Interregional alpha-band synchrony supports temporal cross-modal integration

Neuroimage. 2014 Nov 1;101:404-15. doi: 10.1016/j.neuroimage.2014.07.022. Epub 2014 Jul 17.


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 (8-12 Hz) phase synchrony between localizer-defined auditory and visual regions depended on cross-modal attention: during encoding of a constant 500 ms 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.

Keywords: Alpha-band; Cross-modal integration; Functional connectivity; Phase synchrony; Time perception.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Alpha Rhythm / physiology*
  • Attention / physiology*
  • Auditory Perception / physiology*
  • Bayes Theorem
  • Brain Mapping
  • Electroencephalography / methods*
  • Female
  • Humans
  • Male
  • Psychomotor Performance / physiology*
  • Psychophysics / methods
  • Sensorimotor Cortex / physiology*
  • Time Factors
  • Time Perception / physiology*
  • Visual Perception / physiology*
  • Young Adult