From the mind to the body,and back again

Mind World

ActionBody

Perception

Body

• Descartes: immunity from error

• James: “same old body always

there”

Mind World

Action

Perception

Body

Body

VisualBody

Body representations mediating touch

Primary Touch

TactileObject

Description

Tactile Stimulus

Viewing the body enhances touch

Penfield & Rasmussen (1950)

Weinstein (1968)

Two-point discrimination threshold

One!

Two!

Summary of conditions

Darkness View of ArmMagnified View

of ArmView of Neutral

Object

Control for effects of visuo-spatial attention

Kennett, Taylor-Clarke & Haggard, Current Biology, 2002Kennett, Taylor-Clarke & Haggard, Current Biology, 2002

**

***

Kennett, Taylor-Clarke & Haggard, Current Biology, 2002

Visual presetting of touch: TMS studyFiorio & Haggard, European Journal of Neuroscience, 2005

Visual presetting of touch: TMS studyFiorio & Haggard, European Journal of Neuroscience, 2005

Index fingertip: grating Orientation Test

Visual presetting of touch: TMS studyFiorio & Haggard, European Journal of Neuroscience, 2005

Enhancement of touch when viewing the hand (1) ……is abolished by prior TMS to SI (2)

**

Top-down (2):Pre-existing body image

Bottom-up (1):

Multisensory correlation

Tsakiris & Haggard, J. Exp. Psychol.: HPP (2005)

“Body Ownership”

Building a bodily self

Rubber Hand Illusion

Synchronous Asynchronous

feel

see

Congruent Synchronous

(CS)Con

grue

ntIn

cong

ruen

t

Congruent Asynchronous

(CA)

Incongruent Asynchronous

(IA)

Incongruent Synchronous

(IS)

Bottom-up T

op-d

own

ruler

ruler45

53rulerruler

rulerruler45

53

Proprioceptive measure of body ownership =

perceived position of subject’s hand after stimulation minus

perceived position at pre-test

Time

-1

-0.5

0

0.5

1

1.5

2

2.5

me

an

dri

ft t

ow

ard

s t

he

ru

bb

er

ha

nd

(c

m)

CS CA IS IAViewing Congruent

Rubber HandViewing Incongruent

Rubber Hand

Synchronous Asynchronous Synchronous Asynchronous

A general, top-down factor in body awarenessTsakiris and Haggard, J. Exp. Psychol. (2005)

Vie

w O

bje

ct

Neu

tral

Obj

ect

Rub

ber

Han

d

TMS No TMS TMS No TMS

rTPJ Vertex (Control)

TMS Site

Electrical stimulation of TPJ induces out-of-body experienceBlanke et al., Nature, 2002

Vie

w O

bje

ct

Neu

tral

Obj

ect

Rub

ber

Han

d

TMS No TMS TMS No TMS

rTPJ Vertex (Control)

TMS Site

rTPJ: a brain centre for constructing the bodily self Costantini, Tsakiris and Haggard (in prep.)

rTPJ: a brain centre for constructing the bodily self Costantini, Tsakiris and Haggard (in prep.)

rTPJ: a brain centre for constructing the bodily self Costantini, Tsakiris and Haggard (in prep.)

Neural bases of body awareness

• Mental representation of our ‘reference’ body• Specific brain substrate in right TemporoParietal junction• Enhances and integrates new bodily sensations• Constructs a bodily self, distinct from the external world

Mind World

Action

Perception

Body

Body

605

10

15

20

2530

35

40

45

50

55

605

10

15

20

2530

35

40

45

50

55

“23”

Neural preparation and conscious intentionV

olta

ge a

t Cz

(V

)

Time (s)0Movement Onset

-1

• Readiness potential

• M judgement: conscious awareness of action

-86 ms-206 ms

• W judgement: conscious awareness of intention

??

|+

1. Pre-SMA 2. Dorsal prefrontal 3. IntraParietal

Neural correlates of conscious intention(Lau, Rogers, Haggard, Passingham, Science 2004)

• Judge time of intention – judge time of action

These areas are involved in choice and action selection

Haggard & Eimer, Exp.

Brain Res.

Free selectionLeft or Right actions

C4C3

Haggard & Eimer, Exp.

Brain Res.

Free selectionLeft or Right actions

Distribution of Awareness Times

C4C3

Haggard & Eimer, Exp.

Brain Res.

Free selectionLeft or Right actions

Distribution of Awareness Times

Neural correlates ofAwareness should have

same distribution

C4C3

C4C3

Con

tral

ater

alIp

sila

ter

al

Free selectionLeft or Right actions

Lateralisation: selection of specific body part to

perform the action

Conscious intention is bodily-specific

Cz

Non-lateralised midline readiness potential does

not correlate with conscious awareness

Non-lateralised readiness potential

Intentional BindingHaggard, Clark & Kalogeras, Nature Neuroscience, 2002

Time

Action

Awareness

of Action

Time

Action Effect(Beep)Shifted

Awareness

of Action

Perceptual Shift:

+15 ms

Time

Beep

Awareness

of Beep

Time

Action Effect(Beep)Shifted

Awareness

of Beep

Perceptual Shift:

-46 ms

Intentional BindingHaggard, Clark & Kalogeras, Nature Neuroscience, 2002

Shifted

Awareness

of Action

+15

Intentional BindingHaggard, Clark & Kalogeras, Nature Neuroscience, 2002

Action Effect (beep)

250 ms Reality

189 ms JudgementShifts

Beep Awareness

Individual Judgements

Action Awareness

Shifted

Awareness

of Beep

-46

+15

Intentional BindingHaggard, Clark & Kalogeras, Nature Neuroscience, 2002

Action Effect (beep)

250 ms Reality

189 ms Voluntary Action-46

-27 308 ms

Involuntary TMS-induced twitch

+31

Mind WorldBody

Mechanisms of Intentional Binding

Mind WorldBody

Mechanisms of Intentional Binding

Mind WorldBody

1. Predictive preconstruction

Mechanisms of Intentional Binding

2. Inferential reconstruction

Beep Awareness

Individual Judgements

Action Awareness

+12Action + Effect

50%

50% +5 ???

+13Action + Effect

75%

25% +11 ???

Conclusions

• The brain contains mental representations of our body

• These representations mediate our actions and our

perceptions of the external world

• Our awareness of action links our body to the external

world, in a temporal ‘atom’ of experience

• The neural bases of bodily sensation and bodily action

offer an experimental window into self-consciousness

Thanks

Family

Teachers

Colleagues

Thanks

Family

Teachers

Colleagues