Research On The EEG Features And Neural Responses Modulated By Rhythmic Visual Stimuli

Neuro modulation has been widely applied to the medical treatment of neual deseases and the cognitive augment for military purpose.Currently,transcranial electric stimulation,transcranial magnetic stimulation and rhythmic sensory stimulation(RSS)are the most popular methods for neuromodulation.They could influence the neural function by changing the pattern of neural osccilations.RSS brings about evoked electroencephalography(EEG)oscillations by rhythmic stimuli on sensory organs.Numerous studies have shown that RSS at specific frequencies can alter behavioral performance periodically,but there is still little understanding of the RSS modulation on neural responses,which severely hampers the development of the RSS-based neuromodulation technique.A new paradigm was proposed to investigate the modulation of RSS on cognitive function of the brain.On the basis of the conventional visual/auditory two-alternative forced-choice paradigm,rhythmic visual stimuli(RVS)with different parameters were added as background stimuli.Transient visual stimuli included three different contrast.The behavioral data and EEG data of 31 subjects were randomly assigned to complete equal-volume of visual and auditory tasks.Relevant characteristics of subjects' behavioral accuracy and reaction time in the above experiments were statisticsed and analyzed,as well as the time-domain waveform,event-related spectral perturbation and inter-trial coherence of the EEG data.The following results were obtained:(1)RVS can significantly shorten the reaction time in the two-choice paradigm of visual and auditory tasks,but there is no significant effect on the accuracy of the behavioral response;(2)RVS in different frequency parameters modulated subjects' behavioral reaction time in different gain models,response gain at 10 Hz while contrast gian at 15 Hz;(3)the ITC gain pattern in the temporal cortex was consistent with the behavioral response gain pattern within135-320 ms after stimulation.According to the results of data analysis,the main conclusions of this thesis include:(1)RVS can affect the process of brain response,and is not limited to the visual pathway,the auditory pathway can also have a significant impact;(2)RVS in different frequency parameters modulated brain responses in different gain model,maily reflected on subjects' behavioral reaction time and the phase synchronization of neure in the temporal-lobe ?-band;(3)This thesis first drawed the behavioral and neural response gain curves under different frequencies of RVS.The thesis provided brain-computer interface technology acha new way brain-computer interface technology Interface technology achieving congnitive enhancement with a brand new way,as well as theoretical support on other applications such as the brain-machine integration technology and man-machine automation technology.