University Studies 15A: Consciousness I

University Studies 15A:Consciousness IPhilosophical Skepticismabout 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.No such thing as selves exist in the world; nobody ever was or had a self Thomas MetzingerWe should be so lucky.Let us begin with Humes 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?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 Humes 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.Lets consider another pair of examples of perceptions:

What is that black doing in the blue sky?It is far too simple to say that these two paintings of cornfields are Van Goghs 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.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:

Did you find a self in the shifting consciousness here?Can you propose a neuroscientific account of this self from what you have learned?Blackmores 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 elementsKeep this neuroscientific model in mind as we turn to Blackmores accountBlackmore offers the Buddhist analysis as an early bundle theoryIn 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.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 TheoriesLets consider some of Blackmores test cases.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)Can you be the same you in a different body?Can you be the same you if you lose a limb?Im 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?Neuroscientific Models of the SelfBlackmore discusses:Ramachandranexecutive process using the limbic systemDamasioproto-self (the brain stem, thalamus, and insula)autobiographical self (cortical structures built drawing on the proto-self)Baars Global Workspace Theoryself-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