The timing and accuracy of perceptual decision-making is exquisitely sensitive to fluctuations in arousal. Although extensive research has highlighted the role of various neural processing stages in forming decisions, our understanding of how arousal impacts these processes remains limited. Here we isolated electrophysiological signatures of decision-making alongside signals reflecting target selection, attentional engagement and motor output and examined their modulation as a function of tonic and phasic arousal, indexed by baseline and task-evoked pupil diameter, respectively. Reaction times were shorter on trials with lower tonic, and higher phasic arousal. Additionally, these two pupil measures were predictive of a unique set of EEG signatures that together represent multiple information processing steps of decision-making. Finally, behavioural variability associated with fluctuations in tonic and phasic arousal, indicative of neuromodulators acting on multiple timescales, was mediated by its effects on the EEG markers of attentional engagement, sensory processing and the variability in decision processing.

Achieving behavioral goals requires integration of sensory and cognitive information across cortical laminae and cortical regions. How this computation is performed remains unknown. Using local field potential recordings and spectrally resolved conditional Granger causality (cGC) analysis, we mapped visual information flow, and its attentional modulation, between cortical layers within and between macaque brain areas V1 and V4. Stimulus-induced interlaminar information flow within V1 dominated upwardly, channeling information toward supragranular corticocortical output layers. Within V4, information flow dominated from granular to supragranular layers, but interactions between supragranular and infragranular layers dominated downwardly. Low-frequency across-area communication was stronger from V4 to V1, with little layer specificity. Gamma-band communication was stronger in the feedforward V1-to-V4 direction. Attention to the receptive field of V1 decreased communication between all V1 layers, except for granular-to-supragranular layer interactions. Communication within V4, and from V1 to V4, increased with attention across all frequencies. While communication from V4 to V1 was stronger in lower-frequency bands (4 to 25 Hz), attention modulated cGCs from V4 to V1 across all investigated frequencies. Our data show that top-down cognitive processes result in reduced communication within cortical areas, increased feedforward communication across all frequency bands, and increased gamma-band feedback communication.

Top-down coordination of local cortical state during selective attention Highlights d Cortical excitability fluctuations are coordinated across visual areas d During selective attention, these fluctuations are driven in a top-down manner d The degree of coordination depends on shared spatial representation d Increased cortical state coordination predicts better behavioral performance

12Spontaneous fluctuations in cortical excitability influence sensory processing and behavior. 13These fluctuations, long known to reflect global changes in cortical state, were recently 14 found to be modulated locally within a retinotopic map during spatially selective attention. 15We found that periods of vigorous (On) and faint (Off) spiking activity, the signature of 16 cortical state fluctuations, were coordinated across brain areas along the visual hierarchy 17 and tightly coupled to their retinotopic alignment. During top-down attention, this 18 interareal coordination was enhanced and progressed along the reverse cortical hierarchy. 19The extent of local state coordination between areas was predictive of behavioral 20 performance. Our results show that cortical state dynamics are shared across brain regions, 21 modulated by cognitive demands and relevant for behavior. 22 23 One Sentence Summary: 24 Interareal coordination of local cortical state is retinotopically precise and progresses in a 25 reverse hierarchical manner during selective attention. 26 27