ELECTROMAGNETIC NEUROIMAGING OF THE AGING BRAIN

血流动力学神经成像方法(PET、fMRI)的时间分辨率较差。血流变化太慢(持续几秒)，无法跟踪动态的认知过程。这一局限性在衰老的神经心理学研究中很重要。即使对抽象认知、记忆力或灵活性的测量没有显示出正常衰老的影响，老年人也总是被发现比年轻人慢。此外，评估阿尔茨海默病痴呆的早期智力衰退将受益于追踪特定记忆功能过早减慢的神经成像技术。我们建议开发一种先进的密集传感器阵列脑电(EEG)系统，该系统针对与全头脑磁图(MEG)系统的集成进行了优化。我们介绍了一种256通道传感器网络，它使用碳纤维电极实现低磁噪声，以及一个专为高头皮阻抗传感器和低磁干扰而设计的生理放大器。最重要的是，我们提出了一种完全的电磁信号分析策略，在该策略中，电场和磁场的不同优势结合在一个交钥匙软件包中。尽管拟议的电磁神经成像系统最初将出售给研究实验室，但在了解老年人大脑心理操作时间过程的变化方面取得的进展将具有重要的临床应用。建议的商业应用：通过以毫微秒的精度跟踪神经生理学减慢，密集阵列脑磁图可以优化我们对老年人神经疾病的理解，从而在治疗仍然有效的情况下对痴呆疾病进行准确评估。

Hemodynamic neuroimaging methods (PET, fMRI) have poor temporal resolution. Blood flow changes too slowly (over several sec6nds) to track dynamic cognitive processes. This limitation is important in neuropsychological studies of aging. Even when measures of abstract cognition, memory, or flexibility show no effects of normal aging, the older person is consistently found to be slower than the young person. Furthermore, assessing the early mental decline of Alzheimer's Dementia would benefit from a neuroimaging technology to track the premature slowing of specific memory functions. We propose to develop an advanced dense sensor array electroencephalographic (EEG) system that is optimized for integration with whole-head magnetoencephalographic (MEG) systems. We introduce a 256-channel sensor net that achieves low magnetic noise with carbon-fiber electrodes and a physiological amplifier that is engineered for high scalp impedance sensors and low magnetic interference. Most importantly, we propose a fully electromagnetic signal analytic strategy, in which the differing advantages of electrical and magnetic fields are combined within a single turnkey software package. Although the proposed electromagnetic neuroimaging system would be sold initially to research laboratories, advances in understanding the changes in the time course of mental operations in the aged brain will have significant clinical applications. PROPOSED COMMERCIAL APPLICATIONS: By tracking neurophysiological slowing with rnillisecond precision, dense array MEG/EEG could optimize our understanding of neurological disorders of the aged, leading to accurate assessment of dementing illness when treatment is still useful.