The objective of this proposal is to support the candidate's development into an independent clinical researcher. The outlined training plan will equip the applicant with the necessary skills to conduct patient- oriented research with specific didactic training in biostatistics, neuroanatomy, behavioral neurology, and the ethical and responsible conduct of basic and clinical research. The overall goal of this project is to determine whether functional brain alterations in attention and memory systems may better elucidate early vulnerable brain regions in MCI patients at risk for cognitive decline. It remains poorly understood why some MCI patients progress to dementia, exhibiting selective vulnerability of cognitive-specific brain regions, while others remain stable or even improve. Alterations in brain activation have been exclusively assessed using episodic memory tasks. This approach remains limited in scope as many MCI patients exhibit pronounced deficits in both attention/executive function and memory domains. To accomplish this goal, our proposal will focus on a functional MRI paradigm of attention and memory in which subjects must first maintain focus during an anticipation period (attention) and then encode and recognize a visually-presented stimulus (memory). We will investigate the differential, task-specific activation of select brain regions in MCI patients and healthy controls. In addition, the neural response during the attention and memory phases will be compared to brain atrophy and cognitive performance. The goal of Aim 1 is to characterize alterations in neural activity during an attention and memory paradigm and assess the relationship between functional and structural MRI in MCI patients. The goal of Aim 2 is to measure the association between traditional neuropsychological tests of attention and memory and functional brain activation. The long-term objectives of this research are to investigate fluctuations in underlying neural networks of attention and memory in a large-scale, longitudinal study of MCI and healthy controls. In future research, we would collect multiple time points of fMRI and cognitive data and investigate changes in the underlying BOLD signal as cognition declines, improves, or remains stable. This will improve our understanding of the relationship between the BOLD signal and cognition. Ultimately, this will allow us to determine the utility of early neural fluctuations as a biomarker of those with or at risk for cognitive decline.
Although there are great advances being made on understanding AD and other dementias, there are still no effective methods available for early diagnosis. The identification of MCI patients who are likely to suffer from further cognitive decline is a critical, public health issue, but no effective biomarkers have yet been identified. Functional MRI is a promising new method for in vivo investigation of early neural changes in those with or at risk for cognitive decline.
