Broadband neural encoding in the cricket cercal sensory system enhanced by stochastic resonance.
Sensory systems are often required to detect a small amplitude signal embedded in broadband background noise. Traditionally, ambient noise is regarded as detrimental to encoding accuracy. Recently, however, a phenomenon known as stochastic resonance has been described in which, for systems with a nonlinear threshold, increasing the input noise level can actually improve the output signal-to-noise ratio over a limited range of signal and noise strengths. Previous theoretical and experimental studies of stochastic resonance in physical and biological systems have dealt exclusively with single-frequency sine stimuli embedded in a broadband noise background. In the past year it has been shown in a theoretical and modelling study that stochastic resonance can be observed with broadband signals. Here we demonstrate that broadband stochastic resonance is manifest in the peripheral layers of neural processing in a simple sensory system, and that it plays a role over a wide range of biologically relevant stimulus parameters. Further, we quantify the functional significance of the phenomenon within the context of signal processing, using information theory.
Levin
J E
JE
Department of Molecular and Cell Biology, University of California, Berkeley, CA 94720, USA.
Miller
J P
JP
D000200:Action Potentials; D000388:Air; D000818:Animals; D006135:Gryllidae; D007395:Interneurons / Q000502:physiology*; D009431:Neural Conduction / Q000502:physiology*; D009475:Neurons, Afferent / Q000502:physiology*; D012684:Sensory Thresholds; D013269:Stochastic Processes