Cortical Origin of Theta Error Signals

Abstract

A multi-scale approach elucidated the origin of the error-related-negativity (ERN), with its associated theta-rhythm, and the post-error-positivity (Pe) in macaque supplementary eye field (SEF). Using biophysical modeling, synaptic inputs to layer-3 (L3) and layer-5 (L5) pyramidal cells (PCs) were optimized to account for error-related modulation and inter-spike intervals. The intrinsic dynamics of dendrites in L5 but not L3 PCs generate theta rhythmicity with random phase. Saccades synchronized the phase of this theta-rhythm, which was magnified on errors. Contributions from L5 PCs to the laminar current source density (CSD) observed in SEF were negligible. The CSD derived from L3 PCs could not explain the observed association between their error-related spiking modulation and scalp-EEG. Laminar CSD comprises multipolar components, with dipoles explaining ERN features, and quadrupoles reproducing those for Pe. The presence of monopoles indicates diffuse activation. These results provide the most advanced explanation of the cellular mechanisms generating the ERN.