Split-brain subjects talk about themselves using the first-person, singular, pronoun. Of course, by hypothesis, it’s always just one of two split-brain thinkers doing the talking. (In some subjects, R seems to have learned to speak a bit, but never in whole sentences.) Still, this thinker and speaker—L—consistently uses the first-person pronoun to refer to anything either L or R has done. Granted, L may often say, of R’s actions, “I didn’t mean to do that” or “Why did I do that?” or “I must have done it unconsciously.” But L never says, of R’s actions, “She did it” or “Why are you asking me—ask the right hemisphere guy!” (I suspect that this is largely what neuropsychologists have picked up on when they spoke of split-brain subjects’ social normalcy, by the way, and one could think of this as a respect in which split-brain behavior is “unified”.)
I assume that if L began using the third-person (or the second-person) pronoun to refer to actions that have their origins in RH processing, our immediate impressions of split-brain personal identity would change: it would start to pre-theoretically seem that there were two psychological beings speaking out of one mouth. And if R could speak in turn similarly used the first-person to refer to only its own actions, and the second- or third-person to refer to L’s actions, the impression would grow stronger.
This does not happen, however. And here there is a further significant challenge for the duality claims. If R and L really are distinct thinkers, then why do they appear not to recognize each other’s existence? Of course, it is harder to judge, decisively, whether or not R recognizes L’s existence, since again R doesn’t issue I-statements. L does, however, and L does not seem to recognize R’s existence. Why does L assume it’s the “only one home”? Obviously one possibility is: because there is no R and no L after all—psychologically speaking, there is just S!
Later chapters in the book, then, are devoted first to laying out and next to explaining, consistently with the duality claims, respects in which self-awareness and self-consciousness remain unified after split-brain surgery, and finally to using facts about self-consciousness after split-brain surgery to defend the unity claim: that a split-brain subject is one person.
In what sense is self-consciousness unified after split-brain surgery? After all, if R and L are distinct thinkers, and if some of their thoughts are self-conscious thoughts, then split-brain self-consciousness will of course be dual in one sense. Indeed, I argue that R and L are distinct thinkers of distinct I-thoughts. But the way I put it in the book is to say that self-consciousness doesn’t operate, after split-brain surgery, in the way that it operates within and between two non-split thinkers—human beings—interacting with each other. In particular, R and L don’t use their I-thoughts to distinguish themselves from each other as thinkers; neither, for instance, thinks of itself as an object of the other’s thought.
The basic reason for this is that R and L are co-embodied. The ordinary grounds of self-distinction exploit the non-overlap between the one body about which I receive privileged information (e.g. via proprioception) and over which I exert proprietary control (the body directly moved by my intentions) and all the other bodies that I can perceive. But R’s knowledge of R’s body is not privileged relative to L, because R’s body is also L’s; L’s control over L’s body is not proprietary, relative to R, because L’s body is also R’s. Presumably, R and L could distinguish themselves from each other on theoretical grounds—but not on the immediate pre-theoretic basis that grounds the ordinary and very basic capacity for self-distinction that is an inherent part of self-consciousness as we know it.
The book’s argument for the unity claim appeals to this capacity for self-distinction. Though it is a very primitive capacity, it is also capacity that persons, specifically, necessarily have, in part because this capacity makes possible specifically interpersonal life. But the capacity for self-distinction is also a very basic element of the kind of self-consciousness that is required for personhood. This self-consciousness is not only the ability to think about oneself as the thinker of one’s own thoughts; it’s the ability to think about oneself as the object of others’ thoughts.
R and L lack this capacity for self-distinction, not all together, but only with respect to each other: that is, they can distinguish the split-brain subject as a whole, S, from everyone else, but they cannot distinguish themselves from each other, because of the very high degree to which they are co-embodied. As a result, they lack the capacity to relate to each other as or to live as distinct persons. And instead, they relate to each other and to other parties as parts of one person. Again, lacking the capacity to distinguish themselves from each other, they cannot do otherwise. Ultimately, this makes them jointly constitute one person.
One way to put the thought is that R and L must (together) be one of us because the two together are not two of us. That is, multiple persons are capable of jointly constituting certain kinds of social entities that R and L together cannot constitute
Hi Elizabeth,
It is an interesting post.
Schechter: One way to put the thought is that R and L must (together) be one of us because the two together are not two of us. That is, multiple persons are capable of jointly constituting certain kinds of social entities that R and L together cannot constitute.
Vimal: R and L as a whole (RL) are greater than the sum of parts (R+L): is this correct? If this is true then why R and L together cannot constitute certain kinds of social entities?
Cheers!
Kind regards,
Rām
———————————————————-
Rām Lakhan Pāndey Vimal, Ph.D.
Amarāvati-Hīrāmaṇi Professor (Research)
Vision Research Institute Inc, Physics, Neuroscience, & Consciousness Research Dept.
25 Rita Street, Lowell, MA 01854 USA
Ph: +1 978 954 7522; eFAX: +1 440 388 7907
rlpvimal@yahoo.co.in; https://sites.google.com/site/rlpvimal/Home
https://www.researchgate.net/profile/Ram_Lakhan_Pandey_Vimal
Researched at the University of Chicago and Harvard Medical Schools
Hi Ram,
Thank you for your question!
So, often when philosophers speak about self-consciousness, they speak about it in terms of introspection and as significant primarily for enabling people to scrutinize and evaluate their own motives and reasoning and so on. And obviously self-consciousness (of the sort required for personhood) IS significant (to say the least) for this reason. But I argue that self-consciousness of the relevant sort is also a kind of social capacity, one that enables people to think of themselves (and their motives and reasoning and so on) as the object of *others’* scrutiny and evaluations. Note that this is why people are apt to behave somewhat differently when they (think they) are alone, unobserved. If you try to imagine life and culture without this aspect of self-consciousness–well I can’t do it. Maybe one foothold into this is to try to imagine human life without the possibility of common knowledge–but again, if I pause to try to do it, I can’t. I mean I start to just imagine us as being like rather clever cats or something. Because I’m no longer imagining us as persons.
Obviously one basic element of or pre-condition for this kind of self-consciousness is self-distinction. (And self-distinction is a VERY basic capacity–even cats can do it!) I can’t feel shy or embarrassed in front of you–or annoyed at you for your mere presence making me feel shy or embarrassed–if I don’t distinguish between us, but rather see both of us as me.
Multiple persons are capable of relating to each other (in thought and in action) as multiple persons–as potential objects of each other’s evaluations, for instance. But R and L aren’t capable of relating to each other in this way. Instead they can only relate to each other as parts of one person–R can no more feel shy or embarrassed in front of L than I can feel shy or embarrassed in front of my left hand.
Now depending on what you mean by “social entities”, R and L together–S, the split-brain subject as a whole–might still constitute a social entity of some kind. I think S is a kind of group entity, anyway. But the claim is that persons are capable of jointly constituting *special* kinds of social entities–social entities structured by mutual recognition: by each constituent member’s recognizing the others as distinct thinkers and indeed distinct self-conscious thinkers. That’s what R and L together cannot constitute.
Hi Dr. Schechter, thank you for your posts.
It seems to me that we all exhibit some version of this phenomenon. None of us have a ‘self’ in the brain. Instead, the brain is a community of neurons, interacting with each other. The concept of ‘self’ is a model that describes the brain’s function to itself, in order to help keep straight that brain/body’s relationship to the outside world. I don’t and can’t see my community of neurons as ‘us’ because it would presumably be bad for my survival if I didn’t recognize all of my brain and body as ‘me’.
In truth, our brains have nodes that work directly against each other, both activating and inhibiting the same functions. This is to create a feedback system that tends toward balance and homeostasis. As Whitman said, ‘I contain multitudes’. But those internal contradictions are just experienced as ‘voices’ or ‘sides of my personality’. We recognize some conflict, especially when it comes to things like our ‘will to diet’, but internally, it’s all evened out as part of ‘me’.
So it seems reasonable to me that the split-brain patient is laboring under the same mechanism and the same illusion, the one which collapses all internal distinction into a fictional singular model of self. Their brains are just trying to rationalize the same kind of internal division that we normals do, but to an even greater extent.
Dear Matt (if I may),
Thanks for your comment! If I understand correctly, part of what you’re implying is that even if it were true that split-brain subjects have two minds apiece, as I argue, it wouldn’t be surprising for neither of these minds/thinkers to fail to recognize this fact and to instead identify the whole animal and all its behaviors as “me” and “mine.” I’ve fielded questions from a lot of people who don’t agree, and think that *they* would surely notice if they were one of only two conscious thinking agents within their body. But how? Sure, from each thinker’s perspective, it often does something it doesn’t want to do, says something it doesn’t want to say–or, if there is interhemispheric unity of emotional experience, feeling something that seems to come from out of nowhere. But while they should experience this much more than a non-split subject would, it’s arguable that it’s not a novel kind of experience. As you say, “internal contradictions are just experienced as ‘voices’ or ‘sides of my personality’.”
Of course in the split-brain case the *internal* aspects of the contradictions won’t even be experienced (at least for the most part)–neither R nor L can introspect the potentially conflicting desires or thoughts or intentions of the other. (There’s an interesting paper by Nishikawa et al., 2001–I’ll give the reference below–on some cases of organic callosal damage–not destroying the entire corpus callosum–in which there does seem to be awareness of conflicting desires and intentions to act.) If consciousness and introspection are themselves divided by split-brain surgery, all either thinker should be aware of is of the performance of *actions* contrary to its intentions. How out-of-control of your behavior would you have to feel in order to think that there was *literally* a second thinker sharing your body? Even people really struggling with addiction (you mention the “will to diet”)–quitting and then using and then quitting again, all within the course of hours, over and over again–don’t draw that conclusion. They just think, “What is wrong with ME?”
I will also note that R and L in a split-brain subject might be especially unlikely to recognize each other’s existence relative to R and L in a non-split subject (that is, if you performed split-brain surgery on a theretofore neurotypical human being, her R and her L might be a little more likely to recognize each other). Split-brain surgery was performed on people who were experiencing very severe epilepsy and severe impairment because of it. If you think about experiencing seizures over and over again, and you can’t stop them or control them and nothing seems to work (until the surgery)–this was a population that is used to feeling less in control of their behavior and even (in some sense) their mental lives. And even in the case of a heretofore neurotypical subject who undergoes split-brain surgery–the fact of having undergone *neurosurgery* offers another explanation for the disunity they seem to be experiencing.
Thank you for your reply, Dr. Schechter.
You mention ” How out-of-control of your behavior would you have to feel in order to think that there was *literally* a second thinker sharing your body? ”
And I think that’s essentially what schizophrenia is, kind of the reverse syndrome from what you described with the split-brain patients. Even though the perceived ‘inserted thought’ is generated by the schizophrenic’s brain, it is missing some sort of metadata tag which says: “this is mine” or “I did this” and therefore it is perceived as coming from outside of the schizophrenic’s brain.
So in the case of split-brain patients (or all of us with a community of neurons in our heads), we perceive ‘I’ when the cognitive structure is more like ‘we’.
But with a schizophrenic, they perceive ‘me + not me’ from the same kind of community.
Same thing with somebody with anarchic hand syndrome. The movement of the hand is done by ‘me’ (i.e. my community of neurons) but for some reason the metadata of ownership is missing from the behavior, and thus, the hand seems to be moved by someone else.
All of which suggests that ‘consciousness’ is not an intelligence or a driving force in any way. That’s all handled by the community (or in the case of your subjects, by the two hemispheres), and is not perceived directly.
Rather ‘consciousness’ is a story the brain tells itself, about what ‘I’ did and felt and thought. For the sake of simplicity, the self-representational system that we call ‘consciousness’ has cheated, and developed a perceived ‘self’ that feels responsible for every action of the community, even self-contradictory ones. But that self is only a convenient fiction, useful for the sake of narrative and learning.
In non-neurotypical brains, like schizophrenics and people with anarchic hand syndrome, their perception is missing the unification of self, and so the perception feels quite out-of-control and distressing.
So, all of this makes me wonder what split-brain patients think of all this philosophy people are doing about them. I mean, if I read a book about how I was actually two people, even if I had previously never felt like that, it would… well, it would put me into an interesting frame of mind. Trying to discern the influence of my body-mate in the movements of my other hand… then thinking ‘hang on, which body-mate am I?’, etc.
(I mean, I take it that at least some people are pretty suggestible about the idea of another intelligence moving their body – cf. Ouija boards, hidden-observer hypnosis, some religious experiences, people who may be schizophrenic or may be sub-clinical but still feel like they ‘hear voices’. I have a suspicion there may be a significant element of individual variation here, but then you’d expect at least some split-brain patients to have the susceptible sort of personality.)
I think there’s another important take-away from Dr. Schechter’s work, which is that the self is confabulated.
We neurotypicals do not perceive the community of neurons. Split-brain patients do not notice the two separate hemispheres. And L’s self-stories ignore the odd contradictory things that R does, in favor of an entirely fake story of self-unity.
In other words, the ‘self’ within perception is not, in any way, equivalent to the community of neurons. The neurons actually enact behavior, but the self within perception is only an after-the-fact construct, and is based upon assumptions and incomplete inputs.
Surely, this is true of all us. We are constantly confabulating our perceived selves, and are just guessing at our actual motivation for behavior.
Descartes said “I think, therefore I am”. But in reality, it was a community of neurons that did the thinking, and the fictional self-perceived Rene that Descartes thought was incontrovertible, was really just an after-the-fact attempt to make sense of what that community was already doing.
And a follow-up question for Dr. Schechter: do you know whether the surgery that split the corpus collosum also split the hippocampal commissure?
The reason why I ask is that if the two hippocampi are still connected, then episodic memories would be formed, with information from both hemispheres. Thus, any retrospection by the split-brain patient would involve looking back at the episodic memory flow, and finding both hemispheres represented within the memory.
So even if the split-brain patient cannot have internal communication between the two hemispheres in real time, his/her rcalled memories would include a confabulated, unified self within them. Thus any retrospect should fool the subject into the illusion of self-unity.