Hippocampus and independent component analysis

[Andras Lorincz]

I would like to announce the availability of a new paper on 
the functional model of the hippocampus. The model fits
smoothly the overall anatomical structure and its two-phase
operational mode. The model is built on two basic postulates:
(1) the entorhinal-hippocampal loop serves as a control 
    loop with control errors initiating plastic changes 
    in the hippocampus and 
(2) the hippocampal output develops independent components 
    in the entorhinal cortex

The paper

        AUTHOR:   Andras Lorincz
        TITLE:    Forming independent components via temporal 
                  locking of reconstruction architectures: 
                  a functional model of the hippocampus 
        JOURNAL:  Biological Cybernetics (in press)

may be obtained from:

http://iserv.iki.kfki.hu/New/pub.html


Abstract:

The assumption is made that the formulation of relations as
independent components (IC) is a main feature of computations 
accomplished by the brain.  Further, it is assumed that memory traces
made of non-orthonormal ICs make use of feedback architectures to form 
internal representations. Feedback then leads to delays and delays in 
cortical processing form an obstacle to this relational processing. 
The problem of delay compensation is formulated as a speed-field tracking 
task and is solved by a novel control architecture. It is shown that in
addition to delay compensation the control architecture can also shape 
long term memories to hold independent components if a two-phase
operation mode is assumed. Features such as a trisynaptic loop and
a recurrent collateral structure at the second stage of that loop emerge
in a natural fashion. Based on these properties a functional model of the 
hippocampal loop is constructed.


Andras Lorincz
Department of Information Systems
Eotvos Lorand University, Budapest, Hungary