Funding for Cognitive Imaging

磁共振成像(MRI)是一种强大的研究工具，可以在不对受试者造成风险的情况下研究人脑的解剖和功能。我们正在使用这项技术来研究三种常见的疾病：左脑中风；轻到中度的阿尔茨海默病；以及一种被称为颞叶癫痫的慢性癫痫。中风我们正在调查左脑中风后沟通障碍(失语症)的患者。每年约有25,000名患者在中风后留下持续性失语症。对这种情况的治疗还远远不是完美的，在许多情况下，很大程度上是未经证实的益处。它主要采取行为再培训的形式，在言语和语言治疗师的监督下。一个特别的困难是预测将发生的自然恢复程度的问题。这通常是最长的三个月，但恢复的数量可能非常不稳定。中风的大小确实会影响结果。然而，似乎还涉及其他因素，这些因素是什么还不得而知。许多人认为，语言的恢复是因为语言从左脑切换到右脑，但这种情况发生的证据很少。有更好的证据表明，恢复是由于左半球未受损部分的广泛重组，我们的预测是，如果关键通路保持完好，恢复就会好得多。因此，我们招募了50名失语症中风患者，在第一阶段，我们评估了他们在中风后第一周内的语言能力。我们对语音产生特别感兴趣，因为患者发现表达自己的能力受到了损害，这是他们病情最令人沮丧的方面。然后我们在三个月后对他们进行重新评估，这样我们就有了一个衡量他们复苏轨迹的指标：好的、坏的还是无动于衷的。我们还在早期和晚期做了详细的磁共振成像，以评估中风的界限，患者试图说话时整个大脑的功能，以及整个大脑的路径(白质束)的完整性。我们预测，这将使人们对良好的自然恢复所必需的因素有相当大的了解，这些知识将在提供改进的未来治疗策略时至关重要。阿尔茨海默病阿尔茨海默病(AD)的基本特征是健忘，特别是语言信息的健忘。记住刚刚被告知的内容有三个阶段：记录信息(即注意说话者以理解所说的话)；将信息编码为更持久的记忆；然后在需要时检索该记忆。这些不同的阶段依赖于大脑中非常不同的网络。大多数研究都集中在编码和提取阶段。我们正在研究第一阶段，特别是注意力的作用。在AD的早期阶段，语言功能是完整的，因此理解言语不是问题。相反，我们认为，病人是粗心大意的。注意力依赖于右脑系统。我们正在使用功能性和解剖学的MRI序列来研究沟通过程中的这一系统。我们还在观察用于缓解AD一些症状的药物是否对这个右脑系统有特别强的作用。一些癫痫患者做了手术来防止他们的发作。一种常见的手术是切除大脑的一个脑叶，即颞叶的前部。令人惊讶的是，这对患者的高级心理功能的影响相对较小。我们正在研究一种假说，即患者一生中频繁的癫痫发作活动导致了颞叶网络的重组，从而保护患者在手术完成后免受重大缺陷的影响。这将使我们更多地了解大脑的保护性“可塑性”。

Magnetic resonance imaging (MRI) is a powerful research tool, allowing both the anatomy and function of the human brain to be studied without risk to the subject. We are using this technique to study three common diseases: left cerebral hemisphere stroke; mild-to-moderate Alzheimer's disease; and a form of chronic epilepsy, know as temporal lobe epilepsy.StrokeWe are investigating patients who have impaired communication (aphasia) after a left cerebral hemisphere stroke. About 25,000 patients each year are left with persistent aphasia after stroke. Treatment for this condition is far from perfect, and in many instances largely of unproven benefit. It mostly takes the form of behavioural retraining, under the supervision of speech and language therapists. A particular difficulty is the problem of predicting the degree of natural recovery that will occur. This is usually maximal by three months, but the amount of recovery can be very variable. The size of the stroke does influence outcome. However, other factors seem to be involved, and what these are are not knowm. Many people believe that recovery is because language 'switches' from the left to the right cerebral hemisphere, but the evidence that this happens is slender. There is much better evidence that recovery is due to wide reorganisation of undamaged parts of the left hemisphere, and our prediction is that if critical pathways remain intact then recovery is much better. Therefore, we are recruiting 50 patients after aphasic stroke, and in the first phase we are assessing their language abilities within the first week of stroke. We are particularly interested in speech production, as patients find an impaired ability to express themselves the most frustrating aspect of their condition. We then reassess them at three months, and so we have a measure of their 'trajectory' of recovery: good, bad or indifferent. We also do detailed MRI, early and late, to assess the boundaries of the stroke, the function of the whole brain as the patients try to speak, and the integrity of pathways (white matter tracts) throughout the brain. We predict that this will give considerable insight into the factors necessary for good natural recovery, and this knowledge will be essential in informing improved future therapeutic strategies.Alzheimer's diseaseThe cardinal feature of Alzheimer's disease (AD) is forgetfulness, particularly for verbal information. There are three stages for remembering what one has just been told: registering the information (that is paying attention to the speaker to understand what is being said); encoding the information as a longer lasting memory; and then retrieving that memory when required. These different stages rely on very different networks in the the brain. Most research has concentrated on the encoding and retrieval stages. We are researching the first stage, and specifically the role of attention. In the early stages of AD, language functions are intact, so undertanding speech is not the problem. Rather, we argue, the patients are inattentive. Attention depends on a right cerebral hemisphere system. We are investigating this system during communication, using functional and anatomical MRI sequences. We are also observing whether the drugs used to alleviate some of the symptoms of AD have a particularly strong action on this right hemisphere system.EpislepsySome patients with epilepsy have surgery to prevent their attacks. One common operation is to remove the front pary of one lobe of the brain, the temporal lobe. Surprisingly, this has a relatively minor effect on the patient's higher mental functions. We are invetigating the hypothesis that frequent seizure activity throughot the lifetime of the patient has resulted in reorganisation of the temporal lobe networks, thus protecting the patient from a major deficity after the surgery has been completed. This will inform us more about the protective 'plasticity' of the brain.