Figure 1. Brain regional activities during chewing. (A) The task paradigm used. (B,C) Significant signal increases associated with the chewing of X (B) and G (C) types of gum by individual subjects. Upper section: Activated areas superimposed on a template. Lower section: Activated regions superimposed on a T₁-weighted MRI. Abbreviations: smc, primary sensorimotor cortex; sma, supplementary motor area; i, insula; t, thalamus; c, cerebellum. Color scale: t value. (D) Changes in signal intensity on an image-by-image basis for 64 successive images during 4 cycles of chewing and no chewing. The task paradigm is represented in the insets with the periods of chewing and no chewing indicated. The vertical axis shows the signal intensity in arbitrary units. White circles: X-type gum. Red circles: G-type gum.