Brain Mechanism Of Information Processing Speed: An ERP Study

Information processing speed(IPS)is a fundamental part of the human cognitive activity.In the view of information transfer efficiency in the brain,some researchers suggest that IPS can affect other cognitive functions,such as working memory.There are quite a few studies focused on the relationship between IPS and brain structure,but the relationship between IPS and electrical activities of nerve is not clear.This study mainly focuses on the relationship between IPS and electrical activities of nerve.Regarding the variety of the IPS indices,we examined different factors in two kinds of IPS index(Pencil Pen,PP;Keyboard Pressing,KP)by principal component analysis(PCA).The results show that there are two main factors in those IPS indices,and the first factor has high factor loadings both with all KP tasks and a part of PP tasks.Therefore we consider that the KP tasks as a more precise measure of IPS.To explore the relationship between IPS and electrical activities of nerve,we used PCA to extract the main factor of KP tasks,tapping task and inspection time as information processing speed and employed P300 latency induced by the perceptual process in the inspection time as electrical activities of nerve.In addition to these,we also considered the effects of fatigue state in IPS.We found that P300 latency induced by perceptual process prolong with the increasing duration time of target stimulus,and P300 latency is related to information processing speed in fatigue state.