首次发病且未用药的成年早发和晚发抑郁症患者脑功能连接差异研究

目的比较成年早发抑郁症(EOD)和成年晚发抑郁症(LOD)患者默认网络(DMN)内部功能连接的差异,探究不同发病年龄的抑郁症患者是否有不同的发病机制。方法选取在昆明医科大学第一附属医院精神科门诊或住院的EOD患者(n=58)和LOD患者(n=62)为研究对象,同期招募年轻健康对照组(n=60)和年老健康对照组(n=52)。对受试者进行静息态功能磁共振扫描,选择左侧楔前叶为种子点,计算该种子点与全脑的功能连接,并比较各组间该种子点的功能连接差异。结果四组之间功能连接具有差异的脑区涉及双侧额叶、颞叶、基底节、枕叶、顶叶及小脑等脑区。EOD组左侧楔前叶与左侧小脑Crus1区、左侧小脑IX区、左侧颞中回、右侧楔前叶、右侧前扣带回、右侧额中回、右侧角回、右侧脑岛、右侧内侧额上回、右侧颞中回的功能连接均高于年轻健康对照组(Z=3. 752 4～5. 867 8,P均0. 05);而左侧楔前叶与左侧额中回、左侧中央旁小叶、右侧缘上回、右侧额上回、右侧颞下回、右侧中央后回、右侧中央前回、右侧枕上回的功能连接均低于年轻健康对照组(Z=-5. 007 6～-3. 797 7,P均0. 05)。LOD组左侧楔前叶与左侧小脑Crus2区、左侧尾状核、左侧颞下回、左侧小脑Crus1区、左侧角回、左侧额中回、右侧额中回、右侧角回、右侧眶额部额中回的功能连接均高于年老健康对照组(Z=4. 122 8～6. 579 4,P均0. 05);与左侧海马旁回、左侧额上回、右侧枕中回、右侧中央前回、右侧内侧额上回、右侧锯状回、右侧颞下回、右侧中央旁小叶、右侧梭状回、右侧后扣带回的功能连接均低于年老健康对照组(Z=-5. 884 0～-3. 617 2,P均0. 05)。EOD组左侧楔前叶与左侧锯状回、左侧小脑IV-VI区、左侧小脑Crus2区的功能连接比LOD组高(Z=4. 087 7、3. 937 4、3. 672 1,P均0. 05);EOD组左侧楔前叶与右侧额中回、右侧眶额部额下回、右侧额上回的功能连接比LOD组低(Z=-4. 274 8、-3. 956 8、-4. 724 3、-3. 663 2,P均0. 05)。结论 DMN内部功能连接增高及额顶网络功能连接降低可能与EOD的发病机制相关,而DMN前部功能连接增高和后部功能连接降低可能与LOD的发病机制相关,不同发病年龄的成年抑郁症患者可能有不同的发病机制。     

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。     

Double-blind randomized trial of risperidone versus divalproex in pediatric bipolar disorder: fMRI outcomes

The aim of this research was to determine the relative effects of risperidone and divalproex on brain function in pediatric mania. This is a double-blind 6-week functional magnetic resonance imaging trial with 24 unmedicated manic patients randomized to risperidone or divalproex, and 14 healthy controls (HCs) matched for IQ and demographic factors (mean age: 13.1 ± 3.3 years). A pediatric affective color matching task, in which subjects matched the color of a positive, negative or neutral word with one of two colored circles, was administered. The primary clinical measure was the Young Mania Rating Scale (YMRS). The risperidone group, relative to HC, showed an increase in activation from pre- to post-treatment in right pregenual and subgenual anterior cingulate cortex and decreased activation in bilateral middle frontal gyrus during the negative condition; and decreased activation in left inferior and medial, and right middle frontal gyri, left inferior parietal lobe, and right striatum with positive condition. In the divalproex group, relative to HC, there was an increased activation in right superior temporal gyrus in the negative condition; and in left medial frontal gyrus and right precuneus with the positive condition. Greater pre-treatment right amygdala activity with negative and positive condition in the risperidone group, and left amygdala activity with positive condition in divalproex group, predicted poor response on YMRS. Risperidone and divalproex yield differential patterns of prefrontal activity during an emotion processing task in pediatric mania. Increased amygdala activity at baseline is a potential biomarker predicting poor treatment response to both the risperidone and divalproex.     

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.     

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.     

Two types of mental fatigue affect spontaneous oscillatory brain activities in different ways

Background

Fatigue has a multi-factorial nature. We examined the effects of two types of mental fatigue on spontaneous oscillatory brain activity using magnetoencephalography (MEG).

Methods

Participants were randomly assigned to two groups in a single-blinded, crossover fashion to perform two types of mental fatigue-inducing experiments. Each experiment consisted of a 30-min fatigue-inducing 0- or 2-back test session and two evaluation sessions performed just before and after the fatigue-inducing mental task session.

Results

After the 0-back test, decreased alpha power was indicated in the right angular gyrus and increased levels in the left middle and superior temporal gyrus, left postcentral gyrus, right superior frontal gyrus, left inferior frontal gyrus, and right medial frontal gyrus. After the 2-back test, decreased alpha power was indicated in the right middle and superior frontal gyrus and increased levels in the left inferior parietal and superior parietal lobules, right parahippocampal gyrus, right uncus, left postcentral gyrus, left middle frontal gyrus, and right inferior frontal gyrus. For beta power, increased power following the 0-back test was indicated in the left middle temporal gyrus, left superior frontal gyrus, left cingulate gyrus, and left precentral gyrus. After the 2-back test, decreased power was suggested in the left superior frontal gyrus and increased levels in the left middle temporal gyrus and left inferior parietal lobule. Some of these brain regions might be associated with task performance during the fatigue-inducing trials.

Conclusions

Two types of mental fatigue may produce different alterations of the spontaneous oscillatory MEG activities. Our findings would provide new perspectives on the neural mechanisms underlying mental fatigue.     

Abnormal functional connectivity in patients with vascular cognitive impairment, no dementia: a resting-state functional magnetic resonance imaging study

The functional connectivity (FC) method was used to investigate the changes in the resting state of patients with vascular cognitive impairment, no dementia (VCIND). Resting-state functional magnetic resonance images (fMRIs) were acquired from 16 patients with subcortical ischemic vascular disease (SIVD) who fulfilled the criteria for VCIND, as well as 18 age- and sex-matched subjects with SIVD with no cognitive impairment (control group). Posterior cingulate cortex connectivity was gathered by investigating synchronic low-frequency fMRI signal fluctuations with a temporal correlation method. Compared with the control group, the patients showed FC decrease in the left middle temporal gyrus, the left anterior cingulate/left middle frontal gyrus, the right caudate, the right middle frontal gyrus, and the left medial frontal gyrus/paracentral lobule. There were also some regions that showed increased connectivity. These regions included the right inferior temporal gyrus, the left middle temporal gyrus, the left precentral gyrus, and the left superior parietal lobule. Our findings revealed the change in resting-state patterns of neuronal activity in patients with VCIND. This change may be caused by subcortical white matter lesions that destroyed direct and indirect fiber tract connectivity across the cerebral white matter and influenced the cortical FC and hypoperfusion resulted from small vascular disease. The results of the increased connectivity may be evoked by the compensatory recruitment and plasticity mechanism. Our findings suggest that the simplicity and noninvasiveness of this method makes it a potential tool to help thoroughly understand the pathogenesis of VCIND.     

Analysis of Altered Baseline Brain Activity in Drug-Naive Adult Patients with Social Anxiety Disorder Using Resting-State Functional MRI

Objective

We hypothesize that the amplitude of low-frequency fluctuations (ALFF) is involved in the altered regional baseline brain function in social anxiety disorder (SAD). The aim of the study was to analyze the altered baseline brain activity in drug-naive adult patients with SAD.

Methods

We investigated spontaneous and baseline brain activities by obtaining the resting-state functional magnetic resonance imaging data of 20 drug-naïve adult SAD patients and 19 healthy controls. Voxels were used to analyze the ALFF values using one- and two-sample t-tests. A post-hoc correlation of clinical symptoms was also performed.

Results

Our findings show decreased ALFF in the bilateral insula, left medial superior frontal gyrus, left precuneus, left middle temporal gyrus, right middle temporal pole, and left fusiform gyrus of the SAD group. The SAD patients exhibited significantly increased ALFF in the right inferior temporal gyrus, right middle temporal gyrus, bilateral middle occipital gyrus, orbital superior frontal gyrus, right fusiform gyrus, right medial superior frontal gyrus, and left parahippocampal gyrus. Moreover, the Liebowitz Social Anxiety Scale results for the SAD patients were positively correlated with the mean Z values of the right middle occipital and right inferior occipital but showed a negative correlation with the mean Z values of the right superior temporal gyrus and right medial superior frontal gyrus.

Conclusion

These results of the altered regional baseline brain function in SAD suggest that the regions with abnormal spontaneous activities are involved in the underlying pathophysiology of SAD patients.     

抑郁症患者对正性面部表情功能识别

目的：利用任务态功能核磁共振成像技术,初步探讨抗抑郁治疗对正性情绪识别脑区功能的影响。方法：检测19例抑郁症患者治疗前和治疗10周后在识别正性及中性面部表情视频时的激活脑区,并与19例匹配的健康者对照比较。结果：与正常对照组相比,治疗前抑郁症患者左右颞上回（BA39）、左后扣带回（BA23）、右后扣带回（BA30）、左丘脑、右岛叶（BA13）等脑区激活显著降低;治疗后患者左颞上回（BA39）、右颞上回（BA22）、左颞中回（BA37）、左右海马旁回（BA30）、右后扣带回（BA29）、右梭状回（BA36）、左额中回（BA8）、右额下回（BA47）、左顶下小叶（BA40）、右岛叶（BA13）等脑区激活较治疗前增强;但与正常组相比,左颞上回（BA22）、左额中回（BA10）、左梭状回（BA20）、左楔叶（BA19）、右顶上小叶（BA7）、右岛叶（BA13）等脑区激活仍存在一定程度的降低。结论：经抗抑郁治疗,抑郁症患者正性情绪识别脑区功能较治疗前有所改善,但与正常对照组相比,仍存在一定程度的功能损害。进一步证实了积极有效的抗抑郁治疗能够部分逆转正性情绪相关脑区损害。     

Acupuncture at the Taixi （KI3） acupoint activates cerebral neurons in elderly patients with mild cognitive impairment

Our previous ifndings have demonstrated that acupuncture at the Taixi （KI3） acupoint in healthy youths can activate neurons in cognitive-related cerebral cortex. Here, we investigated whether acupuncture at this acupoint in elderly patients with mild cognitive impairment can also activate neurons in these regions. Resting state and task-related functional magnetic resonance imaging showed that the pinprick senstation of acupuncture at the Taixi acupoint differed signiifcantly between elderly patients with mild cognitive impairment and healthy elderly controls. Results showed that 20 brain regions were activated in both groups of participants, including the bi-lateral anterior cingulate gyrus （Brodmann areas [BA] 32, 24）, left medial frontal cortex （BA 9, 10, 11）, left cuneus （BA 19）, left middle frontal gyrus （BA 11）, left lingual gyrus （BA 18）, right medial frontal gyrus （BA 11）, bilateral inferior frontal gyrus （BA 47）, left superior frontal gyrus （BA11）, right cuneus （BA 19, 18）, right superior temporal gyrus （BA 38）, left subcallosal gyrus （BA 47）, bilateral precuneus （BA 19）, right medial frontal gyrus （BA 10）, right superior frontal （BA 11）, left cingulate gyrus （BA 32）, left precentral gyrus （BA 6）, and right fusiform gyrus （BA 19）. These results suggest that acupuncture at the Taixi acupoint in elderly patients with mild cogni-tive impairment can also activate some brain regions.     

Brain functional changes in facial expression recognition in patients with major depressive disorder before and after antidepressant treatment A functional magnetic resonance imaging study

Functional magnetic resonance imaging was used during emotion recognition to identify changes in functional brain activation in 21 first-episode, treatment-naive major depressive disorder patients before and after antidepressant treatment. Following escitalopram oxalate treatment, patients exhibited decreased activation in bilateral precentral gyrus, bilateral middle frontal gyrus, left middle temporal gyrus, bilateral postcentral gyrus, left cingulate and right parahippocampal gyrus, and increased activation in right superior frontal gyrus, bilateral superior parietal lobule and left occipital gyrus during sad facial expression recognition. After antidepressant treatment, patients also exhibited decreased activation in the bilateral middle frontal gyrus, bilateral cingulate and right parahippocampal gyrus, and increased activation in the right inferior frontal gyrus, left fusiform gyrus and right precuneus during happy facial expression recognition. Our experimental findings indicate that the limbic-cortical network might be a key target region for antidepressant treatment in major depressive disorder.     

Neural correlates of the Pythagorean ratio rules

Millennia ago Pythagoras noted a simple but remarkably powerful rule for the aesthetics of tone combinations: pairs of tones--intervals--with simple ratios such as an octave (ratio 2 : 1) or a fifth (ratio 3 : 2) were pleasant sounding (consonant), whereas intervals with complex ratios such as the major seventh (ratio 243 : 128) were harsh (dissonant). These Pythagorean ratio rules are the building blocks of Western classical music; however, their neurophysiologic basis is not known. Using functional MRI we have found the neurophysiologic correlates of the ratio rules. In musicians, the inferior frontal gyrus, superior temporal gyrus, medial frontal gyrus, inferior parietal lobule and anterior cingulate respond with progressively more activation to perfect consonances, imperfect consonances and dissonances. In nonmusicians only the right inferior frontal gyrus follows this pattern.     

Interconnected large-scale systems for three fundamental cognitive tasks revealed by functional MRI

The specific brain areas required to execute each of three fundamental cognitive tasks - object naming, same-different discrimination, and integer computation - are determined by whole-brain functional magnetic resonance imaging (fMRI) using a novel technique optimized for the isolation of neurocognitive systems. This technique (1) conjoins the activity associated with identical or nearly identical tasks performed in multiple sensory modalities (conjunction) and (2) isolates the activity conserved across multiple subjects (conservation). Cortical regions isolated by this technique are, thus, presumed associated with cognitive functions that are both distinguished from primary sensory processes and from individual differences. The object-naming system consisted of four brain areas: left inferior frontal gyrus, Brodmann's areas (BAs) 45 and 44; left superior temporal gyrus, BA 22; and left medial frontal gyrus, BA 6. The same-different discrimination system consisted of three brain areas: right inferior parietal lobule, BA 40; right precentral gyrus, BA 6; and left medial frontal gyrus, BA 6. The integer computation system consisted of five brain areas: right middle frontal gyrus, BA 6; right precentral gyrus, BA 6; left inferior parietal lobule, BA 40; left inferior frontal gyrus, BA 44; and left medial frontal gyrus, BA 6. All three neurocognitive systems shared one common cortical region, the left medial frontal gyrus, the object-naming and integer computation systems shared the left inferior frontal gyrus, and the integer computation and same-different discrimination systems shared the right precentral gyrus. These results are consistent with connectionist models of cognitive processes where specific sets of remote brain areas are assumed to be transiently bound together as functional units to enable these functions, and further suggest a superorganization of neurocognitive systems where single brain areas serve as elements of multiple functional systems.     

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。     

Depressive mood in pre-dialytic chronic kidney disease: Statistical parametric mapping analysis of Tc-99m ECD brain SPECT

The purpose of this study was to investigate depression-related regions in pre-dialytic patients with chronic kidney disease (CKD) patients. Participants comprised 33 patients with stage 4 and 5 CKD (age, 55 [42–63]) and 32 healthy volunteers (age, 53.5 [49.5–57]). Depressed mood was assessed in the patients, and both groups underwent Tc-99m-labeled ethylcysteinate dimer (Tc-99m ECD) single photon emission computed tomograpy (SPECT). Statistical parametric mapping identified 18 areas of hypoperfusion in the patients in comparison with the normal controls. The largest clusters were areas including left precentral gyrus, right superior and middle temporal gyrus, both cerebellar posterior lobes, both inferior frontal gyrus, right superior and middle frontal gyrus, right cuneus, right inferior parietal lobule, and right putamen. However, there were no specific hypoperfusion areas in CKD patients with depression compared with CKD patients without depression. Interestingly, several hypoperfusion areas in CKD patients (inferior frontal gyrus [BA46], superior temporal gyrus [BA42], anterior cingulate gyrus [BA24]) were concordant with hypoperfusion areas found in patients with major depression who were free of kidney disease. In conclusion, this study did not demonstrate specific depression-related cerebral hypoperfusion areas. However, the cerebral blood flow pattern in CKD patients was similar to that of patients with major depression in some areas. Although further investigations are needed in the future, we suggest that the causes of the higher prevalence of depression in CKD might be associated with this finding.     

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.     

老年抑郁症患者的脑正电子发射体层摄影术显像分析

目的 探讨老年抑郁症患者脑^18氟-脱氧葡萄糖（18^F-FDG）正电子发射体层摄影术（PET）显像的特点。方法 分别对6例老年抑郁症患者（GD组）及10名健康体检者（对照组）进行脑^18 F-FDGPET显像，按年龄、简易智力状态检查量表总分和性别构成配对，用统计参数图第2版软件比较两组间脑局部葡萄糖代谢的差别。结果 GD组较对照组在双侧尾状核、额下回、颞上回、额中回，右侧核外、额上回、舌回和左侧扣带回、中央前回等脑区局部葡萄糖代谢减低（均P〈0．005）。GD组无局部脑葡萄糖代谢增加的脑区。结论 老年抑郁症患者存在基底节区、前额叶、颞叶和边缘系统的局部葡萄糖代谢下降。     

Object identification and lexical/semantic access in children: a functional magnetic resonance imaging study of word-picture matching

Theoretical models for lexical access to visual objects have been based mainly on adult data. To investigate the developmental aspects of object recognition and lexical access in children, a large-scale functional MRI (fMRI) study was performed in 283 normal children ages 5-18 using a word-picture matching paradigm in which children would match an aurally presented noun to one of two pictures (line drawings). Using group Independent Component Analysis (ICA), six task-related components were detected, including (a) the posterior superior temporal gyrus bilaterally; (b) the fusiform, inferior temporal, and middle occipital gyri bilaterally; (c) the dorsal aspect of the inferior frontal gyrus bilaterally, the left precuneus, the left superior/middle temporal gyrus, and the anterior cingulate; (d) the right medial fusiform gyrus; (e) a left-lateralized component including the inferior/middle frontal, middle temporal, medial frontal, and angular gyri, as well as the thalamus and the posterior cingulate; and (f) the ventral/anterior aspect of the inferior frontal gyrus bilaterally. Increased activation associated with age was seen in the components (b) and (d) (ventral visual pathway) for object recognition, and (c) and (f) likely associated with semantic maintenance and response selection. Increased activation associated with task performance was seen in components (b) and (d) (ventral visual pathway) while decreased activation associated with task performance was seen in component (f) (ventral/anterior inferior frontal gyrus). The results corroborate the continued development of the ventral visual pathway throughout the developmental period.     

Neural correlates of declarative memory for emotionally valenced words in women with posttraumatic stress disorder related to early childhood sexual abuse.

BACKGROUND: Animal studies have shown that early stressors result in lasting changes in structure and function of brain areas involved in memory, including hippocampus and frontal cortex. Patients with childhood abuse-related posttraumatic stress disorder (PTSD) have alterations in both declarative and nondeclarative memory function, and imaging studies in PTSD have demonstrated changes in function during stimulation of trauma-specific memories in hippocampus, medial prefrontal cortex, and cingulate. The purpose of this study was to assess neural correlates of emotionally valenced declarative memory in women with early childhood sexual abuse and PTSD. METHODS: Women with early childhood sexual abuse-related PTSD (n = 10) and women without abuse or PTSD (n = 11) underwent positron emission tomographic (PET) measurement of cerebral blood flow during a control condition and during retrieval of neutral (e.g., "metal-iron") and emotionally valenced (e.g., "rape-mutilate") word pairs. RESULTS: During retrieval of emotionally valenced word pairs, PTSD patients showed greater decreases in blood flow in an extensive area, which included orbitofrontal cortex, anterior cingulate, and medial prefrontal cortex (Brodmann's areas 25, 32, 9), left hippocampus, and fusiform gyrus/inferior temporal gyrus, with increased activation in posterior cingulate, left inferior parietal cortex, left middle frontal gyrus, and visual association and motor cortex. There were no differences in patterns of brain activation during retrieval of neutral word pairs between patients and control subjects. CONCLUSIONS: These findings are consistent with dysfunction of specific brain areas involved in memory and emotion in PTSD. Regions implicated in this study of emotionally valenced declarative memory are similar to those from prior imaging studies in PTSD using trauma-specific stimuli for symptom provocation, adding further supportive evidence for a dysfunctional network of brain areas involved in memory, including hippocampus, medial prefrontal cortex, and cingulate, in PTSD.     

An fMRI investigation of detection of semantic incongruities in autistic spectrum conditions

The aim of this study was to investigate differences in the brain's haemodynamic response to semantically incongruent and congruent sentences in adults with an autistic spectrum condition (ASC) and a typically developing Control group. We used functional magnetic resonance imaging to measure regional variations in neural activity during detection of semantic incongruities within written sentences. Whilst the 12 controls showed a pattern of activity extending from posterior cingulate cortices bilaterally and the left occipitotemporal region to the left superior and inferior temporal lobes, right anterior cingulate and right inferior frontal gyrus, the 12 participants with an ASC presented a more spatially restricted activation pattern, including the left inferior frontal gyrus, left anterior cingulate cortex and right middle frontal gyrus. These results are coherent with the hypothesis that impaired integration of multiple neural networks in people with an ASC is related to previous observations that this group have difficulties in the use of context to predict the final word of sentences.