Fig. 2.

Other applications of INS in central nervous system. (a) to (c) Functional tract tracing tool. (a) View of somatosensory cortex (areas 3a, 3b, 1, and 2) seen through magnetic resonance imaging (MRI)-compatible optical chamber in squirrel monkey. Dots: locations of significant blood-oxygen-level dependent (BOLD) signal obtained in response to INS stimulation at yellow dot. (b) Structure MRI with tangential (red) and sagittal (green) slices indicated. (c) Sagittal slice with locations of significant BOLD activations in response to INS stimulation in area 1 (yellow dot). Activations are confined to specific cortical laminae. (d) to (f) Induction of behavioral effect. (d) Visuotopic mapping of V4 in macaque monkey (cf. Ref. 23). White dotted lines: isoeccentricities. Black solid lines: isopolarities. Yellow dot: INS fiber optic location. (e) Fiber optic applied to visual cortex. (f) INS at specific cortical site leads to eye movements to visuotopic location represented at that site.