Greg Detre
Wednesday, 10 October, 2001
Prof. Richard Gregory, 1st week
consciousness = an empirical question � build the machines and see
expect it to have some sort of function
consider the thought experiment � one cannot run upstairs while thinking carefully about it � if you do, you either slow down or fall over
consciousness makes the present moment special
e.g. the risk of absentmindedness when crossing the road if we are not conscious of the present moment
Luria � Mr S, whose incredible memory made the present seem no stronger or more vivid than the past
he had such a good memory that he�d confuse the current alarm clock with the remembered one from the night before
perception = 99% knowledge stored from the past
J J Gibson�s direct theory of perception: information comes from the ambient light in the environment picked up by the brain
can�t be purely evolved knowledge, because we wouldn�t be able to learn to use a telephone, for example
Gregory prefers an indirect theory of perception, mediated by the nervous system
if you followed Gibson, then you�d say that the qualia reside in the object
rather, seeing the object is created in the brain, based on past experience � constructive, Helmholzian
compares the vividness of seeing vs remembering a bright object (at least in normal circumstances)
in dreams/hallucinations, the brain is working abnormally
in dreams, you don�t have to deal with the present
how much of colour is generated in the brain? Gregory thinks all qualia are generated in the brain
blindspot � if you then blank the scree, you get a kind of afterimage effect where you see your created qualia
qualia generated at a higher level than just afferent input
brain mechanisms responding to qualia �/span> qualia, which are responded to �/span> an infinite regress?
probably some hierarchy of top-downness
how would an engineer deal with top-down interference???
multiple drafts
consciousness represented purely as executive function???
surely it�s the other way round � memories are stored in synapses and input = activity � the vividness arises naturally out of this � surely the brain would never confuse the two???
dreams, LSD etc???
surely dreams show that the vivdness is not so much a function as a property of certain brain processes???
Russell on Locke�s PQ/SQ distinction???
wouldn�t you be evolutionarily better off knowing there�s a blindspot???
how will we empirically determine whether our built machines are actually conscious???
present and memory are represented differently � 99% top down is not ture, given how much we react to the present
arguably though, our behaviour is so fitted to a very stable environment
do autistic people see illusions??? apparently so
in Luria�s case of Mr S, that sounds like a different sort of problem, not being able to distinguish present from past � after all, it would be relatively easy to encode less vividness into memories than the present moment without having that as the reason we have qualia � Mr S must have had this vivid memory as a separate defect that perhaps was a secondary result of his incredibly detailed memory
surely, with the exception of perhaps Putnam and a few others, Gregory is fighting a straw man against direct theories of perception???