Methods Towards Synchronous Recording And Analysis Of Eye Movements And Electroencephalograph

Eye tracking and electroencephalography (EEG) analysis have been widelyused in cognitive psychology research as tools of experimental measurements.Because of technical limitations of synchronous recording and analysis of EEGdata and eye movements (EMs), especially eye tracking based on videorecording, it is difficult to realize the synchronization. In this thesis, thesimultaneous recording and analysis of eye movements and EEG were studied.At the same time, a number of technologies were proposed and implemented.Based on the simultaneous analysis of EMs and EEG, saccadic movements werestudied on visual perception. The eye behavior as an indicator of cognitiveprocesses may help us to understand the mechanism of brain cognition.In order to synchronize EEG signals and video recordings, a method ofsynchronization employing pseudorandom-sequence-coded signals wasproposed. An eye tracker system comprised of a high-speed USB camera and anEEG amplifier was designed for the implementation of the method. Starburstalgorithm was applied to identify the pupil center and gaze points weredetermined by a2nd-order mapping from a calibration process. Thissynchronization method was utilized in a Steady-State Visual Evoked Potential(SSVEP) experiment. The accuracy of the synchronization was10ms when thecamera frame rate was100f/s.Eye-tracking technology as a means of human-computer interaction (HCI)and eye behavior measurement has been widely used in psychology andcognitive scientific research. Meanwhile brain-computer interface (BCI) basedon SSVEP is also a concerned method for disabled patients. Two kinds ofelectrophysiological signals, Electrooculography (EOG) and EEG, weresimultaneous analyzed with the eye tracker system. The screen coordinates ofthe target could be used as benchmark parameters for calibration of gaze pointtracking.After the study on the basis relation of eye movement behavior and EOGwaveform, two cognition experiments were designed to study the EMs as behavioral indicators of cognitive process. One was about the stochasticresonance effect in motion-onset visual evoked potential (m-VEP). Another wasusing anti-saccade task to study autonomy cognition. In both of two experiments,the EMs were the response to the visual stimulus. The differences such as that intime delays between EMs and keyboard response indicated that there might bemore than one pathway of visual perception or there might be different braindynamic networks of processing. The ERP signals are needed further analyzedas the number of subjects is not enough.