Chapter 17: The Unity
- Why is consciousness unified?
- "[I] s not the conclusion of the whole matter this? --
the soul is in the very likeness of the divine, and
immortal, and intelligible, and uniform, and indissoluble, and
unchangeable; and the body is in the very likeness of the human, and
mortal, and unintelligible, and multiform, and dissoluble, and
changeable. ... But if this is true, then is not the body liable to
dissolution? and is not the soul almost or altogether indissoluble?
- I cannot distinguish in myself any parts but apprehend myself
to be clearly one and entire." (Descartes)
- "The consciousness, which is itself and integral thing not made
of parts, 'corresponds' to the entire activity of
the brain, whatever that may be, at the moment." (James)
- The problem: How does such unity come from such diversity?
- on the brain side "we see nothing but complexity and diversity"
-- it's a welter of things happening everywhere everywhen
- At any single time "your visual system is ... dealing with
color, motion and other feature in different visual areas. At the same
processing is going on in other sensory area, in memory systems and in
emotional system. Thoughts, are bubbling along, movements
are being planned and coordinated and sentences are being constructed."
- Dualist "solution" (= "give up" Dennett would say)
- "Dualists believe that consciousness is intrinsically unitary,
each person having their own single consciousness
that is quite different from their physical brain." (243)
- Popper and Eccles: "the unity of conscious experience is
by the self-conscious mind and not by the neural
machinery of the liaison areas f othe cerebral hemisphere. (1977: 362)
- "A far more constructive approach is t try t find ut how the
carries ut the integrating and unifying
- "A third, and final, approach is to try to find out how the brain
carries out these integrating and unifying functions."
The Binding Problem
How is visual experience unified?
- "your visual system is ... dealing with color, motion and their
features in different visual areas."
- yet, when you view a flipping coin "bits don't fly off. The
silver color doesn't depart from the shape, and the shape doesn't lag
behind the motion."
- The more general binding problem in cognitive science concerns
conjunctions of properties are represented, ranging from the
binding of shape and color in detecting blue triangles or red squares,
binding of words and phrases to their roles in sentences.
- "There are obviously close relationships between attention,
consciousness, and binding, but just what sort of
relationships is not yet clear." (246)
Binding by Synchrony
- Crick & Koch, & more
- studies of cats' visual systems show "oscillations in the range
f 35-75 hertz (i.e., 35-75 cycles per second), in which large numbers
of neurons all fired in synchrony with one another. "
- Christof von der Malsburg suggests "that this coordinated
firing might be the basis of visual binding"
- Crick & Koch go further, suggesting, "this synchronized
firing on, or near, the beat of a gamma oscillation (in the 35- to
range) might be the neural correlate of visual awareness" (Crick 1994:
- Other theories allow "for many kinds of synchronized neural
activity apart from that based on oscillations." (247)
- "although they explain how selected information is held
together to provide unified percepts, we may still
wonder whether this accounts for subjectivity"
- they say things that suggest they're committed to "Cartesian
- Crick speaks of "a single explicit representation"
- Engel et al speak of "access to phenomenal consciousness"
- Singer speaks of "inner-eye function" (2000: 134)
- Zeki's view: "a multiplicity of consciousnesses is the norm; the
unification that comes with self consciousness is an exception that is
only possible through language." (249)
- "[B]inding has to occur between the senses as well as within
- Synesthesia: "events in one sensory modality induce experiences
- tasting & hearing shapes & colors
- seeing different pitches (of sound) as different colors
- "Multisensory integration makes possible a world in which objects
can be recognized as the same thing, whether they
are touched, seen, tasted or heard." (251)
Rentry and the Dynamic Core
- Edelman and Tononi: two key features of consciousness
"Consciousness abhors holes or discontinuities" (2000b: 141)
Two types of consciousness:
- "each conscious state is an indivisible whole"
- "each person can choose among an immense number of different
- primary consciousness: had by many animal species
- short term memory giving them a "remembered present"
hither order consciousness [self-awareness?]
- hypothesized mechanism: "reentrant connections" among
- evidence: computer simulations "revealed how reentry can
solve the binding problem by coupling neuronal responses of distributed
cortical areas to achieve synchronization and global coherence."
- depends on renentrant connections between language and
- "these allow for the construction of a 'dynamic core'" which
"can involve completely different brain areas, leaving others still
active but not part of the core."
Unity as Illusion
- Enactive or Action Theories of
- Humphrey: "These
come to belong together as one Self that I am because they are engaged
in one and the same enterprise: the enterprise of steering me ...
through the physical and social world ... my selves have become
conscious through collaboration. (2002: 12)
- Hard Problem: why does the coordinating feel like something?
- Unity Denial: "does it
only seem continuous to itself by illusion?" (James 1890, i: 200)
- Dennett's theory of multiple
- there are multiple parallel processes going all the time
- when I reflect on the exercise ("Am I conscious now?"),
"[t]hen and only then, is a temporary stream of consciousness
concocted, making it seem as though we have been conscious all along."
- SB's summation: "Just as the fridge door is usually closed, so
we are usually in a state of parallel multiple drafts. Only when
we briefly open the door is the illusion created that the light is
always on." (255-6)
Superunity and Disunity
- Superunity: synesthesia
- multiple personality disorder,
- divided personality: out of body & near death experiences,
trance & hypnosis