Recurrent Connections Might Be Important for Hierarchical Categorization.

Narihisa Matsumoto,Masaumi Shimizu,Yasuko Sugase-Miyamoto,Masato Okada,Yusuke Taguchi,Shun Katakami

doi:10.3389/fnsys.2022.805990

Abstract

Visual short-term memory is an important ability of primates and is thought to be stored in area TE. We previously reported that the initial transient responses of neurons in area TE represented information about a global category of faces, e.g., monkey faces vs. human faces vs. simple shapes, and the latter part of the responses represented information about fine categories, e.g., facial expression. The neuronal mechanisms of hierarchical categorization in area TE remain unknown. For this study, we constructed a combined model that consisted of a deep neural network (DNN) and a recurrent neural network and investigated whether this model can replicate the time course of hierarchical categorization. The visual images were stored in the recurrent connections of the model. When the visual images with noise were input to the model, the model outputted the time course of the hierarchical categorization. This result indicates that recurrent connections in the model are important not only for visual short-term memory but for hierarchical categorization, suggesting that recurrent connections in area TE are important for hierarchical categorization.

Highlights

Visual short-term memory is an important ability of primates
The combined model outputted different categories during the time course. These results indicate that recurrent connections in the Hopfield model are important for short-term memory and for hierarchical categorization, suggesting that recurrent connections in area TE are important for hierarchical categorization
We constructed a deep neural network (DNN), i.e., AlexNet (Krizhevsky et al, 2012), to compare the information represented in each layer and the information encoded by a neural population in area TE with a visual stimulus set that included human and monkey faces (Matsumoto et al, 2021)

Summary

Introduction

Visual short-term memory is an important ability of primates. The information about the objects is processed from the retina to the visual cortex in the brain. The object information is processed from V1 to area TE of the inferior temporal cortex (Mishkin et al, 1983). Visual short-term memory is thought to be stored in area TE (Sugase-Miyamoto et al, 2008) and the prefrontal cortex (Freedman et al, 2001). In area TE, some neurons respond to complex objects, faces, and so on and represent information about a global category, e.g., human vs monkey vs simple shapes, earlier than fine category information about faces, e.g., facial expression or identity (Sugase et al, 1999; Matsumoto et al, 2005a; Sugase-Miyamoto et al, 2014).

Methods

Results

Conclusion