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Author Notes:

Mukesh Dhamala: Department of Physics and Astronomy, Georgia State University, 29 Peachtree Center Ave., Science Annex, Rm 456, Atlanta, GA, 30303. Phone: 404-413-6043., mdhamala@gsu.edu.

We express our sincere thanks to Mingzhou Ding for generously providing us the Matlab programs for ASEO method.

There is no conflict of interest for any of the authors.

Subjects:

Research Funding:

This work was supported by the Atlanta VAMC Rehabilitation R&D Center of Excellence.

MD was supported by an NSF CAREER Award (BCS 0955037); and KS by NIH grants R01EY12440 and K24EY17332; and by the Veterans Administration.

Keywords:

  • Science & Technology
  • Life Sciences & Biomedicine
  • Neurosciences
  • Neuroimaging
  • Radiology, Nuclear Medicine & Medical Imaging
  • Neurosciences & Neurology
  • Oscillations
  • Brain rhythms
  • EEG
  • ERP
  • Somatosensory
  • Touch
  • Connectivity
  • Granger causality
  • Perceptual decision-making
  • MEDIAN NERVE-STIMULATION
  • SOMATOSENSORY CORTICAL NETWORK
  • LATERAL OCCIPITAL COMPLEX
  • EVENT-RELATED POTENTIALS
  • HUMAN PREFRONTAL CORTEX
  • GAMMA-BAND ACTIVITY
  • GRANGER CAUSALITY
  • ATTENTIONAL MODULATION
  • DECISION-MAKING
  • MAGNETIC-FIELDS

Oscillatory activity in neocortical networks during tactile discrimination near the limit of spatial acuity

Tools:

Journal Title:

NeuroImage

Volume:

Volume 91

Publisher:

, Pages 300-310

Type of Work:

Article | Post-print: After Peer Review

Abstract:

Oscillatory interactions within functionally specialized but distributed brain regions are believed to be central to perceptual and cognitive functions. Here, using human scalp electroencephalography (EEG) recordings combined with source reconstruction techniques, we study how oscillatory activity functionally organizes different neocortical regions during a tactile discrimination task near the limit of spatial acuity. While undergoing EEG recordings, blindfolded participants felt a linear three-dot array presented electromechanically, under computer control, and reported whether the central dot was offset to the left or right. The average brain response differed significantly for trials with correct and incorrect perceptual responses in the timeframe approximately between 130 and 175. ms. During trials with correct responses, source-level peak activity appeared in the left primary somatosensory cortex (SI) at around 45. ms, in the right lateral occipital complex (LOC) at 130. ms, in the right posterior intraparietal sulcus (pIPS) at 160. ms, and finally in the left dorsolateral prefrontal cortex (dlPFC) at 175. ms. Spectral interdependency analysis of activity in these nodes showed two distinct distributed networks, a dominantly feedforward network in the beta band (12-30. Hz) that included all four nodes and a recurrent network in the gamma band (30-100. Hz) that linked SI, pIPS and dlPFC. Measures of network activity in both bands were correlated with the accuracy of task performance. These findings suggest that beta and gamma band oscillatory networks coordinate activity between neocortical regions mediating sensory and cognitive processing to arrive at tactile perceptual decisions.

Copyright information:

© 2014 The Authors.

This is an Open Access work distributed under the terms of the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License (http://creativecommons.org/licenses/by-nc-nd/4.0/).

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