%0 Journal Article %T Understanding the Pathophysiology of Alzheimer's Disease and Mild Cognitive Impairment: A Mini Review on fMRI and ERP Studies %A Takao Yamasaki %A Hiroyuki Muranaka %A Yumiko Kaseda %A Yasuyo Mimori %A Shozo Tobimatsu %J Neurology Research International %D 2012 %I Hindawi Publishing Corporation %R 10.1155/2012/719056 %X The prevalence of Alzheimer's disease (AD) is predicted to increase rapidly in the coming decade, highlighting the importance of early detection and intervention in patients with AD and mild cognitive impairment (MCI). Recently, remarkable advances have been made in the application of neuroimaging techniques in investigations of AD and MCI. Among the various neuroimaging techniques, functional magnetic resonance imaging (fMRI) has many potential advantages, noninvasively detecting alterations in brain function that may be present very early in the course of AD and MCI. In this paper, we first review task-related and resting-state fMRI studies on AD and MCI. We then present our recent fMRI studies with additional event-related potential (ERP) experiments during a motion perception task in MCI. Our results indicate that fMRI, especially when combined with ERP recording, can be useful for detecting spatiotemporal functional changes in AD and MCI patients. 1. Introduction Dementia is one of the most serious conditions associated with longevity, and represents a pressing public health problem. Alzheimer¡¯s disease (AD) is the most common form of dementia, affecting millions of people around the world. AD is a progressive neurodegenerative disorder, resulting in a gradual, irreversible loss of memory and cognitive function [1]. Recently recognized as the prodromal stage of AD, mild cognitive impairment (MCI) represents a transitional period between normal aging and AD [2, 3]. MCI pathology can reveal the early stages of AD, including neuritic plaques, neurofibrillary tangles, and loss of basal forebrain cholinergic neurons [4]. As a subtype of MCI, amnestic MCI constitutes a syndrome presenting with cognitive decline that is more pronounced than expected for the individual¡¯s age and educational level, but does not fulfill the criteria for AD. Patients with amnestic MCI have a high risk of AD progression, with a 10¨C15% yearly transition rate [5]. In addition, large numbers of novel compounds, which have the potential to modify the course of AD and slow its progression, are currently under development. However, there is currently no cure for the disease. For this reason, there is an urgent need for biomarkers to detect MCI. In the past two decades, several functional imaging techniques have been used to investigate changes in brain function in patients with AD and MCI. Functional magnetic resonance imaging (fMRI), positron emission tomography (PET) and single-photon emission computed tomography (SPECT) are effective methods. Among these techniques, fMRI has a %U http://www.hindawi.com/journals/nri/2012/719056/