Visualizing Topographic Independent Component Analysis with Movies

TL;DR

This paper visualizes the activations of topographic ICA components in response to movies, revealing clustered and continuous activity patterns that resemble visual cortex organization.

Contribution

It introduces a method to visualize TICA basis activations over time, highlighting their topographic and dynamic properties in response to stimuli.

Findings

TICA basis activities are often clustered.

Activations move continuously over time.

Resemblance to visual cortex activity patterns.

Abstract

Independent component analysis (ICA) has often been used as a tool to model natural image statistics by separating multivariate signals in the image into components that are assumed to be independent. However, these estimated components oftentimes have higher order dependencies, such as co-activation of components, that are not accounted for in the model. Topographic independent component analysis(TICA), a modification of ICA, takes into account higher order dependencies and orders components topographically as a function of dependence. Here, we aim to visualize the time course of TICA basis activations to movie stimuli. We find that the activity of TICA bases are often clustered and move continuously, potentially resembling activity of topographically organized cells in the visual cortex.