Transitions between Multiband Oscillatory Patterns Characterize Memory-Guided Perceptual Decisions in Prefrontal Circuits

Abstract

Neuronal activity in the lateral prefrontal cortex (LPFC) reflects the structure and cognitive demands of memory-guided sensory discrimination tasks. However, we still do not know how neuronal activity articulates in network states involved in perceiving, remembering, and comparing sensory information during such tasks. Oscillations in local field potentials (LFPs) provide fingerprints of such network dynamics. Here, we examined LFPs recorded from LPFC of macaques while they compared the directions or the speeds of two moving random-dot patterns, S1 and S2, separated by a delay. LFP activity in the theta, beta, and gamma bands tracked consecutive components of the task. In response to motion stimuli, LFP theta and gamma power increased, and beta power decreased, but showed only weak motion selectivity. In the delay, LFP beta power modulation anticipated the onset of S2 and encoded the task-relevant S1 feature, suggesting network dynamics associated with memory maintenance. After S2 onset the difference between the current stimulus S2 and the remembered S1 was strongly reflected in broadband LFP activity, with an early sensory-related component proportional to stimulus difference and a later choice-related component reflecting the behavioral decision buildup. Our results demonstrate that individual LFP bands reflect both sensory and cognitive processes engaged independently during different stages of the task. This activation pattern suggests that during elementary cognitive tasks, the prefrontal network transitions dynamically between states and that these transitions are characterized by the conjunction of LFP rhythms rather than by single LFP bands.

Prefrontal Neurons Represent Motion Signals from Across the Visual Field But for Memory-Guided Comparisons Depend on Neurons Providing These Signals

“…First, the saccades reporting the trial type were only allowed 1000 ms after S2, long after the CEs first emerged. Second, similar CEs were observed in previous experiments in which monkeys reported their decision with button presses rather than saccades (Zaksas and Pasternak, 2006;Hussar andPasternak, 2012, 2013;Wimmer et al, 2016). Finally, the observed loss of comparison signals on trials with spatially separated S1 and S2 makes it unlikely that CEs were associated with saccade direction.…”

“…Comparison signals require stimuli at the same location As in our previous work, we found that responses of many LPFC neurons during S2 were modulated by the preceding direction in S1 (Zaksas and Pasternak, 2006;Lui and Pasternak, 2011;Hussar andPasternak, 2012, 2013;Wimmer et al, 2016). These CEs strongly correlated with perceptual decisions and were unrelated to the largely transient stimulus-selective delay activity (Hussar andPasternak, 2012, 2013).…”

Oscillatory Dynamics of Prefrontal Cognitive Control

“…Here we reviewed recent evidence that supports the notion that the PFC employs oscillatory dynamics to coordinate large-scale neuronal interactions, which support the integration of task-relevant goals and rules in activity-silent cortical states [30,107,108] and predict behavior [28,33,38,41,82]. In particular, these findings suggest that phase resetting [33,35] and neuronal entrainment [72,109] reflect key mechanisms of PFC mediated top-down control.…”

Роль Бета- И Гамма-Ритмов В Реализации Функций Рабочей Памяти

“…В работе К. Виммера с соавт. (Wimmer et al, 2016) регистрирова лись спайковая активность и локаль ный потенциал (L FP) в дорзолатеральной префронтальной коре (dlPF C ) обезьян, выполняющих зада чу на отложенное установление соот ветствия (delayed m atch-to-sam ple task, DM S), в которой требовалось сопоставлять скорости или направле ния движ ения двух зрительных паттернов, разнесенных во времени. В качестве контрольной ситуации использовалась пассивная фиксация взгляда с предъявлением аналогич ных стимулов.…”