Attentional fluctuations induce shared variability in macaque primary visual cortex

• Published in: Nature communications Vol. 9; no. 1; pp. 2654 - 14
• Main Authors: Denfield, George H., Ecker, Alexander S., Shinn, Tori J., Bethge, Matthias, Tolias, Andreas S.
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 09.07.2018; Nature Publishing Group; Nature Portfolio
• Subjects: 631/378/2613/1875; 631/378/2649/1310; Action Potentials - physiology; Animals; Attention - physiology; Correlation; Cues; Eye Movements - physiology; Fluctuations; Humanities and Social Sciences; Hypotheses; Macaca mulatta; Male; multidisciplinary; Nerve Net - physiology; Neurons; Neurons - physiology; Neurosciences; Noise; Photic Stimulation; Population; Science; Science (multidisciplinary); Variability; Visual cortex; Visual Cortex - physiology; Visual Pathways - physiology; Visual stimuli
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/s41467-018-05123-6

Variability in neuronal responses to identical stimuli is frequently correlated across a population. Attention is thought to reduce these correlations by suppressing noisy inputs shared by the population. However, even with precise control of the visual stimulus, the subject’s attentional state varies across trials. While these state fluctuations are bound to induce some degree of correlated variability, it is currently unknown how strong their effect is, as previous studies generally do not dissociate changes in attentional strength from changes in attentional state variability. We designed a novel paradigm that does so and find both a pronounced effect of attentional fluctuations on correlated variability at long timescales and attention-dependent reductions in correlations at short timescales. These effects predominate in layers 2/3, as expected from a feedback signal such as attention. Thus, significant portions of correlated variability can be attributed to fluctuations in internally generated signals, like attention, rather than noise. Attention reduces correlated variability in population activity, however the effect of fluctuations in attentional state has not been studied. Here, the authors report in a novel visual task that fluctuations in attentional allocation have a pronounced effect on correlated variability at longer timescales.