Frontiers in Aging Neuroscience (Apr 2018)
Theta-Gamma Coupling and Working Memory in Alzheimer’s Dementia and Mild Cognitive Impairment
- Michelle S. Goodman,
- Michelle S. Goodman,
- Sanjeev Kumar,
- Sanjeev Kumar,
- Sanjeev Kumar,
- Reza Zomorrodi,
- Reza Zomorrodi,
- Zaid Ghazala,
- Zaid Ghazala,
- Zaid Ghazala,
- Zaid Ghazala,
- Amay S. M. Cheam,
- Amay S. M. Cheam,
- Mera S. Barr,
- Mera S. Barr,
- Mera S. Barr,
- Zafiris J. Daskalakis,
- Zafiris J. Daskalakis,
- Zafiris J. Daskalakis,
- Daniel M. Blumberger,
- Daniel M. Blumberger,
- Daniel M. Blumberger,
- Daniel M. Blumberger,
- Corinne Fischer,
- Corinne Fischer,
- Alastair Flint,
- Alastair Flint,
- Linda Mah,
- Linda Mah,
- Nathan Herrmann,
- Nathan Herrmann,
- Christopher R. Bowie,
- Christopher R. Bowie,
- Benoit H. Mulsant,
- Benoit H. Mulsant,
- Benoit H. Mulsant,
- Benoit H. Mulsant,
- Tarek K. Rajji,
- Tarek K. Rajji,
- Tarek K. Rajji,
- Tarek K. Rajji
Affiliations
- Michelle S. Goodman
- Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health, Toronto, ON, Canada
- Michelle S. Goodman
- Temerty Centre for Therapeutic Brain Intervention, Centre for Addiction and Mental Health, Toronto, ON, Canada
- Sanjeev Kumar
- Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health, Toronto, ON, Canada
- Sanjeev Kumar
- Temerty Centre for Therapeutic Brain Intervention, Centre for Addiction and Mental Health, Toronto, ON, Canada
- Sanjeev Kumar
- Geriatric Psychiatry Division, Centre for Addiction and Mental Health, Toronto, ON, Canada
- Reza Zomorrodi
- Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health, Toronto, ON, Canada
- Reza Zomorrodi
- Temerty Centre for Therapeutic Brain Intervention, Centre for Addiction and Mental Health, Toronto, ON, Canada
- Zaid Ghazala
- Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health, Toronto, ON, Canada
- Zaid Ghazala
- Temerty Centre for Therapeutic Brain Intervention, Centre for Addiction and Mental Health, Toronto, ON, Canada
- Zaid Ghazala
- Geriatric Psychiatry Division, Centre for Addiction and Mental Health, Toronto, ON, Canada
- Zaid Ghazala
- Department of Psychiatry, University of Toronto, Toronto, ON, Canada
- Amay S. M. Cheam
- Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health, Toronto, ON, Canada
- Amay S. M. Cheam
- Temerty Centre for Therapeutic Brain Intervention, Centre for Addiction and Mental Health, Toronto, ON, Canada
- Mera S. Barr
- Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health, Toronto, ON, Canada
- Mera S. Barr
- Temerty Centre for Therapeutic Brain Intervention, Centre for Addiction and Mental Health, Toronto, ON, Canada
- Mera S. Barr
- Department of Psychiatry, University of Toronto, Toronto, ON, Canada
- Zafiris J. Daskalakis
- Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health, Toronto, ON, Canada
- Zafiris J. Daskalakis
- Temerty Centre for Therapeutic Brain Intervention, Centre for Addiction and Mental Health, Toronto, ON, Canada
- Zafiris J. Daskalakis
- Department of Psychiatry, University of Toronto, Toronto, ON, Canada
- Daniel M. Blumberger
- Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health, Toronto, ON, Canada
- Daniel M. Blumberger
- Temerty Centre for Therapeutic Brain Intervention, Centre for Addiction and Mental Health, Toronto, ON, Canada
- Daniel M. Blumberger
- Geriatric Psychiatry Division, Centre for Addiction and Mental Health, Toronto, ON, Canada
- Daniel M. Blumberger
- Department of Psychiatry, University of Toronto, Toronto, ON, Canada
- Corinne Fischer
- Department of Psychiatry, University of Toronto, Toronto, ON, Canada
- Corinne Fischer
- Keenan Research Centre for Biomedical Science, St. Michael’s Hospital, Toronto, ON, Canada
- Alastair Flint
- Department of Psychiatry, University of Toronto, Toronto, ON, Canada
- Alastair Flint
- Centre for Mental Health, University Health Network, Toronto, ON, Canada
- Linda Mah
- Department of Psychiatry, University of Toronto, Toronto, ON, Canada
- Linda Mah
- Rotman Research Institute, Baycrest Health Sciences Centre, Toronto, ON, Canada
- Nathan Herrmann
- Department of Psychiatry, University of Toronto, Toronto, ON, Canada
- Nathan Herrmann
- Sunnybrook Health Sciences Centre, Toronto, ON, Canada
- Christopher R. Bowie
- Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health, Toronto, ON, Canada
- Christopher R. Bowie
- Geriatric Psychiatry Division, Centre for Addiction and Mental Health, Toronto, ON, Canada
- Benoit H. Mulsant
- Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health, Toronto, ON, Canada
- Benoit H. Mulsant
- Temerty Centre for Therapeutic Brain Intervention, Centre for Addiction and Mental Health, Toronto, ON, Canada
- Benoit H. Mulsant
- Geriatric Psychiatry Division, Centre for Addiction and Mental Health, Toronto, ON, Canada
- Benoit H. Mulsant
- Department of Psychiatry, University of Toronto, Toronto, ON, Canada
- Tarek K. Rajji
- Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health, Toronto, ON, Canada
- Tarek K. Rajji
- Temerty Centre for Therapeutic Brain Intervention, Centre for Addiction and Mental Health, Toronto, ON, Canada
- Tarek K. Rajji
- Geriatric Psychiatry Division, Centre for Addiction and Mental Health, Toronto, ON, Canada
- Tarek K. Rajji
- Department of Psychiatry, University of Toronto, Toronto, ON, Canada
- DOI
- https://doi.org/10.3389/fnagi.2018.00101
- Journal volume & issue
-
Vol. 10
Abstract
Working memory deficits are common among individuals with Alzheimer’s dementia (AD) or mild cognitive impairment (MCI). Yet, little is known about the mechanisms underlying these deficits. Theta-gamma coupling—the modulation of high-frequency gamma oscillations by low-frequency theta oscillations—is a neurophysiologic process underlying working memory. We assessed the relationship between theta-gamma coupling and working memory deficits in AD and MCI. We hypothesized that: (1) individuals with AD would display the most significant working memory impairments followed by MCI and finally healthy control (HC) participants; and (2) there would be a significant association between working memory performance and theta-gamma coupling across all participants. Ninety-eight participants completed the N-back working memory task during an electroencephalography (EEG) recording: 33 with AD (mean ± SD age: 76.5 ± 6.2), 34 with MCI (mean ± SD age: 74.8 ± 5.9) and 31 HCs (mean ± SD age: 73.5 ± 5.2). AD participants performed significantly worse than control and MCI participants on the 1- and 2-back conditions. Regarding theta-gamma coupling, AD participants demonstrated the lowest level of coupling followed by the MCI and finally control participants on the 2-back condition. Finally, a linear regression analysis demonstrated that theta-gamma coupling (β = 0.69, p < 0.001) was the most significant predictor of 2-back performance. Our results provide evidence for a relationship between altered theta-gamma coupling and working memory deficits in individuals with AD and MCI. They also provide insight into a potential mechanism underlying working memory impairments in these individuals.
Keywords
- mild cognitive impairment
- Alzheimer’s dementia
- electroencephalography
- neural oscillations
- theta-gamma coupling
- working memory
