Noise in neurons is message dependent

CECCHI, GUILLERMO A.; SIGMAN, MARIANO; ALONSO, JOSÉ-MANUEL; MARTÍNEZ, LUIS; CHIALVO, DANTE R.; MAGNASCO, MARCELO O.

PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA

NATL ACAD SCIENCES

Año: 2000 vol. 97 p. 5557 - 5561

0027-8424

Neuronal responses are conspicuously variable. We focus on one particular aspect of that variability: the precision of action potential timing. We show that for common models of noisy spike generation, elementary considerations imply that such variability is a function of the input, and can be made arbitrarily large or small by a suitable choice of inputs. Our considerations are expected to extend to virtually any mechanism of spike generation, and we illustrate them with data from the visual pathway. Thus, a simplification usually made in the application of information theory to neural processing is violated: noise is not independent of the message. However, we also show the existence of error-correcting topologies, which can achieve better timing reliability than their components.