| dc.description.abstract | One characteristics of attention is to facilitate relevant information and inhibit irrelevant distractors. Recent studies demonstrate that behavioral performance during visual spatial attention fluctuates at theta (4-8 Hz) and alpha (8-16 Hz) frequencies, linked to phase amplitude coupling of neural oscillations within the visual system (i.e., frontal-parietal network and visual cortex). Moreover, previous studies suggest that attentional sampling rhythms are task-dependent. This is evidenced with varying behavioral performance at different frequencies when comparing spatial resolutions, numbers of distractors, and task difficulties. However, the role of prior spatial prediction in behavioral rhythms remains unclear. To address this issue, we employed an adaptive Posner-like discrimination task with variable CTOA durations ranging from 300 ms to 1300 ms in steps of 20 ms while manipulating spatial prediction via cue validity (100% & 50%), with concurrently electroencephalography (EEG) recording. An adaptive analytical method, namely the Holo-Hilbert Spectral Analysis (HHSA) and Holo-Hilbert Cross-frequency Phase Clustering (HHCFPC) was applied for the EEG data analysis to explore the dynamic changes of perception during sustained attention. Our findings indicate that informative cues enhance spatial and temporal modulation, improving response precision for near-threshold Landolt rings. Furthermore, spatial prediction influences the speed of behavioral rhythms at the theta-band (4 Hz) with certain predictions and at alpha & beta bands (15 & 19 Hz) with uncertain predictions. We also discovered that spatial prediction strengthens theta-alpha modulations at parietal-occipital areas, frontal theta phase and parietal-occipital alpha amplitude coupling, within frontal theta phase/ alpha amplitude coupling, and the phase alignments of low frequency (1.2-5.7 Hz) oscillations between trials at frontal and parietal-occipital areas. Notably, during the pre-target period, beta-modulated gamma oscillations in parietal-occipital areas predict response precision in spatially uncertain conditions, while frontal theta phase and parietal-occipital alpha amplitude coupling predict response precision in spatially certain conditions. Overall, our results suggest that different levels of spatial certainty lead to distinct preparations for sampling unpredictable targets. Specifically, we found that certain spatial cues promote more robust communication between different brain areas (theta-alpha coupling) and override the phasic contributions of a natural filtering mechanism (i.e.,beta-gamma coupling) within the early visual cortex during perception. In conclusion, our study supports the notion that the speed of periodic sampling in perception depends on the task at hand, indicating that neural rhythms serve as an adaptive resource allocation mechanism in the brain and highlighting the critical role of spatial prediction in attentional sampling rhythms. | en_US |