强迫症患者脑灰质基于体素的形态学研究

目的 运用基于体素的形态学测量(VBM)分析方法研究强迫症患者大脑灰质体积的改变,以及强迫症患者大脑灰质体积和耶鲁布朗强迫量表(Y-BOCS)评分的相关性.方法 收集20例未服药强迫症患者和20例健康对照组,对被试的大脑结构进行磁共振扫描.采用VBM分析方法对所获得的数据进行统计分析.结果 ①强迫症患者组较对照组在3个MNI坐标点的灰质体积显著增加;②经过多重比较校正后发现,强迫症患者灰质体积减小的脑区有:右侧罗兰迪克岛盖、中央前回、中央后回、右侧颞极、左侧枕下回、左侧枕中回、右侧小脑以及双侧直回(P＜0.05);③以颅内体积为协变量,对强迫症患者大脑灰质体积与Y-BOCS评分作回归分析发现,患者右侧额中回、左侧内侧额上回、左侧背外侧额上回、右侧罗兰迪克岛盖、双侧眶额叶下回、右侧眶额叶中回、右侧颞中回、右侧颞极、小脑、左侧脑岛以及小脑的蚯体的灰质体积与Y-BOCS评分存在负相关(P＜0.05);④发现强迫症患者灰质体积减小的脑区的灰质体积与Y-BOCS量表呈负相关的脑区有重叠部分,分别位于右侧颞极、右侧小脑、右侧罗兰迪克岛盖.结论 ①强迫症患者灰质体积存在异常,主要表现大脑皮质灰质体积的减小;②除皮质-纹状体-丘脑-皮质环路的结构异常外,大脑的后部区域如顶叶、颞叶、枕叶和小脑灰质体积减小可能与强迫症的发病机制相关;③强迫症患者症状严重程度与大脑部分脑区灰质体积的改变成显著负相关.     

基于脑网络组图谱的首发-未服药抑郁症白质结构网络研究

使用图论的分析方法对首发-未服药抑郁症（MDD）的扩散磁共振数据进行分析,探讨其白质结构网络变化。结果显示相较于健康对照组,MDD患者的网络节点拓扑属性受到了破坏,主要位于双侧海马旁回、双侧基底节、双侧顶下小叶、左侧中央后回、左侧中央旁小叶、右侧颞中回、右侧顶上小叶、右侧岛叶、右侧枕叶皮层腹中部、右侧扣带回以及右侧丘脑。进一步的相关分析结果表明,MDD患者的右侧顶上小叶、右侧岛叶的节点介数与病程呈正相关,右侧丘脑、左侧海马旁回的节点介数,左侧海马旁回、右侧顶下小叶的节点度与汉密尔顿的抑郁得分呈显著正相关。     

女性抑郁症病人脑灰质容量改变的研究

目的:比较女性抑郁病人与正常对照组的大脑灰质容量。方法:采用优化的基于像素的形态测量学方法(VBM)对15名未服药的抑郁症女性患者与15名条件匹配的正常志愿者脑灰质容量进行了对比研究。结果:与正常对照组相比,抑郁病人的左侧额中回眶部、左侧额下回三角部、左侧旁中央小叶、右侧辅助运动区、右侧顶上叶的灰质容量减低。结论:女性抑郁病人大脑灰质容量存在异常。     

广泛性焦虑障碍和强迫障碍的基于体素的大脑灰质体积研究

目的:应用磁共振成像(MRI)技术探讨广泛性焦虑障碍(GAD)和强迫障碍(OCD)患者大脑灰质体积的特征性表现。方法:选取符合精神障碍诊断与统计手册第四修订版(DSM-IV-TR)或疾病和有关健康问题的国际统计分类第十次修订本(ICD-10)诊断标准的28例GAD、25例OCD及39例健康对照。全部研究对象完成高分辨率结构磁共振成像扫描,使用汉密顿焦虑量表(HAMA)和耶鲁布朗强迫量表(Y-BOCS)评估患者的焦虑或强迫症状严重程度。在全脑范围内采用基于体素的形态学分析方法,分别比较各组研究对象之间灰质体积的差异,并探讨GAD和OCD患者全脑灰质体积与HAMA和Y-BOCS总分的相关性。结果:与健康对照相比,GAD左侧前扣带回脑区灰质体积增加(P=0.016,小体积校正),OCD患者双侧眶额皮层等脑区灰质体积下降(P0.001,未校正);GAD患者较OCD患者在双侧眶额皮层等多个脑区灰质体积增加(P0.001,未校正)。GAD患者的HAMA总分与右侧颞叶的灰质体积增加相关,而OCD患者的HAMA总分则与眶额皮层等脑区的灰质体积变化相关(P0.001,未校正)。讨论:GAD和OCD患者并未共享相同的灰质体积异常脑区,两种疾病可能具有完全不同的大脑结构特征,并且其焦虑症状具有不同的神经机制。     

精神分裂症及其健康同胞脑灰质体积异常的研究

目的:研究精神分裂症及其健康同胞的脑灰质体积的异常,为寻找精神分裂症大脑灰质异常内表型提供新的线索。方法:对27例精神分裂症、26例精神分裂症健康同胞以及27例年龄、性别及教育年限相匹配的健康对照进行结构磁共振扫描。运用基于体素的形态学分析方法比较各组的全脑灰质体积的差异。结果:与健康对照相比,健康同胞存在左侧枕中回、左侧楔前叶以及右侧丘脑的体积增大,精神分裂症存在左侧颞中回,左侧额上回,双侧颞下回的灰质体积下降以及右侧丘脑体积的增大;与其健康同胞相比,精神分裂症存在左侧额上回、双侧颞下回的灰质体积减小。其中,左侧额上回的灰质损失与精神分裂症的阳性症状总分以及阳性和阴性症状量表总分呈显著相关。结论:研究中发现精神分裂症患者主要表现为脑灰质体积下降,而精神分裂症健康同胞则存在脑灰质体积增大。健康同胞的脑灰质体积增大可能是使其免于罹患精神分裂症的代偿性改变,这些异常的改变可能反映了健康同胞对其遗传易感性相关的脑区灰质异常的代偿性保护作用。     

多发性硬化和视神经脊髓炎的脑灰质结构分析

目的 利用基于体素的形态学测量(VBM)和基于皮层的脑形态学测量(SBM)方法对多发性硬化(MS)和视神经脊髓炎(NMO)患者脑灰质体积及皮层厚度进行比较分析,探讨这两种疾病的脑灰质结构变化的差异。方法 对21例MS患者,16例NMO患者以及19例健康对照者行磁共振常规序列扫描,基于Matlab2014a平台的统计参数工具SPM12以及SPM12下的小工具CAT12,对VBM和SBM方法处理的数据进行分析。结果 MS组与正常对照(NC)组相比,经高斯随机场(GRF)校正后,MS组在左侧枕上回、左侧楔叶、左侧距状皮质、左侧楔前叶、左侧中央后回、左侧中央旁小叶、右侧楔叶、左侧额中回、左侧额上回和左侧额内侧回灰质体积显著性减少(P<0.05);经族系错误(FWE)法校正后,MS组在左侧中央旁小叶、左侧额上回和左侧楔前叶皮层厚度显著性减少(P<0.05)。NMO组与NC组相比,经GRF校正后,NMO组在左侧中央后回、左侧中央前回、左侧顶下小叶、右侧中央前回和右侧额中回灰质体积显著性增加(P<0.05);NMO组在左侧枕中回、左侧枕上回、左侧颞下回、右侧枕中回、左侧额上回眶部、...     

经历丧子事件所致创伤后应激障碍患者的脑结构磁共振研究

目的:探讨经历丧子这一特殊创伤性事件后出现创伤后应激障碍(PTSD)患者脑内结构形态学的改变。方法:选取经历过丧子事件所致PTSD的患者15例(PTSD组)和性别、年龄、受教育程度均与PTSD组相匹配的正常健康人15例(对照组),在取得知情同意后进行功能性磁共振脑扫描,采用基于体素的形态学测量方法(VBM)对图像进行后处理,比较两组脑结构中灰质、白质体积的异同。结果:以性别、年龄、全脑体积作为协变量,使用Matlab 7.1及SPM 5软件包来分析处理高分辨率的MRI结构图,定量检测脑结构组织成分的浓度;分析发现PTSD组患者与对照组相比,右侧中央前回的皮质运动前区(t=3.88,Z=3.44)、右侧额中回(t=3.95,Z=3.49)、左侧楔前叶(t=4.44,Z=3.83)、右侧丘脑背内侧核(t=4.10,Z=3.60)的灰质体积有明显缩小,差异均具有显著统计学意义(P0.001),两组其他脑区的灰质或白质体积的差异无统计学意义。结论:PTSD组患者的右侧中央前回的皮质运动前区、右侧额中回、左侧楔前叶、右侧丘脑背内侧核的灰质体积较正常对照组有明显缩小,提示这些脑区的结构存在病理性改变。     

改良电休克治疗对抑郁症脑结构影响的磁共振成像研究

目的:分析改良电休克治疗(MECT)治疗前后抑郁症患者脑体积的变化,探讨MECT发挥抗抑郁作用的神经影像学机制。方法:采用自身对照设计,根据DSM-IV诊断标准共纳入13例抑郁症患者,分别在治疗前和治疗第3周末(完成8次MECT)使用汉密尔顿抑郁量表(HAMD)进行临床症状评估,同时采用GE 3.0T磁共振获得影像学数据。采用基于体素的全脑形态学测量方法比较MECT治疗前后脑灰质和脑白质的改变。结果:HAMD评分的减分率为(61.8±20.4)%,其中4例75%,7例为50%~75%,1例为25%~50%,1例25%,有效率为84.6%。与M ECT治疗前相比,患者左侧颞上回、顶下小叶、枕中回、右侧颞中回以及小脑前叶的脑灰质体积增加(均P0.05)。同时左侧顶上小叶脑灰质体积减少(P0.05),左侧额叶和右侧楔前叶的脑白质体积降低(均P0.05)。结论:改良电休克治疗可能改变抑郁症患者前额叶、颞叶及顶叶等多个脑区的脑体积,提示神经可塑性作用可能参与了MECT发挥抗抑郁作用的过程。     

反社会行为人群大脑灰质结构改变的Meta分析

目的:通过Meta分析梳理反社会行为(Antisocial behavior,AB)人群大脑灰质结构改变的特点。方法:检索Pubmed、ScienceDirect、Web of Science和中国知网等数据库收录的有关AB人群大脑灰质结构的VBM研究文献,同时追踪相应参考文献,采用AE-SDM软件对纳入的研究进行基于体素的Meta分析。结果:共计纳入24个研究进入Meta分析。AB人群双侧额下回、缘上回和豆状核;左侧岛叶、杏仁核、额中回、颞上回和直回以及右侧中央后回等边缘-旁边缘系统脑区的灰质体积显著低于正常对照人群。Meta回归分析发现,AB人群上述脑区变化与其行为学特征具有显著相关。结论:反社会行为人群大脑灰质结构主要表现为额下回-岛叶-杏仁核-纹状体-缘上回等与情绪和共情加工能力有关脑区的改变。     

正常人和精神分裂症患者脑灰质体积分析的性别效应

目的:通过比较男性和女性正常人、男性和女性精神分裂症患者之间的脑灰质体积差异,探讨脑结构分析中的性别效应。方法:采集60例正常人(30例男性)和96例精神分裂症患者(48例男性)的高分辨率三维脑结构磁共振图像,运用基于体素的形态测量法(VBM)进行分析,获得每一个体的脑灰质体积图像。采用两样本t检验分别比较男性和女性正常人,男性和女性精神分裂症患者之间的脑灰质体积差异。结果:与女性正常人相比,男性正常人左侧的颞中回和额中回、右侧的边缘叶和颞中回的灰质体积较大(P<0.001),而左侧尾状核和右侧海马的灰质体积较小(P<0.001)。与女性精神分裂症患者相比,男性患者双侧的颞下回和海马、左侧的颞上回和颞中回的灰质体积较大(P<0.001),而未发现灰质体积较小的脑区。结论:性别效应是影响正常人或精神分裂症患者脑结构分析的重要因素。     

Voxel-based morphometry study of gray matter abnormalities in obsessive-compulsive disorder

To examine regional abnormalities in the brains of patients with obsessive-compulsive disorder (OCD), we assessed the gray matter (GM) density using voxel-based morphometry (VBM). We compared magnetic resonance images (MRIs) acquired from 71 OCD patients and 71 age- and gender-matched normal controls and examined the relationship between GM density and various clinical variables in OCD patients. We also investigated whether GM density differs among the subtypes of OCD compared to healthy controls. We detected significant reduction of GM in the inferior frontal gyrus, the medial frontal gyrus, the insula, the cingulate gyrus, and the superior temporal gyrus of OCD patients. A significant increase in GM density was observed in the postcentral gyrus, the thalamus, and the putamen. Some of these regions, including the insular and postcentral gyrus, were also associated with the severity of obsessive- compulsive symptoms. These findings indicate that the frontal-subcortical circuitry is dysfunctional in OCD, and suggest that the parietal cortex may play a role in the pathophysiology of this disease.     

Gray matter differences between pediatric obsessive-compulsive disorder patients and high-risk siblings: A preliminary voxel-based morphometry study

Neuroimaging studies have identified alterations in frontostriatal circuitry in obsessive-compulsive disorder (OCD). Voxel-based morphometry (VBM) allows for the assessment of differences in gray matter density across the whole brain. VBM has not previously been used to examine regional gray matter density in pediatric OCD patients and the siblings of pediatric OCD patients. Volumetric magnetic resonance imaging (MRI) studies were conducted in 10 psychotropic naïve pediatric patients with OCD, 10 unaffected siblings of pediatric patients with OCD, and 10 healthy controls. VBM analysis was conducted using SPM2. Statistical comparisons were performed with the general linear model, implementing small volume random field corrections for a priori regions of interest (anterior cingulate cortex or ACC, striatum and thalamus). VBM analysis revealed significantly lower gray matter density in OCD patients compared to healthy in the left ACC and bilateral medial superior frontal gyrus (SFG). Furthermore, a small volume correction was used to identify a significantly greater gray matter density in the right putamen in OCD patients as compared to unaffected siblings of OCD patients. These findings in patients, siblings, and healthy controls, although preliminary, suggest the presence of gray matter structural differences between affected subjects and healthy controls as well as between affected subjects and individuals at risk for OCD.     

Voxel-based assessment of gray and white matter volumes in Alzheimer's disease

Using the study-specific templates and optimized voxel-based morphometry (VBM), this study investigated abnormalities in gray and white matter to provide depiction of the concurrent structural changes in 13 patients with Alzheimer's disease (AD) compared with 14 age- and sex-matched normal controls. Consistent with previous studies, patients with AD exhibited significant gray matter volume reductions mainly in the hippocampus, parahippocampal gyrus, insula, superior/middle temporal gyrus, thalamus, cingulate gyrus, and superior/inferior parietal lobule. In addition, white matter volume reductions were found predominately in the temporal lobe, corpus callosum, and inferior longitudinal fasciculus. Furthermore, a number of additional white matter regions such as precentral gyrus, cingulate fasciculus, superior and inferior frontal gyrus, and sub-gyral in parietal lobe were also affected. The pattern of gray and white matter volume reductions helps us understand the underlying pathologic mechanisms in AD and potentially can be used as an imaging marker for the studies of AD in the future.     

Overlapping clusters of gray matter deficits in paranoid schizophrenia and psychotic bipolar mania with family history

The purpose of this study was to assess volumetric abnormalities of gray matter throughout the entire brain in patients with paranoid schizophrenia or with bipolar mania compared with control groups. We obtained weighted 3D T1 magnetic resonance images from 23 patients with paranoid schizophrenia, 24 patients with psychotic bipolar mania, and 36 healthy controls. Gray matter volume differences were assessed using optimized volumetric voxel-based morphometry (VBM). Both paranoid schizophrenia and bipolar mania group showed reduction of gray matter volume in the superior temporal gyrus (STG) (Brodmann Area, BA 22 areas), and the inferior parietal lobule, and enlargement of putamen, although different sides of the inferior parietal lobule and putamen were affected in the groups. Our findings showed the presence of overlapping clusters of gray matter deficits in paranoid-type schizophrenia and psychotic bipolar mania. The overlap in gray matter pathology between the two disorders may be attributed to risk factors common to both disorders.     

A voxel-based morphometry study of temporal lobe gray matter reductions in Alzheimer's disease

Several MRI studies have reported reductions in temporal lobe volumes in Alzheimer's disease (AD). Measures have been usually obtained with regions-of-interest (ROI) drawn manually on selected medial and lateral portions of the temporal lobes, with variable choices of anatomical borders across different studies. We used the fully automated voxel-based morphometry (VBM) approach to investigate gray matter abnormalities over the entire extension of the temporal lobe in 14 AD patients (MMSE 14-25) and 14 healthy controls. Foci of significantly reduced gray matter volume in AD patients were detected in both medial and lateral temporal regions, most significantly in the right and left posterior parahippocampal gyri and the left posterior inferior temporal gyrus/fusiform gyrus (P<0.05, corrected for multiple comparisons). At a more flexible statistical threshold (P<0.001, uncorrected for multiple comparisons), circumscribed foci of significant gray matter reduction were also detected in the right amygdala/enthorinal cortex, the anterior and posterior borders of the superior temporal gyrus bilaterally, and the anterior portion of the left middle temporal gyrus. These VBM results confirm previous findings of temporal lobe atrophic changes in AD, and suggest that these abnormalities may be confined to specific sites within that lobe, rather than showing a widespread distribution.     

脑结构形态学改变是精神分裂症的遗传内表型

目的 通过对首发精神分裂症患者及其未患病同胞的磁共振成像脑结构分析,探讨遗传因素对脑结构改变的影响程度,为发现精神分裂症的遗传内表型提供实验依据.方法 采用优化的基于体素的形态学研究方法对15例首发精神分裂症患者、19名首发精神分裂症患者未患病同胞及38名正常对照的大脑磁共振图像进行处理,采用一般线性模型进行统计分析.结果 与正常对照组相比,患者组在双侧颢叶、双侧枕叶、左侧岛叶、左侧额叶额上回及右豆状核苍白球灰质有明显减少;在双侧顶叶及双侧边缘叶扣带回灰质增加;未患病同胞组在右侧颞叶、双侧枕叶、左侧岛叶及左侧额叶中央前回等区域灰质明显减少;在左侧顶叶及双侧小脑后叶灰质增加.患者较同胞左侧顶叶楔前叶灰质有增加,未发现两者其他区域存在明显差异.结论 精神分裂症患者及其同胞存在相似的脑结构异常,遗传因素可能是导致精神分裂症脑结构异常的重要因素,提示脑结构形态学改变是精神分裂症的遗传内表型.     

Brain structure and symptom dimension relationships in obsessive-compulsive disorder: a voxel-based morphometry study

BACKGROUND: Obsessive-compulsive disorder (OCD) is a clinically heterogenous disorder characterized by temporally stable symptom dimensions. Past inconsistent results from structural neuroimaging studies of OCD may have resulted from the effects of these specific symptom dimensions as well as other socio-demographic and clinical variables upon gray matter (GM) volume. METHODS: GM volume was measured in 25 adult OCD patients and 20 adult healthy controls using voxel-based morphometry (VBM), controlling for age and total brain GM volume. Univariate and multivariate regression analyses were carried out between regions of GM difference and age, age of onset, medication load, OCD severity, depression severity, and separate symptom dimension scores. RESULTS: Significant GM volumetric differences in OCD patients relative to controls were found in dorsal cortical regions, including bilateral BA6, BA46, BA9 and right BA8 (controls>patients), and bilateral midbrain (patients>controls). Stepwise regression analyses revealed highly significant relationships between greater total OCD symptom severity and smaller GM volumes in dorsal cortical regions and larger GM volumes in bilateral midbrain. Greater age was independently associated with smaller GM volumes in right BA6, left BA9, left BA46 and larger GM volumes in right midbrain. Greater washing symptom severity was independently associated with smaller GM volume in right BA6, while there was a trend association between greater hoarding symptom severity and lower GM volume in left BA6. LIMITATIONS: The sample was relatively small to examine the relationship between symptom scores and GM volumes. Multiple patients were taking medication and had comorbid disorders. CONCLUSIONS: These analyses suggest dorsal prefrontal cortical and bilateral midbrain GM abnormalities in OCD that appear to be primarily driven by the effects of total OCD symptom severity. The results regarding the relationship between GM volumes and symptom dimension scores require examination in larger samples.     

Altered Structure and Intrinsic Functional Connectivity in Post-stroke Aphasia

Previous studies have demonstrated that alterations of gray matter exist in post-stroke aphasia (PSA) patients. However, so far, few studies combined structural alterations of gray matter volume (GMV) and intrinsic functional connectivity (iFC) imbalances of resting-state functional MRI to investigate the mechanism underlying PSA. The present study investigated specific regions with GMV abnormality in patients with PSA (n?=?17) and age- and sex- matched healthy controls (HCs, n?=?20) using voxel-based morphometry. In addition, we examined whether there is a link between abnormal gray matter and altered iFC. Furthermore, we explored the correlations between abnormal iFC and clinical scores in aphasic patients. We found significantly increased GMV in the right superior temporal gyrus, right inferior parietal lobule (IPL)/supramarginal gyrus (SMG), and left middle occipital gyrus. Decreased GMV was found in the right caudate gyrus, bilateral thalami in PSA patients. Patients showed increased remote interregional FC between the right IPL/SMG and right precuneus, right angular gyrus, right superior occipital gyrus; while reduced FC in the right caudate gyrus and supplementary motor area, dorsolateral superior frontal gyrus. Moreover, iFC strength between the left middle occipital gyrus and the left orbital middle frontal gyrus was positively correlated with the performance quotient. We suggest that GMV abnormality contributes to interregional FC in PSA. These results may provide useful information to understand the pathogenesis of post-stroke aphasia.     

Medial frontal and dorsal cortical morphometric abnormalities are related to obsessive-compulsive disorder

Whole-brain voxel-based morphometry (VBM) studies provide support for orbitofrontal, medial frontal as well as for dorsal cortical volumetric alteration in obsessive-compulsive disorder (OCD). However, there is still a need to replicate a priori unpredicted findings and to elucidate white matter volumetric abnormalities and relationships between grey (GM) and white (WM) matter volume and clinical characteristics of OCD. We compared GM and WM volume in a group of 14 patients with OCD and 15 healthy controls using a 3 T MRI scanner and an optimized VBM protocol. Regression analysis was used to examine relationships between GM and WM volume and clinical variables. In OCD we have found total WM volume reduction and marked mediofrontal, right temporo-parieto-occipital, right precentral, left middle temporal, left cerebellar and bilateral pons and mesencephalon GM volume reduction in the voxel-based analysis (p ≤ 0.05, FDR corrected, extent threshold 100 voxels). Regression analysis indicated a positive relationship between left orbitofrontal GM volume and severity of obsessive-compulsive symptoms and a negative relationship between symptom severity and GM volume in supramarginal gyri. Earlier age of OCD onset and longer illness duration were associated with smaller left occipital GM and right parietal WM and with greater left medial frontal GM and left frontal WM (p ≤ 0.001, uncorrected, extent threshold 50 voxels). Our results confirm volumetric abnormalities in the medial frontal and dorsal cortical areas in OCD. The relationships between OCD and clinical variables provide further evidence that frontal, parietal and occipital structures play a role in the disorder.     

Abnormalities of the left temporal lobe and thought disorder in schizophrenia. A quantitative magnetic resonance imaging study.

BACKGROUND. Data from postmortem, CT, and magnetic resonance imaging (MRI) studies indicate that patients with schizophrenia may have anatomical abnormalities of the left temporal lobe, but it is unclear whether these abnormalities are related to the thought disorder characteristic of schizophrenia. METHODS. We used new MRI neuroimaging techniques to derive (without knowledge of the diagnosis) volume measurements and three-dimensional reconstructions of temporal-lobe structures in vivo in 15 right-handed men with chronic schizophrenia and 15 matched controls. RESULTS. As compared with the controls, the patients had significant reductions in the volume of gray matter in the left anterior hippocampus-amygdala (by 19 percent [95 percent confidence interval, 3 to 36 percent]), the left parahippocampal gyrus (by 13 percent [95 percent confidence interval, 3 to 23 percent], vs. 8 percent on the right), and the left superior temporal gyrus (by 15 percent [95 percent confidence interval, 5 to 25 percent]). The volume of the left posterior superior temporal gyrus correlated with the score on the thought-disorder index in the 13 patients evaluated (r = -0.81, P = 0.001). None of these regional volume decreases was accompanied by a decrease in the volume of the overall brain or temporal lobe. The volume of gray matter in a control region (the superior frontal gyrus) was essentially the same in the patients and controls. CONCLUSIONS. Schizophrenia involves localized reductions in the gray matter of the left temporal lobe. The degree of thought disorder is related to the size of the reduction in volume of the left posterior superior temporal gyrus.