Two types of information processing devices includes circuitry to display, on a display device, a position representation area indicating a position of each of a group of sensors that detects biomedical signals of a test subject, display on the display device a selection acceptance area accepting selection of a plurality of positions of a plurality of desired sensors, the plurality of positions being selected from the group of sensors using an operating unit, and display on the display device a waveform display area displaying a waveform output from the plurality of desired sensors corresponding to the plurality of selected positions. In the first type of information processing device, single-region data indicating a region including the plurality of selected positions is displayed in the position representation area. In the second type of information processing device, the plurality of selected positions are enlarged and displayed in the position representation area.