[Seminar] "Individual differences in nonlinear neural dynamics and human behavior" by Dr. Keiichi Kitajo
Dr. Keiichi Kitajo
RIKEN Brain Science Institute, BSI-TOYOTA Collaboration Center
Individual differences in nonlinear neural dynamics and human behavior
The human brain is a nonlinear dynamical system, which exhibits a variety of interesting nonlinear features, such as oscillations, synchrony, and noise-induced dynamics. In this talk, I show empirical evidence that individual-level variations in brain functions and behavior can be probed solely by analyzing resting-state or perturbation-induced nonlinear EEG (electroencephalography) dynamics. First, I demonstrate the dynamical repertoire of resting-state EEG dynamics accounts for the degree of ADL (activities of daily living) recovery in stroke patients and attentional abilities in healthy individuals. Next, I provide experimental evidence that noise-induced human brain responses exhibit highly consistent temporal patterns to a repeatedly-presented identical noisy visual input within individuals. The results indicate that visual noise can harness EEG dynamics and that noise-induced dynamics can serve as a robust dynamical individual marker. Finally, I show experimental results that non-invasive brain stimulation techniques are useful for investigating individual-level EEG dynamics. Our novel TMS (transcranial magnetic stimulation)-EEG co-registration technique show that we can dissect individual differences in perception by the patterns of TMS-induced EEG dynamics. These results indicate that individual-level variations in EEG-level nonlinear neural dynamics causally constrain the capacity of information processing in the brain associated with human behavior.