PT  - JOURNAL ARTICLE
AU  - Akash Umakantha
AU  - Rudina Morina
AU  - Benjamin R. Cowley
AU  - Adam C. Snyder
AU  - Matthew A. Smith
AU  - Byron M. Yu
TI  - Bridging neuronal correlations and dimensionality reduction
AID  - 10.1101/2020.12.04.383604
DP  - 2020 Jan 01
TA  - bioRxiv
PG  - 2020.12.04.383604
4099  - http://biorxiv.org/content/early/2020/12/04/2020.12.04.383604.short
4100  - http://biorxiv.org/content/early/2020/12/04/2020.12.04.383604.full
AB  - Two commonly used approaches to study interactions among neurons are spike count correlation, which describes pairs of neurons, and dimensionality reduction, applied to a population of neurons. While both approaches have been used to study trial-to-trial correlated neuronal variability, they are often used in isolation and have not been directly related. We first established concrete mathematical and empirical relationships between pairwise correlation and metrics of population-wide covariability based on dimensionality reduction. Applying these insights to macaque V4 population recordings, we found that the previously reported decrease in mean pairwise correlation associated with attention stemmed from three distinct changes in population-wide covariability. Overall, our work builds the intuition and formalism to bridge between pairwise correlation and population-wide covariability and presents a cautionary tale about the inferences one can make about population activity by using a single statistic, whether it be mean pairwise correlation or dimensionality.Competing Interest StatementThe authors have declared no competing interest.