Consciousness I Philosophical Skepticism about a Neuronal Self An initial pair of questions Are there things about yourself that you would like to change What keeps you from changing them Let me suggest a theme for todays lecture ID: 249454
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Slide1
University Studies 15A:Consciousness I
Philosophical Skepticismabout a Neuronal SelfSlide2
An initial pair of questions:
Are there things about yourself that you would like to change?What keeps you from changing them?
Let me suggest a theme for today’s lecture.
“No such thing as selves exist in the world; nobody ever
was
or
had
a self” Thomas Metzinger
We should be so lucky.Slide3
Let us begin with Hume’s linkage of consciousness, perception and the self (or lack of one):
For my part, when I enter most intimately into what I call myself, I always stumble on some particular perception or other, of heat or cold, light or shade, love or hatred, pain or pleasure. I never can catch myself at any time without a perception, and never can observe any thing but the perception. (David Hume, A Treatise on Human Nature)
He “never can observe any thing but the perception.” Indeed. Is that really true?Slide4
Immanuel Kant concluded that, if one reflects, one realizes that all perceptions have a frame that is not part of the things perceived:
Kant accepts Hume’s critique that we cannot find causality in the world; we infer that when event B regularly follows immediately upon action A,
A
causes
B
, but this conclusion is not really justified. Kant argues that here we have to postulate a self that orders perception through the additional category of causality that this self provides.
Kant sees a self in the form of the perception.Slide5
Let’s consider another pair of examples of perceptions:Slide6
What is that black doing in the blue sky?Slide7
It is far too simple to say that these two paintings of cornfields are Van Gogh’s perception of the fields at different times. The technical aspects reflect painterly questions of how to use the brush, paint, and color and how to organize the canvas to convey a particular sense of
both what it was like to look at a cornfield and what it was like to engage a painting as a work of art.
Still, to say that the perceptions behind the paintings were perceptions not framed most viscerally by a self is not to be looking at the paintings.
So, what is this self?
The challenge is to keep this self in mind when reading all the arabesques of argumentation in Blackmore.Slide8
In this context, let me slightly rephrase an exercise Blackmore proposes.
She wants you constantly to ask the question, “Who is conscious now?”She asks, “Can you see, hear, or feel the
experiencer
as opposed to the experienced world?” Good question.
Let me give you an example:Slide9
Did you find a self in the shifting consciousness here?
Can you propose a neuroscientific account of this self from what you have learned?Slide10
Blackmore’s framework is to consider two classes of models of the self:
1. “Ego theories:” there is a substantial, persisting self2. “Bundle theories:” the “self” is a temporary aggregation of elements
Keep this neuroscientific model in mind as we turn to Blackmore’s account
Blackmore offers the Buddhist analysis as an early “bundle theory”
In classic Vedic thought, the self,
atman
, was a part of the larger world-soul,
Brahman
. Ascetics sought to purify the self so as to return to the purity and formless totality of
Brahman
. Gautama (the Buddha) initially followed the Vedic tradition but then, in a moment of enlightenment, concluded there was no
atman
to return to
Brahman
, and with no
atman
, the self extinguished.
Instead of a permanent
atman
, the self was a condensation of five “heaps” (
skandha
: form, sensation, conception, volition, discernment) that scattered again on death. This is indeed a “bundle theory.”Slide11
Blackmore asserts, “It might seem obvious that materialist scientists should… be bundle theorists. After all, if the brain consists of millions of interconnected neurons whose activity gives rise to behaviors, memories and perceptions, then there is no need for an experiencing self as well
.” (p. 117)As well? Where is she looking for this self? What does she want it to be?
Blackmore continues, “Yet,… some scientists still try to count the number of selves in a split-brain patient, or ask whether multiple personalities are really separate selves, implying at least some components of ego theory
.” (p. 117)
However, is there a compelling reason why one could not have several competing bundles of self rather than several competing ego-selves?
Ego Theories – Bundle Theories
Let’s consider some of Blackmore’s test cases.Slide12
Example One – The Brain Transplant: what would change in your “self” if your brain ended up inside another body?
Neuropsychology describes personal space in terms of kinds of 'near-ness' to the body.Extrapersonal Space: The space that occurs outside the reach of an individual.
Peripersonal
Space
: The space within reach of any limb of an individual. Thus to be 'within-arm's length' is to be within one's
peripersonal
space.Pericutaneous
Space: The space just outside our bodies but which might be near to touching it. Visual-tactile perceptive fields overlap in processing this space so that, for example, an individual might see a feather as not touching their skin but still feel the inklings of being tickled when it hovers just above their hand.Previc further subdivides extrapersonal space into focal-extrapersonal space,
action-
extrapersonal
space, and
ambient-
extrapersonal
space. Focal-
extrapersonal
space is located in the lateral
temporo
-frontal
pathways at
the center of our vision, is
retinotopically
centered and tied to the position of our eyes, and is involved in object search and recognition.
Action-
extrapersonal
-space
is located in the medial
temporo
-frontal pathways, spans the entire space, and is head-centered and involved in orientation and locomotion in topographical space. Action-
extrapersonal
space provides the "presence" of our world. Ambient-
extrapersonal
space initially courses through the peripheral
parieto
-occipital visual pathways before joining up with vestibular and other body senses to control posture and orientation in earth-fixed/gravitational space. Numerous studies involving
peripersonal
and
extrapersonal
neglect have shown that
peripersonal
space is located dorsally in the parietal lobe whereas
extrapersonal
space is housed ventrally in the temporal lobe
. (Wikipedia)Slide13
Can you be the same “you” in a different body?
Can you be the same “you” if you lose a limb?I’m gambling that someone said “The same in all the essentials.”
What are the essentials?
Where
are the essentials?
Example Two – The
Teleporter
: Suppose a machine scanned you, sent all information about you to a different location, reassembled an identical version of you, and destroyed the original:
Would the new version be you?Slide14
Neuroscientific Models of the Self
Blackmore discusses:Ramachandran
“executive process” using the limbic system
Damasio
proto-self
(the brain stem, thalamus, and insula)
autobiographical self (cortical structures built drawing on the proto-self)
Baars
’ Global Workspace Theory
self-system (including self as observer, self as agent)
Baars
shows that consciousness can become detached from the
self-system in a variety of “
dissociative conditions”