The Neuropsychologia Study Of Hemispatial Neglect

Hemispatial neglect, one of the most common dysfunction after stroke, severely impedes the rehabilitation of functions and the life quality of patients. Investigation to the neural mechanism of neglect and the effective method of rehabilitation has a crucial meaning in clinical recovery and life quality improvement. It also has a scientific meaning in promoting the comprehension in cognitive processing of consciousness and attention. The current study is focusing on the analysis of lesion areas in neglect patient, the mechanism of visual perception, the information processing level in contralateral deficit and the psuedo-neglect.Study A, the analysis of lesion areas in neglect patient: the neural localization has been a controversial topic in neglect study. We adapted lesion overlapping technique to analyze 20 patients with left unilateral neglect. The result demonstrated that tempo-parietal junction is the most related part with neglect, the specific proportion of other related brain area is: frontal lobe 3/20, occipital lobe 4/20, temporal lobe 15/20, and parietal lobe 10/20.Study B, the manipulation of connectedness in neglect: Patients with neglect generally ignore the left part of chimeric pictures when simultaneously performing a naming task. Some studies revealed that patients were more likely to make the correct response if the two parts of chimeric pictures were intentionally spearated; the particular mechanism underlying this phenomenon is still unclear. We observed the correct rate of response to chimeric pictures in neglect patients under different conditions and have discovered the significant manipulative influence of connectedness in neglect patients' visual perception.Study C, the word-length effect and semantic effect in neglect dyslexia: The neglect patients commonly manifest the neglect dyslexia. We investigated the semantic processing of Chinese vocabulary in neglect dyslexia. The result showed that neglect patients demonstrated variable dyslexia types including omission, substitution and addition with a significantly word-length effect. The correct rate of response in true words reading was evidently higher than that of pseudo-words, suggested that the information presented in neglect side could be semantically processed. Through the study of phonogram, there is no evidence showed that the left sublexical semantic transparency has the priming effect to phonogram.Study D, the dissociation of numerical bisection and line bisection in schizophrenia (pseudo-neglect): The topic on the mechanism of numerical bisection and line bisection is still controversial. We compared the bias degree of numerical bisection and line bisection in both schizophrenic patients and healthy control, investigated the underlying mechanism of those two. The result showed that, compared with control group, the schizophrenia group demonstrated significantly left bias in line bisection while the result of numerical bisection had no statistical discrepancy, suggested a dissociation of numerical bisection and line bisection.