Newsgroups: comp.ai.philosophy
From: ohgs@chatham.demon.co.uk (Oliver Sparrow)
Path: cantaloupe.srv.cs.cmu.edu!das-news2.harvard.edu!news2.near.net!howland.reston.ans.net!news.sprintlink.net!peernews.demon.co.uk!chatham.demon.co.uk!ohgs
Subject: Re: When is a simulation of a Y a Y? (Was Bag the Turing
References: <3enci8$9kt@tadpole.fc.hp.com> <3es3qa$g0o@agate.berkeley.edu> <3esfj0$kfv@tadpole.fc.hp.com> <789814632snz@chatham.demon.co.uk> <D2D0sM.55o@spss.com>
Organization: Royal Institute of International Affairs
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Date: Mon, 16 Jan 1995 14:55:00 +0000
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In article <D2D0sM.55o@spss.com> markrose@spss.com "Mark Rosenfelder" writes:

 > Oliver Sparrow <ohgs@chatham.demon.co.uk> wrote:

>>The nature of the simplified representation is important, however. Our foveal 
>>vision subtends about half a degree (your thumbnail at arms length) and it is 
>>only within this that we can see detail. Everything else is an impressionist 
>>blur. 
  
 > The fact that we are not aware of everything outside the fovea being a blur
 > does *not* show that we have a "detailed internal representation".
 >                                    ......crunch ....  We never construct
 > such a filled-in picture *because we never need it*; when we need to know
 > the details at a particular location we *look* there, focussing our foveal
 > vision on it. 

Yes; certainly; but my point is that we act upon a generalised visualisation
of our surroundings *even though we cannot ever see all of it at the same
time*. That we have to update; and that we switch our attention in order to 
do so does not alter the fact that we act upon the basis of a virtual reality
which we generate internally. It may be illusory - whatever that means in this
field! - but it is fit for purpose.

_________________________________________________

  Oliver Sparrow
  ohgs@chatham.demon.co.uk
