Tests of M.G.’s interactions with a different subject (2007)
  7. Comparison of interactions with S.M. on the same points, 2007 versus 2009
  8. Different subjects also reported complex visual experiences (2009)
  9. Subjects had a wide range of sensations and physical reactions (2009)
  10. Preliminary blinded trials of randomized “touch” and “no touch” cases (2009)
  11. M.G.’s own sensations and physical reactions during the tests (2009)
  12. 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
  1. Run mirror box with M.G. to see whether she can come to “move” her phantom fingers
  2. 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.
  3. Repeat key “touching” experiments from earlier sessions (subject S.M. and others)
  4. 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.
  5. Run double-blinded “touch”/“no touch” tests with several subjects
  6. Videotape possible interactions with sleeping animals (suggested by Sheldrake (2002))
  7. Encourage other researchers to test other phantom limb subjects experiencing this phenomenon
  8. 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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