PT  - JOURNAL ARTICLE
AU  - Sihn, Duho
AU  - Kim, Sung-Phil
TI  - Spatio-temporally efficient coding assigns functions to hierarchical structures of the visual system
AID  - 10.1101/2021.08.13.456321
DP  - 2021 Jan 01
TA  - bioRxiv
PG  - 2021.08.13.456321
4099  - http://biorxiv.org/content/early/2021/09/04/2021.08.13.456321.short
4100  - http://biorxiv.org/content/early/2021/09/04/2021.08.13.456321.full
AB  - Hierarchical structures constitute a wide array of brain areas, including the visual system. One of the important questions regarding visual hierarchical structures is to identify computational principles for assigning functions that represent the external world to hierarchical structures of the visual system. Given that visual hierarchical structures contain both bottom-up and top-down pathways, the derived principles should encompass these bidirectional pathways. However, existing principles such as predictive coding do not provide an effective principle for bidirectional pathways. Therefore, we propose a novel computational principle for visual hierarchical structures as spatio-temporally efficient coding underscored by the efficient use of given resources in both neural activity space and processing time. This coding principle optimises bidirectional predictions over hierarchical structures by simultaneously minimising temporally differences in neural responses and maximising entropy in neural representations. Simulations demonstrated that the proposed spatio-temporally efficient coding was able to assign the function of appropriate neural representations of natural visual scenes to visual hierarchical structures. Furthermore, spatio-temporally efficient coding was able to predict well-known phenomena, including deviations in neural responses to unfamiliar inputs and bias in preferred orientations. Our proposed spatio-temporally efficient coding may facilitate deeper mechanistic understanding of the computational processes of hierarchical brain structures.Competing Interest StatementThe authors have declared no competing interest.