Attention Networks In Patients With Brain Lesions And Parkinson Disease

Objective Posner and Petersen proposed that the sources of attention form a specific system of anatomical areas,which can be further broken down into three networks. These networks carry out the functions of alerting,orienting,and executive control. Alerting is defined as achieving and maintaining an alert state;orienting is the selection of information from sensory input;and executive control is defined as resolving conflict among responses.The three systems have been respectively associated with the frontal, parietal and the anterior cingulate regions.A method has been developed to assay the three attention networks within one experiment.The attention network test provides a survey of the efficiency of the alerting,orienting and executive attention networks.We want to determine whether attention networks were impaired in patients with different regions of brain injury and Parkinson disease patients or not and examine the characteristics of the impairment.Methods The attention network test was used to compare patients with controls on the efficiency of three anatomically defined attention networks:alerting,orienting,and executive control.The patients include persons with lesion of frontal,lobe parietal lobe,temporal lobe and people of Parkinson disease.Results 1,Firstly,patients with frontal lobe injury showed a significant deficit in the executive network(frontal lobe injury,controls:143.7±46.6ms,91.6±46.4ms,Z = -4.714,P＜0.01) and also a significant deficit in the orienting network(frontal lobe injury,controls:71.2±35.2ms,55.1±21.8ms,Z = -2.125,P＜0.05).There was no deficit in the alerting network(Z =-0.901,P＞0.05).Secondly,the orienting network effect was significantly lower in patients with parietal lobe injury(34.9±25.2ms) than in normal controls(55.1±21.8ms,Z = -2.418,P＜0.05).However,there were no significant differences between the other two networks and controls(Z=-1.873,-0.186,P＞0.05). Thirdly,patients with temporal lobe injury showed no deficit in the three networks(Z= -0.037,-1.224,-0.718,Ps＞0.05) as well as in overall RT and accuracy(Z=-1.385,-0.699,Ps＞0.05).2,The correct rate of attention network test was significantly lower(P＜0.05 ) in PD patients(98.4%±0.3%) than in normal controls(99.2%±0.2%).The orienting network effect was significantly higher(P＜0.05 ) in PD patients(65.7±31.1ms) than in normal controls(43.5±32.3ms).The alerting and executive networks effects was lower in PD patients than in normal controls,but there was no significant difference(P＞0.05).The relative analysis showed that the Hoehn Yahr stage,a positive relationship to the value of executive network(r=0.794,P＜0.001),a negative relationship to the value of alerting network(r=-0.379,P＜0.05).No relationship was found between the Hoehn Yahr stage and the value of orienting network.Conclusions These results suggested that there were selective impairments of the orienting and executive networks in patients with the frontal lobe and the parietal lobe injury,while the alerting network is spared.Furthermore,it was important for the frontal lobe to the executive network,meanwhile,the orienting network connected tightly with the parietal lobe.Orienting network impairment was found in PD patients. As disease advanced both the alerting and executive networks abnormities were found exacerbated.