Ockham’s Razor
Is it really me? A question of bodily integration and identity
Professor John Bradshaw, a neuropsychologist from Monash University in Melbourne, has a neurological explanation for a not uncommon phenomenon, that of experiencing the powerful and disturbing sensation of someone watching us or standing behind us, whether or not there is really someone there.
Robyn Williams: Are you being watched? From behind? By someone, or something you never see? Can't say it's an experience I've had, but perhaps I'm not very interesting. Of course Rupert Shelldrake has a paranormal explanation, and a book to go with it, but this program, in the spirit of our mentor, William of Ockham, prefers to be sceptical.
Which is where John Bradshaw comes in. He's Australia's answer to Oliver Sacks and a record-breaking contributor to these talks. And he has neurological explanation or two to offer.
John Bradshaw: Nearly 50 years ago, when just beginning student life, I had two curious experiences, which bear in an interesting way upon what I have to say today about certain phenomena relating to one's personal or corporeal identity and individuation.
In the first, I was looking out of the window of a 16th century building wherein I shared a sitting-room with a fellow undergraduate. We gazed idly down into the Fellows' Garden and saw the eminent philosopher and head of our college, Warden Mure, strolling pensively, presumably deep in metaphysical thought, and with hands clasped behind his back, amongst the famous lines where Tolkien had composed 'The Lord of the Rings'. Sadly these same trees are now felled because of fears of litigation and liability. We wondered whether, by force of united but silent will-power, we could get him to stop, turn and look behind him. The very moment we commenced willing, he indeed stopped, turned abruptly but looked back up to our very window. Such was our embarrassment at the apparently successful transfer of thought process that we immediately dropped down out of sight, and only later wondered whether it was coincidence, rather than a successful demonstration of the occult. And yet, as sceptical scientists or credulous commoners alike, I'm sure we have all experienced the powerful and disturbing sensation of someone watching us, or standing behind us, whether or not there is really someone there.
Later that year, on a winter vacation walking with a friend on the fells of England's Lake District, we found ourselves early one frosty morning high upon the exposed ridge of Striding Edge. The sun, at head level, had only recently risen over an adjacent valley to our left, while to our right was a bank of fog rising high above the next valley. On the edge of this fog bank I saw an image of myself, surrounded by a beautiful halo, purple radiating out into concentric bands through all the spectral colours. I could not see my companion, who also could not see me. When I raised my camera to capture this doubly-spectral image, the image did the same. This was the rare phenomenon of the so-called 'Brocken Spekter', named eponymously after the highest peak in the German Harz mountains, a range renowned in Teutonic folklore. We had each met our Doppelganger, our double; however this uncommon meteorological circumstance of precise alignment of illuminating sun, viewer and a projection screen of wine water droplets (which provided the prismatic effects) did not of course lead to instant mutual annihilation, as the fable held, like the meeting in modern physics of matter and antimatter. After all, the phenomenon had a sound basis in meteorology and optics. Can we similarly explain our apparent sensation of being watched from behind?
In a very recent article in the august and usually sceptical science journal, Nature, the authors note that the anomalous sensation that someone is nearby, when there is nobody, has often been reported by psychiatric and neurological patients, as well as by healthy individuals, but the exact mechanisms of this illusion, or is it really a hallucination? - are not well understood. The authors describe the repeated induction of this sensation in a 22-year-old woman, of normal psychiatric history, who was undergoing focal electrical stimulation on the left temporoparietal junction of the brain, as evaluation for possible surgical treatment of epilepsy. The illusory person apparently just behind her closely shadowed or mimicked changes in her own posture or body position. Temporoparietal regions are known to be involved in the integration of multisensory body-related information, the self-versus-other distinction, and other illusory own-body perceptions. Interestingly, the patient did not recognise that the apparent being was an illusion of her own body, projected into extra-personal space. Similarly, many patients with schizophrenia, with hyperactivity in these same temporoparietal regions, may misattribute their own actions to some other individual or agency, and suffer from delusory feelings of alien control.
One of my early graduate students, who later progressed to a cabinet position in the Federal Government, once described to me an Out-of-the-Body experience she had during a prolonged and painful dental procedure. As so often in such accounts, when the individual has been exposed to a period of great stress, threat or pain, she seemed to be looking down upon herself lying in the dental chair. Rather than there being an illusory shadow person lurking behind her, she seemed, from a different vantage point, actually to be looking at herself. A prominent Swiss group of neurologists recently proposed that such autoscopic hallucinations (literally, in Greek, 'seeing yourself') are two variants of an apparent reduplication of one's own body and self. In the former, an exact mirror image of oneself, occasionally only of one's face or bust, is perceived visually. In heautoscopy proper, one is confronted by one's own double, or Doppelganger, which may or may not exactly mirror one's immediate appearance, but is nevertheless felt to be one's double. Frequently, heautoscopic echopraxia, or the imitation by the double of one's own bodily movements, gives the impression that one's real identity actually resides in the double. Focal brain lesions of the temporo-parieto-occipital junction may precipitate the phenomenon, as may extreme pain, discomfort, or stress in the otherwise healthy.
Maybe we should in fact distinguish between classical Out-of-the-body experiences (where the individual has the impression of seeing a second, own, body, out in extrapersonal space) from autoscopic hallucinations (where one sees a double of oneself, not necessarily looking or behaving completely identically, out in extrapersonal space without leaving one's own body) and from heautoscopy. In the last, one again sees oneself out in extrapersonal space, but cannot easily decide whether or not one is disembodied. In fact such individuals may claim that they experience seeing the world from two simultaneous or alternating perspectives. In all such instances, there are varying levels of failure at integrating visual, tactual, vestibular and kinaesthetic information. Thus the various senses no longer agree as to bodily position and posture.
While there is no reason to suspect psychiatric disturbance in instances of heautoscopic hallucinations, or Out-of-the-Body experiences, this is not usually true of the group of syndromes collectively known as subjective doubles where someone else is believed to have been transformed into oneself, or another person is believed to have taken on the physical characteristics and identity of oneself.
If, under certain circumstances, it is as if our personal or corporeal identity can somehow be copied, can the opposite occur? Clearly, the complete phenomenal disappearance of one's entire corporeal self would be extremely counter-intuitive, though with cut-out syndrome, patients may claim that they are in fact already dead. However patients with asomatognosia typically describe parts of their body as temporarily or permanently missing from corporeal awareness, generally with preservation of full insight; they are surprised and disturbed by the experience. This year a middle-aged woman, without neurological or psychiatric antecedents, described how when sitting in front of her computer she unexpectedly felt dizzy and found that the lower extent of her left arm was no longer to be seen. Indeed, much to her surprise she seemed to see the table through the arm; she could see her arm only above the elbow, with a clear-cut demarcation or border at the apparent termination. Gradually, after some minutes, there was progressive restoration of the whole limb. Such asomatognosia, or failure to perceive parts of one's own body, is to be contrasted with the phenomenon of unilateral neglect, where it may be more a matter of failure to recognise one's body parts, typically on the left, though both syndromes seem to involve the same parietal lesions. Both conditions, however, have as their phenomenological obverse the common experience of many amputees, the so-called 'phantom limb phenomenon', which I and my group are currently investigating. Here, there may be a powerful illusion of the continuing existence, complete with pain or itching, of an amputated and no longer present member.
Asomatognosia may therefore be considered a loss of embodiment of a real limb, and the phantom limb phenomenon as the persisting embodiment of a missing limb. Motor mechanics using such tools as a screwdriver often describe sensations of roughness or vibration as being localised at the very end of the tool, as a sort of extended embodiment of the actual hand or arm. Functional brain imaging confirms that in such expert tool users, there is indeed an apparent extension in the brain map of the limb, so as to encompass the tool as an actual part of that limb. Illusory embodiment may also be experienced by anyone with the 'rubber hand' illusion. If one's right arm, say, is concealed from view and replaced by an apparently identical rubber replica in full view, and which adopts a position (perhaps via a system of mirrors) and posture as similar as possible to that of the real, concealed arm, and if the rubber arm is seen by the subject to be gently stroked by the experimenter, then there is often a powerful illusion of touch or tickle.
In light of such considerations, what are we to make of the recently-described phenomenon of apotemnophilia? The Greek literally translates as 'a desire for amputation', and is best illustrated by a typical case report, published last year, of a male, married with a child, who successfully sought to have his leg surgically amputated above the knee, as he had always felt somehow incomplete or 'wrong' with two normal arms and legs, and believed that the amputation would paradoxically make him more 'whole'. According to a recent survey of 34 individuals recruited from the internet, most who now have their own website, are male, and may often report a sexual component. They are frequently well-educated, involved intimate relationship and have long harboured hidden desires, often back to childhood, for an amputation, 'so as to restore my true identity'. In a substantial minority of instances, they may have attempted self-amputation via a variety of dangerous procedures such as use of shot guns, chain-saws, wood-chippers, dry ice (as with one of our own correspondents) or lying on rail-road tracks. Those desiring a leg amputation far outnumber those wanting an arm removal; amputation was typically sought on the left side, though some wanted it done bilaterally. Given the close proximity in the brain of those cortical areas mapping and controlling functions of the lower leg to those representing the genitals, while the upper-limb mapping is adjacent to that of the face, one wonders about the underlying role of possible emotional and sexual drives. However it is noteworthy that the majority of the individuals displayed no significant psychiatric symptoms apart from a preoccupation with amputation. The study's author suggests that the condition may best be conceptualised as an extremely unusual dysfunction in the development of one's fundamental sense of corporeal identity or integrity, and proposes the label 'Body Integrity Identity Disorder'. Certainly those who have somehow succeeded an amputation under proper surgical conditions typically report themselves as delighted with the result.
Bodily integrity and identity clearly may be disturbed at various levels, wholly or in part, with or without psychiatric or neurological involvement. The French philosopher, Descartes, over 300 years ago, declared 'Cogito, ergo sum', 'I think, therefore I am', in his search for a proof of personal existence. However our corporeality is clearly fragile and potentially easily disturbed; so too, of course, is the apparent unity of our mental and cognitive processes, whatever the views of Descartes. How often do we say 'One part of me wants to do this, while another wants to do that'? But that of course, is another story, for another time.
Robyn Williams: John Bradshaw, who's still being watched. He's Professor of Neuropsychology at Monash University.
