Spatial Analysis of Magnetoencephalographic Activities in Relation to Subjective Preference for a Sound Field
Yoshiharu Soeta, Seiji Nakagawa, Mitsuo Tonoike and Yoichi Ando
The relationship between human brain response and subjective preference for a sound field was investigated. The source signal was the word gpianoh, which had a 0.35-s duration. The delay time of reflection in reference to the direct sound, Dt1, was varied. The scale value of the subjective preference of each subject was obtained by paired-comparison tests. In MEG measurements, combinations of a reference stimulus (Dt1 = 0 ms) and test stimuli (Dt1 = 0, 5, 20, 60, and 100 ms) were presented 50 times alternately at a constant 1-s interstimulus interval. The magnetic responses were recorded with a 122-channel whole-head neuromagnetometer and analyzed using a cross-correlation function (CCF). The results showed that the maximum amplitude of the CCF, |f(t)|max, between MEG between 8-13 Hz recorded at two different channels becomes larger during presentations of the preferred condition. The results indicated that the brain repeats a similar temporal rhythm over a wider area under preferred sound fields.
Key words: cross-correlation function (CCF), magnetoencephalography (MEG), subjective preference