Download Multisensory brain mechanisms of bodily self

Ecole Polytechnique Fédérale de Lausanne
Multisensory brain mechanisms of bodily
self-consciousness
Olaf Blanke
http://lnco.epfl.ch/
http://cnp.epfl.ch/
Laboratory of Cognitive Neuroscience
Center for Neuroprosthetics
What is a Self ?
The self seems distinct
from the environment and
other humans and may be
described as an entity to
which certain mental
events and actions are
ascribed. [David &
Kircher, 2003]
The Self in Cognitive Neuroscience
Autobiographical Memory
Thought: Cogito Ergo Sum
Visual Mirror Recognition
Bodily self-consciousness: How the brain processes
signals from the body is the foundation for the self
Jeannerod, Frith, Ramachandran
Damasio, Craig
Bodily self (consciousness) without a body
Phantom limbs
The physical body is NOT necessary
for the experience of the bodily self.
Melzack proposed “that the brain
generates the experience of the body
and that sensory inputs merely
modulate our bodily experience.”
Phantom limbs are “produced by
the same brain processes that
underlie the experience of the body
when it is intact”
[Halligan, 2002; Melzack, 1990; Ramachandran, 1993; Brugger et al., 2000]
Bodily self for the entire body
Are there phantom bodies and phantom selves?
Out-of-body experiences: abnormal bodily selfconsciousness
Extracorporeal Self-location (or disembodiment)
I am localized outside my body
Extracorporal first-person perspective
I perceive the world (and my body) from a disembodied perspective
Self-identification
I identify with the elevated body
Neurology of out-of-body experiences
Brain damage is localized in right superior temporal gyrus/angular gyrus
-OBEs are illusory own body perceptions
-Brain damage centers in temporo-parietal junction
-Brain damage leads to double disintegration of multisensory
bodily information ( Visual-tactile-proprioceptive signals and
visuo-vestibular signals)
[Devinsky et al., Arch Neurol 1989; Brugger, Neuropsychiatr 2002;
Blanke et al., Nature 2002; Brain 2004; Ionta et al., Neuron 2011]
Manipulating Self-location and
Self-identification in healthy subjects
Video ergo sum
Self-consciousness & visuo-tactile integration:
The rubber hand illusion
[see also video on youtube: « Virtual rubber hand illusion »]
A fake arm feels like my arm and is
associated with abnormal arm localization
~The rubber hand illusion~
Arm position recalibration
Questionnaire responses
« I feel the touch where I see the touch »
« The fake hand feels like my real hand »
[Botvinick and Cohen, 1998; Armel & Ramachandran, 2003; Ehrsson et al., 2005; Tsakiris
& Haggard, 2005; Evans & Blanke, NeuroImage 2012]
From hand to body:
Projecting the bodily self to a fake body
Subject with Head Mounted Display (covered)
Video camera with 3-D
converter
Virtual
body
2m
Actual
body
[Lenggenhager et al., Science 2007]
Embodiment of virtual and artificial bodies
A virtual or filmed body feels like my body and “I”
am localized at the virtual body’s position
Self-identifcation
Self-location
anterior shift
*
Questionnaire
Position
Recalibration
[Lenggenhager et al., 2007]
[youtube: « Virtual out-of-body experience »]
Laboratory of Cognitive Neuroscience
These changes in self-consciousness are body
specific, change touch perception, and decrease pain
[Aspell et al., 2009; 2010]
[Ehrsson, 2007; Petkova and
Ehrsson, 2008]
Study 2 [Lenggenhager et al., 2007]
Increase in pain thresholds
EEG &
Virtual Reality
[Palluel et al., J Neurophysiol, 2011; Hänsel et al., 2011]
Laboratory of Cognitive Neuroscience
The brain mechanisms of bodily selfconsciousness: Neuroscience robotics
Body condition
Control condition
Self-location
Synchronous/asynchronous
[Ionta et al., Neuron 2011;
Duenas et al., IEEE 2012; Pfeiffer et al., POne 2013]
Activity in right and left posterior superior temporal gyrus reflects
self-location that depends on the first-person perspective
[Ionta et al., 2011]
Laboratory of Cognitive Neuroscience
Pathologically & experimentally induced
changes in bodily self-consciousness converge
onto bilateral (right) temporo-parietal cortex
VLSM
TPJ activity (within a network of related brain regions)
reflects one of the most fundamental subjective feelings
in humans: Self-location and first-person perspective
Bodily self-consciousness brain mechanisms
extend beyond temporo-parietal cortex
Self location dependant fc fMRI
Self-related fc fMRI
Functional connectivity between the right and the left TPJ with the right
insula (and right medial prefrontal cortex) reflects self-location and 1PP
[Ionta et al., submitted]
The Self in Cognitive Neuroscience
Autobiographical Memory
Thought: Cogito Ergo Sum
Visual Mirror Recognition
Bodily self-consciousness: How the brain processes
signals from the body is the foundation for the self
Jeannerod, Frith, Ramachandran
Damasio, Craig
Bodily self-consciousness based on exteroceptive
bodily cues versus interoceptive cues
Visceroception and the insula
AIC MIC PIC
[Damasio, 2000; Critchley et al., Nat Neurosci 2004; Craig, Nat Neurosci Rev 2002, 2009]
Do exteroceptive (i.e. visuo-tactile) and interoceptive cues interact and
affect bodily self-consciousness?
Conflict between interoceptive (heart) and
exteroceptive (visual) signals:
Online detection of QRS complex was used to illuminate an
avatar synchronously and asynchronously with one’s own
heartbeat (cardio-visual conflict)
-  Cardio-visual illumination of the avatar
-  a flashing silhouette around the avatar was either sync or asnyc with
respect to the participant’s heartbeat (QRS)
[Aspell et al., Psychological Science 2013]
Turning body and self inside out: Visualized
heartbeats alter self-identification and selflocation
Self-identifcation
Self-location
Questionnaire
Position
Recalibration
-  Body-specific and synchrony dependant changes in self identification and selflocation
-  Participants were not aware of the heartbeat manipulation (middle) and this did
not differ among exp. conditions
Cardiac signals converge with visual & tactile
signals and alter a late SEP component (insula?)
Synchrony dependent changes
in sthe visuo-tactile crossmodal
congruency effect
P45 differs between snyc and
async cardio-visual illumination
P45 amplitude correlates with
self-identification
[Heydrich, et al., submitted]
Laboratory of Cognitive Neuroscience
[Heydrich and Blanke, Brain 2013]
[Ionta et al., in revision]
What is Self-consciousness ?
Working hypothesis:
The conscious experience of being this entity (of
being a person) is caused by brain activity during
spatially congruent self-identification, self-location
and first-person perspective. This is based on a
bottom-up body representation based on the
integration of specific somatosensory-vestibularvisual and interoceptive signals in areas VIP, PIVC,
MST, and insula.
1- Bodily self-consciousness as the foundation of the
many-dimensional Self (and the Person)
• Visual Recognition: Recognizing one's image in a mirror
• Memory: Autobiographical memory
• Language: first-person pronouns, self-narrative
• Social: ability to adapt the perspective of the other to
oneself,
• Thought: Ability to think “I” thoughts; ability to think of
oneself as oneself, have a self concept, “to know that I
know”
• …
2- Although self-consciousness is often regarded as the
greatest mystery in science (and consciousness studies), it
may turn out to be less complex than we think and less
complex than consciousness.
Ecole Polytechnique Fédérale de Lausanne
Thank you!
http://lnco.epfl.ch/
http://cnp.epfl.ch/
Center for Neuroprosthetics
EPFL
Self-location depends on the experienced direction
of the first-person perspective
Up-Lookers
[Q1: Did you have the
impression to look up at
the body above you or
down at the body below
you?]
(n=11)
Down-Lookers
(n=11)
sync. stimulation leads to
opposite drift in self-location in
up- and down-lookers “towards
the virtual body”)
The experienced direction of the first-person perspective
can be manipulated by a visuo-vestibular conflict
Visuo-tactile-proprioceptive integration
(visuo-vestibular integration)
Hand and Trunk-centered trimodal neurons in parietal and frontal cortex
Visual receptive fields
Tactile receptive fields
[Iriki et al., Neuroreport 1996; Graziano et al., Science 2000; Duhamel et al.,
J Neurophysiol 1998; Blanke, Nat Rev Neurosci 2012]
Interoceptive out-of body experiences (Heautoscopy):
Statistical lesion analysis localizes brain damage to left insula
He-autoscopy
[Heydrich and Blanke, Brain 2012]
Out-of-body experiences in normal folks
Example:
«I was asleep on a settee with my wife. I was aware at one stage
that I was out of my own body poised six feet or so above and
peering down at the two of us laying on the settee.» [Green, Out-ofthe-body experiences, 1968]..
“One day, at age 17, I was walking alone at
night during a snowstorm in a singularly
quiet place. I noticed that the ground
looked further away than usual, and then
it seems that I was looking down from a
height of perhaps 10 meters, watching
myself crossing the field.”
Marvin Minsky
The many selves in Cognitive Neuroscience
• Visual Recognition: Recognizing one's image in a mirror
• Memory: Autobiographical memory
• Thought: “Cogito ergo sum”, Ability to think “I” thoughts; ability to
think of oneself as oneself, have a self concept
• Language: first-person and self-reflexive pronouns
• Intentions/free will
• Social: ability to adapt the perspective of the other to oneself;
capacity to discriminate self from other
Bodily Self-consciousness (relevance for
philosophy)
Self-location
(Where am I localized ?)
First-person perspective
(Where do I perceive from?)
Self-identification
(What do I experience as my body?)
[Blanke & Metzinger, TiCS 2009]