|Budget Amount *help
¥2,000,000 (Direct Cost : ¥2,000,000)
Fiscal Year 1997 : ¥1,000,000 (Direct Cost : ¥1,000,000)
Fiscal Year 1996 : ¥1,000,000 (Direct Cost : ¥1,000,000)
The head investigator (H.Fujii) and his collaborators have proposed a new hypothesis on the encoding mechanism of the brain-the dynamical cell assembly hypothesis . The hypothesis is intended to understand in a unified way recent experimental data exhibiting the dynamics undergoing in the brain, by, e.g., neuro-imaging, Joint PSTH and so on, which are sometimes difficult to interpret within the framework of conventional network "theories" based on "rate code hypothesis", and also to resolve theoretical difficulties on the brain coding, e.g., the binding problem. This research is the first step to confirm the theory from both experimental and theoretical standpoints.
As a continued work of the "dynamical cell assembly hypothesis", I have, firstly, summarized our standpoint on the binding mechanism which the brain may actually uses -the "correlational scinario of binding", and secondly, I have constructed a constructive, but conceptual computer model of "binding" of two objects with two attributes (i.e., two bars with different lengths and colors). The model is constructed with abstract coincidence detector neurons. The behavior of the model is :
(I) It presrves a complete position invariancy of the stimuli.
(ii) It contains a dynamic mechanism of binding of attributes which are processed in a distant regions. Dynamical linking and re-organization of cell assemblies are performed in the context dependent manner.
(iii) Multiple correlational dynamics are running, each of which represents a unified image of one of the visual object. A member of a cell assembly are identified dynamically by cross correlations.