There is some evidence that the basal ganglia modulates the thalamus in
its relationship to the prefrontal cortex. Disorders of this system are
believed to be responsible for some of the cognitive symptoms of
parkinson's disease and schizophrenia. We modeled the modulation of
oscillating thalamocortical loops by a projection from the basal ganglia.
These oscillations may be responsible for short-term persistence in
working memory. Two papers were published on the subject,
V. Gullapalli and J. Gelfand, A Model of the Dynamics of
Prefrontal Cortico-Thalamo-Basal Ganlionic Loops, in Grafman, J. et al.,
Eds., Structure and Functions of the Human Prefrontal Cortex, The Annals
of the New York Academy of Sciences, Vol. 769, (1996), p.765-769.
J. Gelfand, V. Gullapalli, C. Raye, M. Johnson and J. Henderson,
The Dynamics Of Prefrontal Cortico-Thalamo-Basal Ganglionic Loops and
Short-Term Memory Interference Phenomena, M. Shafto and P. Langley, Eds.,
Proceedings of the 19th Annual Cognitive Science Conference, Lawrence
Erlbaum, (1997), p. 253-258.
The later is available in PostScript form on my Web page,
Also see,
Cohen, J., Braver, T., O'Reilly, R., A computational approach to
prefrontal cortex, cognitive control and schizophrenia: recent
developments and current challenges, Phil. Trans. R. Soc. London. B, 351,
1515-1527 (1996).
Jack
--------------------------
Jack Gelfand
Princeton University
Department of Psychology
Princeton, NJ 08544
On Tue, 30 Mar 1999, Comp-Neuro
Mailing List wrote:
>
> From ASIM.ROY@asu.edu Mon Mar 29 17:19:27 1999
> Date: Tue, 23 Mar 1999 23:27:06 -0700
> From: Asim Roy <ASIM.ROY@asu.edu>
> Subject: Request for information
>
> (My apologies if you get multiple copies of this.)
>
> I have been arguing for some time now that control theoretic notions are
> indeed applicable to the brain - that there are parts of the brain that
> control other parts of the brain. Not being a neuroscientist, my arguments
> have depended on: (1) a careful examination of the connectionist learning
> algorithms and the discovery that they indeed use control theoretic notions,
> that they couldn't get away from it, and (2) an external observation of the
> living systems that have brains (humans, animals) and the discovery that
> their brains control the rest of the system (a profound discovery indeed by
> any scientific standard and it certainly deserves a Nobel prize!!). A
> control theoretic approach resolves many of the inherent problems of
> connectionism.
>
> This note is to enquire whether there have been any studies in
> neuroscience/neurobiology to show that some parts of the brain control other
> parts. I understand that the modulatory transmitters have their own
> characteristic sources in the midbrain. For example, dopamine originates
> from the ventral tegmentum and the substantia nigra; serotonin from the
> raphe nucleus; norepinephrine from the locus ceruleus; and acetylcholine
> from the nucleus basalis.
>
> My question is: if these neuromodulatory sources or other relevant regions
> of the brain were lesioned, what would be the impact on the functioning of
> the brain? Would it have a wide impact on the functioning of the brain, or
> would it just result in the loss of one or more particular functions of the
> brain? Any references and summaries of studies would be highly appreciated.
>
> With regards,
> Asim Roy
> Arizona State University
>