How do medical students understand disease behaviors?Evidence from event-related potentials

Objective: To investigate how medical students process Western medicine(WM) terms vs. traditional Chinese medicine(TCM) terms and how this is impacted by analogical priming from the perspective of cognitive neuroscience.Methods: The experiments were designed as a 2(TCM terms vs. WM terms) × 2(correct terms vs.incorrect terms) × 2(analogical priming task vs. non-priming task) scheme. A total of 26 medical students completed a non-priming judgment task and an analogical priming judgment task on medical terms. During the tasks, the participants were asked to make correct/incorrect judgments on WM terms and TCM terms, and their behavioral data and event-related potentials(ERPs) were recorded.Results: Behaviorally, the response speed and accuracy of WM terms were higher than those of TCM terms(both P <.001), indicating a prominent concreteness effect. Analogical priming shortened the response time to medical terms(P <.001), and the response time to TCM terms was shortened more significantly(P =.001). For ERPs, WM terms induced a larger P200(an early positive ERP component), a smaller N400(a negative ERP component), and a higher late positive ERP component, indicating superiority of attention adjustment, smaller-scale semantic activation, and a higher cost of late semantic analysis and integration. However, the analogical priming eliminated the difference between WM and TCM terms in P200 and N400 while maintaining it in the LPC. This suggests that WM terms are sensitive to analogical attention adjustment, and TCM terms are susceptible to analogical semantic integration.Conclusion: Our findings suggest that WM and TCM disease behavior terms may initially differ in concreteness or the use of a verbal-linguistic system. Analogy is more conducive to understanding TCM terms. This research provides important neuroscientific evidence of the difference in thinking between TCM and WM.

Correlations between Event-related Potentials with Pictures Recognition and WMS-RC Scores in Patients with Memory Disorder Caused by Severe Traumatic Brain Injury

This study explored the possibility of using event-related potentials （ERP） for the measurement of picture-recognition memory and examined its correlation with the Chinese Wechsler Memory Scale-revised （WMS-RC） in patients with memory disorder caused by severe traumatic brain injury （sTBI）. The subjects included 20 sTBI patients with memory disorder and 22 healthy individuals. Memory function was measured by using WMS-RC. Behavioral and ERP responses were recorded on-line during performance on a battery of picture recognition and the responses were analyzed off-line for recognition memory effects. Mean memory quotient （MQ） of patients with sTBI was significantly lower than that of the control group. Mean reaction time （RT） was significantly longer and the mean correctness rate （CR） of picture recognition was significantly lower in sTBI group than that of the controls. In controls, the main components of average ERP of picture recognition includes two positive-going waves, designated as P170 and P500, that appear 170 ms and 500 ms after stimulation when the subject could later successfully recall and recognize the pictures. P500 amplitude of target stimulus was significantly higher than that of non-target stimulus. Compared to controls, P500 responses of sTBI group were significantly delayed in latency （P〈0.001） and lower in amplitude （P〈0.001）. P500 latency showed significant negative correlation with MQ and the scores of ＂addition＂, ＂visual recognition＂, ＂picture recall＂, ＂visual reproduction＂ and ＂tactile memory＂ in WMS-RC. ERP of picture recognition provides a neurophysiological approach to directly assess memory impairment, and P500 may serve as a helpful index for memory disorder caused by sTBI in forensic practice.

Sensitivity of P300 auditory event-related potentials for assessing cognitive impairment in elderly type 2 diabetic patients

BACKGROUND：In previous studies, cognitive function in elderly type 2 diabetic patients was evaluated by psychometric tests. These studies have confirmed that P300 event-related potential is an objective way of assessing cognitive function. OBJECTIVE： To analyze the objectivity of P300 for assessment of cognitive function in elderly type 2 diabetic patients. DESIGN, TIME AND SETTING： This case-control experiment was performed at the Department of Endocrinology of the Fourth Affiliated Hospital, Guangxi Medical University from January 2004 to December 2006. PARTICIPANTS： Seventy-two patients （38 males and 34 females） with type 2 diabetes mellitus were enrolled in this study. The patients were divided according to those with diabetes alone （diabetes alone group） （n=38） and those with diabetes and cerebral ischemia （diabetes and cerebral ischemia group） （n=34）. A further 31 healthy individuals （16 males and 15 females）, who received health examinations over the same period, were included as normal controls （normal control group）. METHODS： All subjects were assessed by Mini-Mental State Examination （MMSE）. Abnormalities in cognitive functions were identified by analyzing the auditory P300 event-related potentials. MAIN OUTCOME MEASURES： Auditory event-related potentials and MMSE scores. Multiple linear regression analysis was conducted using the ＂enter method＂ with the 72 elderly patients with type 2 diabetes mellitus. P3 latency, P3 amplitude and N2 latency served as dependent variables. Age, sex, education, course of the disease, glycosylated hemoglobin, and ischemic brain damage were used as independent variables. RESULTS： No significant difference in scores of MMSE was detected between the diabetes alone and normal control groups （P 〉 0.05）. MMSE score was significantly lower in the diabetes and cerebral ischemia group （P 〈 0.01） than in the normal control group. N2 and P3 latencies of auditory event-related potential were significantly longer, and P3 amplitude was significantly lower in the diabetes alone and diabetes and cerebral ischemia groups （P 〈 0.01） than in the normal control group. N2 and P3 latencies were significantly longer in the diabetes and cerebral ischemia group than in the diabetes alone group （P 〈 0.01）, but amplitude was not significantly different. N2 and P3 latencies were negatively correlated with MMSE score in elderly type 2 diabetic patients （r=–0.421, –0.604; both P 〈 0.01）. P3 amplitude was positively related to the score of MMSE （r =0.517; P 〈 0.01）. P3 latency was positively associated with age, course of disease, glycosylated hemoglobin and ischemic brain damage in elderly type 2 diabetic patients （t=2.186 to 3.490; all P 〈 0.05）. P3 amplitude was negatively correlated with age, course of disease and glycosylated hemoglobin （t=–2.220, –2.491, and –2.024, respectively; all P 〈 0.05）. N2 latency was positively correlated with age, course of disease and ischemic brain damage （t=2.946, 2.511, and 2.331, respectively; P 〈 0.05）. CONCLUSION： The course of disease, glycosylated hemoglobin and ischemic brain damage are key influential factors for cognitive impairment in elderly type 2 diabetic patients. The P300 event-related potential is a sensitive index for objective assessment of cognitive impairment in elderly diabetic patients.

Characterization of event-related potentials in obsessive compulsive disorder patients: Comparison with depression and generalized anxiety disorder patients

BACKGROUND： Study results of event-refated potential in obsessive compulsive disorder （OCD） remain controversial, potentially as a result of different instruments utilized and their differing technical characteristics. OBJECTIVE： To investigate the differences in several common event-related potentials, Le. contingent negative variations, P300, and mismatch negativity （MMN）, in OCD patients, depression patients, generalized anxiety disorder （GAD） patients, and healthy controls. DESIGN, TIME AND SETTING： A case-control study was performed in the Department of Electrophysiology, Shanghai Mental Health Center from May 2002 to December 2005. PARTICIPANTS： A total of 38 OCD patients, 20 depression patients, and 18 GAD patients, who were diagnosed according to the criteria of Chinese Classification of Mental Disorders （Version 3）, formulated by the Chinese Psychiatry Association, were selected from the Outpatient Department of Shanghai Mental Health Center. Patients with two or more the above diseases were excluded. In addition, 28 healthy people, gender and age matched, were selected as controls. METHODS： Contingent negative variations, P300, and MMN were recorded by a Nicolet Spirit Instrument. All electrodes were attached at Cz according to the Intemationa11020 system, with the mastoid leads as reference and Fpz as ground. MAIN OUTCOME MEASURES： Amplitude and latency of contingent negative variations, P300, and MMN. RESULTS： The contingent negative variations, P300, and MMN were different （P 〈 0.01）. OCD patients showed an increased MI amplitude compared with controls, depression, and GAD patients （P 〈 0.01）. Target P300 amplitudes were significantly lower in OCD, depression, and GAD patients compared with controls （P 〈 0.01）. Moreover, N2 latency and latency of MMN were prolonged in OCD and depression groups compared with controls （P 〈 0.05）. CONCLUSION： Event-related potentials were different in depression, GAD, and OCD patients and healthy controls. In particular, OCD patients exhibited unique characteristics.

Enhanced inhibitory control during re-engagement processing in badminton athletes:An event-related potential study

Purpose:The purpose of present study was to investigate the impact of sport experience on response inhibition and response re-engagement in expert badminton athletes during the stop-signal task and change-signal task.Methods:A total of 19 badminton athletes and 20 nonathletes performed both the stop-signal task and change-signal task.Reaction times(RTs)and event-related potentials were recorded and analyzed.Results:Behavioral results indicated that badminton athletes responded faster than nonathletes to go stimuli and to change signals,with faster change RTs and change-signal RTs,which take into consideration the variable stimulus onset time mean.During successful change trials in the change-signal task,the amplitudes of the event-related potential components N2 and P3 were smaller for badminton athletes than for nonathletes.Moreover,change-signal RTs and N2 amplitudes as well as change RTs and P3 amplitudes were significantly correlated in badminton athletes.A significant correlation was also found between the amplitude of the event-related potential component N1 and response accuracy to change signals in badminton athletes.Conclusion:Moderation of brain cortical activity in badminton athletes was more associated with their ability to rapidly inhibit a planned movement and re-engage with a new movement compared with nonathletes.The superior inhibitory control and more efficient neural mechanisms in badminton athletes compared with nonathletes might be a result of badminton athletes’ professional training experience.

Chinese emotional words in patients with major depressive disorder during a subliminal Stroop task An event-related potential study

Patients with major depressive disorder （MDD） develop a negative cognitive bias, but how they respond to information in Chinese emotional words is unclear. Here we used a Stroop paradigm with subliminal Chinese emotional words to explore the event-related potential components of abnormal emotional processing Jn patients with MDD. The correct rate was similar in MDD and normal control groups, but MDD reaction time was longer than the normal controls, especially to the negative and neutral stimuli. In N270, repeated-measure analysis of variance demonstrated a significant main effect of the relation electrode and valence on peak amplitude and interactions between valence and electrode site. The peak amplitudes of the three kinds of words were different in the two groups （positive 〉 negative 〉 neutral）. The topography of the difference waves indicated that the difference distributed in the frontal and left parietal-temporal sites across the scalp. In N400, there was a significant main effect of the relation electrode and valence on peak amplitude, and the latency showed a main effect of the electrode and an interaction between electrode and group. The amplitudes induced by type of words were significantly different from each other in both groups （positive 〉 negative 〉 neutral）. The topography of the difference waves indicated that the effect of relation type was primarily at left and right frontal and central and left parietal-temporal regions. Both MDD patients and normal controls exhibited significant emotional Stroop effects during the processing of positive/negative Chinese emotional words. MDD patients showed interference in emotional stimuli in early cognitive processing that induced psychological resource intervention during late emotional information processing.

Effect of emotional valence on episodic memory stages as indexed by event-related potentials

Several investigations have shown that emotional events show superior recall than non-emotional ones. However, the cortical mechanisms underlying the episodic recall of emotional scenes are still poorly understood. Our main aim was to compare the magnitude of the Event-Related brain Potentials (ERP) old-new effect related to emotionally unpleasant, pleasant and neutral photographic images. As expected, correct recognition of all types of images elicited three topographically distinct ERP components sensitive to the classical old-new recognition effect. The results revealed that the behavioral performances were mainly sensitive to arousal, while the ERP old/new effect over posterior regions (300 - 1000 ms) was exclusively affected by unpleasantness. A later component (1000 - 1400 ms) showed an inverted old/ new effect at parietal sites, which was also sensitive to unpleasantness. These results imply that ERP reflecting episodic conscious recollection and post-retrieval monitoring are clearly affected both by valence and arousal.

The Effect of Emotional Conflict on Attention Allocation: An Event-Related Potential Study

Attention allocation research frequently focuses on the valence of emotion. However, there is increasing evidence to indicate that arousal may be more relevant at some stages of affective processing. The present study employed a combined priming and cue-target paradigm and examined event-related potentials (ERPs) in order to explore the effects of emotional conflict of arousal on attention allocation. The background context of arousal was manipulated (using photos of facial expressions) while subjects performed a cognitive task in which a central arrow cue indicated the location of a peripheric target square, and a response was made according to the direction of the square. There was no main effect between incongruent emotion and congruent emotion in the response time, which means the resolution of the emotional conflict facilitate the participant behavioral response. There was a main effect of different emotional states on ERP component. In the present study, incongruent arousal also triggered greater positive potential compared with congruent arousal.

An event-related potential observation of preposition processing in Chinese: Is N280 a specific component for Chinese prepositions?

BACKGROUND： Studies have shown that closed-class words, such as prepositions and conjunctions, induce a left anterior negativity （N280）, indicating that N280 should be a specific component of the word category. OBJECTIVE： To observe if Chinese prepositions and verbs exhibit different linguistic functions, to determine whether they are processed by different neural systems, and to verify that N280 is a specific component. DESIGN, TIME AND SETTING： The observed neurolinguistics experiment was performed at Xuzhou Normal University between November and December 2006. PARTICIPANTS： Sixteen undergraduate students, comprising 8 females and 8 males, with no mental or neuropathological history, were selected. METHODS： A total of 15 verbs and prepositions were used as linguistic stimuli, and each verb and preposition was combined to produce four correct phrase collocations and four incorrect ones. MAIN OUTCOME MEASURES： Event-related potentials were recorded in the subjects while they read correct or incorrect phases flashed upon a video screen. RESULTS： Both verbs and prepositions elicited negativity at the frontal site in a 230-330 ms window, as well as at the fronto-temporal and central sites in a 350-500 ms window. Neither exhibited significant differences in peak [F（1, 15） = 0.144, P = 0.710] and latency [F（1, 15） = 0.144, P= 0.710]. Both verbs and prepositions elicited negativity at the left and right hemisphere in a 270-400 ms window. CONCLUSION： There was no significant difference between Chinese prepositions and verbs in the neural system process and N280 was not the specific component for closed-class words.

A Study of Visual Event-Related Potential and Reaction Time in Elderly People: Comparative Analysis of the Scores of Intelligence Test in 30 Subjects

The results of visual event-related potential(ERP)examinations and reactiontime(RT)tests were reported in 30 elders and compared with their performanceintellegence quotient(PIQ)scores.The subjects consisted of 18 males and 12 femalesaged 50-71(mean 61.4)years old.No history of central nervous system disease wasfound.The visual stimuli were randomly presented to the subject,including three sym-bols:E as target stimulus with 0.15 probability,and H and E as nontarget stimuliwith 0.15 and 0.70 probability respectively.The recording electrodes were placed on Fzand Pz.The duration from the subject seeing the target to touching a button immediatelywas considered as reaction time(RT).It was shown that the P3 latency at Pz was longer than that at Fz and the P3amplitude at Pz was larger than that at Fz,and that the RT was longer than P3 latencywith obvious effect of distribution(P【0.05 at Fz and P】0.05 at Pz)as well .The higherthe PIQ scores,the longer the RT and the P3 latency.It is suggested that the ERPmight reflect the differences of PIQ scores,and the P3 is an objective index.We considerthat the research of ERP is of great interest in the neuropsychological and neurological sci-ences.

Effects of different cue positions on evoked potentials in the cerebral cortex during global and local processing of compound stimuli A study of event-related potential

BACKGROUND： Previous studies of attentional control have focused primarily on pre-cue control of attentional cue and direction. OBJECTIVE： To measure the differences in electrical activity of brain cells while processing pre-cue and post-cue compound stimuli, and to explore brain electrical activity during global and local processing of compound stimuli according to electroencephalogram （EEG） recordings. DESIGN, TIME AND SETTING： A within-subject design study was performed at the School of Psychology, State Key Laboratory of Cognitive Neuroscience and Learning, Beijing Normal University, China from March to May 2006. PARTICIPANTS： A total of 30 healthy, undergraduate students, aged 17-24 years, comprising 12 males and 18 females, were voluntarily enrolled from Beijing Normal University. Subjects exhibited normal or corrected-to-normal visual acuity. No significant non signal wave drift was detected during testing. METHODS： A total of 30 subjects were subjected to pre-cue and post-cue compound stimulus processing using event-related potential and EEG recordings. MAIN OUTCOME MEASURES： Evoked potential was recorded in different brain regions utilizing event-related potential to observe hemispheric symmetry, cue consistency and global-local features. RESULTS： Pre-cue compound stimuli resulted in hemispheric asymmetry for early wave （N1） and late wave （P3） in anterior brain regions. Early- and late-wave induced hemispheric asymmetry for electrode points （O1, 02, P3, P4, Pz, F3, F4, F7, F8, Fz, FP1, FP2, T7, TS, C3, C4, and Cz） during processing of pre-cue compound stimuli （P 〈 0.05）. Post-cue compound stimuli did not induce hemispheric asymmetry of brain waves induced by the above-described electrode points. No significant differences in global and local responses were determined during processing of post-cue compound stimuli. Under pre-cue conditions, significant differences were observed in N1 and P3 in the above-mentioned electrode points （P 〈 0.05）. However, under post-cue conditions, no significant differences were observed in N1 and P3 using the above-mentioned electrode points. Significant differences in early waves （N1 and P1） using the above-mentioned electrode points were detected between anterior and posterior brain regions, regardless of consistent or inconsistent, large or small letters （P 〈 0.05）. CONCLUSION： Cue location effected mechanisms underlying global and local processing of compound stimuli. Pre- or post-cue conditions resulted in differences in hemispheric symmetry, cue consistency, and global and local features. Under pre-cue conditions, hemispheric dominance was detected in global and local processing following compound stimuli. Under post-cue conditions, hemispheric dominance was not determined.

Mechanisms underlying syntactic and semantic processing of Chinese simple sentences Evidence from event-related brain potentials

This study sought to test the processing of three types of sentences in Chinese, as correct sentences, semantic violation sentences, and sentences containing semantic and syntactic violations, based on the following sentence pattern： ＂subject （noun） ＋ yi/gang/zheng ＋ predicate （verb）＂. Event-related potentials on the scalp were recorded using 32-channel electroencephalography. Compared with correct sentences, target words elicited an early left anterior negativity （N400） and a later positivity （P600） over frontal, central and temporal sites in sentences involving semantic violations. In addition, when sentences contained both semantic and syntactic violations, the target words elicited a greater N400 and P600 distributed in posterior brain areas. These results indicate that Chinese sentence comprehension involves covert grammar processes.

Identification of a Novel Dynamic Red Blindness in Human by Event-related Brain Potentials

Dynamic color is an important carrier that takes information in some special occupations.However,up to the present,there are no available and objective tests to evaluate dynamic color processing.To investigate the characteristics of dynamic color processing,we adopted two patterns of visual stimulus called "onset-offset" which reflected static color stimuli and "sustained moving" without abrupt mode which reflected dynamic color stimuli to evoke event-related brain potentials (ERPs) in primary color amblyopia patients (abnormal group) and subjects with normal color recognition ability (normal group).ERPs were recorded by Neuroscan system.The results showed that in the normal group,ERPs in response to the dynamic red stimulus showed frontal positive amplitudes with a latency of about 180 ms,a negative peak at about 240 ms and a peak latency of the late positive potential (LPP) in a time window between 290 and 580 ms.In the abnormal group,ERPs in response to the dynamic red stimulus were fully lost and characterized by vanished amplitudes between 0 and 800 ms.No significant difference was noted in ERPs in response to the dynamic green and blue stimulus between the two groups (P】0.05).ERPs of the two groups in response to the static red,green and blue stimulus were not much different,showing a transient negative peak at about 170 ms and a peak latency of LPP in a time window between 350 and 650 ms.Our results first revealed that some subjects who were not identified as color blindness under static color recognition could not completely apperceive a sort of dynamic red stimulus by ERPs,which was called "dynamic red blindness".Furthermore,these results also indicated that low-frequency ERPs induced by "sustained moving" may be a good and new method to test dynamic color perception competence.

Selective attention to orientation and closure: An event- related potential study

Event-related potentials (ERPs) were recorded when the subjects attended selectively to stimuli in one visual field and responded to the targets including designated feature (orientation or closure) value. Attention to spatial location elicited enlarged P1 and N1 at posterior electrodes contralateral to the stimulus location, whereas selection to orientation or closure elicited selection negativity (SN) and a late negative component (LNC). The selection of spatial location was prior to the selection of orientation or closure. SN was elicited only by the stimuli in the attended visual field, suggesting that the selection of orientation and closure are contingent on the prior selection of location. Moreover, the onset latency of SN was earlier for closure selection than for orientation selection, indicating that the processing of closure occurred earlier than the processing of orientation. The results are consistent with the early-selection theories of attention and provide psycho-physiological evidence for the topology theory of visual perception.

Event-related potential N170 for early diagnosis of face recognition impairment in Parkinson's disease

Event-related potential （ERP） studies of cognitive function in Parkinson＇s disease （PD） have focused on P300 and N270. However, little is known regarding face recognition ERP in PD. The present study assessed cognitive function in PD patients using neuropsychological scales and analyzed N170 of visuospatial function impairment （VFI） in PD. Results showed that Montreal cognitive assessment can be used for assessing cognitive impairment when visuospatial functioning is changed during the early stage of PD. Face recognition has clinical significance for detecting changes in visuospatial functioning. However, N170 is not sensitive for detection of VFI in PD, which implies that VFI does not appear in the stage of structure coding in face recognition. In addition, VFI affects face recognition.

Components and sequential changes in event-related potential induced by gaze orientation processing under a reflective attention cue paradigm

Gaze orientation induces activation of relevant brain regions, presents differences in specificity and time course, and is exhibited in patients with brain injury. However, the components of activated event-related potential remain controversial. Previous studies of behavior and cognitive neuroscience related to gaze orientation investigated conscious attention of visual orientation. The present study explored gaze orientation processing-induced event-related potential components and changes with time using reflective orientation of visual attention under a reflective attention cue paradigm. Visual attention processing of gaze orientation was recorded using event-related potential and electroencephalographic recording. Results demonstrated that the reflective attention cue task evoked early directing attention negativity and anterior directing attention negativity, but did not trigger late directing attention positivity. These results suggest that reflective attention occurs over a short time of visual stimulus presentation. During the early stage of attention processing, early directing attention negativity and anterior directing attention negativity were detected, but late directing attention positivity did not occur. These results confirmed reflectivity and time-course superiority of gaze orientation attention processing.

Effect of variable number of tandem repeats polymorphism in the human dopamine transporter gene on conflict information processing according to event-related potential

The dopamine transporter （DAT） is responsible for dopamine reuptake from the synaptic cleft. A variable number of tandem repeats polymorphism in the DAT gene is related to DAT availability and has been associated with cognition. With the advantage of high-time resolution, event-related potential is an important method to study the time course of human information processing. Previous results have suggested that dopamine exhibits a close relationship with conflicting information processing. Therefore, the present study assumed that conflicting information processing could be influenced by DAT variable number of tandem repeats polymorphism. To confirm this, the present study analyzed the influence of DAT genotypes on N270, which is presumed to reflect neural activity of conflict information processing in young healthy adults. A S1-S2 matching task was performed in healthy adults with 10/10 genotype （n = 14） and 10/9 genotypes （n = 14）, respectively, when event-related potentials were recorded. Results demonstrated that subjects with the 10/10 genotype exhibited shorter N270 latency and quicker reaction times compared with subjects with the 10/9 genotype. There were no differences in N270 amplitude between the two genotypes. These results suggested that 10/10 genotype subjects more efficiently processed conflict information.

Task Co-Representation in Aging: An Event-Related Potential Study

The goal of the present study was to investigate age-related changes in attentional allocation for shared task representations during joint performance;event-related potentials were recorded while participants performed a modified visual three-stimulus oddball task, both alone and together with another participant. Younger adults and older adults (14 each) participated in the study. Participants were required to identify rare target stimuli while ignoring frequent standards, as well as rare non-targets assigned to a partner’s action (i.e., no-go stimuli for one’s own task). ERP component, nogo-P3 and P3b were measured to investigate the inhibition and the attentional allocation to the partner’s stimuli. Results showed that younger adults elicited larger frontal nogo P3 and parietal P3b for non-targets in the joint than in the individual condition. Contrary to expectation, older adults induced frontal no-go P3 in the joint condition not in the individual condition. In the sharing of the task with another, the result suggested that the efficiency of matching of incoming information with the representation of the other’s task declined with age, whereas aging did not affect the suppression of incorrect preparation of motor responses instigated by this representation.

Cognitive malingering assessed using event-related potential P300 evoked by the old-new task in the oddball paradigm

The P300, an endogenous subcomponent of the event-related potential, is thought to reflect cognitive processes. The event-related potential evoked by the old-new memory recognition task in the oddball paradigm is suitable for examining the neural processes involved in malingered neurocognitive deficits. Forty-four undergraduates were randomly assigned to a simulated malingering group and a truth-telling group, Another 22 patients with head injudes were enrolled as a control group. All participants completed the old-new memory recognition task in the oddball paradigm. The mean P300 amplitude of the simulated malingering group was significantly reduced compared with the truth-telling group （P 〈 0.01）, but was increased compared with the control group （P〈 0.01）. These results revealed that the P300, evoked by the old-new memory recognition task of the oddball paradigm, may be a helpful indicator for determining cognitive malingering.

Effect of Neurofeedback on Visual-Spatial Attention in Male Children with Reading Disabilities: An Event-Related Potential Study

Recent studies describe a number of difficulties associated with attention deficit in children with reading disabilities. Information about visual-spatial attention mainly arises from studies using event-related potentials (ERPs) during Posner’s spatial cueing paradigm. This study aims to use neurofeedback with a special protocol for treating children with reading disabilities, and moreo-ver, to evaluate visual-spatial attention ability by means of Posner paradigm task and ERPs. The study was conducted in a single subject design in 20 sessions. Participants were 2 male children, aged between 10 - 12 years old, who completed twelve 30-min neurofeedback sessions. Repeated measurements were performed during the baseline, treatment, and post treatment phases. Results showed some improvement in Posner paradigm parameters (correct response, valid and invalid reaction times). Furthermore, grand average ERPs for both of the participants in each of the four conditions (Valid-right, Invalid-right, Valid-left and Invalid-left) were analyzed. The analysis of P3 component showed a reduction in latency, indicating an improvement in the timing of cognitive processes. In addition, the graphs showed a decrease in amplitude level, which meant easier processing than before.