Left Prefrontal Lobe Research Articles

Fuzzy Neural Network based Real-Time Driver Fatigue Detection and Warning System using EEG Waves

Driving fatigue has been considered as a significant risk factor in transportation accidents, and the development of the human cognitive State based on Electro Encephalo Gram (EEG) has become a major focus in the field of driving safety for many drivers. In adaptive online prediction framework which is capable of capturing subject-specific predictive patterns autonomously by constructing a subject-specific pattern library, based on which a probabilistic prediction rule is established. A real-time wireless Electro Encephalo Gram (EEG) based Brain Computer Interface (BCI) system for drowsiness detection has been proposed to reduce the time delay. A new method for driver fatigue detection based on EEG waves using Recurrent Self-Evolving Fuzzy Neural Network (RSEFNN)is proposed. The model uses Mindwave to collect the attention waves of EEG from the left prefrontal lobe of the subject, and measures the data when the subject is in the State of concentration, relaxation, fatigue and sleep. The Mindwave device and Matlab is interfaced using the Think Gear Library module. The correlation coefficient of the driver attention is classified to detect driver fatigue. Thus the system using brain wave sensor warns the driver when he/she feels drowsy.

Age-related alterations in phase synchronization of oxyhemoglobin concentration changes in prefrontal tissues as measured by near-infrared spectroscopy signals

The prefrontal cortex plays an important role in planning complex cognitive behavior, personality expression, and decision making. This study aims to assess the phase synchronization of signals of the oxyhemoglobin concentration changes (Δ[HbO2]) in the left and right prefrontal tissues through near-infrared spectroscopy (NIRS) with wavelet phase coherence (WPCO) method. The NIRS signals were continuously recorded from the left and right prefrontal lobes in 43 healthy elderly subjects (age: 69.6±8.4years) and 40 young healthy subjects (age: 24.5±1.7years) during the resting state. Phase synchronization between the left and right prefrontal oscillations in six frequency intervals (I, 0.6–2Hz; II, 0.145–0.6Hz; III, 0.052–0.145Hz; IV, 0.021–0.052Hz; V, 0.0095–0.021Hz; and VI, 0.005–0.0095Hz) was analyzed using the WPCO method. The WPCO values of elderly subjects were significantly lower in frequency intervals I (F=7.376, p=0.010) and III (F=6.418, p=0.016) than those of the young subjects. Low phase coherence in intervals I and III indicates reduced synchronization of cardiac activity in the prefrontal area and weakened prefrontal functional connectivity, respectively.

Alterations in Anatomical Covariance in the Prematurely Born.

Preterm (PT) birth results in long-term alterations in functional and structural connectivity, but the related changes in anatomical covariance are just beginning to be explored. To test the hypothesis that PT birth alters patterns of anatomical covariance, we investigated brain volumes of 25 PTs and 22 terms at young adulthood using magnetic resonance imaging. Using regional volumetrics, seed-based analyses, and whole brain graphs, we show that PT birth is associated with reduced volume in bilateral temporal and inferior frontal lobes, left caudate, left fusiform, and posterior cingulate for prematurely born subjects at young adulthood. Seed-based analyses demonstrate altered patterns of anatomical covariance for PTs compared with terms. PTs exhibit reduced covariance with R Brodmann area (BA) 47, Broca's area, and L BA 21, Wernicke's area, and white matter volume in the left prefrontal lobe, but increased covariance with R BA 47 and left cerebellum. Graph theory analyses demonstrate that measures of network complexity are significantly less robust in PTs compared with term controls. Volumes in regions showing group differences are significantly correlated with phonological awareness, the fundamental basis for reading acquisition, for the PTs. These data suggest both long-lasting and clinically significant alterations in the covariance in the PTs at young adulthood.

Prefrontal lobe structural integrity and trail making test, part B: converging findings from surface-based cortical thickness and voxel-based lesion symptom analyses

Surface-based cortical thickness (CT) analyses are increasingly being used to investigate variations in brain morphology across the spectrum of brain health, from neurotypical to neuropathological. An outstanding question is whether individual differences in cortical morphology, such as regionally increased or decreased CT, are associated with domain-specific performance deficits in healthy adults. Since CT studies are correlational, they cannot establish causality between brain morphology and cognitive performance. A direct comparison with classic lesion methods is needed to determine whether the regional specificity of CT-cognition correlations is similar to that observed in patients with brain lesions. We address this question by comparing the neuroanatomical overlap of effects when 1) whole brain vertex-wise CT is tested as a correlate of performance variability on a commonly used neuropsychological test of executive function, Trailmaking Test Part B (TMT-B), in healthy adults and 2) voxel-based lesion-symptom mapping (VBLSM) is used to map lesion location to performance decrements on the same task in patients with frontal lobe lesions. We found that reduced performance on the TMT-B was associated with increased CT in bilateral prefrontal regions in healthy adults and that results spatially overlapped in the left dorsomedial prefrontal cortex with findings from the VBLSM analysis in patients with frontal brain lesions. Findings indicate that variations in the structural integrity of the left dorsomedial prefrontal lobe, ranging from individual CT differences in healthy adults to structural lesions in patients with neurological disorders, are associated with poor performance on the TMT-B. These converging results suggest that the left dorsomedial prefrontal region houses a critical region for the complex processing demands of TMT-B, which include visuomotor tracking, sequencing, and cognitive flexibility.

Asymmetry of the prefrontal lobe in patients with attention deficit hyperactivity disorder: A three-dimensional volumetric magnetic resonance imaging study

Asymmetries have been reported in several regions of the brain of patients with developmental disorders such as autism, developmental language disorder, and attention deficit hyperactivity disorder (ADHD). This study focused on age-related anatomical asymmetries of the prefrontal lobe, which can be manifestations of regional specialization of systems organization where there are functional differences between the left and right hemispheres, in children with ADHD. Subjects were 7 right-handed boys with ADHD aged 6–12 years and 5 age-matched controls. Exclusion criteria were full-scale intelligence quotient less than 80, comorbid learning disorder or developmental delay, evidence of medical or neurological disease on examination or by history, or Tourette's syndrome. No subjects met criteria for conduct disorder or oppositional disorder. Volume of the frontal and prefrontal lobes was determined using a workstation and the prefrontal-to-frontal lobe and left-to-right volume ratios were calculated. Both control and ADHD groups had a larger aggregate volume of left frontal and prefrontal lobes than of right frontal and prefrontal lobes. The leftward bias of the frontal lobe was significantly pronounced in ADHD subjects than in control subjects (P = 0.026). In addition, the leftward bias of the prefrontal lobe was more pronounced in ADHD subjects than in control subjects (P = 0.0041). The left-to-right volume ratio of the prefrontal lobe increased with age in both groups. The left-to-right volume ratio of the frontal lobe was more pronounced in ADHD (r = 0.922, P = 0.0014) than control group (r = 0.521, P = 0.414). In addition, the left-to-right volume ratio of the prefrontal lobe was more pronounced in ADHD (r = 0.903, P = 0.0029) than control group (r = 0.701, P = 0.219). These findings support the argument that right-sided prefrontal structural anomalies may occur disproportionately in ADHD.

Repetitive transcranial magnetic stimulation induced modulations of resting state motor connectivity in writer's cramp.

Writer's cramp (WC) is a focal task-specific dystonia of the hand which is increasingly being accepted as a network disorder. Non-invasive cortical stimulation using repetitive transcranial magnetic stimulation (rTMS) has produced therapeutic benefits in some of these patients. This study aimed to visualize the motor network abnormalities in WC and also its rTMS induced modulations using resting state functional magnetic resonance imaging (rsfMRI). Nineteen patients with right-sided WC and 20 matched healthy controls (HCs) were prospectively evaluated. All patients underwent a single session of rTMS and rsfMRI was acquired before (R1) and after (R2) rTMS. Seed-based functional connectivity analysis of several regions in the motor network was performed for HCs, R1 and R2 using SPM8 software. Thresholded (P<0.05, false discovery rate corrected) group level mean correlation maps were used to derive significantly connected region of interest pairs. Writer's cramp showed a significant reduction in resting state functional connectivity in comparison with HCs involving the left cerebellum, thalamus, globus pallidus, putamen, bilateral supplementary motor area, right medial prefrontal lobe and right post central gyrus. After rTMS there was a significant increase in the contralateral resting state functional connectivity through the left thalamus-right globus pallidus-right thalamus-right prefrontal lobe network loop. It is concluded that WC is a network disorder with widespread dysfunction much larger than clinically evident and changes induced by rTMS probably act through subcortical and trans-hemispheric unaffected connections. Longitudinal studies with therapeutic rTMS will be required to ascertainwhether such information could be used to select patients prior to rTMS therapy.

Altered gray matter density and disrupted functional connectivity of the amygdala in adults with Internet gaming disorder.

The aim of this study was to evaluate the altered brain structure and functional connectivity (FC) among subjects with Internet gaming disorder (IGD). We recruited 30 males with IGD and 30 controls and evaluated their gray matter density (GMD) and FC using resting fMRI. The severities of IGD, gaming urge, and impulsivity were also assessed. The results demonstrated that the subjects with IGD had a higher impulsivity and a greater severity of IGD. The subjects with IGD had a lower GMD over the bilateral amygdala than the controls. Further, the subjects with IGD had lower FC with the left amygdala over the left dorsolateral prefrontal lobe (DLPFC) and with the right amygdala over the left DLPFC and orbital frontal lobe (OFL). They also had higher FC with the bilateral amygdala over the contralateral insula than the controls. The FC between the left amygdala and DLPFC was negatively correlated with impulsivity. The FC of the right amygdala to the left DLPFC and orbital frontal lobe was also negatively correlated with impulsivity. Our results indicated that the altered GMD over the amygdala might represent vulnerability to IGD, such as impulsivity. Further analysis of the amygdala demonstrated impaired FC to the frontal lobe, which represents impulsivity. The results of this study suggested that the amygdala plays a very influential role in the mechanism of IGD. Its detailed role should be further evaluated in future study and should be considered in the treatment of IGD.

청각자극에 따른 세타파와 알파파의 스펙트럼적 반응

감정을 유발하는 청각자극에 따라 발생되는 EEG(Electroencephalographic) 스펙트럼 강도와 감정 반응 간의 상관관계는 중요한 변수이다. 약 20여 년 전 쾌감을 주는 청각자극에 대하여 측정된 신호의 강도가 전전두엽에서 비대칭적으로 반응을 보였다는 연구 결과가 발표되었다. 본 연구에서는 자극관련 스펙트럼적 반응(Event-related Spectral Perturbation: ERSP)이 전두엽에서 비대칭적으로 발생되는지 고찰하기 위하여 청각자극 실험을 수행하였다. 30명의 건강한 대학생 지원자들이 IADS(International Affective Digital Sounds) 실험에 참여하였다. 이 청각자극은 행복, 공포, 그리고 중립의 3단계로 분류되었으며, 데이터의 분석은 세타파(4-8Hz)와 알파파(8-13Hz)에서 이루어졌다. 알파대역의 ERSP 지도는 오른쪽 전두엽에서 행복감과 공포감의 자극에서 높은 신호의 강도를 보여주는 반면 중립성 자극에서는 왼쪽 전두엽에서 높은 신호가 발생되었다. 그러나 세타파는 행복감과 공포감의 자극에 따라 좌측 전두엽에서 높은 신호가 나타나는 반면, 중립적 자극에 따라 우측 전두엽에서 높은 신호를 보여주었다. 높은 쾌감성 자극(행복)은 상대적으로 우측 전두엽에서 높은 EEG 신호가 측정되었으며, 낮은 쾌감성 자극(중립과 공포)은 왼쪽 전두엽에서 측정되었다. 또한 가장 큰 세타파의 변화가 전두엽의 중앙에서 발생되었다. 알파파에서 행복한 청각자극에 가장 강한 신호가 전두엽 전체에서 관찰되었다. 이 결과들은 기존의 감정들과 일치되며, 세타파와 알파파가 감정처리에서 중요한 역할을 하고 있음을 시사한다. The correlations between electroencephalographic (EEG) spectral power and emotional responses during affective sound clip listening are important parameters. Hemispheric asymmetry in prefrontal activation have been proposed in two decades ago, as measured by power value, is related to reactivity to affectively pleasure audio stimuli. In this study, we designed an emotional audio stimulus experiment in order to verify frontal EEG asymmetry by analyzing Event-related Spectral Perturbation (ERSP) results. Thirty healthy college male students volunteered the stimulus experiment with the standard IADS(International Affective Digital Sounds) clips. These affective sound clips are classified in three emotion states, high pleasure-high arousal (happy), middle pleasure-low arousal (neutral) and low pleasure-high arousal (fear). The analysis of the data was performed in both theta (4-8Hz) and alpha (8-13Hz) bands. ERSP maps in the alpha band revealed that there are the stronger power responses of high pleasure (happy) in the right frontal lobe, while the stronger power responses of middle-low pleasure (neutral and fear) in the left frontal lobe. Moreover, ERSP maps in the theta band revealed that there are the stronger power responses of high arousal (fear and happy) in the left pre-frontal lobe, while the stronger responses of low arousal (neutral) in the right pre-frontal lobe. However, the high pleasure emotions (happy) can elicit greater relative right EEG activity, while the low and middle pleasure emotions (fear and neutral) can elicit the greater relative left EEG activity. Additionally, the most differences of theta band have been found out in the medial frontal lobe, which is proved as the frontal midline theta. And there are the strongest responses of happy sounds in the alpha band around the whole frontal regions. These results are well suited for emotion recognition, and provide the evidences that theta and alpha powers may have the more important role in the emotion processing than previously believed.

Focal cortical thickness correlates of exceptional memory training in Vedic priests.

The capacity for semantic memory—the ability to acquire and store knowledge of the world—is highly developed in the human brain. In particular, semantic memory assimilated through an auditory route may be a uniquely human capacity. One method of obtaining neurobiological insight into memory mechanisms is through the study of experts. In this work, we study a group of Hindu Vedic priests, whose religious training requires the memorization of vast tracts of scriptural texts through an oral tradition, recalled spontaneously during a lifetime of subsequent spiritual practice. We demonstrate focal increases of cortical thickness in regions of the left prefrontal lobe and right temporal lobe in Vedic priests, in comparison to a group of matched controls. The findings are relevant to current hypotheses regarding cognitive processes underlying storage and recall of long-term declarative memory.

Phase synchronization analysis of prefrontal tissue oxyhemoglobin oscillations in elderly subjects with cerebral infarction

This study aims to assess the phase relationship of prefrontal tissue oxyhemoglobin oscillations using wavelet phase coherence analysis of cerebral Delta [HbO₂] signals in cerebral infarction (CI) patients during the resting state. Continuous recordings of near-infrared spectroscopy signals were obtained from the left and right prefrontal lobes in 21 subjects with CI (Group CI, age: 76.6 ± 8.5 yr) and 21 healthy elderly subjects (Group Healthy, age: 69.0 ± 7.4 yr) during the resting state. The Group CI was further divide into two groups: CI with hypertension and CI without hypertension. The phase synchronization between left and right prefrontal Delta [HbO₂] oscillations in four frequency intervals (I, 0.6-2 Hz; II, 0.145-0.6 Hz; III, 0.052-0.145 Hz; and IV, 0.021-0.052 Hz) was analyzed using wavelet phase coherence method. The phase coherences in intervals III and IV were significantly lower in CI with hypertension than in healthy elderly subjects (F = 12.974, p = 0.001 for III and F = 10.073, p = 0.004 for interval IV). The phase coherence of CI without hypertension in interval III was significantly lower than in healthy elderly subjects (F = 9.909, p = 0.004). Also, the phase coherence in interval IV was significantly lower in CI with hypertension than in CI without hypertension (F = 5.665, p = 0.028). Also, the phase agreement in interval IV showed evident difference between Group CI with hypertension and without hypertension. The difference in phase characteristics of prefrontal tissue oxyhemoglobin oscillations between the CI patients and healthy elderly indicates altered phase synchronization. Moreover, the CI combined with hypertension would aggravate this process. This study provides new insight into the phase dynamics of cerebral oxygenation and may be useful in assessing the risk for stroke.

아침, 저녁시간대 유산소운동이 남자대학생의 뇌파 및 자율신경계에 미치는 영향

This study was designed to investigate the effect of aerobic exercise on the brain waves and automatic nervous systems according to the time zone of the exercise. To this end, the difference according to the time of exercise was compared by dividing 18 male college students in their 20s into morning exercise group(n=9), and evening exercise group (n=9). The summary of the above results found that there was a significant increase of alpha waves in the left and right prefrontal lobe, left and right frontal lobe, left parietal lobe and right temporal lobe. However, there was no significant difference in the automatic nervous system (the average heart rate, SDNN, RMSSD, TP, LF, HF). It turned out that the aerobic exercise is effective in changing alpha waves of male college students, and there was no differences by the time zone of exercise. Accordingly, it is required to conduct regular aerobic exercise according to the individual``s lifestyle to ensure effective changes in alpha waves.

Wavelet coherence analysis of prefrontal oxygenation signals in elderly subjects with hypertension

This study aims to assess the prefrontal functional connectivity in elderly subjects with hypertension during the resting state using wavelet coherence analysis of changes in prefrontal tissue oxyhaemoglobin concentrations (Δ[HbO2]) signals measured by near-infrared spectroscopy (NIRS). Continuous recordings of NIRS signals were obtained from the left and right prefrontal lobes in 24 elderly subjects with hypertension (age: 70.7 ± 8.4 years) and 26 elderly normotensive subjects (age: 70.6 ± 7.9 years) during the resting state. The coherence between the left and right prefrontal oscillations in four frequency intervals (I, 0.4 Hz to 2 Hz; II, 0.15 Hz to 0.4 Hz; III, 0.05 Hz to 0.15 Hz; and IV, 0.02 Hz to 0.05 Hz) was analyzed using wavelet coherence method. The Δ[HbO2] oscillations showed significant wavelet coherence (WCO) in intervals I and III, and significant wavelet phase coherence (WPCO) in intervals from I to IV. Remarkably, in elderly subjects with hypertension, the WCO and WPCO in interval III were significantly lower in the left and right prefrontal regions than in healthy elderly subjects (p = 0.014 for WCO, p = 0.007 for WPCO). The lower coherence in interval III indicates a decreased synchronization of neural control in the left and right prefrontal regions in elderly subjects with hypertension. This might suggest a weakened brain functional connectivity in the elderly subjects with hypertension.

Acute pancreatitis affects the metabolism of catecholamine neurotransmitters in rats

Abnormalities of mental status represent a severe complication and an important cause of death in acute pancreatitis (AP), which is characterized by a pattern of neurological signs and symptoms. As some of the symptoms of AP are also affected by catecholamine neurotransmitters, they cannot be ruled out of the pathophysiology of AP; however, little research has been performed exploring this hypothesis. Our study aimed to elucidate whether AP affects the metabolism of catecholamine neurotransmitters in rats.A total of 300 male SD rats were randomly divided into five groups: control, 6H, 24H, 48H and 72H experimental groups. AP was induced in rats by an injection of a sodium taurocholate solution via a cannulated bile-pancreatic duct. In the striatum, hippocampus and cerebellum, catecholamine neurotransmitters were tested using high performance liquid chromatography equipped with a electrochemical detector, and the activities and protein concentration levels of monoamine oxidase A (MAO-A) and tyrosine hydroxylase (TH) were also evaluated using ELISA and Western blotting analyses.In the hippocampus, the dopamine (DA) concentrations increased in the 48-h and 72-h groups. The 3,4-dihydroxyphenylacetic acid (DOPAC) concentration of the 72-h group also increased. The MAO-A and TH activity of the 6-h and 24-h groups decreased, respectively. The TH activities of the 48-h groups also decreased. The MAO-A and TH protein concentration of the 6-h and 24-h groups decreased. In the corpus striatum, the homovanillic acid concentration of the 72-h group and norepinephrine concentrations of the 24-h and 48-h groups increased, respectively. The MAO-A and TH activities of the 6-h and 24-h groups decreased. The MAO-A and TH protein concentrations of the 6-h and 24-h groups decreased. In the prefrontal cortex (left prefrontal lobe), the DA and DOPAC concentrations of the 48-h group increased. The MAO-A and TH activities of the 6-h, 24-h and 48-h groups decreased. The MAO-A and TH protein concentrations of the 6-h and 24-h groups also decreased. The other catecholamine concentration and enzyme activities fluctuated, but there was no statistically significant difference compared with the control group.Catecholamine neurotransmitter metabolic systems are widely affected in AP, and these fluctuations may play an important role in determining the symptomatology of AP.

Participation of the insula in language revisited: A meta-analytic connectivity study

Abstract Despite the insula's location in the epicenter of the human language area, its specific role in language is not sufficiently understood. The left insula has been related to a diversity of speech/language functions, including articulatory planning, language repetition ability, and phonological recognition. To further our understanding of the role of the insula in language, a meta-analytic connectivity study using the Activation Likelihood Estimation (ALE) technique was developed. By means of the BrainMap functional database, 26 papers corresponding to 39 paradigms, and including 522 participants were selected. Thirteen different activation clusters were found; insula connections included not only areas involved in language production (such as the Broca's area) and language understanding (such as the Wernicke's area), but also areas involved in language repetition (such as the supramarginal gyrus) and other linguistic functions, such as BA9 in the left prefrontal lobe (involved in complex language processes) and BA37 (involved in lexico-semantic associations). In conclusion, the insula represents a core area in language processing, as it was suggested during the 19th century.

Atypical cerebral language dominance in a right-handed patient: An anatomoclinical study

ObjectiveApproximately 97% of the right-handers has left hemisphere language dominance. Within the language dominant hemisphere Broca's area is of crucial importance for a variety of linguistic functions. As a result, tumour resection in and around Broca's area is controversial. However, studies showed that by means of Direct Electrical Stimulation (DES) tumour resection in this region can be safely performed. We report unexpected anatomoclinical findings in a right-handed patient who underwent tumour resection in the left prefrontal lobe. MethodsLanguage functions in this right-handed patient were extensively examined in the pre-, intra-, and postoperative phase by means of a standardised battery of neurolinguistic and neurocognitive tests. Results obtained in the pre- and postoperative phase are compared. In addition, intraoperative DES findings and postoperative functional Magnetic Resonance Imaging (fMRI) and Diffusion Tensor Imaging (DTI) results are reported. ResultsTumour resection near Broca's area was safely performed since no positive language sites were found during intraoperative DES. Since no linguistic deficits occurred in the pre-, intra-, or postoperative phase, atypical language dominance was suspected. Neuropsychological investigations, however, disclosed permanent executive dysfunction. Postoperative fMRI and DTI confirmed right cerebral language dominance as well as a crossed cerebro-cerebellar functional link with the left cerebellar hemisphere. DiscussionAtypical right hemisphere language dominance in this right-handed patient is reflected by: (1) the total absence of language problems in the pre-, intra- and postoperative phase, (2) absence of positive stimulation sites during DES, (3) a clearly more pronounced arcuate fasciculus in the right cerebral hemisphere (DTI), (4) a crossed functional connection between the right cerebrum and the left cerebellum (fMRI). Two hypothetical explanations for the pattern of crossed cerebral language dominance are put forward: (1) preoperative brain plasticity mechanisms inducing a shift of language functions to the right hemisphere or (2) right hemisphere language dominance as a maturational variant. This case with atypical cerebral language dominance shows that although DES is the ‘gold standard’ to identify eloquent language regions and their pathways, fMRI and DTI are important adjuncts to guide surgery, to identify language lateralisation and to study anatomoclinical correlations.

Evaluation of Headache and Regional Cerebral Flood Flow in Patients With Migraine

The aim of this study is to observe the abnormalities of regional cerebral blood flow (rCBF) in migraine patients and to evaluate its relation to the severity of the headache in patients with migraine. The rCBF imaging was done on 19 patients with migraine and 15 normal controls using single-photon emission computed tomography (SPECT). The abnormal character of cerebral perfusion function was analyzed with Statistical Parametric Mapping (SPM) software, and the headache grade of patients was evaluated with the headache severity measuring scale. The results of SPM analysis demonstrated a decreased rCBF on both sides of the frontal and temporal lobes, left parietal lobe, and right occipital lobe (P < 0.001), and increased rCBF focus on the left prefrontal lobe and right temporal lobe (P < 0.001). The headache scores in migraineurs were correlated to the rCBF on the bilateral temporal lobes and right frontal lobe (P < 0.001). The migraineurs had lower rCBF at the frontal and temporal lobes, and the lower rCBF was correlated to the degree of headache.

Dysfunctional Cortical Connectivity During the Auditory Oddball Task in Patients with Schizophrenia

Background:We studied the imaginary coherence (IC) of gamma frequency oscillations between brain regions of male schizophrenia patients during an auditory oddball task using magnetoencephalography (MEG) and electroencephalography (EEG).Methods:Subjects were 10 right-handed male schizophrenia patients, evaluated by the positive and negative symptom scale (PANSS), and 10 healthy controls. Functional connectivity during the auditory oddball task was reconstructed in low (30-50 Hz) and high (50-100 Hz) gamma bands, and represented by imaginary coherence (IC) based on significant oscillatory power changes. We calculated correlations between PANSS scores and IC.Results:In the high gamma band, IC between left occipital and right prefrontal lobe areas during the time window 750-1000 ms from stimulus onset showed negative correlations with total negative scores, total positive scores, the sum of positive and negative scores in PANSS, conceptual disorganization, and social avoidance scores. In the low gamma band, IC between the same areas from 250-500 ms also showed a negative correlation with the conceptual disorganization score. In the same time window, IC between left occipital and right frontoparietal lobe areas in the low gamma band showed a positive correlation with hallucinatory behavior; IC between right temporal pole and left prefrontal lobe areas showed a positive correlation with delusion scores, although these ICs were decreased relative to controls.Conclusions:Functional disconnection of high and low gamma bands in auditory oddball task may play an important role in the auditory processing in schizophrenia patients.

Effect of repetitive transcranial magnetic stimulation on serum brain derived neurotrophic factor in depressive patients

Objective To explore the effect of repetitive transcranial magnetic stimulation(rTMS)treatment on the brain derived neurotrophic factor(BDNF)serum levels in depressive patients. Methods Sixty-eight unipolar depressions treated with venlafaxine were randomly assigned to the real rTMS group(n=34)and the sham rTMS group(n=34), which were accepted the real or the shame rTMS treatment on the left dorsolateral prefrontal lobes respectively. The Hamilton Rating Scale for Depression(HAMD)and BDNF serum was assayed before and after 4 weeks’ treatment. Results 1)A significant increase of serum BDNF((12.2±1.3)μg/L vs(5.6±0.8)μg/L, t=-9.167, P=0.000; (11.4±1.5)μg/L vs (6.0±1.0)μg/L, t=-7.421, P=0.000)and a significant decline of HAMD((11.6±1.7)score vs (32.6±2.5)score, t=14.654, P=0.000; (4.2±2.8)score vs (31.8±3.2)score, t=12.089, P=0.000) were found after the treatment in the real and the shame group, and the real group changed more significantly than the shame group ((6.7±0.8)μg/L vs (5.1±1.2)μg/L, t=2.690, P=0.009; (21.0±2.1)score vs (17.6±2.6)score, t=2.693, P=0.000). 2)A negative correlation was found between the serum BDNF levels and the HAMD scores before the treatment(r=-0.530, P=0.003; r=-0.490, P=0.004), and a positive correlation between changes of BDNF levels and HAMD scores changes(r=0.439, P=0.006; r=0.454, P=0.005). Conclusion The rTMS treatment can increase serum BDNF levels in depressive patients. Key words: Repetitive transcranial magnetic stimulation; Depression; Brain derived neurotrophic factor

Proton magnetic resonance spectroscopy study on prefrontal lobe and thalamus in schizophrenics

Objective To explore the metabolite status on prefrontal lobe and thalamus by proton magnetic resonance spectroscopy (1H-MRS) and affecting factors in patients of schizophrenia. Methods 159 schizophrenics met with CCMD-3 and 45 normal controls were examined at prefrontal lobe and thalamus by multi-voxel 1H-MRS. The N-acetylaspartate (NAA), Choline-congtaining compounds (Cho), and Creatine compounds (Cr) were measured and the ratios of NAA/Cr, Cho/Cr were determined. Positive and Negative Syndrome Scale (PANSS), Social Disability Screening Schedule (SDSS), and Wisconsin Card Sorting Test (WCST) were also assessed. Results On left prefrontal lobe of patients, the NAA/Cr ratio demonstrated lower than that in normal controls (1.42±0.34 vs.1.64±0.39, t=3.70, P<0.01). The same phenomenon were appeared on left thalamus (1.46±0.35 vs.1.66±0.38, t=3.32, P<0.01) and on right thalamus (1.49±0.34 vs. 1.62±0.37, t=2.04, P<0.05). Contributing to the NAA/Cr ratio, main influencing factors on left prefrontal lobe were age of onset, duration of illness, score of negative symptoms, antipsychotic treatment, total score of PANSS, Categories completed of WCST, total score of SDSS, year of education. Main influencing factors on left thalamus were age of onset, duration of illness, antipsychotic treatment. Main influencing factors on right thalamus were duration of illness, age of onset, score of negative symptoms, antipsychotic treatment, and family history. Conclusions Abnormalities in neuronal function and/or integrity presented on prefrontal lobe and thalamus in schizophrenics are related to many respects, especially age of onset, duration of illness and antipsychotic treatment. Key words: Schizophrenia; Magnetic resonance spectroscopy; Related factors

Proton magnetic resonance spectroscopy study of prefrontal lobe and thalamus in schizophrenics on modified electroconvulsive therapy

To explore the potential effects of modified electroconvulsive therapy (MECT) in prefrontal lobe and thalamus in patients with schizophrenia by proton magnetic resonance spectroscopy ((1)H-MRS). From November 2010 to June 2011, a total of 31 schizophrenics fulfilling the third edition of the Chinese Classification of Mental Disorders (CCMD-III) were recruited. And prefrontal lobe and thalamus were evaluated by multi-voxel (1)H-MRS before and after 8 sessions of MECT. The subjects were evaluated by the positive and negative syndrome scale (PANSS). And the N-acetylaspartate (NAA), choline-containing compounds (Cho) and creatine compounds (Cr) were measured and the ratios of NAA/Cr and Cho/Cr determined. (1) In left prefrontal lobe and bilateral thalamus, the NAA/Cr ratio at post-treatment demonstrated higher than that at pre-treatment (1.50 ± 0.31 vs 1.35 ± 0.30, t = 2.07, P < 0.05; 1.53 ± 0.31 vs 1.38 ± 0.27, t = 2.03, P < 0.05; 1.51 ± 0.29 vs 1.36 ± 0.26, t = 2.14, P < 0.05). (2) The major influencing factors of the changes of NAA/Cr in left prefrontal lobe were age of onset, decrease rate of PANSS, baseline PANSS total score and duration of illness. And the major influencing factors for left thalamus were age of onset and duration of illness while a major influencing factor for right thalamus was baseline PANSS total score. MECT may modify brain metabolism as measured by (1)H-MRS. The pattern of changes suggests possible neuroprotective effects in schizophrenics. And these effects are correlated with age of onset, duration and severity of illness.