Study Of Spatial Attention Under Region Cues Of Hemianopia Stroke Patients

The recovery of visual function is crucial to hemianopia stroke patients.Rehabilitation methods focused on vision recovery have been brought intoattention. While the visual search needs not only the participation of eyemovement, but also the regulation of visual attention. But the mechanism ofspatial attention of hemianopia stroke patients remains unclear. This studyinvestigated the influence of different scaling cues on the spatial attention taskof hemianopia stroke patients, and made comparison among different groupsof subjects.(1)The behavioral results showed that, the effect of scaling cue issignificant in healthy old and healthy young subjects, with the region of cuesgets bigger, the reaction time gets longer and accuracy rate gets lower.However, the effect of scaling cue disappeared in hemianopia stroke patients.Aging resulted in longer reaction time and lower accuracy rate.(2)Theanalysis of event-related potential (ERP) showed that, in posterior parietallobe, scaling effect is significant in healthy old and young subjects, with theregion of cues gets bigger, the amplitude of P1and P3get smaller and theamplitude of N1gets bigger (healthy old: loci P3, P4, P7and Pz; healthy young: loci P3, P7, Pz and O1). For the hemianopia stroke patients, the regioneffect focused on the left hemisphere (loci P3and O1). Aging resulted in thescaling effect more concentrated in posterior parietal lobe. In the occipitallobe (loci O1, O2and Oz), the latentcy of N1and P1in hemianopia strokepatients are shorter and the amplitude of N1is smaller than that of healthy oldsubjects. The aging significantly caused the latency of N1gets shorter and theamplitude of N1and P3get bigger.(3)The resting state brain networkreflected that the left primary visual cortex of hemianopia stroke patients tendto be less active than that of age-matched healthy subjects. However,hemianopia patients showed greater activation in the ipsilesional (left)temporopolar and orbit frontal areas and the contralesional (right) associativevisual cortex, which may resulted from compensation. These results mayoffer new insight into neural substrates of the hemianopia stroke, and thefurther study of neural plasticity and brain reorganization after hemianopia.