Press releases
Please quote Nature Physics as the source of these items.
The April 2006 issue of Nature Physics is available online.
April 2006
The physics behind our sensitive senses
An explanation of how our senses can process physical stimuli that vary over extremely wide ranges is reported by Osame Kinouchi and Mauro Copelli in the May issue of Nature Physics. The study could advance our understanding of how sensory systems can handle environmental signals whose intensities vary, for example, from the sound of a pin drop to that of a bomb blast, or from the subtle smell of the skin to the intense scent of a heavy perfume.
Surprisingly, the unit cells making up our sensory systems can only cope with inputs from a rather small range. This raises the question of how a network of identical elements can be sensitive to a much larger span of signals than its constituent units. Kinouchi and Copelli propose that the answer lies in the dynamics emerging from the interaction of the coupled elements. Using network theory – a branch of statistical physics – the authors show that an appropriately setup network of 'excitable elements' can be both extremely sensitive to small perturbations, and still able to detect large inputs without saturation.
These findings suggest a clear physical basis for the laws of psychophysics, the field concerned with how our perceptions relate to physical stimuli.
Optimal dynamical range of excitable networks at criticalitypp 348 - 351
Osame Kinouchi and Mauro Copelli
Published online: 23 April 2006 | doi 10.1038/nphys289
