Figure 1

Effects of sensory modality and stimulated side on perceived intensities and electrophysiological responses elicited by transient stimuli. Perceived intensities, N1 amplitudes, N2–P2 amplitudes, ‘ERP’ magnitudes, and ‘α-ERD’ magnitudes elicited by nociceptive somatosensory, non-nociceptive somatosensory, auditory, and visual stimuli delivered to the left (red color) and right (blue color) sides are displayed from (A–E). Error bars represent SD (standard deviation) across subjects. Each dot represents the data from a single subject. Perceived intensities and almost all brain responses (N2–P2 amplitude, ‘ERP’ magnitude, and ‘α-ERD’ magnitude) elicited by nociceptive somatosensory stimuli that were delivered to the left side were significantly larger than those to the right side. In contrast, for non-nociceptive somatosensory, auditory, and visual stimuli, perceived intensities and brain responses were not significantly different between the two sides.