Susan Blackmore, Consciousness: A Very Short Introduction, Oxford U. P. 2005. Chapters 3-5. [Comments in square brackets are my own thoughts.] Ch. 3: TIME AND SPACE ^^^^^^^^^^^^^^^^^^^^^ This chapter is about the temporal relations between world events, neural events, and consciously perceived events, the role of attention, and about some theories of consciousness (again, dualist theories; "HOT" theories that say that awareness of what we are experiencing is essential for consciousness; Baars' theory; neuronal loop/assembly theories; and Dennett's multiple-drafts theory, claiming many processes can compete for attention, and we are conscious of whichever ones are most prominent at a given moment) Libet's delay (p.33-36) ^^^^^^^^^^^^^ Consciousness of a feeling (even when evoked by direct brain stimulation) comes about half second after stimulation. [So conscious awareness comes only after significant processing -- not surprising.] But that seems to imply that everything we see and hear happened half a second ago. [I think that's why insects manage to bite us before we can slap them -- they have half a second before we notice, and probably another half second before the hand hits!] However, unconscious reflexes are a bit faster. [So in sports, success depends partly on reflexes, and partly on extrapolating from what was the case half a second ago. That's why a sucker punch, if not signalled by any small posture changes or expression changes, is virtually impossible to block; and why you can't catch that dollar bill dropped suddenly between your fingers.] Why don't we realize all this? "Subjective antedating". Apparently Eccles, Popper, and Penrose think our capacity for fast action, despite the 1/2sec delay, indicates "mind over matter". But most others don't. Blackmore thinks the notion of an external event like a touch on the arm "reaching consciousness" encounters the hard problem. [I would suppose the processing is needed to abstract a location and category of sensation from the signal stream; that leaves the question why the abstracted information becomes conscious.] Clocks and rabbits (p.36-39) ^^^^^^^^^^^^^^^^^^^^^^^^^^^ - retroactive consciousness (e.g., clock chimes) [This suggests to me we abstract quite a bit of information from the auditory inpput stream, storing it at least for a short time (a few seconds?), but don't become conscious of abstracted info till we attend to it (evidence for HOT theories?] - the cutaneous rabbit -- we reorganize the actual events somewhat. [I'm not sure why this tactile illusion challenges the "stream of consciousness".] Driving unconsciously (p.40-43) ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ We need little conscious attention for driving. [But I think the fact that we can't remember what specific events happened along the way doesn't mean we weren't paying attention at the time -- they just weren't important enough to be committed to memory! So in retrospect, it seems as if we were mentally absent.] Some theorists say attention is essential to consciousness. But what directs attention? Conscious processes? See also Arien Mack and Irvin Rock, next chapter, p.62, inattentional blindness. Theories of consciousness (p.43-49) ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ - Eccles, Popper, & Penrose (dualism) - Penrose and Hameroff: microtubules & quantum effects - HOT theories [HOT requires a self-model; so are creatures without self-model not conscious? I think McDermott would say yes.] - Baars' global workspace theory; doesn't explain why any workspace contents are conscious, says Blackmore. [globally available abstractions" available to self-model?] - Dennett's multiple drafts theory - What was I conscious of a moment ago? [Just because the stream of consciousness leaves few traces for recall doesn't mean it didn't happen!] Ch. 4: A GRAND ILLUSION ^^^^^^^^^^^^^^^^^^^^^^^ Illusions, the role of emotion, subliminal perception, etc. All indicating a faulty intuitive conception of consciousness... "Vision is a grand illusion" - visual illusions (p.51) - the illusion that consciousness is needed for really tough problems (p.52-3) - There's much we perceive and don't realize we perceive (p.54-5) e.g., subliminal perception (word priming), intuitive assessment of people, situations - we fill in gaps: occlusion; Dennett's house of Marilyns -- fast detection of oddities gives illusion of total consciousness; Gregory & Ramachandran - filling in textures, colors, even "unreadable" letters (non-foveated) - change blindness (p. 58-60): "the richness of our visual world is an illusion" (the pedestrian & the door carriers, etc) [I disagree: we just don't record much of it; and why should we use up valuable synapses, when it's right before us?!] - there's much we're not aware of, though it's right before us; inattentional blindness (Mack & Rock) -- prominent objects missed if not attended to. [movie??] - "Every time we move our eyes we throw away most of the available information" [I think we don't throw away much, because we don't *record* much in the first place. Mobile robots don't store films, either.] - Levin & Simon -- only the gist is retained; (p.63) somewhat similarly, Ronald Rensink; [sounds plausible; however, MIT cognitive scientist George Alvarez has shown that (a) we do perceive the statistical structure of non- foveated regions, and (b) we do retain enough detail in LTM to be able to categorize thousands of briefly seen images, mixed with new ones, as previously seen or new.] Blackmore thinks we can't find the "movie in the brain" that Crick and Damasio want to find. [But I think we might - it just doesn't get recorded; whatever parts we attend to *do* get transduced into conceptual representations in STM, but this too may be largely forgotten, i.e., not committed to LTM.] Ch. 5: THE SELF ^^^^^^^^^^^^^^ The feeling of "the self" as "owner" of body and brain; [I think there's a confusion here between "having" as "having- as-part" and as "possessing as owner. An exercise: take the first paragraph of the chapter and change all "I"s to "you"s. Look: if someone touches me on the shoulder or on my toe, did they touch ME? Of course they did. So I'm NOT something separate from my parts! I could see how a robot, equipped with an initial "self" concept to which it ascribes its perceptions, could also arrive at a confused notion of what that "self" corresponds to in the world. After all, it has no firm basis a priori on which to decide what parts to include as part of itself, and what parts to regard as just objects that it owns and controls? A person with prosthetic limbs might have a hard time in that respect as well.] Split brains (p.70-74) ^^^^^^^^^^^^^^^^^^^^^ - e.g., show pictures to one hemisphere, words to the other --> two selves; confabulation; Parfit claims there's neither one self nor two selves; there are just experiences, but no-one having them. [Seems silly to me. There are two selves that overlap (mostly in sharing the body, just like extreme Siamese twins). Each has a self-model.] Hypnosis, multiple personalities (dissociative disorder).(p.75-8) ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ [Well, why not multiple self-models? The self-modelling idea doesn't get enough attention here. We could build robots with multiple self-models, even separate knowledge bases; so why shouldn't it be possible in people? Recent example: Sassy Beyonce and Sasha] Theories of self (p.78-81) ^^^^^^^^^^^^^^^^^^^^^^^^^ - William James (p.79) distinguished "me" (objective) and "I" (subjective) [a rare mistake, I think.] "Thought is itself the thinker" [cute, but not too coherent, I think.] - All the theories mentioned -- Ramachandran, even Baars, Damasio -- are formulated in terms of neural activity [and I think as such fail to latch on to the idea of an internal symbol that stands for the self -- an obvious thought from an AI perspective.] Dennett (see p.81) does hint in the direction of a self-model -- "a center of narrative gravity". But language then supposedly "spins" this into an "inner self". [I think it just relies on an inner *symbol* for the self -- where that symbol simply denotes the person as a whole! The "inner self" idea (as opposed to an inner *symbol* for oneself) leads to hopeless confusion, and the conclusion that "there is no-one having these experiences"! That conclusion should trigger some sanity-alarms...]