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Could There Be Several Persons “In” One Body?

As Shakespeare once put it: “This above all: to thine own self be true”[i].  It is through our selves, our personal identity that we remember the past and look to the future.  But is our notion of self or personal identity as secure as we like to believe? After all, what is self?  Is it corporeal, spiritual, singular?  The main purpose of this essay is to discuss whether notions of self can be extended to allow for the concept of having more than one ‘person’ in one physical body, or even no person at all.  For the duration of this essay I shall be ignoring notions of soul, and assessing the problem though a purely physicalist viewpoint.  I shall examine this issue through three specific medical problems, firstly Korsakov’s syndrome and its effect on human personality, secondly those who have had the two hemispheres of their brain split, and finally the example of Multiple Personality Disorder.

However, before we can begin to discuss whether it is possible to have several persons in one body, we must establish a criteria for talking about personal identity.  Locke gave one such definition:

“And as far as this consciousness can be extended backwards to any past Action or Thought, so far reaches the Identity of that Person; it is the same self now it was then; and ‘tis by the same self with this present one that now reflects in it, that the Action was done.”[ii]

Because I have a sense of continuity of self, I feel that I can say that it was me that performed an action many years ago.  We have both physical continuity as in the example of the oak tree that grew from an acorn) and mental continuity of some form.  Nevertheless, does any claim to continuity of self boil down to memories alone?  Consider this quote from someone who was suffering from a mental wasting disease:

“You have to begin to lose your memory, if only in bits and pieces, to realise that memory is what makes our lives.  Life without memory is no life at all… Our memory is our coherence, our reason, our feeling, even our action.  Without it we are nothing…”[iii]

So, if we consider someone who is a close friend, who is slowly having his memories erased, when would we start claiming that this corporeal body in front of us is no longer our friend?  Is memory the sole criteria for personal identity?  After all, without it, we could have no claim to continuity, no claim to be a cohesive being. 

Therefore, my first step towards fulfilling this essay would be to see if it is possible to have no person at all in a body, for if memory is the sole criteria for personal identity then someone without it could not be considered to be a self.  This introduces the problem of people with ‘Korsakov’s syndrome’, which is a neurological disorder related to alcohol abuse where there has been neurone destruction in mammillary bodies in the brain, but the rest of the brain has been left intact.  One case, cited by Oliver Sacks, talks of Jimmie, a man who has total amnesia back to when he was 19.  The curious thing in these cases is that the patients are unable to establish new memories; in this case Jimmie permanently thought it was 1945.  He had no memory of what he did even 5 minutes ago, and although not in a permanent state of confusion, did experience occasional disorientation.  He had lost twenty years of his life and was not even aware of it:

“Jimmie both was and wasn’t aware of this deep, tragic loss in himself, loss of himself.  (If a man has lost a leg or an eye, he knows he has lost a leg or an eye; but if he has lost a self – himself – he cannot know it, because he is no longer there to know it.)”[iv]

In this case, where continuity of memory accounts for personal identity, what can we make of someone like Jimmie?  Is he a person?  He has no memory and no continuity, his lives entirely according to who he was decades ago. However, as another neurologist commented:

“A man does not consist of memory alone.  He has feeling, will, sensibility, moral being... It is here... you may touch him, and see a profound change.”[v]

So if a person is not entirely made from his or her continued memory, or consciousness of self, we should also look to the physical make-up of his or her brain for an idea of ‘person’.

One interesting medical discovery was due to the results of brain bisection on patients with epilepsy.  These people had had the left and right hemispheres of their brain separated from each other, so although previously both sides had been able to work together transmitting information across the corpus callosum, they subsequently became separated from each other.  A series of tests were run on these patients, to see whether lateralisation had any effect on their abilities or consciousness:

“The results are as follows. What is flashed to the right half of the visual field, or felt unseen by the right hand, can be reported verbally.  What is flashed to the left half-field or felt by the left hand cannot be reported, though if the word ‘hat’ is flashed on the left, the left hand will retrieve a hat from a group of concealed objects if the person is told to pick out what he has seen.  At the same time he will insist verbally that he has seen nothing.”[vi]

What is most interesting here, to us, is that the patient will correctly follow instructions with one part of the body, while denying receiving any instructions at all.  This shows that two streams of consciousness can be observed.  So, although these people will be able to continue to function normally unless the two hemispheres are artificially segregated, they still experience problems.  At times they have a sense of not being in control of their own body, and in split brain monkeys it has been possible to observe the hands producing a tug of war effect between them: 

“One woman whose brain had been surgically split found, for example, that it often took her hours to get dressed in the morning because her alien hand kept trying to dictate what she should wear…  Once her left hand had got hold of something it would not let go, and she, of course, had no way of making it obey her conscious will… Interestingly, the clothes selected by this woman’s alien hand were usually rather more colourful and flamboyant than those the woman had consciously intended to wear.”[vii]

Could these people be considered to be more than one person?  According to the memory criteria they would not, as they have one, singular, stream of memory and personal identity.  It could be considered that they just have one mind but that since the content derives from both hemispheres it is just a little dissociated, or that the patients have two separate minds, one of which that can talk, the other which cannot.  This all depends on where ‘consciousness’ resides.  If it is the whole of the brain which causes consciousness, then either they have split partial consciousness or none at all.  Or, if as may yet be discovered, there is a specific part of the brain for the purpose of consciousness, one side may be considered conscious and the other not.  Wherein, then, lies the person, are they just the summation of their own memories and therefore one person, or physically split and therefore two different persons?

Another example is that of the clinical case of Multiple Personality Disorder, which although still not medically verifiable, is still relevant to the discussion at hand.  Although there is nothing in the studies of MPD to rule out its possible existence, all the work so far has been mostly theoretical, and arguably biased in favour of the scientist’s own theories.  The most famous study is that of Eve White, who complained of having memory lapses or blackouts, while her family reported no such thing.  Whilst under observation, the two scientists involved Thigpen and Cleckley, ‘discovered’ three distinct personalities.  They performed tests which showed different mental abilities according to which of her three personas was in charge, and “The three personalities were subjected to electroencephalogram studies, and it was possible to make a clear distinction between the readings of Eve Black and the other two personalities.”[viii]  This is the part which may convince people that this disorder may exist.  It convinced those doing the study:

“They remained convinced that they had witnessed three personalities within the same body.  They noted that this observation created as many problems as it solved, not least of which was the question of what we mean by personality.  In everyday speech we refer to dramatic changes in personality with phrases like ‘he’s a new man’ or ‘she’s not herself’… So, maybe our personalities are not as fixed or stable as we like to believe.”[ix]

So, the philosophical notion of personal identity has example of such cases to question whether it is possible for more than one person to exist in one physical body.  However, this does still depend on the definition of personal identity that is in operation.  Using the naïve notion of personal identity, which states that it is reducible to bodily identity, we would see that in almost all cases there can not be more than one person in one body, although the case of split-brain patients may be relevant here.  If we are using a behaviourist approach, to measure whether there is more than one person in a body, we would need to observe whether there are noticeable behavioural differences in the MPD patients, or even the tug of war effect in the split-brain patients.  If we use the memory based criteria, then people with Korsakov’s do not have a self, split-brain patients are just one self, and those with MPD cause problems as they do not appear to have a continuous stream of consciousness.  In all of these cases there is one continuous history linking to their bodies, which would infer that since there is one body there is one person.  After all, on the street you would assume that anyone you meet is just one person, and not less or more.

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[i] William Shakespeare, Hamlet, Act1 Sc3 l.76
[ii] John Locke, An Essay Concerning Human Understanding, Oxford University Press 1975, p335
[iii] Luis Bunuel
[iv] Oliver Sacks, The Man Who Mistook His Wife For A Hat, Picador 1986, p34
[v] A.R.Luria, Neuropsychology of Memory, New York 1976
[vi] Jonathan Glover (Ed), The Philosophy of Mind, Oxford University Press 1976, p115
[vii] Rita Carter, Mapping The Mind, Weidenfeld and Nicolson 1998, p49
[viii] Philip Banyard, Introducing Psychological Research, Macmillan Press 1996, p205
[ix] Philip Banyard, Introducing Psychological Research, Macmillan Press 1996, p206

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hi

bev on March 18, 2003 10:27 AM

hi bev

bev on March 18, 2003 10:27 AM