Evaluation of Cognitive Decline Using Electroencephalograph Beta/Alpha Ratio During Brain-Computer Interface Tasks

抄録

Japan is currently witnessing an increase in the number of individuals with dementia. According to a survey, there were 4.62 million people with dementia in Japan in 2012 and more than 7 million in 2025. The early detection of dementia is crucial to delay the progression of symptoms. As such, in our laboratory, we are developing a dementia screening tool using a character-input-type brain.computer interface (BCI). In this study, the spelling-type-BCI is used to analyze and verify electroencephalograph (EEG) data obtained in the frequency band. We aim to clarify how EEG characteristics differ between healthy subjects and those with mild cognitive impairment (MCI). As a result, we observed that a high possibility exists that there is a difference in the mean value of β/α and the generation rate of θ waves among healthy subjects, patients with MCI, and patients with Alzheimer's dementia. This difference can likely be attributed to our consideration of β/α as an index of the degree of concentration associated with cognitive decline and θ waves as the characteristics of the EEGs of patients with dementia. Based on these results, measuring β/α and θ waves could lead to the early detection and diagnosis of dementia.