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.     

Neuroanatomical discrimination between manipulating and maintaining processes involved in verbal working memory; a functional MRI study

We used functional magnetic resonance imaging (fMRI) to investigate neural correlates of processes concerning store and manipulation in verbal working memory. We prepared a revised lag 1 digit span, digit span and a simple number detection task. Specific activities in association with manipulating process were identified in the right middle (BA 9/46) and left precentral gyrus (BA 6). Activated areas specific to maintaining process were detected in the right middle (right BA 11/10) and medial (BA 6) frontal gyri, the right inferior parietal lobule (BA 40), and the left middle (BA 9) and inferior frontal gyri (BA 44). The process-nonspecific activated areas common to two processes were identified in the right inferior frontal gyrus (BA 47) and the left superior parietal lobule (BA 7). Using the signal percent change of each subject, we calculated the correlation coefficients among each activated area. The results of this analysis showed that two processes of verbal working memory were clearly discriminated. The two essential processes of manipulation and maintenance in working memory seem to activate process-specific and overlapping (process-nonspecific) areas, but the patterns of combination were definitely different.     

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。     

Functional connectivity during orthographic,phonological, and semantic processing of Chinese characters identifies distinct visuospatial and phonosemantic networks

While neuroimaging studies have identified brain regions associated with single word reading, its three constituents, namely, orthography, phonology, and meaning, and the functional connectivity of their networks remain underexplored. This study examined the neurocognitive underpinnings of these neural activations and functional connectivity of the identified brain regions using a within‐subject design. Thirty‐one native Mandarin speakers performed orthographic, phonological, and semantic judgment tasks during functional magnetic resonance imaging. The results indicated that the three processes shared a core network consisting of a large region in the left prefrontal cortex, fusiform gyrus, and medial superior frontal gyrus but not the superior temporal gyrus. Orthographic processing more strongly recruited the left dorsolateral prefrontal cortex, left superior parietal lobule and bilateral fusiform gyri; semantic processing more strongly recruited the left inferior frontal gyrus and left middle temporal gyrus, whereas phonological processing more strongly activated the dorsal part of the precentral gyrus. Functional connectivity analysis identified a posterior visuospatial network and a frontal phonosemantic network interfaced by the left middle frontal gyrus. We conclude that reading Chinese recruits cognitive resources that correspond to basic task demands with unique features best explained in connection with the individual reading subprocesses.     

汉语单字词音、义加工的脑激活模式

目的：研究汉字音、义加工的脑机制。方法：采用汉字单字词为实验材料，通过功能磁共振成像扫描执行语音和语义两种认知任务的脑区。结果：语音任务激活的脑区有，左侧顶叶下部和颞上回(BA 40／39／22，BA：Brodmann Area，即布鲁德曼分区，下同)，左侧枕中回(BA18／19)，右侧枕下回(BA18／19)，以及左中央前回(BA6)。语义任务激活的脑区有，左侧顶叶下部(BA40／39)和左侧颞上回(BA22)，左侧额下回(BA10／47)，右侧额中回和额上回(BA10／11)，以及左侧额中回(BA11)。语义任务减去语音任务激活的脑区有，左侧额下回(BA47)，左侧海马(BA36)和右侧海马旁回(BA36)。语音任务减去语义任务没有发现任何脑区的显著激活。结论：在语义任务中与语音有关的脑区得到激活；而在语音任务中与语义有关的脑区没有激活。     

太溪和丘墟穴捻针时不同脑功能区的激活

A number of previous studies of acupuncture acupoint specificity have used sham acupoints,sham acupuncture or meridian acupoints at a great distance from each other as controls in functional MRI (fMRI) experiments.However,few studies have compared different meridian acupoints within the same segment,which are associated with similarly intense needle sensations.We performed fMRI on 12 healthy young volunteers and observed differences in brain activation elicited by acupuncture of the Taixi (KI 3) and Qiuxu (GB 40) acupoints.Acupuncture was applied at the Taixi and Qiuxu acupoints,using a multiple-block fMRI design with three blocks,involving three alternations of resting and task phases.After scanning,needle sensation was assessed.The behavioral results revealed that the subjective needle sensation was similar between the Taixi and Qiuxu acupoints.The fMRI results revealed that acupuncture at the right Taixi acupoint activated the right superior temporal gyrus (BA 22),left middle frontal gyrus (BA 46) and inferior frontal gyrus (BA 45),bilateral parietal lobe postcentral gyrus (BA 2),right parietal lobe (BA 3),and left parietal lobe (BA 40).Acupuncture at the right Qiuxu acupoint activated the left superior temporal gyrus (BA 42),right parietal lobe postcentral gyrus (BA 40,BA 43),right inferior frontal gyrus (BA 47),bilateral superior temporal gyrus (BA 22),and right insula BA13.These results suggest that the right Taixi and Qiuxu acupoints activated different brain areas.     

Increased Cognition Connectivity Network in Major Depression Disorder: A fMRI Study

ObjectiveEvidence of the brain network involved in cognitive dysfunction has been inconsistent for major depressive disorder (MDD), especially during early stage of MDD. This study seeks to examine abnormal cognition connectivity network (CCN) in MDD within the whole brain.MethodsSixteen patients with MDD and 16 health controls were scanned during resting-state using 3.0 T functional magnetic resonance imaging (fMRI). All patients were first episode without any history of antidepressant treatment. Both the left and right dorsolateral prefrontal cortex (DLPFC) were used as individual seeds to identify CCN by the seed-target correlation analysis. Two sample t test was used to calculate between-group differences in CCN using fisher z-transformed correlation maps.ResultsThe CCN was constructed by bilateral seed DLPFC in two groups separately. Depressed subjects exhibited significantly increased functional connectivity (FC) by left DLPFC in one cluster, overlapping middle frontal gyrus, BA7, BA43, precuneus, BA6, BA40, superior temporal gyrus, BA22, inferior parietal lobule, precentral gyrus, BA4 and cingulate gyrus in left cerebrum. Health controls did not show any cluster with significantly greater FC compared to depressed subjects in left DLPFC network. There was no significant difference of FC in right DLPFC network between depressed subjects and the health controls.ConclusionThere are differences in CCN during early stage of MDD, as identified by increased FCs among part of frontal gyrus, parietal cortex, cingulate cortex, and BA43, BA22, BA4 with left DLPFC. These brain areas might be involved in the underlying mechanisms of cognitive dysfunction in MDD.     

捻转和非捻转刺激太溪穴后脑激活状态的功能磁共振成像研究

目的：观察功能磁共振成像了解捻转刺激太溪穴和非捻转刺激所引起的脑激活区状态。 方法：纳入健康青年志愿者12名,选取右侧太溪穴,采用组块刺激模式,静息阶段与刺激阶段交替出现,重复3次,分为3个组块。刺激为手法捻转行针或非捻转,非捻转即手放在针柄,但不进行任何操作。扫描后图像使用SPM2进行后处理。 结果：捻转刺激太溪穴主要激活了右侧颞上回BA22,左侧的额中回BA46,其次为左右顶叶的中央后回BA2,BA3,左额叶的额下回BA45和左顶叶的顶下小叶BA40;而非捻转刺激则没有激活。 结论：捻转刺激太溪穴和非捻转刺激的激活不同,与本经相关的经络、脏腑联系密切相关。     

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.     

Specialization of phonological and semantic processing in Chinese word reading

The purpose of this study was to examine the neurocognitive network for processing visual word forms in native Chinese speakers using functional magnetic resonance imaging (fMRI). In order to compare the processing of phonological and semantic representations, we developed parallel rhyming and meaning association judgment tasks that required explicit access and manipulation of these representations. Subjects showed activation in left inferior/middle frontal gyri, bilateral medial frontal gyri, bilateral middle occipital/fusiform gyri, and bilateral cerebella for both the rhyming and meaning tasks. A direct comparison of the tasks revealed that the rhyming task showed more activation in the posterior dorsal region of the inferior/middle frontal gyrus (BA 9/44) and in the inferior parietal lobule (BA 40). The meaning task showed more activation in the anterior ventral region of the inferior/middle frontal gyrus (BA 47) and in the superior/middle temporal gyrus (BA 22,21). These findings are consistent with previous studies in English that suggest specialization of inferior frontal regions for the access and manipulation of phonological vs. semantic representations, but also suggest that this specialization extends to the middle frontal gyrus for Chinese. These findings are also consistent with the suggestion that the left middle temporal gyrus is involved in representing semantic information and the left inferior parietal lobule is involved in mapping between orthographic and phonological representations.     

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.     

Error-related brain activation during a Go/NoGo response inhibition task

Inhibitory control and performance monitoring are critical executive functions of the human brain. Lesion and imaging studies have shown that the inferior frontal cortex plays an important role in inhibition of inappropriate response. In contrast, specific brain areas involved in error processing and their relation to those implicated in inhibitory control processes are unknown. In this study, we used a random effects model to investigate error-related brain activity associated with failure to inhibit response during a Go/NoGo task. Error-related brain activation was observed in the rostral aspect of the right anterior cingulate (BA 24/32) and adjoining medial prefrontal cortex, the left and right insular cortex and adjoining frontal operculum (BA 47) and left precuneus/posterior cingulate (BA 7/31/29). Brain activation related to response inhibition and competition was observed bilaterally in the dorsolateral prefrontal cortex (BA 9/46), pars triangularis region of the inferior frontal cortex (BA 45/47), premotor cortex (BA 6), inferior parietal lobule (BA 39), lingual gyrus and the caudate, as well as in the right dorsal anterior cingulate cortex (BA 24). These findings provide evidence for a distributed error processing system in the human brain that overlaps partially, but not completely, with brain regions involved in response inhibition and competition. In particular, the rostal anterior cingulate and posterior cingulate/precuneus as well as the left and right anterior insular cortex were activated only during error processing, but not during response competition, inhibition, selection, or execution. Our results also suggest that the brain regions involved in the error processing system overlap with brain areas implicated in the formulation and execution of articulatory plans.     

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.     

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.     

Semantic association investigated with functional MRI and independent component analysis

Semantic association, an essential element of human language, enables discourse and inference. Neuroimaging studies have revealed localization and lateralization of semantic circuitry, making substantial contributions to cognitive neuroscience. However, because of methodological limitations, these investigations have only identified individual functional components rather than capturing the behavior of the entire network. To overcome these limitations, we have implemented group independent component analysis (ICA) to investigate the cognitive modules used by healthy adults performing the fMRI semantic decision task. When compared with the results of a standard general linear modeling (GLM) analysis, ICA detected several additional brain regions subserving semantic decision. Eight task-related group ICA maps were identified, including left inferior frontal gyrus (BA44/45), middle posterior temporal gyrus (BA39/22), angular gyrus/inferior parietal lobule (BA39/40), posterior cingulate (BA30), bilateral lingual gyrus (BA18/23), inferior frontal gyrus (L>R, BA47), hippocampus with parahippocampal gyrus (L>R, BA35/36), and anterior cingulate (BA32/24). Although most of the components were represented bilaterally, we found a single, highly left-lateralized component that included the inferior frontal gyrus and the medial and superior temporal gyri, the angular and supramarginal gyri, and the inferior parietal cortex. The presence of these spatially independent ICA components implies functional connectivity and can be equated with their modularity. These results are analyzed and presented in the framework of a biologically plausible theoretical model in preparation for similar analyses in patients with right- or left-hemispheric epilepsies.     

Neuroanatomical correlates of apathy in Parkinson's disease: A magnetic resonance imaging study using voxel‐based morphometry

Apathy is generally defined as a disorder of motivation and is considered one of the most common neuropsychiatric disturbances in Parkinson's disease (PD). Only few studies addressed the neuroanatomical correlates of apathy in PD. The aim of this article was to determine the structural correlates of apathy in PD patients. Fifty‐five PD patients underwent a neuropsychiatric and neuropsychological examination, and a 3 T magnetic resonance imaging scan was acquired. A voxel‐based multiple regression analysis was used to calculate correlation between gray matter density and severity measures of apathy. Apathy correlates with decreased cognitive functioning and more depressive symptoms but not with more severe motor symptoms. High apathy scores were correlated with low gray matter density values in a number of cortical brain areas: the bilateral precentral gyrus (BA 4, 6), the bilateral inferior parietal gyrus (BA 40), the bilateral inferior frontal gyrus (BA 44, 47), the bilateral insula (BA 13), the right (posterior) cingulate gyrus (BA 24, 30, 31), and the right precuneus (BA 31). Apathy in PD correlates with reduced gray matter density in a number of brain regions. The involvement of the cingulate gyrus and inferior frontal gyrus is in line with the results of earlier studies addressing apathy in patients with Alzheimer's disease or depressive disorder. Further studies addressing the pathogenesis of apathy are needed. © 2010 Movement Disorder Society.     

Brain activity underlying stereotyped and non-stereotyped retrieval of learned stimulus-response associations

When humans retrieve learned stimulus-response associations in a stereotyped manner the necessary brain structures may differ from those required when the same associations must be retrieved and adapted to new circumstances. We tested this hypothesis by means of tasks that resembled those employed in monkeys, using positron emission tomography (PET). Stimuli consisted of abstract two-dimensional shapes. Stereotyped retrieval of learned stimulus-response associations was studied by the use of a concurrent discrimination task with fixed pairing. This was contrasted with conditions requiring retrieval and adaptation of learned associations: forced-choice recognition, response reversal and concurrent discrimination with random pairing. Visuomotor control, passive viewing and fixation conditions were also included. During concurrent discrimination with fixed pairing, the left lower precentral gyrus and rostral anterior cingulate demonstrated higher blood flow levels in comparison with recognition, concurrent discrimination with random pairing, and to a lesser degree, response reversal. In the left lower precentral gyrus these blood flow levels were also higher in comparison with control conditions. Conversely, during recognition, concurrent discrimination with random pairing and reversal, a single region within the right inferior frontal gyrus demonstrated higher blood flow levels in comparison with concurrent discrimination with fixed pairing and control conditions. This right inferior frontal gyrus activation did not depend on the need for active familiarity judgements or response inhibition. To conclude, the left lower precentral gyrus is more active during stereotyped retrieval of learned stimulus-response associations and the right inferior prefrontal cortex is more active when a learned stimulus-response association must be retrieved and adapted to new circumstances.     

Compensatory brain activation in children with attention deficit/hyperactivity disorder during a simplified Go/No-go task

Given that a number of recent studies have shown attenuated brain activation in prefrontal regions in children with ADHD, it has been recognized as a disorder in executive function. However, fewer studies have focused exclusively on the compensatory brain activation in ADHD. The present study objective was to investigate the compensatory brain activation patterns during response inhibition (RI) processing in ADHD children. In this study, 15 ADHD children and 15 sex-, age-, and IQ-matched control children were scanned with a 3-T MRI equipment while performing a simplified letter Go/No-go task. The results showed more brain activation in the ADHD group compared with the control group, whereas the accuracy and reaction time of behavioral performance were the same. Children with ADHD did not activate the normal RI brain circuits, which are thought to be predominantly located in the right middle/inferior frontal gyrus (BA46/44), right inferior parietal regions (BA40), and pre-SMA(BA6), but instead, activated brain regions, such as the left inferior frontal cortex, the right inferior temporal cortex, the right precentral gyrus, the left postcentral gyrus, the inferior occipital cortex, the middle occipital cortex, the right calcarine, the right hippocampus, the right midbrain, and the cerebellum. Our conclusion is that children with ADHD tend to compensatorily use more posterior and diffusive brain regions to sustain normal RI function.     

Relative Changes in Regional Cerebral Blood Flow During Spinal Cord Stimulation in Patients with Refractory Angina Pectoris

Spinal cord stimulation applied at thoracic level 1 (T1) has a neurally mediated anti-anginal effect based on anti-ischaemic action in the myocardium. Positron emission tomography was used to study which higher brain centres are influenced by spinal cord stimulation. Nine patients with a spinal cord stimulator for angina pectoris were studied using H₂¹⁵O as a flow tracer. Relative changes in regional cerebral blood flow related to stimulation compared with non-stimulation were assessed and analysed using the method of statistical parametric mapping. Increased regional cerebral blood flow was observed in the left ventrolateral periaqueductal grey, the medial prefrontal cortex [Brodmann area (BA) 9/10], the dorsomedial thalamus bilaterally, the left medial temporal gyrus (BA 21), the left pulvinar of the thalamus, bilaterally in the posterior caudate nucleus, and the posterior cingulate cortex (BA 30). Relative decreases in rCBF were noticed bilaterally in the insular cortex (BA 20/21 and BA 38), the right inferior temporal gyrus (BA 19/37), the right inferior frontal gyrus (BA 45), the left inferior parietal lobulus (BA 40), the medial temporal gyrus (BA 39) and the right anterior cingulate cortex (BA 24). It is concluded that spinal cord stimulation used as an additional treatment for angina applied at TI modulates regional cerebral blood flow in brain areas known to be associated with nociception and in areas associated with cardiovascular control.     

Dissociated brain organization for two-digit addition and subtraction: an fMRI investigation

The present study compared the patterns of brain activation elicited by two-digit addition and subtraction problems. Thirty-two Chinese undergraduates of the same educational background and of similar age were asked to assess whether arithmetic operations were true or false during functional magnetic resonance imaging. Results showed that both complex addition and subtraction were supported by the broad neural system that involved regions within the inferior parietal lobule, the precuneus, and the inferior occipital gyrus, as well as some subcortical structures. Nevertheless, complex problems involving addition elicited more activation mainly in the bilateral medial frontal gyrus, whereas problems involving subtraction had more activation in the precentral gyrus and the thalamus in the right hemisphere, as well as the inferior parietal lobule in the left hemisphere. This pattern of dissociated activation suggests that partially separate neuronal networks might support these different operations. It also suggests that complex addition has a greater reliance on the fronto-parietal cortical circuit and subtraction on the parieto-subcortical circuit.