Reward facilitates tactile judgments and modulates hemodynamic responses in human primary somatosensory cortex

Effects of reward on action are well established, but possible effects on sensory function are less well explored. Here we assessed whether reward can influence somatosensory judgments and modulate activity in human somatosensory cortex, as assessed with functional Magnetic Resonance Imaging (fMRI). Participants discriminated electrical somatosensory stimuli on an index finger with correct performance being rewarded financially at trial end, at one of four different anticipated levels. Higher rewards improved tactile performance and led to increased hemodynamic signals from ventral striatum on rewarded trials. R…