Guest guest Posted October 19, 2003 Report Share Posted October 19, 2003 http://www.ulb.ac.be/event/ASSC4/prog/abstracts.html PL-10"The Disunity of Consciousness"Semir ZekiContact:Semir ZekiUniversity College LondonWellcome Department of Cognitive NeurologyGower Street, London WC1E 6BTU.K.s.zekiThe most fundamental function of the visual brain is to acquireknowledge about the constant, essential properties of the visual world,in conditions in which the information reaching the brain is neverconstant from moment to moment. This requires the brain to undertakecomplex operations on the incoming visual signals, discounting all thatis not essential for it to acquire knowledge about the world, selectingthat which is important and subjecting the latter to operations thatmake the brain independent of the continually changing and non-essentialinformation reaching it. One strategy that the brain uses in undertakingthis task is that of functional specialization, through which differentessential features, such as motion and colour, are extracted inspecialized and geographically distinct visual areas lying outside theprimary visual cortex area V1. Our recent psychophysical experimentsshow that, just as the processing systems for different attributes ofvision are separate, such as colour, form and motion are perceived atdifferent times, with colour leading motion by about 80 ms, thus leadingto a perceptual asynchrony in terms of real time. The end-result of theoperations in these individual areas is the acquisition of knowledge.But knowledge can only be acquired in the conscious state. A consciousawareness is therefore the corollary of activity in the specializedvisual areas. Recent experiments using imaging and time resolutionmethods as well as patients blinded by lesions either in V1 or in moreextensive parts of the visual cortex show that the activity in one or asmall number of visual areas, without involvement of V1, can give riseto both conscious experience and a crude knowledge about the visualworld. This leads us to the conclusion that consciousness itself may bemodular.The work of our laboratory is supported by the Wellcome Trust, London. ....and other nice abstracts. regards sk The New with improved product search Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You are posting as a guest. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.