Tuesday, December 14, 2010

on the definition of the Theory of Mind

According to the APA's dictionary, the theory of mind (ToM) is defined as:

[T]he ability to imagine or make deductions about the mental states of other individuals: What does the other individual know? What actions is that individual likely to take? Theory of mind is an essential component of attributing beliefs, intentions, and desires to others, specifically in order to predict their behavior.

The idea of ToM derives from Premack and Woodruff's 1978 article titled "Does the chimpanzee have a theory of mind?". They showed the short vieotape to a chimpanzee, in which a human actor was struggling in a cage to obtain bananas that were out of reach and inaccessible. And then they offered her a pair of the photographs, one constituting a solution to the problem (reaching out of the cage with a rod) and the other not. She could steadily choose the correct one. The chimpanzee seemed to be able to read the human actor's intention.

They wrote:

[I]n saying that an individual has a theory of mind, we mean that the individual imputes mental states to himself and to others (either to conspecifics or to other species as well). A system of inferences of this kind is properly viewed as a theory, first, because such states are not directly observable, and second, because the system can be used to make predictions, specifically about the behavior of other organisms.
[Premack, D. G. & Woodruff, G. (1978). Does the chimpanzee have a theory of mind? Behavioral and Brain Sciences, 1: 515-526. p.515]

In another part they also wrote:

[I]n assuming that other individuals want, think, believe, and the like, one infers states that are not directly observable and one uses these states anticipatorily, to predict the behavior of others as well as one's own. These inferences, which amount to a theory of mind, are, to our knowledge, universal in human adults.[ibid. p.525]

So, we can find two reasons here, for those they named 'theory' one's ability to infer another person's mental states and to predict his/her behavior.

1. mind is invisible or inaccessible

The mind is not directly observable. No one has direct access to the mind of another. One needs to infer what another knows, thinks, and wants based on a kind of theory.

2. behavior is readable or predictable based on ToM

But the same mind is readable based on the theory of mind. ToM, like other scientific theories or principles, makes us possible to predict the other's behavior.

The notion of ToM has these two presumptions in the background. But are they correct? The other mind is something invisible and hidden inside and what we can do is only to infer his/her mental states and to predict his/her behaviors based on an abstract theory?

It is sure that this is a variation of the classic problem of the other mind, which has been discussed in the philosophy after Descartes' mind-body dualism. If the mind should be separated from the body, we have to find the other's mind behind his/her actions. In order to understand the other, we need to infer the mental states from his/her movements of the body.

Saturday, December 11, 2010

IHSRC 2011

I received an information on a conference of phenomenological psychology from Dr. Tsuneo Watanabe of Toho University.

30th International Human Science Research Conference (IHSRC 2011)
Intertwining body-self-world
27-30 July 2011
Open University/Oxford University, UK

Look at the webpage. The conference theme 'Intertwining body-self-world' sounds very attractive for those who studies Merleau-Ponty. I'd love to be there and present my ideas.

Wednesday, November 17, 2010

the hard problem recasted

In the context of neuroscience and consciousness studies, the 'hard problem' has been discussed. The hard problem of consciousness is "How and why certain physiological or neural processes give rise to subjective and conscious experiences?".

Obviously, this is a modern and modified version of Cartesian mind-body dualism. Hard problem asks the link between
the physical (mechanical activity of the brain) and the mental, after dividing them into two properties. The hard problem, on the one hand, set the mental and the physical in opposition to each other. But on the other hand, it tries to reduce the mental to the physical.

As Thompson (2007) points out, we need to recast the hard problem by focusing on a kind of phenomenon that is already beyond this gap, the life. Life is the living organisms (physiological body), but also the living subjectivity in the phenomenological sense (the lived body). Life=Body appears as a material thing and also a living and feeling being. Thus he recasts the 'mind-body problem' as 'body-body problem'.
[Thompson, E. (2007). Mind in Life: Biology, Phenomenology, and the Sciences of Mind. Harvard University Press]

One and the same body has two modes of appearance. They are known in German as Körper (material body) and Leib (living body). Thinking phenomenologically, this is one possible answer to the mind-body problem.

Wednesday, November 10, 2010

a symposium on Yasuo Yuasa

Next month, in the 20th conference of the Society for Mind-Body Science (December 11-12th), there is going to be held an academic symposium on Yasuo Yuasa.

December 11th, 2010
Rinri Bunka Center, Tokyo, JP
"Yasuo Yuasa's thought and mind-body science"

Yasuo Yuasa (1925-2005) was one of the leading Japanese philosophers in the field of mind-body theory.

His thought encompasses traditional Buddhist thought, Japanese modern philosophy, phenomenology, psychoanalysis. In his main work "The Body: Toward an Eastern Mind-Body Theory", he presented a new framework to understand the importance of Asian mind-body theory and meditation practice from modern perspective.

Kasulis, who edited "The Body", writes as follows in his editor's introduction;

[T]hrough Yuasa's discovery, we can better grasp the nondualism central to so many Asian traditions. In conceiving an integration of body and mind, the various Eastern philosophers undercut such Western dichotomies as spirit-matter, subjectivity-objectivity, and theory-praxis. The Asian philosophers are not merely posing an alternative metaphysics. In fact, they are not doing metaphysics at all in the traditional Western sense. Instead, their task is what Yuasa, following C. G. Jung, calls metapsychics, an approach examined in detail by this book.
[Yuasa, Y. (1987) The Body: Toward an Eastern Mind-Body Theory. State University of New York Press., p.2]

Friday, November 5, 2010

schizophrenic delusion and alien hand syndrome

It is well known that schizophrenic patients often report that their own actions are controlled by others or some outside forces. These actions can be trivial such as opening a door or writing letters. There are also more complicated types, such as "They inserted a computer in my brain. It makes me turn to the left". It is obvious that patients have a kind of delusion of control.

On the other hand, there is a similar neurological disorder which is known as 'alien hand' or 'anarchic hand' syndrome. It is associated with damage to the supplementary motor area in the cortex. The hand contralateral to the lesion performs goal-directed actions which are not intended by the patient. Sometimes the 'alien' hand interferes with the actions which the 'good' hand is trying to do.
[see Feinberg, T. E. (2001) Altered Egos: How the Brain Creates the Self, Oxford U. P.]

Frith et al. compare these symptoms and point out the important difference between them as follows;

[T]he patient with an anarchic hand recognizes that his hand is performing actions that he has not intended....But he does not conclude that his hand is being controlled by alien forces. In contrast, the patient with delusions of control carries out the actions he intends....and yet, at the same time, he experiences these actions as being made for him by alien forces.
[Frith, C. D. et al. (2000). Explaining the symptoms of schizophrenia: Abnormalities in the awareness of action. Brain Research Reviews 31: 357-363]

The difference is interesting enough. The patient with an alien hand don't have the sense of control of his 'alien' hand, but he still has the normal sense of ownership of it. Instead, the patient with schizophrenic delusion can control his movements but he doesn't have the normal sense of body ownership.

This suggests a lot of things to think about our sense of body ownership and our sense of agency for action.

Wednesday, October 27, 2010

Descartes' inconsistency

There is a well-known inconsistency in Descartes' mind-body theory.

On the one hand, Descartes stresses the importance of mind-body dualism. He writes, "My mind, by which I am what I am, is entirely and truly distinct from my body, and may exist without it". But on the other hand, he also insists on the mind-body unity. "I am not only lodged in my body as a pilot in a vessel.... I am besides so intimately conjoined, and as it were intermixed with it, that my mind and body compose a certain unity".(both quotations are from his MEDITATIONS)

These two points seems in contradiction. But what Descartes argued is that the mind and the body are conceivable in isolation from each other in principle. However, as a matter of fact, the mind is always rooted in the body through sensations, emotions, desires, and never be separated from it. According to him, the 'principle' of mind-body relation should be different from the 'fact'.

Is this a persuasive argument?

Sunday, October 24, 2010

anomalous body experience in depersonalization

According to Sierra (2009), the anomalous body experiences in depersonalization can be subdivided into several related concepts:
[Sierra, M. (2009). Depersonalization: A New Look at a Neglected Syndrome. Cambridge University Press.]

- Lack of body ownership feelings; In contrast to the rubber hand illusion, patients with depersonalization are difficult to have the sense of body ownership. They experience parts of their body or the totality of it as alien. One patient describes, 'I see my legs and hear footsteps and feel the muscles but it feels as if I have no body'.

- Feelings of 'loss of agency'; Patients complain about the absence of agency feelings. Their behavior feels automatic and robotic. 'I would notice my hands and feet moving, but as if they did not belong to me and were moving automatically'. Sierra also adds that lacking a sense of agency occupies a central role in the symptoms of depersonalization.

- Disembodiment feelings; Experience that the self is localized outside one's physical body boundaries. Unlike the case of out-of-body experience or autoscopy, it is not accompanied by a feeling of occupying a location in extra-personal space.

- Somatosensory distortions; Perceptual distortions of the body, for example, the hands have grown larger or smaller; the body feels lighter.

- Heightened self-observation; A feeling of being a detached observer of one's own behavior. Patients often describes it as a kind of split of their subjective awareness into two; one in observation and the other in action. This is a noticeable feature of depersonalization.

After all, depersonalization is the 'lived dualism of mind and body', so to speak. Patients experiences the mind separated from the body, thus they can't have the sense of ownership or sense of agency anymore. Now they are totally disembodied self-observers and living the world of perfect mind-body dualism!


Sierra (2009) points out that the four differentiated factors are found in the symptoms of depersonalization.
[Sierra, M. (2009). Depersonalization: A New Look at a Neglected Syndrome. Cambridge University Press.]

1. Anomalous body experience; Abnormalities in the way they experience their bodies such as lack of body ownership feelings, feelings of loss of agency, disembodiment feelings, somatosensory distortions, heightend self-observation.

2. Emotional numbing; Attenuated emotional experience, such as loss of affection, pleasure, fear, or disgust. Inability to feel emotions.

3. Anomalies in subjective recall; Complaints that memories of personal events have lost personal meaning. Patients feel as if what they remember did not really happened to them.

4. Alienation from surroundings; The symptom known as derealization. Feelings of being cut off from the world around, and of things around seeming unreal.

The 'anomalous body experience' in depersonalization includes the disembodiment feelings. It seems to be the most extreme case of our bodily awareness.

Friday, September 24, 2010

afferent feedback and the sense of ownership

In the involuntary action, there is the sense of ownership but there is not the sense of agency.

In this case, proprioceptive, kinesthetic and visual informations tells me that I am moving. The awareness of involuntary movement derives from afferent sensory feedback. But there are no efferent motor commands. This means that the sense of ownership is based on the sensory feedback.

The experiments of rubber hand illusion shows that it is enough with sensory feedback in order to create the sense of agency. The participants start to feel that the rubber hand belongs to himself/herself by being stroked synchronously on the real hand.

Friday, September 17, 2010


Annual Convention of Japanese Psychological Association is going to be held next week.

Japanese Psychological Association
74th Annual Convention
September 20-22, Osaka University, Osaka, JP

I am now preparing the poster which I will present on 21st in the morning. My poster is titled;

"Distinction between body schema and body image: A phenomenological account"
Shogo Tanaka (Tokai University)

I will review the classical work of Henry Head's body schema and Paul Schilder's body image, and then discuss the distinction between them, mainly based on Shaun Gallagher's work. I also add some original considerations.

Wednesday, September 15, 2010

Body Image and Body Schema, again

As I wrote here before, the term 'body image' and 'body schema' are often used indiscriminatingly or confusingly. But it is important to clarify the difference.

Body schema is the system of sensory-motor capacities which functions without awareness when we control the movement or adjust the posture. Body image is the complex images of perceptions, thoughts, emotions, memories pertaining to one's own body.

In my view, there are at least three differences between body schema and body image.

<1. Objectivity>
Body image is a kind of image which can be represented in the mind. It is the intentional object for the consciousness; we perceive, think and feel our own body. Body schema coordinates body parts toward an action pre-consciously and we can never be aware of its function.

<2. Person>
The body usually comes to one's senses as one's own body, not as other's. We perceive the body as something belonging to ourselves. This body is always perceived as 'my' body, not yours nor his/hers. In contrast, the function of body schema is anonymous, although it makes the person 'I' through its activity.

<3. Spatiality>
Body schema is not represented consciously. It is only lived from 'within'. Body image is the image of one's own body, which is perceived or looked from the 'outside'. To build such images, we need to borrow virtually the other person's viewpoint. Body schema is 'here' but body image is represented 'there'.

Tuesday, September 14, 2010

The 'minimal' self

Shaun Gallagher states that it is possible to simplify various notions of the self into two categories; the 'minimal self' and the 'narrative self'.
[Gallagher, S. (2000). Philosophical conceptions of the self: implications for cognitive science. in Trends in Cognitive Sciences. 4(1).]

Narrative self is the coherent self that is constituted with a past and a future in the various stories that we and others tell about ourselves. It is a kind of ordinary self that we experience in our daily lives.

The minimal self is a self which is composed of minimal factors; all of the unessential features are stripped away. It is the consciousness of oneself as an immediate subject of experience, unextended in time. It is the 'I' who is experiencing 'now-here'.

The minimal self has the two aspects; the sense of agency and the sense of ownership. The ownership is the sense that it is my body that is moving, and the agency is the sense that I am the initiator or source of the action. They are indistinguishable in the normal experience of willed action. We have both senses at the same time.

But in the case of involuntary action (e.g. someone moved my hand), it is possible to distinguish between them. I have the sense that I am the one who is moving, but I don't have the sense that I am controlling the movement. That is, I have the sense of ownership but I don't have the sense of agency.

It would be interesting to research the impairments, alterations or lesions of these two basic senses in various body awareness disturbances; phantom limbs, asomatognosia, anosognosia, depersonalization, hemiplegia, etc. It will bring a light to the relation between the body and the self.

Tuesday, August 10, 2010

The premise of embodiment

The basic premise of the notion of embodiment is as following;

[T]he notion of embodiment, the notion of an embodied mind or a minded body, is meant to replace the ordinary notions of mind and body, both of which are derivations and abstractions. Merleau-Ponty famously speaks of the ambiguous nature of the body, and argues that bodily existence is a third category beyond the merely physiological and the merely psychological. The lived body is neither spirit nor nature, neither soul nor body, neither inner nor outer, neither subject nor object. All of these contraposed categories are derivations of something more basic.
[Gallagher and Zahavi. The Phenomenological Mind. p.135]

Thus the notion of embodiment first of all rejects the Cartesian mind-matter dualism of res cogitans and res extensa. It doesn't question how the body interacts with the mind or how the mind influences the body. Instead, it requires the description of the body which appears in our cognition and action. The real question is how the body (the minded body) appears in our experiences and how the body shapes and structures our experiences.

Monday, August 9, 2010

Biological Motions

According to the research on the perception of biological motions, in which the subjects view videos of moving figures wearing point-light displays in the dark, subjects are better at identifying themselves than friends or colleagues (cf. Gibbs, 2006). Why can they do so? What subjects see is how they look from the outside when walking. We see the gaits of friends and colleagues more than we see our own.

Probably we are able to translate our proprioception to the visual image. Proprioceptive sense of our own body cross-modally informs the visual perception.

Sunday, July 4, 2010

perception and kinaesthesia

Husserl claims the close connection between perception and kinaesthesia (sense of movement).

Our perception of the object is always incomplete and accompanied by the object's horizon of absent profiles. I look at the house, for example, standing in front of it. I cannot see its sides, back, or roof. But I see the house as having another aspects to it. This structure of perception which includes the absent profiles of the object is concerned with our ability of moving.

[W]e can illustrate Husserl's idea with a concrete example. I am taking a look at my friend's new dual-fuel vehicle, and am standing in front of it. Whereas the front of the car is correlated with my particular bodily position, the horizon of the cointended but momentarily absent profiles of the car (its back, sides, bottom, etc.) is correlated with my kinaesthetic horizon, i.e. with my capacity for possible movement. The absent profiles are linked to an intentional 'if-then' connection. If I move in this way, then this profile will become visually or tactually accessible. The back of the car which I do not see has the meaning of 'the back of the same car I am currently perceiving' because it can become present through the execution of a quite specific bodily movement on my part.
[Gallagher and Zahavi. The Phenomenological Mind. p.99]

The important point of Husserl's kinaesthesia is not that we can perceive our own movements, but that our capacity of perception presupposes the movements.

Thursday, July 1, 2010

Why phenomenology now?

A talk on 'The Phenomenological mind' continues.

Why do we need to reconsider phenomenology now in the 21st century?
Gallagher and Zahavi indicate these three points;

<1> Consciousness was raised as a scientific question from 1990s (the 'hard problem'), and phenomenology is thought to be important as a methodology.

<2> To design the experiments or to interpret the results of neuroscience and brain-imaging, a methodology to describe properly the conscious experience is needed.

<3> Phenomenology (especially Merleau-Ponty's) offers one of the best examples of embodied approaches to cognition, and brings the embodied, embedded, and extended view of the mind.

Monday, June 28, 2010

Bracketing the theories

I started out to read "Phenomenological Mind" by Gallagher and Zahavi. Their explanation on phenomenology is very clear. Phenomenology sets aside the questions such as, 'Consciousness is generated by brain processes?''The mind is the brain or something immaterial?'. Phenomenology does not deny or affirm any metaphysical assumption. It simply brackets them and requires us to go back to the experiences. They write;

[A]s we indicated, many philosophy of mind textbooks start off by reviewing various theories about the mind - dualism, identity theory, functionalism, etc. It is also the case that psychology and cognitive science may already be informed by specific theories of the mind. Phenomenology, however, does not start with a theory, or with a consideration of theories. It seeks to be critical and non-dogmatic, shunning metaphysical and theoretical prejudices, as much as possible. It seeks to be guided by that which is actually experienced, rather than by what we expect to find given our theoretical commitments.
[Gallagher, S., Zahavi, D. (2008) The Phenomenological Mind. New York: Routledge, p.10]

I'm looking forward to reading the following chapters.

Thursday, May 27, 2010

A passage from Husserl

About the difference between the body and other things, Husserl writes;

[W]hereas, with regard to all other things, I have the freedom to change at will my position in relation to them and thereby at the same time vary at will the manifolds of appearance in which they come to givenness for me, on the other hand I do not have the possibility of distancing myself from my Body, or my Body from me, and accordingly the manifolds of appearance of the Body are restricted in a definite way.....The same body which serves me as means for all my perception obstructs me in the perception of it itself and is a remarkably imperfectly constituted thing.
[Husserl, E (1952/1989). Ideas Pertaining to a Pure Phenomenology and to a Phenomenological Philosophy, Second Book. Dordrecht: Kluwer. p.167]

As he writes, I cannot percept my own body in a perfect way. I cannot see my head, back or eyes. The appearance of my body does not have an unity like other objects. However, I still know that my body is in unity. The unity of my body cannot be recognized through perception, but is lived directly through action.

Sunday, May 23, 2010

recognition before thinking

Impressive passage by Henri Bergson;

In fact, we commonly act our recognition before we think it. Our daily life is spent among objects whose very presence invites us to play a part: in this the familiarity of their aspect consists. Motor tendencies would, then, be enough by themselves to give us the feeling of recognition.
[Bergson, H. (1896/1991). Matter and Memory trans. N. M. Paul and W. S. Palmer. New York: Zone. p.95]

A cup affords us to hold it and drink the coffee in it, a chair affords us to sit down on it, a computer affords us to write an article. All the surrounding objects invites us to act in certain ways. We recognize the objects through our motor capacity. Recognition is not a representation in the mind, but is lived through embodied action.

Wednesday, April 28, 2010

Dynamic Touch

Turvey proposes the notion of dynamic touch, based on Gibsonian notion of active touch.
[Turvey, M. T. (1996) Dynamic Touch. American Psychologist.]

We can feel the weight, the size, and the direction of our own limbs through internal senses, even if we close our eyes. In the similar way, we can feel the weight, the size, and the direction of various tools. Baseball bat, tennis racket, umbrella, fishing rod, and so on. Dynamic touch is the perception of properties of one's own body, or the external objects.

When we use tools, we can feel them as a natural part of our body (swinging a racket, driving a car, etc.). We probably extend our proprioception into them through the sense of dynamic touch.

Near and Far

Berti and Frassinetti reports an interesting case of unilateral neglect.
[Berti, A. & Frassinetti, F. (2000) When far becomes near: Remapping of space by tool use. J of Cognitive Neuroscience.]

The patient showed a neglect of the left space, as is seen in other cases of unilateral neglect. In this case, the neglect was seen only in the peripersonal space (near space), not in the extrapersonal space (far space).

But when the patient performed with a stick, the neglect was also extended to the end of the stick. By using a stick, the 'far' space was converted into the 'near' space, as the patient's body schema incorporated the stick into itself.

The distinction between the peripersonal and the extrapersonal, the near and the far, is not something fixed.

motor control

It is said that a human body has nearly 800 to 1000 articulations. And each articulation needs more than two types of muscles to rotate.

How many muscles and articulations should coordinate in movements? A very simple task, holding a cup and drinking the coffee in it, for example, will require the coordination within tens of articulations and muscles.

It is inappropriate to consider the mind as a 'control tower' which dominates the body movements. Body is too complex to be controlled by the mind.

Of course the body moves in accordance with our intention. But this does not mean the mind 'controls' the body. The body must have its own way to coordinate hundreds of articulations and muscles.

But how?

Sunday, April 25, 2010

A phantom sensation

Ramachandran and Blakeslee describe a case of phantom limb;

Tom lost his left arm just above the elbow......In the weeks afterward, even thow he knew that his arm was gone, Tom could still feel its ghostly presence below the elbow. He could wiggle each "finger," "reach out" and "grab" objects that were within arm’s reach. Indeed, his phantom arm seemed to be able to do anything that the real arm would have done automatically, such as warding off blows, breaking falls or patting his little brother on the back. Since Tom had been left-handed, his phantom would reach for the receiver whenever the telephone rang.
[Ramachandran, V. S. & Blakeslee, S. (1998) The Phantoms in the Brain. William Morrow.]

Apparently, the patient’s body still reacted to certain stimuli in a habitual manner. Whenever the telephone rang, his whole body was led to answer it as he used to, and this action involved the movement of the left hand. The sensation of missing limb seems to occur as a part of a habitual action that has been established between the body and a certain situation. The patient need not to represent in his mind the missing part of the body but may feel it immediately, as a need for an embodied action.

Saturday, April 17, 2010

Rubber Hand Illusion

The rubber hand illusion is a well known somatosensory illusion, which was reported by Botvinick and Cohen in 1998. It has become almost classic in the research of body awareness.
[Botvinick, M. & Cohen, J. (1998). Rubber hands 'feel' touch that eyes see. Nature.]

In the experiment, the participant's real hand is hidden out of sight. Instead, a life-sized rubber hand is placed in front of the participant. The experimenter uses two brushes to stroke the real hand and the rubber hand synchronously. After a short period, most of participants start to feel the touch in the position of rubber hand and experience as if the rubber hand is the real hand.

from: scienceblogs.com

Ehrsson tested the illusion in four conditions to manipulate the feeling of ownership of the rubber hand.
[Ehrsson, H. H., Spence, C., Passingham, R. E. (2004). That's my hand! Activity in premotor cortex reflects feeling of ownership of a limb. Science.]
1. Synchronous and Congruent: stroking synchronously the rubber hand and the real hand,
putting the rubber hand aligned with the real hand.
2. Asynchronous and Congruent: stroking asynchronously, the rubber hand aligned with the real hand.
3. Synchronous and Incongruent: stroking synchronously,
the rubber hand rotated 180 degrees pointing toward the participant.
4. Asynchronous and Incongruent: stroking asynchronously, the rubber hand rotated 180 degrees.

As is expected, the participants felt the most strong illusion in the first condition (synchronous and congruent). The touching stimuli should be synchronous and the orientation of the rubber hand need to be congruent with that of the real hand.

I guess, the position of the rubber hand must be in the circle of possible movements to create the illusion. If the rubber hand is outside the movability of the real hand (very far, rotated conversely, hung upside down, etc.) the participants will not be able to feel the illusion.

Illusion is the possible perceptions, as perception is the possible action.

Sunday, April 11, 2010

The body in Satori

The body image is altered not only in psychotic disorders but also in religious experiences.

Yuasa says;
In satori, there is no distinction between the body of oneself and others, between the body of a person and the Buddha. The body is changed into, as it were, a metaphysical body, and it loses all its objective characteristics found in the everyday dimension.....The distinction between one's own and others' bodies, between being a self and the being of others, completely disappears.
[Yuasa, Y. (1987) The Body: Toward an Eastern Mind-Body Theory. SUNY Press.]

Again, having my own body, is not a matter of course!

Saturday, April 10, 2010

'My' Body

The body image is the image of one's own body in the mind. Thus it has a characteristic of 'my' body. The body image is a kind of body awareness as my own body, not the others.

It is well known that the natural body image is disturbed or even destroyed in Anorexia, Bulimia, or Body dysmorphic disorder. But the nature of body image as one's own body is also altered in psychotic disorders such as Depersonalization or schizophrenia.

In case of depersonalization, patients often feel divorced from their own body. They can intellectually recognize that the body belong to themselves but they can't feel it as theirs. 'My body' is felt like others or a mere physical object. The sense of ownership of the body is disturbed.

In schizophrenia, some patients have delusions of being controlled by an external force. The delusions is sometimes accompanied with body sensations and feelings. They literally feel that they are moved by the force and can visualize it as images. The sense of motor agency is disturbed. Not only the cognition but also the sense of motor agency seems to be affected here.

Having one's own body, is not a matter of course!

being out of body

The phenomenon known as the 'Out-of-Body' experience is related to a failure of integration of multisensory informations from the body, suggests Blanke and Arzy.
[Blanke, O. and Arzy, S. (2005) The Out-of-Body Experience: Disturbed self processing at the Temporo-Parietal Junction. The Neuroscientist.]

In OBE, people often look down their own body from an elevated location like ceiling. The perspective which they look at and the sense of self is located outside the body.

They indicate that the OBE has three characteristics.
1. disembodiment
2. the impression of seeing the world from a distant and elevated visuo-spatial perspective
3. the impression of seeing one's own body from this elevated perspective

OBE--if it really exists--shows that the body image could exist without the sense of self. The experiencing 'I' and the experienced 'my body' are dissociated. Interestingly, the sense of ownership is still functioning (because the body is seemed as 'my body' in OBE), but there is no sense of motor agency.

Saturday, April 3, 2010

Blind Touch

Jacque Paillard says that there is a 'blind touch' (or 'Numbsense') phenomenon which is a tactile equivalent of blind sight.

One of his patients was;

"Unable to detect and to perceive any tactile stimulation delivered at various sites on her right hand when vision was prevented, this patient showed, to her own surprise, a spontaneous ability to point her left finger toward stimulated places on her deafferented right hand.
[Paillard, J.(2005) Vectorial versus configural encoding of body space. in Body Image and Body Schema (ed. Preester and Knockaer).]

This is a very important discovery. Because this phenomena suggests that there is a neural basis for the distinction between body schema and body image, as Paillard also points out.

Mirror and Body Image

When you look at the mirror, you feel that your right hand is the left hand of the mirror-self. You exchange perspectives. But before that, how do you recognize that the person in the mirror is yourself?

You must recognize that the body you feel here through proprioception is equivalent to the body you see there in the mirror.

Animal psychologists say that adult chimpanzees recognizes that the figure in the mirror is him/herself within few hours. It seems that they have their own body image in their mind.

But it is also said that the chimps grown up alone without other chimps don't come to recognize themselves in the mirror.

So, it is possible to speculate that the other individuals body plays a crucial role to create the body image in the mind. Probably we need the other's body to see our own body from third person's perspective and to construct our own body image in the mind.

Body Image

Research literatures on body image in general, stresses too much the unhealthy aspect of them, such as anorexia, bulimia, body dysmorphic disorders, and so on.

It lacks the basic research on body image. For example, how we represent our bodies from the outside of the body, whereas it is impossible. If we have our own body images in the mind, what is it for? Why is it necessary? How we use it? Before stressing the disfunction of the body image, we need to know the ordinary function of it.

Body image is formed with the gaze which represents the body from the outside. In contrast the function of body schema doesn't include this perspective. Neuroscience research on the body seems to ask only the body representation in the brain and doesn't ask the problem of the perspective, which makes the body representation--the perspective from where the body is represented (from within or from outside).

The body image is based on the the perspective of the other person (the third person's perspective).

Body Image and Body Schema

Most of neuroscientists uses the term 'Body Image' and 'Body Schema' indiscriminatingly. But it is important to make clear the difference between them, as is pointed out by Shaun Gallagher.

Body image is the image represented in the mind. It is objectified by the consciousness. We perceive our body, we think about our body, we feel our body as object. And we not only experience our body as an object but also as something belonging to ourselves (the body as my own body). The body image is a source of the sense of body ownership.

In contrast, the body schema is the subject-body and never owned. The sense of motor agency seems to have its origin in body schema but basically its function is anonymous. The body schema works under the conscious reflexion and doesn't have any personhood. It functions unconsciously.

The Body Has a Mind of Its Own

I've read 'The Body has a mind of its own' by Sandra Blakeslee and Matthew Blakeslee.

[Blakeslee, S. & Blakeslee, M. (2007). The Body Has a Mind of Its Own: How Body Maps in Your Brain Help You Do (Almost) Everything Better. Random House.]

The authors are not experts of neuroscience nor cognitive science. But as scientific writers, they encompass a broad range of bodily experiences, from anorexia to yips, from Nintendo game machine to cyborg, from body schema to mirror neurons. All of these topics are written based on the relatively new discoveries in neuroscience. This is a nice book as an introduction to the neuroscience of embodiment.

You can see the online webpage that introduces this book.

Geminoid experiment

I've read the H. Ishiguro's new book, "What is Robot?"(in Japanese, Kodansha, 2009).
[Ishiguro, H. (2009). What is Robot (in Japanese). Kodansha.]

His Geminoid (a humanoid robot that resembles himself!) raises many questions about mind-body relations.

In Ishguro's experiment, 70% of the participants who observed the female android for 2 seconds, noticed that it was not human.

But when they observed the same android with microactions (eye movements, small shoulder movements, etc.) , equally 70% of them believed it to be human.

The appearance of the robot seems very important. Ishiguro gives many other curious examples like this.

Another curious example. When his stuff opened up the geminoid's head to fix it up, he felt 'a curious sensation' as if he was touched and operated.

So, he projected himself to the geminoid's body, in the very similar way in the experiments in rubberhand illusion.

When the robot has the similar appearance to human being and it moves, we can easily project ouselves to the robots.

We can feel touch on the robot's body. The body schema incorporates the robot's body into itself, in the same way as it incorporates tools.

The rubberhand illusion is based on the same principle. We can feel the extended 'touch' on the rubber hand as the body schema incorporates the rubberhand.

Merleau-Ponty's notion of Behavior

Merleau-Ponty's main interest, before he started to be a phenomenologist, were Henri Bergson's philosophy, Gestalt psychology, and neurology.

In his "Structure of Behavior", he denies the notion of reflex. Because it requires one-to-one correspondence between the stimulus and the response.His claim was that the Organisms response to the meanings of the environment or situation, not to the stimuli. Thus the behavior cannot be explained as a complex of reflex acts. He stresses the importance of behavior but it's totally different from that of behaviorist.

Perception as possible actions

Perception is not to receive passively the informations about the object or the environment. Perception is something more active, as Gibson named it 'active touch'.

Perceptions are presentement of actions, so to speak. Through perception we always receive the possibilities of actions which we can take toward the environment. We perceive the action possibilities latent in the environment, what is called affordances.