Poster A98, Saturday, March 25, 5:00 – 7:00 pm, Pacific Concourse
Cross-Frequency Coupling as a Biomarker of Human Cognitive Functions
Maria Mikail1, Reza Zomorrodi2,3, Zafiris J. Daskalakis2,3,4, Tarek K. Rajj2,3,4; 1Royal College of Surgeons, Dublin, Ireland, 2Temerty Centre for Therapeutic Brain Intervention, Centre for Addiction and Mental Health, Toronto, Canada, 3Schizophrenia Division, Centre for Addiction and Mental Health, Toronto, Canada, 4Department of Psychiatry, University of Toronto, Toronto, Canada
Cognitive process and memory function require transient and distributed interaction of neural networks. The most plausible proposed mechanism is cross-frequency coupling between neural oscillations. In this study, we systematically reviewed the current finding in cognitive function in PubMed database (2000-September 2016) for human species, and explored CFC strength from distribution of gamma- amplitude over theta-phase bins using Kullback-Leibler function. Healthy human brain in the resting state shows a significant coupling in the alpha-gamma range in dorsolateral prefrontal, anterior cingulate and parietal and occipital lobe. The strength of this coupling was increased in patients with epilepsy and autism spectrum disorder and significantly decreased in beta-gamma range in Parkinson’s diseases. However, during cognitive process CFC mostly shifts to the lower frequency. In the memory process, delta/theta-gamma coupling was shown in fronto-parietal or parietal-occipital networks and impairments were reported in patients with schizophrenia and epilepsy. In visual and auditory perception tasks, delta-theta in visual cortex and theta-gamma coupling in medial frontal cortex were demonstrated, respectively. In the attention control process, theta-gamma coupling significantly increased in the frontal-posterior region, while an abnormal low strength in ADHD and high in epileptic patients has been reported. In our computational model, we illustrated the same coupling strength or abnormality might occur in different conditions, which might have diverse neurophysiological interpretation. Although method of calculation and interpretation of results still is a challenge, recent evidence indicates the importance of CFC mechanism during cognitive function, which might be considered as a marker to assess neurological and psychiatric diseases.
Topic Area: METHODS: Electrophysiology