Using electrical noise to enhance the ability of humans to detect subthreshold mechanical cutaneous stimuli

Abstract

Stochastic resonance (SR) is a phenomenon wherein the response of a nonlinear system to a weak input signal is optimized by the presence of a particular, nonzero level of noise. Our objective was to demonstrate cross-modality SR in human sensory perception. Specifically, we were interested in testing the hypothesis that the ability of an individual to detect a subthreshold mechanical cutaneous stimulus can be significantly enhanced by introducing a particular level of electrical noise. Psychophysical experiments were performed on 11 healthy subjects. The protocol consisted of the presentation of: (a) a subthreshold mechanical stimulus plus electrical noise, or (b) no mechanical stimulus plus electrical noise. The intensity of the electrical noise was varied between trials. Each subject's ability to identify correctly the presence of the mechanical stimulus was determined as a function of the noise intensity. In 9 of the 11 subjects, the introduction of a particular level of electrical noise significantly enhanced the subject's ability to detect the subthreshold mechanical cutaneous stimulus. In 2 of the 11 subjects, the introduction of electrical noise did not significantly change the subject's ability to detect the mechanical stimulus. These findings indicate that input electrical noise can serve as a negative masker for subthreshold mechanical tactile stimuli, i.e., electrical noise can increase the detectability of weak mechanical signals. Thus, for SR-type effects to be observed in human sensory perception, the noise and stimulus need not be of the same modality. From a bioengineering and clinical standpoint, this work suggests that an electrical noise-based technique could be used to improve tactile sensation in humans when the mechanical stimulus is around or below threshold. (c) 1998 American Institute of Physics.

Auditory white noise reduces postural fluctuations even in the absence of vision

“…The mechanism was then studied in biological systems because of the prevalence of noise, weak signals, and action potential firing thresholds. It has been demonstrated in nonhuman (Douglass et al 1993;Levin and Miller 1996;Russell et al 1999;Bezrukov and Vodyanoy 1995;Schmid et al 2001;Jung and Shuai 2001) and human (Hidaka et al 2000;Collins et al 1996;Richardson et al 1998;Simonotto et al 1997) nervous systems. These studies show that sensory perception in a number of species utilizes noise to optimize performance.…”

The Sixth Sense-Emotional Contagion; Review of Biophysical Mechanisms Influencing Information Transfer in Groups

“…Significantly, even these picotesla level fluctuations did appear to be detectable by the body [181], however the degree of perceptibility of information transfer via environmental fields appears to be subject to large fluctuations linked to a large number of internal and external emergent phenomena which may amplify or degrade signals unpredictably. Individual characteristics of internal processes adds additional variables in attempting to decode the changes in the outside world [182] [183].…”

Fluctuations in Neuronal Synchronization in Brain Activity Correlate with the Subjective Experience of Visual Recognition

“…This concept can be extended to what can be termed psychophysical stochastic resonance (PSR), when there is improved sensory discrimination for certain noise levels [5]. For example, noise-enhanced sensorimotor discrimination in human subjects has been shown in several modalities [3,[6][7][8][9][10][11]; indications of stochastic resonance in the mammalian nervous system have been obtained using other preparations [12,13]. It should be noted that it is one thing to determine stochastic resonance occurring in the brain and another to study how the brain (perception) responds to stimuli constructed according to the principles of SR.…”