Conference 2021 Pre-Recorded Video


Project title

Functional Connectivity Reductions in the Default Mode Network of Obese Patients Uncovered Using MEG Imaging


Authors and Affiliations

Layan Elfaki1, Ben Dunkley2,3

1. Human Biology Department, University of Toronto, Toronto, Canada
2. Mental Health and Neuroscience, The Hospital for Sick Children Research Institute, Toronto, Canada
3. Department of Medical Imaging, University of Toronto, Toronto, Canada




Underlying over 60 chronic diseases, obesity is implicated with genetic, environmental and sociocultural factors which interact to facilitate deposition of excess body fat. Despite the debilitating symptomology observed in obesity, research into the underlying neurological patterns remains limited. Of interest was the default mode network (DMN), an intrinsic brain network implicated with attention, inward introspection and memory processes (Di & Biswal, 2014). DMN abnormalities were reported in various psychological disorders including obesity, autism and other psychological disorders (Baliki et al., 2008; Tregellas et al., 2011).


Therefore, this study aimed to explore discrepancies in functional connectivity patterns within the DMN of obese individuals. Utilizing magnetoencephalography (MEG) imaging and the resting state network recordings of 30 adolescents participants, adjacency matrices of functional connectivity patterns were computed and subjected to statistical analyses. The degree of pairwise cortical oscillation synchrony was established with respect to 7 frequency bands: Alpha, Beta, low Gamma 1, low Gamma 2, high Gamma, Delta and Theta. In addition to examination of brain-wide network alterations, segregation of individual areas into sub-networks was also uncovered through node degree calculation.


Network-based statistics analysis identified significantly impaired networks in the alpha, beta and low gamma 2 frequencies. This finding was still evident after correction through false discovery rate analysis, which classified these dampened connections to be within the DMN as well as between the DMN and external networks. Through node degree analysis, the posterior cingulate cortex was identified as a key DMN region serving information integration.


We report the first evidence of reduced neuropsychological functioning in the DMN of adolescents with obesity. This provides a promising new avenue for treatment strategies that stimulate this network to ameliorate the symptoms of obesity.