Study Of Attention Networks Function Asymmetry In Schizophrenia

Objective Schizophrenia is a severe mental illness,affecting nearly 1% of the population worldwide.Cognitive impairement is one of the main symptoms of sczhizoprenia.Recent reports have indicated that the normal asymmetries are reduced or even reversed in schizophrenia.Such abnormalities have been found in the structural and functional brain and the attentional functions.But these experimental results are not consistent.This study used the Laterality of the attention network test,which can investigate the efficiency of the networks in both visual fields simply and effectively.Methods Study 1: Health controls(n=48)were tested with LANT(Lateralized attention network test)that allowed us to investigate the efficiency of the networks in both visual fields.Study 2: Schizophrenic patients(n=43)were tested with LANT(Lateralized attention network test)that allowed us to investigate the efficiency of the networks in both visual fields.Health controls met the same inclusion criteria as the patients group and were matched in age and education level.All patients were received antipsychotic medications and could completed the experiments.Results Study 1: Reaction time(RT)of right visual field were significantly longer,error rate(ERR)of right visual field were significantly higher when compared to those of left visual field in orienting.No significant alerting and conflict effects of visual fields were observed either for the RT or the ERR.Study 2: In term of ERR,multivariate factor analysis showed that compared with left visual field,the orienting efficiency is higher in the right visual field in health controls.While in right visual field,the orienting efficiency is higher in health controls compared with schizophrenic.Further analysis showed that there was an interaction effect between the health controls and the right visual field on the performance of orienting.Conclusions Attentional networks are distributed asymmetrically across hemispheres and spatial orientation is controlled by the left hemisphere in health controls.However,alerting and executive conflict are distributed symmetrically across hemispheres.A right visual fields advantage in orienting function was observed in health controls,but the normal asymmetries are reduced in schizophrenia.which may be associated with abnormalities of the left cerebral hemisphere.