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About Sickkids
About SickKids

Sam Doesburg, PhD

The Hospital for Sick Children
Clinical Associate
MEG

Research Institute
Adjunct Scientist
Neurosciences & Mental Health

University of Toronto
Assistant Professor
Medical Imaging


Phone: 416-813-2182
Fax: 416-813-7362
Email: sam.doesburg@sickkids.ca
Alternate Contact: Seetha Sriharan
Alternate Phone: 416-813-5175
Alternate Fax: 416-813-7362
Alternate Email: seetha.sriharan@sickkids.ca

Brief Biography

Dr. Sam Doesburg completed his PhD in Neuroscience at the University of British Columbia (UBC), which focused on the role of communication within distributed cortical networks in perceptual and cognitive processes. This was followed by a postdoctoral fellowship at UBC Pediatrics which employed magnetoencephalographic (MEG) brain imaging to investigate neurocognitive development in children born very prematurely. Doesburg joined SickKids and is researching how functional connectivity among brain regions is related to childhood cognitive development, as well as how interactions among brain regions are altered in clinical child populations including children born very preterm, children with autism spectrum disorder (ASD) and childhood epilepsy.

Research Interests

  • Altered functional connectivity in epilepsy
  • Altered neurocognitive development in preterm children
  • Magnetoencephalographic (MEG) brain imaging
  • Cortical network dynamics in cognition and perception

Research Activities

Oscillatory Network Dynamics in Typical and Atypical Cognitive Development
Brain oscillations, and their synchronization between brain areas, play a critical role in functional brain networks supporting cognition, perception and motor control.  This research investigates how connectivity in brain networks develops throughout childhood and adolescence and is related to the maturation of cognitive abilities.  We investigate the dynamics of network connectivity during specific cognitive tasks, as well as how communication among brain areas is expressed at rest.  Typically this is done using noninvasive magnetoencephalographic (MEG) imaging.  I also investigate how altered network connectivity contributes to difficulties in cognitive development in childhood epilepsy, children with autism spectrum disorders (ASD) and children born very prematurely.

Presurgical Mapping in Childhood Epilepsy
This research investigates the potential role of mapping aberrant functional connectivity among brain regions in presurgical mapping in children with focal drug-resistant epilepsy.  The goal of this work is to develop new clinical methods to identify which brain regions must be removed to stop seizures, as seizures often return following surgery due to inaccurate localization of epileptogenic brain areas..

Altered Cortical Network Dynamics and Neuropsychological Difficulties in Childhood Epilepsy
Communication among brain areas is critical for cognitive and perceptual processes.  This research investigates how spontaneous and task-dependent patterns of interactions among brain regions, develops throughout childhood, and how these maturational changes are related to the development of cognitive abilities.  A complementary goal of this research to understand how altered communication among brain areas in populations such as children with epilepsy, ASD, or those born very prematurely is related to cognitive difficulties in these groups.

Future Research Interests

Difficulties in cognitive development are common in children born prematurely, but the underlying alterations in brain development and their relationship to neonatal experience remains unclear.  Future research will use neuroimaging and neuropsychological assessments on a longitudinal cohort of preterm children to illuminate the relationships between specific aspects, adverse neonatal experience, the development of functional brain systems, and cognitive outcome in these vulnerable children.

External Funding

  • Natural Sciences and Engineering Research Council of Canada (NSERC).  Functional network connectivity and child cognitive development, Doesburg SM
  • Ontario Brain Institute, Epilepsy Integrated Discovery System (Eplink). Mapping network connectivity in childhood epilepsy, Doesburg SM, Snead OC.

Achievements

  • Young Investigator Award – 17th International Conference on Biomagnetism
  • Excellence in MEG Research in Developmental Disabilities Award – Down Syndrome Research Foundation
  • Outstanding Achievement by a Postdoctoral Fellow – Child and Family Research Institute

Publications

Ibrahim GM, Wong S, Anderson R, Singh-Cadieux G, Akiyama T, Ochi A, Otsubo H, Okanishi T, Valiente TA, Donner E, Rutka JT, Snead OC, Doesburg SM (2014) Dynamic modulation of epileptic high frequency oscillations by the phase of slower cortical rhythms. Experimental Neurology. 251: 30-38.

Doesburg SM, Moiseev A, Herdman AT, Ribary U, Grunau RE (2013) Region-specific slowing of alpha oscillations is associated with visual-perceptual abilities in children born very preterm. Frontiers in Human Neuroscience. doi: 10.3389/fnhum.2013.00791.

Doesburg SM, Vidal J, Taylor, MJ (2013) Reduced theta connectivity during set-shifting in children with autism. Frontiers in Human Neuroscience. doi: 10.3389/fnhum.2013.00785.

Doesburg SM, Chau CM, Cheung TP, Moiseev A, Ribary U, Herdman AT, Miller SP, Cepeda IL, Synnes A, Grunau RE (2013) Neonatal pain-related stress, functional cortical activity and visual-perceptual abilities in school-age children born at extremely low gestational age. Pain. 154(10): 1946-1952.

Ibrahim GM, Anderson R, Akiyama T, Ochi A, Otsubo H, Singh-Cadieux G, Donner E, Rutka JT, Snead OC, Doesburg SM (2013) Neocortical pathological high frequency oscillations are associated with frequency-dependent alterations in functional netowork topology. Journal of Neurophysiology. doi: 10.1152/jn.00034.2013

Doesburg SM, Ibrahim GM, Smith ML, Sharma R, Viljoen A, Chu B, Rutka JT, Snead OC, Pang EW (2013) Altered rolandic gamma-band activation associated with motor impairment and ictal network desynchronization in childhood epilepsy. PLoS One. 8(1): e54943.

Doesburg SM, Green JJ, McDonald JJ, Ward LM (2012) Theta modulation of inter-regional gamma synchronization during auditory attention control. Brain Research. 1431: 77-85.

Ibrahim GM, Akiyama T, Ochi A, Otsubo H, Smith ML, Taylor MJ, Donner E, Rutka JT, Snead OC, Doesburg SM (2012) Disruption of rolandic gamma-band functional connectivity by seizures is associated with motor impairments in children with epilepsy. PLoS One. 7(6): e39326.

Doesburg SM, Vinette SA, Cheung MJ, Pang EW (2012) Theta-modulated gamma-band synchronization among activated regions during a verb generation task. Frontiers in Psychology. 3(195): doi: 10.3389/fpsyg.2012.00195.

Doesburg SM, Ribary U, Herdman AT, Miller SP, Poskitt K, Moiseev A, Whitfield MF, Synnes A, Grunau RE (2011) Altered long-range alpha-band synchronization during visual short-term memory retention in children born very preterm. NeuroImage. 54(3): 2330-2339.

Doesburg SM, Ribary U, Herdman AT, Moiseev A, Cheung T, Miller SP, Poskitt K, Weinberg H, Whitfield MF, Synnes A, Grunau RE (2011) Magnetoencephalography reveals slowing of resting peak oscillatory frequency in children born very preterm. Pediatric Research. 70(2): 171-175.

Doesburg SM, Green JJ, McDonald JJ, Ward LM (2011) Theta modulation of inter-regional gamma synchronization during auditory attention control. Brain Research. doi: 10.1016/j.brainres.2011.11.005.

Green JJ, Doesburg SM, Ward LM, McDonald JJ (2011) Electrical neuroimaging of voluntary audio-spatial attention: evidence for a supramodal attention control network.  Journal of Neuroscience. 31(10): 3560-3564.

Doesburg SM, Herdman AT, Ribary U, Cheung T, Moiseev A, Weinberg H, Liotti M, Weeks D, Grunau RE (2010) Long-range synchronization and local desynchronization of alpha rhythms during visual short-term memory retention in children. Experimental Brain Research. 201(4): 719-727.

Doesburg SM, Green JJ, McDonald JJ, Ward LM (2009) From intra-regional inhibition to inter-regional integration: a functional dissociation of alpha-band synchronization across cortical scales in visuospatial attention. Brain Research. 1303: 97-110.

Doesburg SM, Green JJ, McDonald JJ, Ward LM (2009) Rhythms of consciousness: binocular rivalry reveals large-scale oscillatory network dynamics mediating visual perception. PLoS One. 4(7) e6142.

Doesburg SM, Kitajo K, Roggeveen A, Ward LM (2008) Long-range gamma-band synchronization and selective attention. Cerebral Cortex. 18(2) 386-396.

Doesburg SM, Emberson LL, Rahi A, Cameron A, Ward LM (2008) Asynchrony from synchrony:   long-range gamma-band neural synchrony accompanies perception of audiovisual asynchrony in speech. Experimental Brain Research. 185 11-20.

Kitajo K, Doesburg SM, Yamanaka K, Nozaki D, Ward LM, Yamamoto Y (2007) Noise-induced large-scale phase synchronization of human brain activity associated with behavioural stochastic resonance. Europhysics Letters. 80(4) 40009.

Ward LM, Doesburg SM, Kitajo K, MacLean SE, Roggeveen AB (2006) Neural synchrony in stochastic resonance, attention and consciousness. Canadian Journal of Experimental Psychology. 60(4) 319-326.

Doesburg SM, Kitajo K, Ward LM (2005) Increased gamma-band synchrony precedes switching of conscious perceptual objects in binocular rivalry. Neuroreport. 16(11) 1139-1142.