Representational structure or task structure? Bias in neural representational similarity analysis and a Bayesian method for reducing bias.

ABSTRACT: The activity of neural populations in the brains of humans and animals can exhibit vastly different spatial patterns when faced with different tasks or environmental stimuli. The degrees of similarity between these neural activity patterns in response to different events are used to characterize the representational structure of cognitive states in a neural population. The dominant methods of investigating this similarity structure first estimate neural activity patterns from noisy neural imaging data using linear regression, and then examine the similarity between the estimated patterns. Here, we show that this approach introduces spurious bias structure in the resulting similarity matrix, in particular when applied to fMRI data. This problem is especially severe when the signal-to-noise

SUBMITTER: Cai MB 

PROVIDER: S-EPMC6553797 | biostudies-literature | 2019 May

REPOSITORIES: biostudies-literature