Noise-mediated enhancements and decrements in human tactile sensation

Recently, it has been shown that noise can enhance the detection and transmission of weak signals in certain nonlinear systems. Here we demonstrate noise-mediated improvements in human sensory perception. We show that the ability of an individual to detect a subthreshold tactile stimulus can be significantly enhanced by introducing a particular level of noise. We demonstrate that this effect is robust over time. We also show that the ability of an individual to detect a suprathreshold tactile stimulus can be degraded by the presence of noise. These findings indicate that noise can serve as a ‘‘negative masker’’ for the perception of weak stimuli and a ‘‘positive masker’’ for the perception of strong stimuli. We discuss the possibility of developing a noise-based technique for improving tactile sensation in humans. @S1063-651X~97!11507-0#