"ashwin kelkar" <ashwin_k18 at my-deja.com> wrote in message
news:88nldd$ku2$1 at nnrp1.deja.com...
> how do we define a thought ??
> i know how a stimulus might be defined, when it is recieved by the
> appropriate part in the neocoretx it is interpreted and that electrical
> activity pattern can be called a stimulus. but then how do we define a
> thought as it just cannot be defined as a pattern of electircal activity
> as i think no two thoughts may originate in the same way and in the same
> place of the brain. I am basing this on the fact that no two thoughts in
> the mind are exactly identical. there are many things which differ
> about the same thought about the same thing. Then what is a thought ?
> should they be called as a pattern of connectivity rather than a pattern
> of activity ?
I think a 'thought' could be defined as an associatively activated
representation. When events co-occur in the world, the brain forms
associations between those events. For example, with a rat, when a tone is
presented followed by a food pellet, an association develops between that
tone and that food pellet. When the tone is subsequently presented, that
evokes the representation of the pellet by way of the associative link
between the two. As that food pellet is not actually present, it is a
thought of the food pellet, which in turn can actually guide behaviour (c.f.
Pavlovian conditioning). In humans similarly, a particular smell, or strand
of music, evokes a representation of an event (a night at the theatre, a
particular place). That evoked representation is a thought e.g. 'i just
thought about that night when we went to see King Lear'.