Abstract: A brain-wave analysis method for analyzing a brain wave by extracting a power spectrum of the brain wave from detected brain-wave biological signals, detecting the presence or absence of peaks formed in the frequency band of each brain-wave rhythm in the power spectrum, and analyzing the brain wave based on the presence or absence of the peak spectrum; and brain-wave analysis apparatus for realizing the aforementioned method comprising a brain-wave extracting device for extracting a power spectrum with respect to a brain wave from detected brain-wave biological signals, and a peak detecting device for detecting the presence or absence of spectrum peaks formed in each brain-wave rhythm frequency band in the brain-wave power spectrum extracted by the brain-wave extracting device.

Abstract: A mental-concentration measuring method for measuring the degree of mental concentration of a subject by extracting a power spectrum with respect to a brain wave from detected brain-wave biological signals, obtaining an integrated value of the power spectrum and an integrated value of a rhythm spectrum representing mental concentration power, and measuring the mental concentration of the subject based on the ratio of these integrated values, and mental-concentration measuring apparatus as apparatus for realizing the above method comprising a brain-wave extracting device for extracting a power spectrum of a brain wave, a brain-wave spectrum integrating device for integrating the brain-wave power spectrum extracted by the brain-wave extracting device, an .alpha.-rhythm spectrum integrating device for integrating an .alpha.-rhythm spectrum representing mental concentration power, and a mental-concentration calculating device for calculating the ratio of the integrated value obtained with the .alpha.