Brain regions that process case: Evidence from basque

The aim of this event‐related fMRI study was to investigate the cortical networks involved in case processing, an operation that is crucial to language comprehension yet whose neural underpinnings are not well‐understood. What is the relationship of these networks to those that serve other aspects of syntactic and semantic processing? Participants read Basque sentences that contained case violations, number agreement violations or semantic anomalies, or that were both syntactically and semantically correct. Case violations elicited activity increases, compared to correct control sentences, in a set of parietal regions including the posterior cingulate, the precuneus, and the left and right inferior parietal lobules. Number agreement violations also elicited activity increases in left and right inferior parietal regions, and additional activations in the left and right middle frontal gyrus. Regions‐of‐interest analyses showed that almost all of the clusters that were responsive to case or number agreement violations did not differentiate between these two. In contrast, the left and right anterior inferior frontal gyrus and the dorsomedial prefrontal cortex were only sensitive to semantic violations. Our results suggest that whereas syntactic and semantic anomalies clearly recruit distinct neural circuits, case, and number violations recruit largely overlapping neural circuits and that the distinction between the two rests on the relative contributions of parietal and prefrontal regions, respectively. Furthermore, our results are consistent with recently reported contributions of bilateral parietal and dorsolateral brain regions to syntactic processing, pointing towards potential extensions of current neurocognitive theories of language. Hum Brain Mapp, 2012. © 2011 Wiley Periodicals, Inc.     

Cortical reorganization for response regulation with unilateral thalamic stroke detected by functional MRI

To understand neural reorganization of response regulation after stroke, a 54-year-old woman with a chronic left thalamic stroke performed a task requiring decisions about the directionality of an arrow during cerebral functional magnetic resonance imaging. Her performance was compared to 13 matched healthy control subjects. Her behavioral responses were slower but as accurate. Bilateral frontal activations were observed in the right medial frontal gyrus (BA 9), left superior frontal gyrus (BA 45), and left frontal rectus gyrus (BA 11). Activation in the right medial frontal gyrus, along with activity in close proximity to the anterior cingulate cortex, was observed, which may reflect reorganization of activity after the loss of function of the anterior cingulate cortex.     

fMRI detection of early neural dysfunction in preclinical Huntington's disease.

Neuropsychological and neuroimaging changes have been observed in individuals with the Huntington's disease (HD) gene expansion prior to the onset of manifest HD. This cross-sectional fMRI study of preclinical HD (pre-HD) individuals was conducted to determine if functional brain changes precede deficits in behavioral performance and striatal atrophy. Twenty-six pre-HD and 13 demographically matched healthy participants performed a time reproduction task while undergoing fMRI scanning. Pre-HD participants were divided into two groups (n=13 each): FAR (>12 years to estimated onset [YEO] of manifest HD) and CLOSE (<12 YEO). The CLOSE group demonstrated behavioral deficits, striatal atrophy, and reduced neural activation in the left putamen, SMA, left anterior insula and right inferior frontal gyrus. The FAR group showed reduced neural activation in the right anterior cingulate and right anterior insula. The FAR group also demonstrated increased neural activation in the left sensorimotor, left medial frontal gyrus, left precentral gyrus, bilateral superior temporal gyri and right cerebellum. The fMRI changes in the FAR group occurred in the relative absence of striatal atrophy and behavioral performance deficits. These results suggest that fMRI is sensitive to neural dysfunction occurring more than 12 years prior to the estimated onset of manifest HD.     

Neural abnormalities during cognitive generation of affect in treatment-resistant depression.

BACKGROUND: Dysfunctions in brain regions known to be involved in affect and mood states are thought to be implicated in depression and may have a role in determining the type and symptoms of this illness. METHODS: Functional magnetic resonance imaging was used to elucidate neural correlates of cognitive generation of affect, using a previously published paradigm of evoking affect with picture-caption pairs, in patients with unipolar, treatment-resistant depression. RESULTS: Compared with control participants, patients showed relatively decreased response in the anterior cingulate (rostral; right) with both negative and positive picture-caption pairs and in the medial frontal gyrus and hippocampus (all left) with positive picture-caption pairs. They demonstrated increased response in the inferior (right) and middle temporal gyri (left) with negative picture-caption pairs, and in the parahippocampal gyrus (right), inferior frontal gyrus (left), subgenual cingulate (right), striatum (right), and brain stem (left) with positive picture-caption pairs. CONCLUSIONS: Reduced medial/middle prefrontal and hippocampal activity may account for positive affect disturbances and temporal lobe hyperactivity for negative affect disturbances in treatment-resistant depression. The results also corroborate previous observations from resting positron emission tomography studies and further elucidate the association between hypoactive rostral cingulate and nonresponsiveness to treatment in depression.     

A network approach to response inhibition: dissociating functional connectivity of neural components involved in action restraint and action cancellation

The ability to inhibit action tendencies is vital for adaptive human behaviour. Various paradigms are supposed to assess action inhibition and are often used interchangeably. However, these paradigms are based on different conceptualizations (action restraint vs. action cancellation) and the question arises as to what extent different conceptualizations of inhibitory processing are mirrored in a distinct neural activation pattern. We used functional magnetic resonance imaging to investigate the neural correlates of action restraint vs. action cancellation. Analyses of local activity changes as well as network connectivity measures revealed a strong overlap of activation within a common action inhibition network including inferior frontal, pre‐supplementary motor and thalamic brain areas as well as the anterior cingulate cortex. Furthermore, our findings pointed to additional neural networks that are distinct for action restraint (i.e. right superior frontal gyrus, left middle frontal gyrus, and bilateral anterior cingulate cortex) and action cancellation (i.e. right middle frontal gyrus, posterior cingulate cortex, and parietal regions). Our connectivity analyses showed that different inhibitory modalities largely relied on a task‐independent global inhibition network within the brain. Furthermore, they suggested that the conceptually distinct inhibitory aspects of action restraint vs. action cancellation also activated additional specific brain regions in a task‐dependent manner. This has implications for the choice of tasks in an empirical setting, but is also relevant for various clinical contexts in which inhibition deficits are considered a diagnostic feature.     

基于核磁共振成像技术的甲状腺功能减退伴焦虑患者的脑功能区研究

目的 探讨甲状腺功能减退伴焦虑患者脑功能区核磁共振成像(Magnetic resonance imaging,MRI)表现。方法 选取本院2018年5月-2019年8月收治的甲状腺功能减退伴焦虑患者30例为观察组,并选取同期体检健康者30例为对照组; 收集2组研究对象的一般资料,并对脑功能区进行功能磁共振成像(Functional magnetic resonance imaging,fMRI)扫描,采用局部一致性(Regional homogeneity,ReHo)值找出基础状态下自发异常脑功能活动区,Speaeman分析异常脑功能区与甲状腺激素水平、神经精神症状的相关性。结果 fMRI扫描显示甲状腺功能减退患者右海马旁回、左侧颞下回、左右前扣带回脑功能区的ReHo值明显高于对照组(0.81±0.02 vs. 0.78±0.04、0.73±0.07 vs. 0.69±0.05、0.89±0.12 vs.0.84±0.09、0.87±0.11 vs. 0.83±0.07)(P<0.05),左侧内额上回ReHo值明显低于对照组(0.77±0.13 vs. 0.72±0.11)(P<0.05); 不同焦虑程度的右海马旁回、左侧颞下回、左前扣带回、右前扣带回、左侧内侧额上回5个异常脑功能区ReHo值相近(P>0.05); 左、右前扣带回ReHo值与游离甲状腺素(Free thyroxine,FT4)水平显著相关(r=-0.398,P=0.023; r=-0.424,P=0.031); 左、右前扣带回ReHo值与焦虑等级显著相关(r=0.425,P=0.533; r=0.027,P=0.017)。结论 海马旁回、颞下回、前扣带回、内侧额上回4个脑功能区可能参与甲状腺功能减退患者引发焦虑症状的脑部生理机制,甲状腺功能减退患者焦虑症状的脑神经反常活动与前扣带回自发异常活动密切相关,可为甲状腺功能减退伴焦虑患者的临床诊疗提供新思路。     

Mindreading in individuals with an empathizing versus systemizing cognitive style: An fMRI study

Our fMRI study compares the neural correlates of face-based mindreading in healthy individuals with an empathizing (n = 12) versus systemizing cognitive style (n = 12). The empathizing group consists of individuals that score high on empathizing and low on systemizing, while the systemizing group consists of individuals with an opposite cognitive pattern. We hypothesize that the empathizing group will show stronger simulation-type neural activity (e.g., in mirror neuron areas, medial prefrontal cortex, anterior cingulate cortex) or simulation-related neural activity (e.g., in areas involved in perspective taking and experiential processing) compared to the systemizing group. As hypothesized, our study reveals that the empathizing group shows significantly stronger activity in mirror neuron areas of the brain, such as the left inferior frontal gyrus and inferior parietal lobe, and in temporal areas involved in perspective taking and autobiographical memory. Moreover, the empathizing group, but not the systemizing group, shows activity in the medial prefrontal cortex and anterior cingulate cortex which have been related to simulation-type neural activity in the brain and are central to mindreading. Also, the systemizing group shows significantly stronger activity in the left parahippocampal gyrus. In conclusion, both the empathizing and systemizing individuals show simulation-type and simulation-related neural activity during face-based mindreading. However, more neural activity indicative of simulation-based processing is seen in the empathizing individuals, while more neural activity indicative of non-simulation-based processing is seen in the systemizing individuals.     

Changes of cognition and regional cerebral activity during acute hypoglycemia in normal subjects: A H215O positron emission tomographic study

Blurred vision and cognitive difficulties are prominent symptoms during acute insulin‐induced hypoglycemia. Our hypothesis was that changes in cerebral activity reflect these symptoms. Positron emission tomography (PET) with oxygen‐15‐labelled water was used to measure relative changes in regional cerebral blood flow (rCBF) as a marker of cerebral activity. Hypoglycemia was induced by intravenous insulin infusion in 19 healthy men performing two different cognitive tasks of varying complexity. The hypoglycemic stimulus [plasma glucose 2.2 mmol/liter (0.4)] produced a significant hormonal counterregulatory response. During the low cognitive load, rCBF decreased in response to hypoglycemia in a large bilateral area in the posterior part of the temporal lobe, and rCBF increased bilaterally in the anterior cingulate gyrus, the right frontal gyrus, the fusiform gyrus, thalamus, and the left inferior part of the frontal gyrus. During the high cognitive load, rCBF decreased bilaterally in a large region in the posterior part of the temporal gyrus and increased in the left and right anterior cingulate gyrus, left and right frontal gyrus, right parahippocampal and lingual gyrus, and left superior temporal gyrus. Visual impairment during hypoglycemia was associated with deactivation in the ventral visual stream. The anterior cingulate gyrus was activated during hypoglycemia in a load‐dependent manner. Areas on the frontal convexity were differentially activated in response to the cognitive load during hypoglycemia. Our findings suggest that hypoglycemia induces changes in sensory processing in a cognition‐independent manner, whereas activation of areas of higher order functions is influenced by cognitive load as well as hypoglycemia. © 2009 Wiley‐Liss, Inc.     

A functional magnetic resonance imaging paradigm of expressed emotion in schizophrenia

Chronic exposure to adverse interpersonal environment in schizophrenia is associated with vulnerability to relapse. The construct of expressed emotion (EE) measures the quality of interpersonal environment, of which criticism is a main component. To use functional magnetic resonance imaging and to investigate the neural basis of vulnerability of schizophrenic patients to EE, the effects of critical comments on brain mechanisms in 11 patients with schizophrenia were examined, comparing evoked responses to familiar (key relative) and unfamiliar (matched stranger) critical and neutral commentary. High EE stimuli evoked enhanced activation of brain regions concerned with the processing of aversive social information. Activations in the right BA44, rostral anterior cingulate, middle superior frontal gyrus, bilateral middle frontal gyrus, left temporal pole, left inferior frontal gyrus, and left insula were significantly modulated to familiar criticism. Such a pattern of neural response may represent a putative neural network responsible for mediating High EE in schizophrenia.     

Abnormal baseline brain activity in low-grade hepatic encephalopathy: a resting-state fMRI study

Resting-state functional magnetic resonance imaging (fMRI) has been used to detect the alterations of spontaneous neuronal activity in various neuropsychiatric diseases, but rarely in low-grade hepatic encephalopathy (HE), a common neuropsychiatric complication of liver cirrhosis. We conducted a resting-state fMRI in 19 healthy controls, 18 cirrhotic patients without HE, and 22 cirrhotic patients with low-grade HE. The amplitude of low-frequency fluctuations (ALFF) of fMRI signal was computed to measure the spontaneous neuronal activity. Several regions showing significant ALFF differences among three groups were the precuneus, occipital lobe, left frontal lobe and anterior/middle cingulate cortex, and left cerebellum posterior lobe. Compared to controls or patients without HE, patients with low-grade HE showed decreased ALFF in the precuneus and adjacent cuneus, visual cortex, and left cerebellum posterior lobe. Compared to controls, patients with low-grade HE showed higher ALFF in both cortical and subcortical regions, including the right middle cingulate gyrus, and left anterior/middle cingulate gyrus, inferior frontal gyrus, insula lobe, parahippocampal gyrus, middle temporal gyrus and lentiform nucleus; compared to patients without HE, patients with low-grade HE showed higher ALFF in the left medial frontal gyrus and anterior cingulate gyrus, bilateral superior frontal gyrus, and right middle frontal gyrus. Moreover, correlations between ALFF changes and poor neurocognitive performances were found in patients with low-grade HE. These results suggested the existence of aberrant brain activity at the baseline state in low-grade HE, which may be implicated in the neurological pathophysiology underlying HE.     

Frequency-specific alterations in the fractional amplitude of low-frequency fluctuations in amyotrophic lateral sclerosis

This study used resting-state functional magnetic resonance imaging and fractional amplitude of low-frequency fluctuations (fALFF) method to investigate low-frequency spontaneous neural activity at the bands of slow-5 (0.01–0.027 Hz) and slow-4 (0.027–0.073 Hz) in 20 patients with amyotrophic lateral sclerosis (ALS) and 20 healthy controls. We determined that, at slow-5 band, patients with ALS showed increased fALFF in the right middle frontal gyrus and decreased fALFF in the left middle occipital gyrus. However, compared with healthy controls, patients with ALS exhibited higher fALFF in the right caudate nucleus, left superior frontal gyrus, and right anterior cingulate cortex and lower fALFF in the right inferior occipital gyrus and bilateral middle occipital gyrus at slow-4 band. Furthermore, the fALFF value in the left superior frontal gyrus at slow-4 band was negatively correlated with functional rating scale-revised score. Our results demonstrated that the fALFF changes in ALS were widespread and frequency dependent. These findings may provide a novel way to look into the pathophysiology mechanisms underlying ALS.     

Neural correlates of episodic and semantic memory retrieval in borderline personality disorder: An fMRI study

Verbal memory impairment in borderline personality disorder (BPD) is still a matter of debate. In this study we combine investigations of both, memory retrieval as well as underlying neural circuits in BPD. Functional magnetic resonance imaging (fMRI) was used to study regional brain activation in 18 right-handed female patients with BPD and 18 matched controls during the retrieval of an episodic memory retrieval (EMR) task (free recall of a word list) and a semantic memory retrieval (SMR) task (verbal fluency). Despite unaffected performance in EMR and SMR, patients with BPD showed task-specific increased activation compared with controls. During EMR, the increased activation encompassed the posterior cingulate cortex bilaterally, the left middle and superior temporal gyrus, the right inferior frontal gyrus, and the right angular gyrus. SMR was associated with increased activation of the posterior cingulate cortex, of the right fusiform gyrus, of the left anterior cingulate cortex, and of the left postcentral gyrus. Our findings suggest that BPD patients may need to engage larger brain areas to reach a level of performance in episodic and semantic retrieval tasks that is comparable to that of healthy controls.     

Neuroimaging the semantic system(s)

Background: The organisation of the semantic system is controversially discussed among cognitive scientists. Whereas some authors assume that semantic processing is amodal, others propose modality-specific semantic systems. The amodal account holds that there is a single semantic system independent of the modality of stimulus presentation and nature of the concept. The multi-modal account, on the other hand, postulates that semantic knowledge is represented in modality-specific, distinct semantic systems. Attempts to integrate both accounts resulted in a hybrid model of semantic processing. Although an amodal semantic network is assumed in this view, input-dependent semantic specialisation coexists. Aims: The purpose of this study was to examine contrasting theories of the representation of the semantic knowledge with functional magnetic resonance imaging (fMRI). Methods & Procedures: Nine healthy subjects performed a semantic judgement task on graphemic words and pictures in the experimental condition, as well as a visual identity judgement task on pseudoword and three-dimensional geometric objects in the control condition. Outcomes & Results: A common activation pattern for words and pictures was found in the left inferior frontal gyrus and in the left middle temporal gyrus. Word-specific effects occurred in the left superior parietal, the left inferior occipital, the left anterior cingulate gyrus, and the right inferior frontal gyrus as well as bilaterally in the anteriomedial temporal area. Picture-specific areas involved the left supramarginal gyrus and the left cingulate gyrus. Further activation was found in the right middle frontal gyrus and bilaterally in the fusiform and inferior occipital gyrus. Conclusions: The results can best be accommodated in the framework of an integrative, hybrid model of semantic representation combining features of the amodal and the modality-specific account.     

Age-related changes in right middle frontal gyrus volume correlate with altered episodic retrieval activity

Age-related deficits in episodic retrieval have been associated with volume reductions in the middle frontal gyrus (MFG). However, it remains unclear how this age-related reduction in MFG volume correlates with neural activity during retrieval. To address this, we conducted in vivo volumetry of the frontal cortex in young and older human adults and found more volume loss on the right than on the left MFG with age. We then examined how left and right MFG volume correlated with fMRI activity during successful retrieval of item, spatial context, and temporal context information in both age groups. In young adults, larger right MFG volume was positively correlated with greater activity in a commonly found episodic retrieval network that included bilateral dorsolateral prefrontal cortex (DLPFC) and bilateral inferior parietal cortex. Within this network, left DLPFC and right inferior parietal cortex activity predicted memory performance. In older adults, a positive structure-function association in DLPFC for either left or right MFG/DLPFC was not observed. Instead, right MFG volume was negatively correlated with activity in several regions in older adults, including the parahippocampal cortex (PHC) and anterior cingulate. Less activity in the PHC region predicted better item memory, and less activity in the anterior cingulate predicted better spatial context accuracy in older adults. We conclude that age-related change in the structure-function association in MFG/DLPFC impacts retrieval activity and performance, and those older adults with larger right MFG volume attempt to compensate for this change by modifying activity in other brain regions to help retrieval performance.     

弥散张量成像在继发全面性发作癫痫患者中的应用研究

目的 评价弥散张量成像(DTI)对于常规MRI未发现病灶的部分性继发全面性发作癫痫患者的病灶检出能力.方法 使用Siemens 3.0T磁共振成像系统对30例成年继发全面性发作癫痫患者和30例正常对照者进行扫描,得到弥散加权成像,采用基于体素的分析方法对癫痫患者和正常对照组的数据进行分析.结果 癫痫组右侧梭状回和楔前叶、右侧额内侧回和钩回、左侧扣带回、左侧颞下回、左侧小脑扁桃体和左侧中央前回的脑区FA值较正常对照组降低,差异有统计学意义(P＜0.001);癫痫组右侧海马旁回、右侧颞下回、右侧胼胝体、右侧额内侧回、右侧额下回、扣带回、右侧前扣带回、右侧舌回、右侧梭状回和枕中回,左侧颞中回、左侧钩回和左侧中央前回的脑区ADC值较正常对照组升高,差异具有统计学意义(P＜0.001);左侧直回的脑区ADC值较正常对照组降低,差异具有统计学意义(P＜0.001).结论 DTI检查可发现常规MRI检查为阴性的部分性继发全面性发作癫痫患者存在的广泛脑白质微结构异常.     

长期海洛因依赖者前额叶功能连接的变化

以前额叶为种子点,利用静息态fMRI进行全脑时域相关的功能连接分析,观察长期海洛因成瘾者前额叶功能连接的变化。结果发现相比于正常对照,以左侧前额叶为种子点进行功能连接分析,海洛因成瘾者左侧前额叶与左侧海马、右侧前扣带回、左侧额中回、右侧额中回、右侧楔前叶功能连接明显降低;以右侧前额叶为种子点进行功能连接分析,海洛因成瘾者右侧前额叶与左侧眶额叶、左侧额中回功能连接明显降低。提示长期海洛因成瘾者前额叶与相关脑区的功能连接减弱,可能与海洛因成瘾的维持与戒断后复吸相关。     

Frontal lobe gray matter density decreases in bipolar I disorder.

BACKGROUND: This study was conducted to explore differences in gray and white matter density between bipolar and healthy comparison groups using voxel-based morphometry (VBM). METHODS: Brain magnetic resonance imaging was performed for 39 subjects with bipolar I disorder and 43 comparison subjects. Images were registered into a proportional stereotaxic space and segmented into gray matter, white mater, and cerebrospinal fluid. Statistical parametric mapping was used to calculate differences in gray and white matter density between groups. RESULTS: Bipolar subjects had decreased gray matter density in left anterior cingulate gyrus (Brodmann's area [BA] 32, 7.3% decrease), an adjacent left medial frontal gyrus (BA 10, 6.9% decrease), right inferior frontal gyrus (BA 47, 9.2% decrease), and right precentral gyrus (BA 44, 6.2% decrease), relative to comparison subjects. CONCLUSIONS: The observation of a gray matter density decrease in the left anterior cingulate, which processes emotions, in bipolar subjects is consistent with prior reports that used region-of-interest analytic methods. Decreased gray matter density in the right inferior frontal gyrus, which processes nonverbal and intrinsic functions, supports nondominant hemisphere dysfunction as a component of bipolar disorder.     

Different localizations underlying cortical gelastic epilepsy: Case series and review of literature

BackgroundGelastic seizures (GS) are classically observed with hypothalamic hamartomas but they can also be associated with cortical epileptogenic foci.ObjectiveTo study the different cortical localizations associated with GS.MethodsWe reviewed the data from all patients with cortical GS investigated in our epilepsy unit from 1974 to 2012 and in the literature from 1956 to 2013.ResultsSixteen cases were identified in our database and 77 in the literature. Investigations provided confident focus localization in 9 and 18, respectively. In our series, the identified foci were located in the mesial temporal structures (2 left, 1 right), lateral temporal cortex (1 right), superior frontal gyrus (1 left), and operculoinsular region [3 right (orbitofrontal or frontal operculum extending into the anterior insula) and 1 left (frontal operculum extending into the anterior insula)]. In the literature, the identified foci (13 right/5 left) were located in the temporal lobe of 4 (1 right inferior, 1 right medial and inferior, 1 right posterior middle, inferior extending posteriorly to the lingual gyrus, and 1 left middle, inferior, and medial), in the frontal lobe of 12 [10 (6 right/4 left) medial (i.e., superior, medial frontal, and/or anterior cingulate gyri), 1 lateral (right anterior inferior frontal gyrus), and 1 right medioposterior orbitofrontal cortex] and in the parietal lobe of 2 (1 left superior parietal lobule and 1 right parietal operculum) patients.ConclusionIctal laughter is a poorly lateralizing and localizing feature as it may be encountered in patients with a focus in the left or right frontal, temporal, parietal, or insular lobe.     

Speech planning and execution in children who stutter: Preliminary findings from a fNIRS investigation

Few studies have investigated the neural mechanisms underlying speech production in children who stutter (CWS), despite the critical importance of understanding these mechanisms closer to the time of stuttering onset. The relative contributions of speech planning and execution in CWS therefore are also unknown. Using functional near-infrared spectroscopy, the current study investigated neural mechanisms of planning and execution in a small sample of 9–12 year-old CWS and controls (N = 12) by implementing two tasks that manipulated speech planning and execution loads. Planning was associated with atypical activation in bilateral inferior frontal gyrus and right supramarginal gyrus. Execution was associated with atypical activation in bilateral precentral gyrus and inferior frontal gyrus, as well as right supramarginal gyrus and superior temporal gyrus. The CWS exhibited some activation patterns that were similar to the adults who stutter (AWS) as reported in our previous study: atypical planning in frontal areas including left inferior frontal gyrus and atypical execution in fronto-temporo-parietal regions including left precentral gyrus, and right inferior frontal, superior temporal, and supramarginal gyri. However, differences also emerged. Whereas CWS and AWS both appear to exhibit atypical activation in right inferior and supramarginal gyri during execution, only CWS appear to exhibit this same pattern during planning. In addition, the CWS appear to exhibit atypical activation in left inferior frontal and right precentral gyri related to execution, whereas AWS do not. These preliminary results are discussed in the context of possible impairments in sensorimotor integration and inhibitory control for CWS.     

抑郁症患者情绪图片刺激早期低频脑磁图研究

目的：探讨抑郁症患者给予视觉情绪图片刺激早期0～100ms、100～200ms、200～300ms3个时段8～30Hz的神经磁场激活特征。方法：8例抑郁症患者及12例健康右利手对照者,在给予国际情绪图片库（IAPS）正性、中性、负性情绪图片刺激同时记录脑磁图信号,使用SPM8b软件进行数据分析：设两样本t检验P〈0.01（未校正）和K值≥10个体素范围为差异有统计学意义。结果：与对照组相比,抑郁组在正性情绪图片刺激下,100～200ms内的左侧额下回,右侧的终板旁回、额内侧回、海马回激活增强。在中性情绪图片刺激下,抑郁组在0～100ms的右侧豆状核、岛叶、额上回,左内侧额叶,100～200ms内的右侧岛叶、豆状核壳核及屏状核,左侧额下回、额上回、颞上回,200～300ms内的右侧岛叶、豆状核、尾状核体激活增强。负性情绪图片刺激下抑郁组在0～100ms内的右侧颞上回、岛叶、尾状核头部、额中下回激活增强,100～200ms内的右侧额中回、尾状核体,200～300ms内右额下回激活增强。此外还比较一致的发现抑郁组在楔前叶、后扣带回等顶叶脑区激活降低。结论：抑郁个体起注意调节功能的顶叶脑区如楔前叶功能不足,对视觉皮质向前部脑区情绪信息颞叶底部传递通路抑制不足,腹侧前额皮质、岛叶过度的激活,可能是抑郁症的一个发病基础。