We are developing screening tools for dementia using character input BCI (Brain-Computer Interface). In previous study, Spelling-Error Distance Value (SEDV) could be an index of the low attention with dementia in the limited MMSE average group. However, it was not statistically clear whether classification between normal group or MCI group and dementia group was possible. Therefore, we used FAB and MOCA-J to regroup the elderly with the initial cognitive decline level and to determine if early discrimination was possible. Furthermore, we compared the elderly people who were judged as NC or MCI or DLB or AD. As a result of comparing SEDV divided into two groups by the sub-item 10 points to examine the frontal lobe function of MOCA-J, a difference of 0.80 characters was found in SEDV. Furthermore, as a result of comparing SEDV in the NC group, MCI group, DLB group and AD group, there was a difference of SEDV 1.01 characters between MCI group and AD group. In addition, there was a difference of SEDV 0.79characters between NC group and AD group. Therefore, it was shown that NC group, MCI group and AD group can be distinguished by using SEDV.

Early diagnosis is important for the treatment of dementia, but people with dementia are often reluctant to see a doctor. In our laboratory, we are developing an inexpensive and easy screening tool for cognitive function using the P300-based Spelling Brain- Computer Interface (Spelling-BCI). By creating an attention-focused plot using discrimination scores and comparing the results, we hope to confirm the differences among patients with dementia and the value of screening for dementia. BCI estimates characters using discrimination scores calculated based on the P300 component for rows and columns. Therefore, we developed an attention-focused plot based on the score for each character. As a result, NC was displayed whiter and blacker as it became MCI/AD. NC was estimated to be 83.3%, MCI was estimated to be 63.0%, and AD was estimated to be 33.3% of the total number of characters. In addition, there was a tendency for AD to respond in addition to the rows and columns containing the target character. These results are thought to be due to a decrease in attention concentration caused by a decrease in cognitive function. Therefore, it was suggested that the difference among patients with dementia could be confirmed from the attention concentration plot, which is useful for dementia screening.