EEG signal in Delboeuf illusion by evaluation based on "same size" and "not same size

Abstract

Our study focus on relationship with optical illusion effect and EEG in human. In this paper, we record EEG signals during Delboeuf illusion task.In the experiment, we prepare a concentric circle (Delboeuf illusion stimulus) and a single circle (comparison stimulus). Subjects judge whether an inner circle of a concentric circle and a single circle is the same size. An order of one trial is shown as the followings. 1) A concentric circle is presented on the center of a computer display for 1.0[sec]. 2) A single circle is presented on the left side of the concentric circle for 0.5[sec]. 3) A blank screen is presented for 1.0[sec]. Subjects press a computer's key when subjects judge an inner circle of a concentric circle and a single circle is the same size.From results, we estimate positive potentials in 0.3[sec] after presenting concentric circle is related to effect of optical illusion.