Functional magnetic resonance imaging(fMRI) is em-ployed in many behavior analysis studies, with blood oxygen level dependent-(BOLD-) contrast imaging being the main method used to generate images. The use of BOLD-con...Functional magnetic resonance imaging(fMRI) is em-ployed in many behavior analysis studies, with blood oxygen level dependent-(BOLD-) contrast imaging being the main method used to generate images. The use of BOLD-contrast imaging in f MRI has been refined over the years, for example, the inclusion of a spin echo pulse and increased magnetic strength were shown to produce better recorded images. Taking careful precautions to control variables during measurement, comparisons between different specimen groups can be illustrated by f MRI imaging using both quantitative and qualitative methods. Differences have been observed in comparisons of active and resting, developing and aging, and defective and damaged brains in various studies. However, cognitive studies using f MRI still face a number of challenges in interpretation that can only be overcome by imaging large numbers of samples. Furthermore, f MRI studies of brain cancer, lesions and other brain pathologies of both humans and animals are still to be explored.展开更多
BACKGROUND： An increasing number of studies have shown the effects of aging in basic cognitive processing and higher cognitive functions using functional magnetic resonance imaging （fMRI）. However, little is known ...BACKGROUND： An increasing number of studies have shown the effects of aging in basic cognitive processing and higher cognitive functions using functional magnetic resonance imaging （fMRI）. However, little is known about the aging effects in diverse cognitive abilities, such as spatial learning and reasoning. OBJECTIVE： To investigate the effect of aging on spatial cognitive performance and regional brain activation based on fMRI. DESIGN, TIME, AND SETTING： A block design for fMRI observation. This study was performed at the fMRI Laboratory, Brain Science Research Center, Korea Advanced Institute of Science and Technology from March 2006 to May 2009. PARTICIPANTS： Eight right-handed, male, college students in their 20s （mean age 21.5 years） and six right-handed, male, adults in their 40s （mean age 45.7 years）, who graduated from college, participated in the study. All subjects were healthy and had no prior history of psychiatric or neurological disorders. METHODS： A spatial task was presented while brain images were acquired using a 3T fMRI system （ISOL Technology, Korea）. The spatial tasks involved selecting a shape that corresponded to a given figure using four examples, as well as selecting a development figure of a diagram. MAIN OUTCOME MEASURES： The accuracy rate （number of correct answers/total number of items x 100%） of spatial tasks was calculated. Using the subtraction procedure, the activated areas in the brain during spatial tasks were color-coded by T-score. The double subtraction method was used to analyze the effect of aging between the two age groups （20s versus 40s）. RESULTS： The cerebellum, occipital lobe, parietal lobe, and frontal lobe were similarly activated in the two age groups. Increased brain activations, however, were observed in bilateral parietal and superior frontal lobes of the younger group. More activation was observed in bilateral middle frontal and right inferior frontal lobes in the older group. Compared with the older group, the younger men exhibited greater spatial performance （P = 0.012）. CONCLUSION： Reduced cognitive function correlated with decreased activation areas in the parietal lobe and altered activation in the frontal lobe.展开更多
In this study, we used functional magnetic resonance imaging(fMRI) to investigate longitudinal changes in brain activation during a verbal working memory(VWM) task performed by patients who had experienced a transient...In this study, we used functional magnetic resonance imaging(fMRI) to investigate longitudinal changes in brain activation during a verbal working memory(VWM) task performed by patients who had experienced a transient ischemic attack(TIA). Twenty-five first-ever TIA patients without visible lesions in conventional MRI and 25 healthy volunteers were enrolled. VWM task-related fMRI was conducted 1 week and 3 months post-TIA. The brain activity evoked by the task and changes over time were assessed. We found that, compared with controls, patients exhibited an increased activation in the bilateral inferior frontal gyrus(IFG), right dorsolateral prefrontal cortex(DLPFC), insula, inferior parietal lobe(IPL), and cerebellum during the task performed 1 week post-TIA. But only the right IFG still exhibited an increased activation at 3 months post-TIA. A direct comparison of fMRI data between 1 week and 3 months post-TIA showed greater activation in the bilateral middle temporal gyrus, right DLPFC, IPL, cerebellum, and left IFG in patients at 1 week post-TIA. We conclude that brain activity patterns induced by a VWM task remain dynamic for a period of time after a TIA, despite the cessation of clinical symptoms. Normalization of the VWM activation pattern may be progressively achieved after transient episodes of ischemia in TIA patients.展开更多
Neurological abnormalities identified via neuroimaging are common in patients with Alzheimer’s disease.However,it is not yet possible to easily detect these abnormalities using head computed tomography in the early s...Neurological abnormalities identified via neuroimaging are common in patients with Alzheimer’s disease.However,it is not yet possible to easily detect these abnormalities using head computed tomography in the early stages of the disease.In this review,we evaluated the ways in which modern imaging techniques such as positron emission computed tomography,single photon emission tomography,magnetic resonance spectrum imaging,structural magnetic resonance imaging,magnetic resonance diffusion tensor imaging,magnetic resonance perfusion weighted imaging,magnetic resonance sensitive weighted imaging,and functional magnetic resonance imaging have revealed specific changes not only in brain structure,but also in brain function in Alzheimer’s disease patients.The reviewed literature indicated that decreased fluorodeoxyglucose metabolism in the temporal and parietal lobes of Alzheimer’s disease patients is frequently observed via positron emission computed tomography.Furthermore,patients with Alzheimer’s disease often show a decreased N-acetylaspartic acid/creatine ratio and an increased myoinositol/creatine ratio revealed via magnetic resonance imaging.Atrophy of the entorhinal cortex,hippocampus,and posterior cingulate gyrus can be detected early using structural magnetic resonance imaging.Magnetic resonance sensitive weighted imaging can show small bleeds and abnormal iron metabolism.Task-related functional magnetic resonance imaging can display brain function activity through cerebral blood oxygenation.Resting functional magnetic resonance imaging can display the functional connection between brain neural networks.These are helpful for the differential diagnosis and experimental study of Alzheimer’s disease,and are valuable for exploring the pathogenesis of Alzheimer’s disease.展开更多
Objective： TO determine whether jaw-tapping movement, a classically described as an indication of personal well-being and mental health, stimulates the memory and the cognitive regions of the brain and is associated ...Objective： TO determine whether jaw-tapping movement, a classically described as an indication of personal well-being and mental health, stimulates the memory and the cognitive regions of the brain and is associated with improved brain performance. Methods： Twelve healthy right-handed female subjects completed the study. Each patient performed a jaw-tapping task and an n-back task during functional magnetic resonance imaging （fMRI）. The subjects were trained to carry out the jaw-tapping movement at home twice a day for 4 weeks. The fMRI was repeated when they returned. Results： During the first and second jaw-tapping session, both sides of precentral gyrus and the right middle frontal gyrus （BA 6） were activated. And during the second session of the jaw-tapping task, parts of frontal lobe and temporal lobe related to memory function were more activated. In addition, the total percent task accuracy in n-beck task significantly increased after 4 weeks of jaw- tapping movement. After jaw-tapping training for 4 weeks, brain areas related to memory showed significantly increased blood oxygen level dependent signals. Conclusion： Jaw-tapping movement might be a useful exercise for stimulating the memory and cognitive regions of the brain.展开更多
Understanding the neural underpinning of human gait and balance is one of the most pertinent challenges for 21st-century translational neuroscience due to the profound impact that falls and mobility disturbances have ...Understanding the neural underpinning of human gait and balance is one of the most pertinent challenges for 21st-century translational neuroscience due to the profound impact that falls and mobility disturbances have on our aging population.Posture and gait control does not happen automatically,as previously believed,but rather requires continuous involvement of central nervous mechanisms.To effectively exert control over the body,the brain must integrate multiple streams of sensory information,including visual,vestibular,and somatosensory signals.The mechanisms which underpin the integration of these multisensory signals are the principal topic of the present work.Existing multisensory integration theories focus on how failure of cognitive processes thought to be involved in multisensory integration leads to falls in older adults.Insufficient emphasis,however,has been placed on specific contributions of individual sensory modalities to multisensory integration processes and cross-modal interactions that occur between the sensory modalities in relation to gait and balance.In the present work,we review the contributions of somatosensory,visual,and vestibular modalities,along with their multisensory intersections to gait and balance in older adults and patients with Parkinson’s disease.We also review evidence of vestibular contributions to multisensory temporal binding windows,previously shown to be highly pertinent to fall risk in older adults.Lastly,we relate multisensory vestibular mechanisms to potential neural substrates,both at the level of neurobiology(concerning positron emission tomography imaging)and at the level of electrophysiology(concerning electroencephalography).We hope that this integrative review,drawing influence across multiple subdisciplines of neuroscience,paves the way for novel research directions and therapeutic neuromodulatory approaches,to improve the lives of older adults and patients with neurodegenerative diseases.展开更多
BACKGROUND： Go, a traditional Chinese chess-like game, requires many unknown functions of the brain including attention, imaging, problem solving and processing of spatial working memory. To date, it remains uncertai...BACKGROUND： Go, a traditional Chinese chess-like game, requires many unknown functions of the brain including attention, imaging, problem solving and processing of spatial working memory. To date, it remains uncertain whether the intellectual activities required to play Go are related to the frontal lobe. OBJECTIVE： To investigate various patterns of brain region activity while schizophrenic patients and normal subjects engaged in memorizing piece placement in the Chinese game of Go. Spatial working memory was measured in order to validate whether the prefrontal lobe participates in this memory process. DESIGN, TIME AND SETTING： Non-randomized, concurrent control trial was performed at Second Xiangya Hospital of Central South University, between May and December 2004. PARTICIPANTS： A total of nine Chinese schizophrenic patients with no brain or bodily diseases and not undergoing electroshock treatment, who were in accordance with the DSM-Ⅳ criteria for schizophrenia, as well as thirteen healthy staffs and students with matched age, sex, and education were included. Patients and control subjects had no neurological disorders or mental retardation. In addition, all participants were right-handed. METHODS： The cognitive task for functional magnetic resonance imaging was a block design experiment. Both groups were asked to remember the placement of pieces in the Chinese game of Go on a computer screen. A brain activation map was analyzed in SPM99. MAIN OUTCOME MEASURES： Brain responses were compared with regard to activation region size, volume, and asymmetry indices. RESULTS： Compared with the control group, the reaction time was significantly delayed in schizophrenics performing the working memory task （P 〈 0.05）. When performing the tasks, normal subjects showed significant activation of the bilateral dorsolateral prefrontal lobe with left dominance; the asymmetry indices were： frontal lobe, ＋0.32; temporal lobe, 0.58; parietal lobe, 0.41 ; and occipital lobe, 0.34. On the other hand, schizophrenics showed right dominance and had a broader activation region of the prefrontal lobe （asymmetry indices： frontal lobe, 0.10; temporal lobe, ＋0.38; parietal lobe, ＋0.24; and occipital lobe, 0.00）. When comparing the normal group subtracted with the schizophrenic group, no significant lateralization was found in the frontal lobes but significant activation was found in the left anterior central gyrus, left middle frontal gyrus and in both sides of the cingulate gyrus. Comparing the schizophrenic group subtracted with the normal group, there was significant right lateralization of the frontal lobe and abnormally activated regions on both sides of the anterior central gyrus, middle frontal gyrus, left inferior frontal gyrus, right medial frontal gyrus and the right insular lobe. CONCLUSION： Different brain activation regions are involved in memorizing the placement of pieces in Chinese Go between schizophrenia and healthy subjects. Schizophrenics showed right dominance and border activation range, indicating that the prefrontal cortex plays an important role in memory information processing and resource allocation when remembering piece placement in the game of Go.展开更多
Episodic autobiographical memory(AM) allows one, through the recollection of sensory-perceptual details, thoughts and feelings, to become aware of an event as belonging to one's own past as well as being able to p...Episodic autobiographical memory(AM) allows one, through the recollection of sensory-perceptual details, thoughts and feelings, to become aware of an event as belonging to one's own past as well as being able to project into one's future. Because AM provides a sense of self-continuity, contributes to the integrity of the self, and helps predicting future experiences, any deficit of AM may have debilitating consequences for everyday life functioning. Understanding AM failure and the underlying neural mechanisms has the potential to shed light on brain reorganization mechanisms and engagement of compensatory processes. Functional magnetic resonance imaging(fMRI) provides the most promising imaging method to tackle these issues. We reviewed evidence from the few studies that used fMRI to investigate the functionality of the residual tissue, the neural reorganization and compensatory mechanisms in patients with neurological conditions due to impaired medial temporal lobe. Overall, these studies highlight the importance of the left hippocampus, which when atrophied and not functional leads to AM deficits but its residual functionality may support relatively normal AM recollection. When damaged hippocampal tissue is not functional, other brain regions(e.g., the medial prefrontal cortex) may be involved to compensate impairment, but they appear generally ineffective to support detailed episodic recollection.展开更多
目的探讨功能MRI(functional MRI,fMRI)评估高频重复经颅磁刺激(repetitive transcranial magnetic stimulation,rTMS)对老年脑卒中患者记忆功能的影响。材料与方法前瞻性纳入2021年1月至2021年12月我院收治的90例老年脑卒中记忆功能障...目的探讨功能MRI(functional MRI,fMRI)评估高频重复经颅磁刺激(repetitive transcranial magnetic stimulation,rTMS)对老年脑卒中患者记忆功能的影响。材料与方法前瞻性纳入2021年1月至2021年12月我院收治的90例老年脑卒中记忆功能障碍患者为研究对象,采用随机数字表法将其分为对照组(n=45)及观察组(n=45)。对照组给予对症治疗、健康指导以及常规记忆功能训练,观察组在对照组的基础上联合高频rTMS治疗。分别于治疗前、治疗4周后,应用Rivermead行为记忆能力测试-Ⅱ(Rivermead Behavioural Memory Test,RBMT-Ⅱ)测定两组患者记忆功能,并在测试时进行fMRI扫描,采用生活质量综合评定问卷-74(Generic Quality of Life Inventory,GQOL-74)评估患者生活质量。结果治疗4周后,与对照组比较,观察组RBMT-Ⅱ测试中记姓与名(t=2.802,P=0.006)、记所藏物品(t=2.091,P=0.039)、记约定(t=2.172,P=0.033)、图片再认(t=2.174,P=0.032)、脸部再认(t=2.191,P=0.031)、定向及日期(t=3.096,P=0.003)、信件即时回忆(t=2.293,P=0.024)、故事即时回忆(t=2.075,P=0.041)以及路线即时回忆(t=2.300,P=0.024)评分均较高,观察组fMRI低频振幅(amplitude of low frequency fluctuations,ALFF)值高于对照组(t=9.877,P<0.001);治疗4周后,观察组患者激活脑区数目多于对照组,GQOL-74问卷评分高于对照组[躯体健康(t=3.338,P=0.001),社会功能(t=3.400,P=0.001),心理健康(t=2.221,P=0.029),物质生活(t=2.298,P=0.024)]。结论高频rTMS治疗有利于改善老年脑卒中记忆功能障碍患者的记忆功能,进而提升患者生活质量;应用fMRI证明其作用机制可能与增强区域血流及神经活动强度相关。展开更多
目的通过功能磁共振成像(functional magnetic resonance imaging,fMRI)技术研究健康人脑空间工作记忆的功能脑区。方法10名右利手健康志愿者进行空间工作记忆任务的同时进行fMRI扫描,实验采用组块设计和SPM99软件进行数据分析和脑功能...目的通过功能磁共振成像(functional magnetic resonance imaging,fMRI)技术研究健康人脑空间工作记忆的功能脑区。方法10名右利手健康志愿者进行空间工作记忆任务的同时进行fMRI扫描,实验采用组块设计和SPM99软件进行数据分析和脑功能区定位。结果大脑皮质所激活的主要脑区有双侧顶叶(BA7/40,BA:Brodmann area,布鲁德曼分区),双侧额叶(BA6/9/47),双侧枕颞交界处(BA19/37);被激活的大脑皮质下结构有右侧尾状核、左侧丘脑和左侧中脑黑质;双侧小脑也均被显著激活(P<0.001)。结论人脑处理空间工作记忆信息是由大脑皮质下结构及小脑与大脑皮质共同完成的。展开更多
文摘Functional magnetic resonance imaging(fMRI) is em-ployed in many behavior analysis studies, with blood oxygen level dependent-(BOLD-) contrast imaging being the main method used to generate images. The use of BOLD-contrast imaging in f MRI has been refined over the years, for example, the inclusion of a spin echo pulse and increased magnetic strength were shown to produce better recorded images. Taking careful precautions to control variables during measurement, comparisons between different specimen groups can be illustrated by f MRI imaging using both quantitative and qualitative methods. Differences have been observed in comparisons of active and resting, developing and aging, and defective and damaged brains in various studies. However, cognitive studies using f MRI still face a number of challenges in interpretation that can only be overcome by imaging large numbers of samples. Furthermore, f MRI studies of brain cancer, lesions and other brain pathologies of both humans and animals are still to be explored.
文摘BACKGROUND： An increasing number of studies have shown the effects of aging in basic cognitive processing and higher cognitive functions using functional magnetic resonance imaging （fMRI）. However, little is known about the aging effects in diverse cognitive abilities, such as spatial learning and reasoning. OBJECTIVE： To investigate the effect of aging on spatial cognitive performance and regional brain activation based on fMRI. DESIGN, TIME, AND SETTING： A block design for fMRI observation. This study was performed at the fMRI Laboratory, Brain Science Research Center, Korea Advanced Institute of Science and Technology from March 2006 to May 2009. PARTICIPANTS： Eight right-handed, male, college students in their 20s （mean age 21.5 years） and six right-handed, male, adults in their 40s （mean age 45.7 years）, who graduated from college, participated in the study. All subjects were healthy and had no prior history of psychiatric or neurological disorders. METHODS： A spatial task was presented while brain images were acquired using a 3T fMRI system （ISOL Technology, Korea）. The spatial tasks involved selecting a shape that corresponded to a given figure using four examples, as well as selecting a development figure of a diagram. MAIN OUTCOME MEASURES： The accuracy rate （number of correct answers/total number of items x 100%） of spatial tasks was calculated. Using the subtraction procedure, the activated areas in the brain during spatial tasks were color-coded by T-score. The double subtraction method was used to analyze the effect of aging between the two age groups （20s versus 40s）. RESULTS： The cerebellum, occipital lobe, parietal lobe, and frontal lobe were similarly activated in the two age groups. Increased brain activations, however, were observed in bilateral parietal and superior frontal lobes of the younger group. More activation was observed in bilateral middle frontal and right inferior frontal lobes in the older group. Compared with the older group, the younger men exhibited greater spatial performance （P = 0.012）. CONCLUSION： Reduced cognitive function correlated with decreased activation areas in the parietal lobe and altered activation in the frontal lobe.
基金supported by the National Natural Science Foundation of China (81300943 and 81472162)the Postdoctoral Science Special Foundation of China (2014T70867)
文摘In this study, we used functional magnetic resonance imaging(fMRI) to investigate longitudinal changes in brain activation during a verbal working memory(VWM) task performed by patients who had experienced a transient ischemic attack(TIA). Twenty-five first-ever TIA patients without visible lesions in conventional MRI and 25 healthy volunteers were enrolled. VWM task-related fMRI was conducted 1 week and 3 months post-TIA. The brain activity evoked by the task and changes over time were assessed. We found that, compared with controls, patients exhibited an increased activation in the bilateral inferior frontal gyrus(IFG), right dorsolateral prefrontal cortex(DLPFC), insula, inferior parietal lobe(IPL), and cerebellum during the task performed 1 week post-TIA. But only the right IFG still exhibited an increased activation at 3 months post-TIA. A direct comparison of fMRI data between 1 week and 3 months post-TIA showed greater activation in the bilateral middle temporal gyrus, right DLPFC, IPL, cerebellum, and left IFG in patients at 1 week post-TIA. We conclude that brain activity patterns induced by a VWM task remain dynamic for a period of time after a TIA, despite the cessation of clinical symptoms. Normalization of the VWM activation pattern may be progressively achieved after transient episodes of ischemia in TIA patients.
基金This work was supported by the Science and Technology Support Plan of Guizhou Province of China,No.QianKeHe-Zhicheng[2020]4Y129(to HB)the Scientific Research Foundation of Guizhou Health Committee of China,No.gzwkj2017-1-022(to HB)the Scientific Research Project of Guizhou Traditional Chinese Medicine Bureau of China,No.QZYY-2018-044(to HB).
文摘Neurological abnormalities identified via neuroimaging are common in patients with Alzheimer’s disease.However,it is not yet possible to easily detect these abnormalities using head computed tomography in the early stages of the disease.In this review,we evaluated the ways in which modern imaging techniques such as positron emission computed tomography,single photon emission tomography,magnetic resonance spectrum imaging,structural magnetic resonance imaging,magnetic resonance diffusion tensor imaging,magnetic resonance perfusion weighted imaging,magnetic resonance sensitive weighted imaging,and functional magnetic resonance imaging have revealed specific changes not only in brain structure,but also in brain function in Alzheimer’s disease patients.The reviewed literature indicated that decreased fluorodeoxyglucose metabolism in the temporal and parietal lobes of Alzheimer’s disease patients is frequently observed via positron emission computed tomography.Furthermore,patients with Alzheimer’s disease often show a decreased N-acetylaspartic acid/creatine ratio and an increased myoinositol/creatine ratio revealed via magnetic resonance imaging.Atrophy of the entorhinal cortex,hippocampus,and posterior cingulate gyrus can be detected early using structural magnetic resonance imaging.Magnetic resonance sensitive weighted imaging can show small bleeds and abnormal iron metabolism.Task-related functional magnetic resonance imaging can display brain function activity through cerebral blood oxygenation.Resting functional magnetic resonance imaging can display the functional connection between brain neural networks.These are helpful for the differential diagnosis and experimental study of Alzheimer’s disease,and are valuable for exploring the pathogenesis of Alzheimer’s disease.
基金Supported by the Basic Science Research Program through the National Research Foundation of Korea(NRF) funded by the Ministry of Education,Science and Technology(No.2009-0068230)
文摘Objective： TO determine whether jaw-tapping movement, a classically described as an indication of personal well-being and mental health, stimulates the memory and the cognitive regions of the brain and is associated with improved brain performance. Methods： Twelve healthy right-handed female subjects completed the study. Each patient performed a jaw-tapping task and an n-back task during functional magnetic resonance imaging （fMRI）. The subjects were trained to carry out the jaw-tapping movement at home twice a day for 4 weeks. The fMRI was repeated when they returned. Results： During the first and second jaw-tapping session, both sides of precentral gyrus and the right middle frontal gyrus （BA 6） were activated. And during the second session of the jaw-tapping task, parts of frontal lobe and temporal lobe related to memory function were more activated. In addition, the total percent task accuracy in n-beck task significantly increased after 4 weeks of jaw- tapping movement. After jaw-tapping training for 4 weeks, brain areas related to memory showed significantly increased blood oxygen level dependent signals. Conclusion： Jaw-tapping movement might be a useful exercise for stimulating the memory and cognitive regions of the brain.
文摘Understanding the neural underpinning of human gait and balance is one of the most pertinent challenges for 21st-century translational neuroscience due to the profound impact that falls and mobility disturbances have on our aging population.Posture and gait control does not happen automatically,as previously believed,but rather requires continuous involvement of central nervous mechanisms.To effectively exert control over the body,the brain must integrate multiple streams of sensory information,including visual,vestibular,and somatosensory signals.The mechanisms which underpin the integration of these multisensory signals are the principal topic of the present work.Existing multisensory integration theories focus on how failure of cognitive processes thought to be involved in multisensory integration leads to falls in older adults.Insufficient emphasis,however,has been placed on specific contributions of individual sensory modalities to multisensory integration processes and cross-modal interactions that occur between the sensory modalities in relation to gait and balance.In the present work,we review the contributions of somatosensory,visual,and vestibular modalities,along with their multisensory intersections to gait and balance in older adults and patients with Parkinson’s disease.We also review evidence of vestibular contributions to multisensory temporal binding windows,previously shown to be highly pertinent to fall risk in older adults.Lastly,we relate multisensory vestibular mechanisms to potential neural substrates,both at the level of neurobiology(concerning positron emission tomography imaging)and at the level of electrophysiology(concerning electroencephalography).We hope that this integrative review,drawing influence across multiple subdisciplines of neuroscience,paves the way for novel research directions and therapeutic neuromodulatory approaches,to improve the lives of older adults and patients with neurodegenerative diseases.
基金Supported by:the National Science Foundation for Distinguished Young Scholars,No.60225015the National Natural Science Foundation of China, No.30100054,30570609
文摘BACKGROUND： Go, a traditional Chinese chess-like game, requires many unknown functions of the brain including attention, imaging, problem solving and processing of spatial working memory. To date, it remains uncertain whether the intellectual activities required to play Go are related to the frontal lobe. OBJECTIVE： To investigate various patterns of brain region activity while schizophrenic patients and normal subjects engaged in memorizing piece placement in the Chinese game of Go. Spatial working memory was measured in order to validate whether the prefrontal lobe participates in this memory process. DESIGN, TIME AND SETTING： Non-randomized, concurrent control trial was performed at Second Xiangya Hospital of Central South University, between May and December 2004. PARTICIPANTS： A total of nine Chinese schizophrenic patients with no brain or bodily diseases and not undergoing electroshock treatment, who were in accordance with the DSM-Ⅳ criteria for schizophrenia, as well as thirteen healthy staffs and students with matched age, sex, and education were included. Patients and control subjects had no neurological disorders or mental retardation. In addition, all participants were right-handed. METHODS： The cognitive task for functional magnetic resonance imaging was a block design experiment. Both groups were asked to remember the placement of pieces in the Chinese game of Go on a computer screen. A brain activation map was analyzed in SPM99. MAIN OUTCOME MEASURES： Brain responses were compared with regard to activation region size, volume, and asymmetry indices. RESULTS： Compared with the control group, the reaction time was significantly delayed in schizophrenics performing the working memory task （P 〈 0.05）. When performing the tasks, normal subjects showed significant activation of the bilateral dorsolateral prefrontal lobe with left dominance; the asymmetry indices were： frontal lobe, ＋0.32; temporal lobe, 0.58; parietal lobe, 0.41 ; and occipital lobe, 0.34. On the other hand, schizophrenics showed right dominance and had a broader activation region of the prefrontal lobe （asymmetry indices： frontal lobe, 0.10; temporal lobe, ＋0.38; parietal lobe, ＋0.24; and occipital lobe, 0.00）. When comparing the normal group subtracted with the schizophrenic group, no significant lateralization was found in the frontal lobes but significant activation was found in the left anterior central gyrus, left middle frontal gyrus and in both sides of the cingulate gyrus. Comparing the schizophrenic group subtracted with the normal group, there was significant right lateralization of the frontal lobe and abnormally activated regions on both sides of the anterior central gyrus, middle frontal gyrus, left inferior frontal gyrus, right medial frontal gyrus and the right insular lobe. CONCLUSION： Different brain activation regions are involved in memorizing the placement of pieces in Chinese Go between schizophrenia and healthy subjects. Schizophrenics showed right dominance and border activation range, indicating that the prefrontal cortex plays an important role in memory information processing and resource allocation when remembering piece placement in the game of Go.
文摘Episodic autobiographical memory(AM) allows one, through the recollection of sensory-perceptual details, thoughts and feelings, to become aware of an event as belonging to one's own past as well as being able to project into one's future. Because AM provides a sense of self-continuity, contributes to the integrity of the self, and helps predicting future experiences, any deficit of AM may have debilitating consequences for everyday life functioning. Understanding AM failure and the underlying neural mechanisms has the potential to shed light on brain reorganization mechanisms and engagement of compensatory processes. Functional magnetic resonance imaging(fMRI) provides the most promising imaging method to tackle these issues. We reviewed evidence from the few studies that used fMRI to investigate the functionality of the residual tissue, the neural reorganization and compensatory mechanisms in patients with neurological conditions due to impaired medial temporal lobe. Overall, these studies highlight the importance of the left hippocampus, which when atrophied and not functional leads to AM deficits but its residual functionality may support relatively normal AM recollection. When damaged hippocampal tissue is not functional, other brain regions(e.g., the medial prefrontal cortex) may be involved to compensate impairment, but they appear generally ineffective to support detailed episodic recollection.
文摘目的探讨功能MRI(functional MRI,fMRI)评估高频重复经颅磁刺激(repetitive transcranial magnetic stimulation,rTMS)对老年脑卒中患者记忆功能的影响。材料与方法前瞻性纳入2021年1月至2021年12月我院收治的90例老年脑卒中记忆功能障碍患者为研究对象,采用随机数字表法将其分为对照组(n=45)及观察组(n=45)。对照组给予对症治疗、健康指导以及常规记忆功能训练,观察组在对照组的基础上联合高频rTMS治疗。分别于治疗前、治疗4周后,应用Rivermead行为记忆能力测试-Ⅱ(Rivermead Behavioural Memory Test,RBMT-Ⅱ)测定两组患者记忆功能,并在测试时进行fMRI扫描,采用生活质量综合评定问卷-74(Generic Quality of Life Inventory,GQOL-74)评估患者生活质量。结果治疗4周后,与对照组比较,观察组RBMT-Ⅱ测试中记姓与名(t=2.802,P=0.006)、记所藏物品(t=2.091,P=0.039)、记约定(t=2.172,P=0.033)、图片再认(t=2.174,P=0.032)、脸部再认(t=2.191,P=0.031)、定向及日期(t=3.096,P=0.003)、信件即时回忆(t=2.293,P=0.024)、故事即时回忆(t=2.075,P=0.041)以及路线即时回忆(t=2.300,P=0.024)评分均较高,观察组fMRI低频振幅(amplitude of low frequency fluctuations,ALFF)值高于对照组(t=9.877,P<0.001);治疗4周后,观察组患者激活脑区数目多于对照组,GQOL-74问卷评分高于对照组[躯体健康(t=3.338,P=0.001),社会功能(t=3.400,P=0.001),心理健康(t=2.221,P=0.029),物质生活(t=2.298,P=0.024)]。结论高频rTMS治疗有利于改善老年脑卒中记忆功能障碍患者的记忆功能,进而提升患者生活质量;应用fMRI证明其作用机制可能与增强区域血流及神经活动强度相关。
文摘目的通过功能磁共振成像(functional magnetic resonance imaging,fMRI)技术研究健康人脑空间工作记忆的功能脑区。方法10名右利手健康志愿者进行空间工作记忆任务的同时进行fMRI扫描,实验采用组块设计和SPM99软件进行数据分析和脑功能区定位。结果大脑皮质所激活的主要脑区有双侧顶叶(BA7/40,BA:Brodmann area,布鲁德曼分区),双侧额叶(BA6/9/47),双侧枕颞交界处(BA19/37);被激活的大脑皮质下结构有右侧尾状核、左侧丘脑和左侧中脑黑质;双侧小脑也均被显著激活(P<0.001)。结论人脑处理空间工作记忆信息是由大脑皮质下结构及小脑与大脑皮质共同完成的。
