Interregional alpha-band synchrony supports temporal cross-modal integration

• Published in: NeuroImage (Orlando, Fla.) Vol. 101; pp. 404 - 415
• Main Authors: van Driel, Joram, Knapen, Tomas, van Es, Daniel M., Cohen, Michael X
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.11.2014; Elsevier Limited
• Subjects: Adolescent; Adult; Alpha Rhythm - physiology; Alpha-band; Attention - physiology; Auditory Perception - physiology; Bayes Theorem; Brain; Brain Mapping; Cross-modal integration; Electroencephalography - methods; Female; Functional connectivity; Humans; Male; Phase synchrony; Psychomotor Performance - physiology; Psychophysics - methods; Sensorimotor Cortex - physiology; Sensory perception; Studies; Time Factors; Time perception; Time Perception - physiology; Visual Perception - physiology; Young Adult; Functional connectivity; Cross-modal integration; Alpha-band; Phase synchrony; Time perception
• ISSN: 1053-8119; 1095-9572
• DOI: 10.1016/j.neuroimage.2014.07.022

In a continuously changing environment, time is a key property that tells us whether information from the different senses belongs together. Yet, little is known about how the brain integrates temporal information across sensory modalities. Using high-density EEG combined with a novel psychometric timing task in which human subjects evaluated durations of audiovisual stimuli, we show that the strength of alpha-band (8–12Hz) phase synchrony between localizer-defined auditory and visual regions depended on cross-modal attention: during encoding of a constant 500ms standard interval, audiovisual alpha synchrony decreased when subjects attended audition while ignoring vision, compared to when they attended both modalities. In addition, alpha connectivity during a variable target interval predicted the degree to which auditory stimulus duration biased time estimation while attending vision. This cross-modal interference effect was estimated using a hierarchical Bayesian model of a psychometric function that also provided an estimate of each individual's tendency to exhibit attention lapses. This lapse rate, in turn, was predicted by single-trial estimates of the stability of interregional alpha synchrony: when attending to both modalities, trials with greater stability in patterns of connectivity were characterized by reduced contamination by lapses. Together, these results provide new insights into a functional role of the coupling of alpha phase dynamics between sensory cortices in integrating cross-modal information over time. •We investigated EEG dynamics of cross-sensory integration during time perception•Psychometric functions were fitted on behavior using Bayesian graphical modeling•There was strong auditory dominance when subjects judged audiovisual duration•This correlated with audiovisual interregional alpha (8-12 Hz) phase synchrony•Single-trial alpha phase synchrony predicted the degree of psychometric lapsing