G. Bradski et al., STORE WORKING-MEMORY NETWORKS FOR STORAGE AND RECALL OF ARBITRARY TEMPORAL SEQUENCES, Biological cybernetics, 71(6), 1994, pp. 469-480
Neural network models of working memory, called ''sustained temporal o
rder recurrent'' (STORE) models, are described. They encode the invari
ant temporal order of sequential events in short-term memory (STM) in
a way that mimics cognitive data about working memory, including prima
cy, recency, and bowed order and error gradients. As new items are pre
sented, the pattern of previously stored items remains invariant in th
e sense that relative activations remain constant through time. This i
nvariant temporal order code enables all possible groupings of sequent
ial events to be stably learned and remembered in real time, even as n
ew events perturb the system. Such competence is needed to design self
-organizing temporal recognition and planning systems in which any sub
sequence of events may need to be categorized in order to control and
predict future behavior or external events. STORE models show how arbi
trary event sequences may be invariantly stored, including repeated ev
ents. A preprocessor interacts with the working memory to represent ev
ent repeats in spatially separate locations. It is shown why at least
two processing levels are needed to invariantly store events presented
with variable durations and interstimulus intervals. It is also shown
how network parameters control the type and shape of primacy, recency
, or bowed temporal order gradients that will be stored.