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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
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