Knowledge of cerebral blood flow change for development of Brain-Computer Interface during the silent reading

Abstract

Brain-Computer Interface (BCI) is an interface by which the human can directly operate the machinery using brain activity signals measured noninvasively. In this study, a BCI is developed based on the brain bloodstream change measured by Near-Infrared Spectroscopy (NIRS). So far we have processed the brain bloodstream changes during silent reading by the distance-type fuzzy reasoning method to get the BCI control signals. However, the fuzzy rules could not completely reflect the features of NIRS signals, which reduced the recognition ratio. Therefore, we analyze the signal characteristics of cerebral blood flow during silent reading in order to obtain more proper fuzzy rules. We measure the cerebral blood flow changes on both sides of the prefrontal cortex during silent reading task 4 times a week for 4 weeks and extract the peculiar cerebral blood flow change patterns as knowledge for reasoning.