ABSTRACT
Objective To explore the cognitive process of cognitive flexibility in obsessive-compulsive disorder patients. Methods Thirty-two patients with obsessive-compulsive disorder (OCD) and thirty-two healthy controls were included. The Task Switch paradigm and event-related potentials were used to assess cognitive flexibility. Results The accuracy rate was lower in the OCD than in control group in both repeat and switch trials (P＜0.05). Reaction time analysis revealed significant differences in both repeat and switch between the OCD and controls ( P＜0.05). ERPs revealed significant differences in N2 and P3 amplitudes between OCD and controls (P＜0.05). There was no significant correlation between cognitive flexibility (accuracy rate and reaction time of repeat and switch, and N1, N2 and P3 amplitudes) and clinical forced symptoms in OCD (P＞0.05). Conclusion Obsessive-compulsive disorder of cognitive flexibility by injured.
ABSTRACT
Objective To investigate the influence of impulsivity on the functions of the conflict monitoring and the conflict resolution process for heroin addicts.Methods 80 heroin addicts were drawn randomly using simple random sampling method and finished Opioid Addiction Severity Inventory ( OASI ) and Barratt Impulsivity Scale ( BIS-11) .High impulsivity group( 7 females of 22) and low impulsivity group (8 females of 21) were divided according to 27%of the total BIS-11score followed the grouping method in psychometrics.Then the event-related potentials (ERPs) technique with the classical color-word Stroop task was used to reveal the influence of impulsivity on the executive function for heroin addicts.Results ( 1) The scores of motor impulsivity(23.00±1.73) and no-plan impulsivity(27.77±3.22) were higher in high im-pulsivity group than those in low impulsivity group(19.31±2.80,23.38±3.59)(P<0.01);and there was posi-tive correlation between impulsivity and addiction severity( r=0.415, P<0.05).(2) The behavioral data showed significant Stroop interference effects in both groups(P<0.01).(3) ERPs data showed that there were significant incongruent-N450 and SP effects in the low impulsivity group,whereas incongruent N450 and SP effects disappeared in high impulsivity group ( Low impulsivity group incongruent vs congruent condition N450:(2.82±3.09)μV vs (4.51±2.77)μV, P<0.05; SP:(3.54±1.25)μV vs (2.84±1.03)μV, P<0.05;High impulsivity group incongruent vs congruent condition N450:(4.98±4.10)μV vs (3.39±3.31)μV, P<0.05;SP:(3.43±3.84)μV vs (4.66±4.53)μV, P<0.05).Conclusion The brain time-interval change of executive function such as the conflict monitoring and the conflict resolution process is influenced by the im-pulsivity levels of heroin addicts.
ABSTRACT
@# Objective To investigate the cortical activities for processing exogenous stimulus-related information conflict and endogenous mental-related information conflict.Methods Event-related potentials (ERPs) were recorded while 15 healthy subjects performed a digit matching task. Each trial consisted of two sequentially presented digits (S1～S2), where S2 was either the same as S1 (S-) or different from S1 (S+) in digital value. Subjects pressed a button of a push-pad when S2 was the same as S1 and pressed the other button when S2 was different from S1 in the first session. Furtherly, they were required to calculate the difference between S1 and S2, and compare their calculation result with digit '3' in the second session. They pressed a button when the calculation result was equal to '3' (M-) and pressed the other button when it was not (M+). Three trial types were included: same numbers but their difference was not equal to '3' (S-M+), different numbers but their difference was '3' (S+M-) and different numbers but their difference was not '3' (S+M+). Results Following S2 onset, a component N270 was broadly elicited at all the scalps by S+, S+M- and S-M+. N270 and N400 were elicited in series by S+M+. The maximal amplitude of N270 was at the posterior scalp while the maximal amplitude of the N400 was at the central areas. Conclusion The different spatio-temporal distributions of the two negative potentials suggested that exogenous and endogenous information conflicts were serially processed in the human brain by the conflict processing system of multiple neural substrates.
ABSTRACT
Objective To examine ERP components related to different processings of emotional expression of fury, neutral and smile during face-map recognition. Method Twelve undergraduate students (7 male, 5 female), 19～24 years old, were served as subjects in the experiment. The visual stimuli consisted of six kinds of pictures: three kinds of facial pictures (neutral, smile, fury) and three kinds of non-facial ones. The subjects were asked to complete two tasks, i. e., face recognition (FR) and facial expression classification (FEC). During FR task, two runs of 210 stimuli (duration: 50 ms) with each (3 facial and 3 non-facial pictures) were randomly presented with equal probability (ISI: from 1 500 ms to 2 000 ms randomly), and subjects were asked to react to facial stimuli and non-facial stimuli by pressing the left button and right button respectively as quickly as possible. During FEC task, 210 stimuli (3 facial stimuli and 3 non-facial stimuli) were randomly presented with equal probability (duration: 50 ms, ISI: from 1 500 ms to 2 000 ms), and subjects were asked to react to different facial expressions by pressing 3 different buttons respectively as quickly as possible. Electroencephalogram (EEG) was recorded with NeuroScan-32 cap (10/20 system), in reference to bilateral mastoids. Result: 1) Compared with the ERP elicited by facial stimuli during FR task, the responses during FEC task evoked a P580 component clearly. 2) A positive-potential difference after 450 ms post-stimulation between ERP during FEC task and during FR task was observed, which was significant at central and parietal sites. According to the difference of task demand between two tasks, this wave was termed the expression processing positivity (EPP) to reflect the expression processing during face recognition. 3) The peak latency of furyEPP was the shortest and smile-EPP the longest. Conclusion The mode and site of the EPP are likeIv to represent brain function in late processinq of the expression.
ABSTRACT
Objective To investigate effects of driving fatigue on auditory involuntary attention.Method Between-groups design was used.The control group included 13 taxi drivers after adequate rest while the fatigue group included 13 taxi drivers who had been driving for 10 h.Auditory oddball pattern was adopted.The standard stimulus was 800 Hz,probability 80%;target stimulus was 1 000 Hz,probability 10%;novel stimulus was sound generated by computer or other sound,probability 10%.Subjects were asked to press the mouse upon hearing the target sound.Result The distribution of P3a was mainly around the frontal-central area of the subjects in control group;the amplitude of P3a was evidently lowered in subjects after driving fatigue.Conclusion The ability of auditory involuntary attention declines after driving fatigue.
ABSTRACT
Objective: To study the gender differences in ERPs recorded during a recognition task for Chinese words. Methods: 15 male and 15 female healthy volunteers received a Chinese words recognition task and the EEG signals were recorded from 20 scalp sites simultaneously. The stimuli were meaningful words consisting of two Chinese characters. Results: Both men and females showed a positive-going parietal old/new effect, but females demonstrated larger P500 amplitudes and shorter P500 latency than males. Furthermore, the parietal old/new effect of males was significantly left-lateralized, while that of females showed more bilateral pattern. Only males elicited obvious frontally distributed old/new effect between 250 and 350 ms, which was negative-going and right-lateralized. Conclusion: Gender differences do exist in the recognition processing of Chinese words. Some of the gender differences could be interpreted as reflecting different strengths and speed of brain activation and others could be interpreted as reflecting the involvement of different neural structures.
ABSTRACT
Objective:To investigate the characters of ERP in undergraduates with different trait anxiety during exam stress. Methods: By the State Trait Anxiety Inventory, one group of 15 undergraduates with high trait anxiety and another group with low trait anxiety were chosen from 200 participants in Band 4 College English Test. Their change of P3 were observed through NeuroScan 32 Channel ERP System during pre- exam and post- exam. Results: The amplitude of P3 of the group with low trait anxiety was enhanced while another group with high trait anxiety had no significant difference after exam; The latency of P3 of the group with low trait anxiety were decreased while another group with high trait anxiety had no significant difference after exam; There weren’t significant differences in amplitude and latency of P3 between high trait anxiety group and low trait anxiety group before exam; There were significant enhance of amplitude of P3 and decrease of latency of P3 in low trait anxiety group after exam as compared with high trait anxiety group. Conclusion: The result suggests different trait anxiety groups have different cognitive functions. When confronting with the same stress.
ABSTRACT
Electrophysiologic effects of physical exercise were investigated by comparing a training group and non-training group. ERPs were recorded by oddball paradigm using auditory stimuli as well as count and reaction tasks. EMG-RT was recorded during the reaction task. No reliable exercise effects on N100 amplitudes or latencies were observed. Concerning P300 amplitudes, no significant difference between the training group and non-training group was seen although P300 latencies of the training group were significantly shorter than those of the non-training group in the count task. Moreover, EMG-RT of the training group was significantly shorter than that of the non-training group.<BR>These findings suggest that the long-term physical exercise improved the efficiency of informa-tion processing and superior cognitive function in the brain.
ABSTRACT
We examined here, changes in event-related potentials (ERPs) in eighteen children from 7 to 12 years and twelve adults. In addition to ERPs, we examined changes of EMG-RT. Subjects performed an auditory target discrimination task, in which 1000 Hz tones (target) and 2000 Hz tones (standard) were randomly presented with probabilities of 0.2 and 0.8.<BR>We found P300 as most consistent component of ERPs since childhood. P300 latency and EMG-RT in children was significantly prolonged than in adults (p<0.01) . P300 amplitude in children was significantly larger than in adults (p<0.05) . We concluded that both stimulus evaluation time and response selection time in children are more prolonged than that in adults, although ERPs is confirmed in children.