Attention improves information flow between neuronal populations without changing the communication subspace

Visual attention allows observers to change the influence of different parts of a visual scene on their behavior, suggesting that information can be flexibly shared between visual cortex and neurons involved in decision making. We investigated the neural substrate of flexible information routing by analyzing the activity of populations of visual neurons in the medial temporal area (MT) and oculo-motor neurons in the superior colliculus (SC) while rhesus monkeys switched spatial attention. We demonstrated that attention increases the efficacy of visuomotor communication: trial-to-trial variability in SC population activity could be better predicted by the activity of the MT population (and vice versa) when attention was directed toward their joint receptive fields. Surprisingly, this improvement in prediction was not explained by changes in the dimensionality of the shared subspace or in the magnitude of local or shared pairwise noise correlations. These results lay a foundation for future theoretical and experimental studies into how visual attention can flexibly change information flow between sensory and decision neurons. [Display omitted] •Attention improves linear response prediction between MT and SC•Prediction accuracy within areas is not affected•The dimensionality of the communication subspace between MT and SC remains the same•Improvements in prediction accuracy are not contingent on dimensionality changes Srinath et al. study how attention affects information flow between two areas. Attention improves prediction accuracy of linear models between areas MT and SC, but not within areas. Therefore, attention could affect decision making by preserving local sensory information processing and altering information shared with other areas.