Near-saddle-node bifurcation behavior as dynamics in working memory for goal-directed behavior.
In consideration of working memory as a means for goal-directed behavior in nonstationary environments, we argue that the dynamics of working memory should satisfy two opposing demands: long-term maintenance and quick transition. These two characteristics are contradictory within the linear domain. We propose the near-saddle-node bifurcation behavior of a sigmoidal unit with a self-connection as a candidate of the dynamical mechanism that satisfies both of these demands. It is shown in evolutionary programming experiments that the near-saddle-node bifurcation behavior can be found in recurrent networks optimized for a task that requires efficient use of working memory. The results suggests that the near-saddle-node bifurcation behavior may be a functional necessity for survival in nonstationary environments.
Nakahara
H
H
University of Tokyo, Japan. nakahara@taikan.u-tokyo.ac.jp
Doya
K
K
D000818:Animals; D001519:Behavior / Q000502:physiology*; D006040:Goals; D006801:Humans; D008568:Memory / Q000502:physiology*; D008959:Models, Neurological