Summary
Recent studies suggest that attention samples space rhythmically through oscillatory interactions in the frontoparietal network. However, the precise mechanism through which the prefrontal cortex, at the source of attention control signals, organizes this rhythmic exploration of space remains unknown. We show that, when decoded at a high spatial (0.1°) and temporal resolution (50ms), the prefrontal covert attentional spotlight, aka the mind’s eye, continuously explores space at an alpha 7-12 Hz rhythm. When sensory events are presented at a specific optimal phase (resp. anti-phase) with respect to this rhythm, sensory encoding and behavioral report are accurate (resp. poor). We propose that this rhythmic prefrontal attentional spotlight dynamics corresponds to a continuous overt exploration of space via alpha-clocked attentional saccades. These attentional saccades are highly flexible, their pattern of space exploration depending both on within-trial and across-task contingencies. These results are discussed in the context of exploration and exploitation strategies and prefrontal top-down attentional control.
Highlights
The decoded prefrontal attentional spotlight samples visual space in rhythmic cycles
This rhythmic attentional exploration predicts neuronal sensory processing accuracy
This rhythmic attentional exploration predicts overt behavioral accuracy
These rhythmic cycles define alpha-clocked attentional saccades
Space exploration by attentional saccades is highly flexible and under top-down control