Title
Oscillatory activity in neocortical networks during tactile discrimination near the limit of spatial acuity.
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 175ms. During trials with correct responses, source-level peak activity appeared in the left primary somatosensory cortex (SI) at around 45ms, in the right lateral occipital complex (LOC) at 130ms, in the right posterior intraparietal sulcus (pIPS) at 160ms, and finally in the left dorsolateral prefrontal cortex (dlPFC) at 175ms. Spectral interdependency analysis of activity in these nodes showed two distinct distributed networks, a dominantly feedforward network in the beta band (12–30Hz) that included all four nodes and a recurrent network in the gamma band (30–100Hz) 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.
Year
DOI
Venue
2014
10.1016/j.neuroimage.2014.01.007
NeuroImage
Keywords
Field
DocType
Oscillations,Brain rhythms,EEG,ERP,Somatosensory,Touch,Connectivity,Granger causality,Perceptual decision-making
Tactile discrimination,Developmental psychology,Neuroscience,Prefrontal cortex,Psychology,Somatosensory system,Sensory system,Beta Rhythm,Intraparietal sulcus,Electroencephalography,Parietal lobe
Journal
Volume
ISSN
Citations 
91
1053-8119
5
PageRank 
References 
Authors
0.53
7
5
Name
Order
Citations
PageRank
Bhim Mani Adhikari1104.37
K Sathian215412.56
C M Epstein3153.47
Bidhan Lamichhane4112.01
Mukesh Dhamala5164.15