Modeling the role of the
frontal lobes in sequential performance.
An avalanche model of motor sequence encoding is presented.
The ultimate aim is to reproduce data showing that monkeys with frontal
lobe damage can learn an invariant sequence of movements if it is rewarded,
but cannot learn to perform any one of several variations on a sequence
if all are rewarded. In this article, we present simulations of the
primary learning of sequences, and demonstrate parameters that can lead
to a primacy effect in recalling items of this sequence from long-term
memory. Two different versions of the avalanche network and their
simulations are presented, of which the second version includes a layer
of sequence detectors. Suggestions are made for including yet another
layer to classify these temporal sequences and group them together based
on reward. Analogies are drawn between the classifier layer and the
frontal lobes, and between the avalanche module and part of the basal ganglia.