Age-related changes in noise correlations in a decision-making task

Abstract

Age-related declines in sensory and cognitive performance may arise from changes in neural variability, including how variability is shared across neural populations. Here, we examined age-related changes in noise correlations, which quantify shared trial-to-trial variability between pairs of neurons, in mice performing a visual decision-making task. We analysed large-scale extracellular recordings from 149 mice (male and female) spanning 3 to 20 months of age, comprising 348,937 simultaneously recorded neuron pairs within 17 cortical and subcortical brain regions. Across the dataset, noise correlations showed expected relationships with firing rate, anatomical distance, and signal correlations, consistent with canonical observations of noise correlations. Age associations with noise correlations varied across regions and were bidirectional: the age-related increase in primary visual cortex replicated previous findings in this region, whereas decreases were observed elsewhere. Evidence for age-related differences in stimulus-induced changes was limited. Together, these findings indicate that ageing is associated with regionally heterogeneous changes in shared neural variability rather than a brain-wide shift.