Oscillatory Dynamics of Prefrontal Cognitive Control

Prefrontal oscillatory dynamics coordinate cortical and subcortical large-scale networks, providing a functional basis for flexible cognitive control of goal-directed behavior and do not constitute an epiphenomenon of spiking activity. Nonlinear dynamics, including phase resetting, endogenous entrainment, and CFC, support the spatiotemporal organization of functional networks and predict behavior on the single-trial level. Neuronal oscillations provide the temporal reference frame for activity-silent encoding in neuronal assemblies, which complements the view that the neuron is the structural and functional unit of the nervous system. Multiplexing on different temporal channels reflects distinct canonical computations and increases cortical coding capacity. Directionality analyses reveal the timing of information flow along established anatomical pathways. The prefrontal cortex (PFC) provides the structural basis for numerous higher cognitive functions. However, it is still largely unknown which mechanisms provide the functional basis for flexible cognitive control of goal-directed behavior. Here, we review recent findings that suggest that the functional architecture of cognition is profoundly rhythmic and propose that the PFC serves as a conductor to orchestrate task-relevant large-scale networks. We highlight several studies that demonstrated that oscillatory dynamics, such as phase resetting, cross-frequency coupling (CFC), and entrainment, support PFC-dependent recruitment of task-relevant regions into coherent functional networks. Importantly, these findings support the notion that distinct spectral signatures reflect different cortical computations supporting effective multiplexing on different temporal channels along the same anatomical pathways. The prefrontal cortex (PFC) provides the structural basis for numerous higher cognitive functions. However, it is still largely unknown which mechanisms provide the functional basis for flexible cognitive control of goal-directed behavior. Here, we review recent findings that suggest that the functional architecture of cognition is profoundly rhythmic and propose that the PFC serves as a conductor to orchestrate task-relevant large-scale networks. We highlight several studies that demonstrated that oscillatory dynamics, such as phase resetting, cross-frequency coupling (CFC), and entrainment, support PFC-dependent recruitment of task-relevant regions into coherent functional networks. Importantly, these findings support the notion that distinct spectral signatures reflect different cortical computations supporting effective multiplexing on different temporal channels along the same anatomical pathways. traditionally, active processing has been associated with an increase in neuronal spiking or high frequency activity (HFA). However, meaningful processing with behavioral consequences has also been observed without changes in spiking and is referred to as ‘activity silent’. summarizes various executive functions, such as attention, working memory, error monitoring, inhibitory control, or planning, which reflect the means to achieve fluid behavior. describes a systemic correlation between two oscillations with different frequencies. Most CFC is assessed by phase-amplitude coupling (PAC), where the phase of slow oscillations correlates with the amplitude of a faster oscillation. a measure of interaction between two signals based on their amplitude or phase relations. Most commonly, FC is assessed by coherence or phase-locking analyses of band-limited signals or by linear correlations of the amplitude/power time series. also referred to as high gamma, describes activity in the 70–200-Hz range that is commonly observed in the local field potential (LFP) of electrocorticography (ECoG) studies and closely correlates with population spiking activity. It is often used to infer whether a cortical region is actively engaged in a task or not. describes the directed synchronization of one oscillator by another. Exogenous entrainment occurs when brain oscillations adapt their rhythm to track an exogenous periodicity. Endogenous entrainment explains how one region might drive activity in a second region. here, we mainly refer to rhythmic transcranial magnetic stimulation (rTMS) and transcranial alternating current stimulation (tACS), which both have been suggested to entrain frequency-specific activity to causally link neuronal oscillations to distinct cognitive processes. refers to a process where the phase of the ongoing band-limited brain activity is adjusted to a certain angle by either an external or internal cue. constitutes an elegant mechanism to increase cortical coding capacity. Activity by the same neuronal population might reflect distinct pieces of information, depending on when the activity occurs relative to the phase of the band-limited local field potential (LFP).