| The P300 component of the auditory event - related cortical potential is consistently reduced in patients with schizophrenia, schizotypal personality disorder, and other personality disorders. P300 or P3 is a positive deflection that peaks around 300ms after the onset of a target stimulus which is very important for the subject. This potential is not one wave, but a group of waves including different positive factors. It reflects the different intellegent process comprehensively. More studies improved that P300 was the result of comprehensive cortical activity, is related to multiple psychological factors ( cognitive process) reflect the potential changes of sensation, cognition, memory, understanding, learning , judgment, reasoning and intelligent. So, it has been used to be a objective index to judge the advanced brain function. It has been used extensively for the study of cognitive process in normal subjects and in psychopathology.An important aspect of P300 is that "novel" stimuli (e,g. , dog barks, abstract color forms, etc) can produce an earlier, positive potential called P3a that appears to be distinct from the later P300 or P3b peak. P3a is typically larger in amplitude than P3b over the frontal and central electrode sites and is thought to reflect an alerting process that originates in the frontal cortex. Recent reports indicate that P3a amplitude is directly affected by the discrimination difficulty between the target and standard stimuli and not by novel stimulus characteristics. These studies suggest that P3a reflects attentionnal processes related to signal evaluation, when memory process store the incoming stimulus information, the central/parietal P3b is generated. Thus, P3a reflects the initial response to an incoming signal, and P3b indexes the attentional and mnestic operations invoked to process the stimulus.P3 amplitude has been studied extensively in schizophrenia spectrum disor-ders, and to a lesser extent in severe personality disorders, but relatively few studies have examined the relationship between P3 amplitude and personality traits in normal subjects.According with the energy models of P300 proposed by Mulder and Kok, P300 represents the cortical energy necessary to realize a cognitive operation in which an individual orients his attentionnal processes towards the novel stimulations of the environment. Then, amplitude variation of P300 component is usually considered as a sigh of variation in intensity of activation/inhibition of neural structures in the brain by the task variables. Moreover, the theoretical constructs of surprise and orientation are associated both with TCI dimension and P300.TCI (The Temper and character Inventory) is developed by Cloninger and his colleagues basing on biosocial model to access the seven dimensions of personality. Moreover, in the model of Cloninger, the phenotypic structure of personality may differ from the underlying biogenetic structure because the observed behavioral variation is the result of the interaction of genetic and environmental influenced. Some dimentions have been associated to a specific central neuro-transmitter. And many psychometric and neurobiological investigations have proved the validation of this model.Therefore, the aim of this study is to investigate the relationship between P300, P3a, P3b, LDAEP and the personality dimensions described by the TCI.AimThis study is investigating the relationship between P300, P3a, P3b, LDAEP and the personality dimensions of TCI. P300 reflects the potential changes of cognition. It has been used to be an objective index to judge the advanced brain function and extensively for the study of cognitive process in normal subjects and in psychopathology. So, we want to do this research to provide electrophysiologi-cal evidence for the evaluation and prevention of personality and mental disorder.Methods1. Subjects: The study was conducted in 36 healthy subjects. All of them are right handedness who were not familiar with psychophysiological methods. The sa...
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