A Study Of Face Recognition ERP In PD

[Objective]1. To evaluate PD patients cognitive functioning in early metaphase PD, observe the situation of cognitive impairment in early metaphase PD and find sensitive screening scale for PD cognitive impairment.2. To study changes of N170 in impairment in visuospatial functioning in PD patient and investigate electrophysiological parameters which stand for cognitive impairment in early metaphase PD.3. To explore the mechanism of cognitive processes of visuospatial impairment in early metaphase PD.[Methods]1. Basic clinical data collection, recalling history, physical examination, neurological examination, assessment of cognitive psychology, Lab Examination and Imaging findings were carried out for 65 PD patients. Exclude PDD,50 PD patients participated in the study. Subjects were classified as impairment in visuospatial functioning (groupâ… ,n=30) if scores of visuospatial functioning item in any of above tests aren't full marks. If scores of the above tests are all full marks, subjects were classified as normality in visuospatial functioning (groupâ…¡,n=20). The two groups were matched for age,sex and education.2. We used face learning-recognition experimental model. We recorded EEG data of 10 channels and measured face-specific N170 component in all subjects. In addition, reaction time and correct reaction rate were recorded. Statistical analysis was applied to peak latency and amplitude of N170,behavioral indicators and scores of neuropsychological scale between the two groups. Two groups were engaged in a face recognition task. [Result]1.There are no statistically significant differences in scores of MMSE between the two groups. The scores of MoCA and items of visuospatial functioning the group I are lower than the groupâ…¡(P< 0.05).2.Correct reaction rate in group I are much lower than groupâ…¡(P< 0.05). Statistically significant differences aren't observed in correct reaction time between the two groups.3.There are no statistically significant differences in N170 rate of disappearance between the two groups. The wave amplitudes of N170 evoked by familiar faces in only T6 electrode in group I was increased as compared with that in group II (P< 0.05), there were no statistical difference in peak latency and amplitude of N170 evoked by familiar faces and strange faces in all other electrodes between both groups. There were statistical difference between peak latency of N170 evoked by familiar faces and strange faces in F7,F8 and 01 electrodes in group I and statistical differences were also observed in amplitude of N170 evoked by familiar faces and strange faces in F5 electrode(P<0.05). Peak latency and amplitude of N170 showed no significant difference between in familiar faces condition and in strange faces condition in each other electrode in each group.[Conclusion]1.The MoCA can identify the cognitive function impairment in PD patients in an early stage.2.The method of face recognition has clinical value in detecting impairment in visuospatial functioning in PD patient.3. Statistically significant differences aren't observed in correct reaction time between the two groups, which indicate that visuospatial impairment doesn't arise from visual memory;N170 stands for structure coding of face recognition,there are no significant difference in the amplitudes and peak latency of N170,which denote that cognitive impairment in early metaphase PD doesn't appears in the stage of structure coding.4. Visuospatial impairment in early metaphase PD influences face recognition because Peak latency and amplitude of N170 showed no significant difference between in familiar faces condition and in strange faces condition in groupâ…¡and there are statistical difference in groupâ… .5. We may measure peak latency and amplitude of N170 in face learning stage next and observe their changes. We may also find other ERP to reflect changes of visuospatial functioning in PD.