Learning and plasticity in the human brain

人脑的学习和可塑性

• 批准号: 8745738
• 负责人: Christopher Baker
• 金额: $ 39.27万
• 依托单位: NATIONAL INSTITUTE OF MENTAL HEALTH
• 依托单位国家: 美国
• 资助国家: 美国
• 起止时间: 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/8745738
• 关键词: Adult; Amputation; Amputees; Attention; Autistic Disorder; Blindness; Brain; Brain Part; Brain region; Characteristics; Conflict (Psychology); Decision Making; Development; Discrimination; Disease; Elderly; Esthesia; Feeling; Functional Magnetic Resonance Imaging; Functional disorder; Goals; Human; Impairment; Injury; Journals; Judgment; Learning; Limb structure; Longitudinal Studies; Macular degeneration; Magnetic Resonance Imaging; Measures; Mental disorders; Modeling; Monitor; Motion; Motor; Motor Cortex; Nature; Nervous System Trauma; Nervous system structure; Neurosciences; Pain; Participant; Patients; Performance; Phantom Limb Pain; Population; Prevalence; Process; Property; Recruitment Activity; Rehabilitation therapy; Reporting; Research; Somatosensory Cortex; Structure; Syndrome; Tactile; Time; Training; Trauma; Veterans; Visual; Visual Hallucination; Visual Motion; War; Work; autism spectrum disorder; experience; insight; interest; limb amputation; relating to nervous system; response; retinal damage; somatosensory; theories

The primary goals of this research are i) to establish differences in brain processing in the context of nervous system damage or dysfunction, and ii) to determine the potential for learning-induced plasticity to ameliorate the negative consequences of such changes. Over the past year we have primarily focused on Autism Spectrum Disorders (ASD) and the impact of amputation, and on establishing the structural brain changes that accompany learning/training. 1) Loss of somatosensory input (NCT00623818) Following limb amputation, over 90% of people report phantom sensations in their missing limb, often painful sensations (Phantom Limb Pain, or PLP). One current theory suggests that PLP is a direct result of cortical reorganization, an example of maladaptive plasticity. Mirror therapy has been used as a treatment for PLP. During this therapy, patients move their intact limb while looking in a mirror, making it seem as if their missing limb is moving. We are currently investigating the neural consequences of amputation and the impact of mirror therapy on brain activity over time. We are continuing to recruit unilateral limb amputees and monitoring brain activity with fMRI over a period of four weeks while the amputees undergo mirror therapy. We are trying to establish whether the presence of PLP correlates with cortical reorganization in the somatosensory and motor cortex (similar to that observed in our participants with macular degeneration) and whether the mirror therapy works by reducing the extent of cortical reorganization. 2) Autism Spectrum Disorders (NCT01031407) We have been investigating motion processing, decision-making and attention in Autism Spectrum Disorders (ASD), processes that are supported by well-characteristic brain networks. In the context of motion processing, previous studies had reported conflicting results with some studies finding impaired motion processing in ASD and other finding no impairment. By varying the time allowed to make judgments, we found that motion processing in ASD is impaired, but only at short durations. Further, this deficit in performance is reflected in the activity of brain regions involved in visual motion processing, with reduced responses in autistic compared with control participants. In the context of attention, we asked participants to perform a simple visual discrimination and measured the spatial gradient of attentional enhancement. We found that this gradient was sharper in autism than in matched control participants (Robertson et al, 2013, Journal of Neuroscience). 3) Learning/training (NCT00001360) We are conducting a long-term longitudinal study of participants learning different tasks (e.g. motor sequences) to determine how structural properties of the brain change over time. Establishing the nature, degree and consequences of plasticity in the adult cortex provides important insights into the potential for rehabilitative brain therapies following injury or dysfunction in the nervous system.

这项研究的主要目标是i）在神经系统损害或功能障碍的背景下建立大脑处理的差异，ii）确定学习诱导的可塑性的潜力以减轻此类变化的负面后果。在过去的一年中，我们主要关注自闭症谱系障碍（ASD）和截肢的影响，并建立学习/培训伴随的结构性大脑变化。 1）体感输入的损失（NCT00623818） 肢体截肢后，超过90％的人报告了肢体缺失的幻影感觉，通常是疼痛的感觉（幻影肢体疼痛或PLP）。当前的一种理论表明，PLP是皮质重组的直接结果，这是适应不良可塑性的一个例子。镜像疗法已被用作PLP的治疗方法。在这种疗法期间，患者在镜子里看着肢体时移动完整的肢体，使他们的肢体看上去似乎在移动。我们目前正在研究截肢的神经后果以及镜像疗法随着时间的推移对脑活动的影响。我们将继续在四个星期内通过fMRI募集单侧肢体截肢者，并通过fMRI监测大脑活动，而截肢者接受镜像治疗。我们正在尝试确定PLP的存在是否与体感和运动皮质中的皮质重组相关（类似于在黄斑变性的参与者中观察到的，以及镜像治疗是否通过减少皮质重组的程度来起作用。 2）自闭症谱系障碍（NCT01031407） 我们一直在调查自闭症谱系障碍（ASD）中的运动处理，决策和注意力，这些过程由特殊的脑网络支持。 在运动处理的背景下，以前的研究报告了结果相互矛盾的结果，一些研究发现ASD的运动处理受损，而其他发现没有损害。通过改变允许做出判断的时间，我们发现在ASD中进行的运动处理受损，但仅在短时间内。此外，这种性能的不足反映在与对照参与者相比相比，自闭症的大脑区域的活性减少了自闭症的反应。 在关注的背景下，我们要求参与者执行简单的视觉歧视，并测量注意力增强的空间梯度。我们发现，这种梯度在自闭症中比在匹配的控制参与者中更清晰（Robertson等，2013年，《神经科学杂志》）。 3）学习/培训（NCT0000001360） 我们正在进行一项长期纵向研究，对参与者学习不同的任务（例如运动序列），以确定大脑的结构特性如何随时间变化。 建立成人皮层中可塑性的性质，程度和后果，为神经系统受伤或功能障碍后的康复脑疗法的潜力提供了重要的见解。