Archive for the ‘phantom limb’ Category

Amputation Desire (BIID/Xenomelia) and the Human Experience of Self

Saturday, January 18th, 2014

Amputation desire 0222To say that amputees have phantom limbs and whole-bodied people do not is misleading. The so-called ‘phantom’ is the brain’s representation of the body, something everybody has. As neurologist Ronald Melzack put it, “the phantom represents our normal experience of the body.” [Melzack, 1989, p 4]

Amputees differ from other people in that they notice their phantom limbs, while the rest of us do not. They notice them because the corresponding limb of flesh and blood is missing. The difference between representation and reality is what makes the amputee’s phantom salient. The rest of us fail to notice our body phantoms because, when all is well, we cannot distinguish them from our bodies themselves.

I have started to think of the phantom as ‘the brain’s user interface to the body.’ It’s  a very good interface, one that might have been designed by a genius like Steve Jobs. It gives your brain exquisite control over your body while remaining utterly transparent to you, the user. Most people go through life without ever realizing that the interface exists.

The interface is so transparent, it only becomes visible at all when there are discrepancies between representation and  reality. In this blog, I’ve taken brief looks at two kinds of discrepancy: the phantom limbs which almost all amputees experience, and the rubber-hand illusion which allows an ordinary person to observe her phantom from a new perspective by tricking her brain into shifting the phantom from her real hand to an obviously fake, dummy hand. (more…)

Mirror Neurons for an “Exquisitely Social Species”

Thursday, February 16th, 2012

“A unifying neural hypothesis on how individuals understand the actions and emotions of others” was presented to the world in 2004 by neuroscientists Gallese, Keysers and Rizzolatti. Our understanding of other minds, they claimed, is facilitated by “mirror neurons,” so-called because they fire when an individual performs or observes an action, and when she experiences an emotion herself or observes that emotion in someone else. The authors described mirror neurons as a system that enables humans and other social primates to simulate each other’s behaviour and internal states, thereby enabling learning, communication, and prediction of others’ actions.

Humans are an exquisitely social species. Our survival and success depends crucially on our ability to thrive in complex social situations. One of the most striking features of our experience of others is its intuitive nature. This implicit grasp of what other people do or feel will be the focus of our review. We will posit that, in our brain, there are neural mechanisms (mirror mechanisms) that allow us to directly understand the meaning of the actions and emotions of others without any explicit reflective mediation. Conceptual reasoning is not necessary for this understanding. [Gallese et al, 2004, p 396]

The mirror neuron hypothesis sparked a storm of interest among scientists and philosophers concerned with the human mind. It sparked controversy too, with some researchers cautioning that the data vastly underdetermines the interpretation placed on it, and that animal studies have been extrapolated to conclusions about the human species. This caution is justified, but so is the excitement. The bare facts of what has been discovered so far are hard to reconcile with any hypothesis that could be considered boring, and the current pace of discovery suggests that we will soon know much more. If the Gallese/Keysers/Rizzolatti theory is even approximately right, neuroscience is giving birth to an intellectual revolution with the potential to profoundly change both scientific and common-sense understanding of how our minds work. (more…)

Metzinger on the Unreality of the Self

Saturday, April 2nd, 2011

In the last chapter of Being No One, Thomas Metzinger addresses the questions with which he introduced the book, a list that includes:

What is phenomenal selfhood?  What, precisely, is the nonconceptual sense of ownership going along with the phenomenal experience of selfhood, or of “being someone”?

In the discussion, he makes a striking comment related to the reality of the self.  If the phenomenal self-model (PSM) is “of a nonhallucinatory kind”:

…the system then represents certain aspects of reality as being parts of itself, and it does so correctly.   What it achieves is not only self-experience but self-knowledge. (Metzinger 2004, p 607)

In reading this passage, I wondered how Metzinger can reconcile it with his claim that ‘no such things as selves exist in the world.’   Here he says that the system represents itself to itself  by means of its PSM, and that it does so “correctly.”  Metzinger certainly admits that systems exist.  Are we not, then, such systems? (more…)

The Phantom Self

Thursday, December 10th, 2009

Parfit’s Glass Tunnel

Dali Phantom selfIn the Introduction to this project, I said:

It’s the strong – and I believe, irrational – hold that the idea of the self has over us, and particularly its role in motivating action, that led me to characterize it as the ‘phantom self’.  Like the Phantom of the Opera, the self has a powerful voice that demands to be obeyed.  Like an amputee’s phantom limb, it is a vividly felt presence – but there is nothing really there.

It is time to flesh out that characterization.

No contemporary philosopher – perhaps no philosopher ever, in the West – has done more to break the phantom’s grip than Derek Parfit.  In Reasons and Persons, Parfit argues persuasively that, although we are strongly inclined to believe that our continued existence is “a deep further fact, distinct from physical and psychological continuity”, that belief is not true.  He goes on to describe the difference this philosophical conclusion made to his own life.

Is the truth depressing?  Some may find it so.  But I find it liberating, and consoling.  When I believed that my existence was such a further fact, I seemed imprisoned in myself.  My life seemed like a glass tunnel, through which I was moving faster every year, and at the end of which there was darkness.  When I changed my view, the walls of my glass tunnel disappeared.  I now live in the open air.  There is still a difference between my life and the lives of other people.  But the difference is less.  I am less concerned about the rest of my own life, and more concerned about the lives of others. (RP p 281) (more…)

The Phantom Neuroscientist

Thursday, September 10th, 2009

Cubist KingIn recent weeks, I have been devouring V.S. Ramachandran’s books and videos on what can be learned about the brain by studying patients with neurological damage.  To clarify my title, Ramachandran is not a phantom himself, but a doctor of phantoms – actually a ‘phantom-buster’.  He is famous for curing phantom-limb syndrome – an amputee’s stubborn, often debilitating, physical awareness of a limb that has been surgically removed – by an amazingly simple, low-tech trick with mirrors.

The ‘Phantom-Buster’ Mirror Trick

One of Ramachandran’s patients was desperate for relief from pain in his phantom arm, which he felt to be cramped and paralyzed.  As described in A Brief Tour of Human Consciousness:

We propped up a mirror vertically on a table…so that it was at right angles to his chest, and asked him to position his paralyzed phantom left arm on the left of the mirror and mimic its posture with his right hand, which was on the right side of the mirror.  We then asked him to look into the right-hand side of the mirror so that he saw the mirror reflection of his intact hand optically superimposed on the felt location of the phantom.  We then asked him to try to make symmetrical movements of both hands, such as clapping or conducting an orchestra, while looking in the mirror.  Imagine his amazement and ours when suddenly he not only saw the phantom move but felt it move as well.

(more…)