Correlated variability modifies working memory fidelity in primate prefrontal neuronal ensembles

• DOI: 10.1073/pnas.1619949114
• Publication Date: 2017-03-09T02:10:46Z
• Authors: Matthew L. Leavitt; Florian Pieper; Adam J. Sachs; Julio C. Martinez...
• Keywords: Neural coding; Premovement neuronal activity

Neurons in the primate lateral prefrontal cortex (LPFC) encode working memory (WM) representations via sustained firing, a phenomenon hypothesized to arise from recurrent dynamics within ensembles of interconnected neurons. Here, we tested this hypothesis by using microelectrode arrays examine spike count correlations (rsc ) LPFC neuronal during spatial WM task. We found pattern pairwise rsc maintenance indicative stronger coupling between similarly tuned neurons and increased inhibition dissimilarly then used linear decoder quantify effects high-dimensional structure on information coding ensembles. that could facilitate or impair coding, depending size ensemble tuning properties its constituent A simple optimization procedure demonstrated near-maximum decoding performance be achieved relatively small number These WM-optimized subensembles were more signal correlation (rsignal )-diverse anatomically dispersed than predicted statistics full recorded population neurons, they often contained poorly WM-selective, yet enhanced fidelity shaping ensemble's structure. observed as mechanism for WM-related activity can increase representations. Thus, arises complex synergy single neuron multidimensional, ensemble-level phenomena.