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Coding efficiency of fly motion processing is set by firing rate, not firing precision.

Spavieri DL, Eichner H, Borst A - PLoS Comput. Biol. (2010)

Bottom Line: Although these two environmental variables have a considerable impact on the fly's nervous system, they do not impede the fly to behave suitably over a wide range of conditions.We found that the mean firing rate, but not firing precision, changes with temperature, while both were affected by mean luminance.Because we also found that information rate and coding efficiency are mainly set by the mean firing rate, our results suggest that, in the face of environmental perturbations, the coding efficiency is improved by an increase in the mean firing rate, rather than by an increased firing precision.

View Article: PubMed Central - PubMed

Affiliation: Department of System and Computational Neurobiology, Max-Planck-Institute of Neurobiology, Martinsried, Germany.

ABSTRACT
To comprehend the principles underlying sensory information processing, it is important to understand how the nervous system deals with various sources of perturbation. Here, we analyze how the representation of motion information in the fly's nervous system changes with temperature and luminance. Although these two environmental variables have a considerable impact on the fly's nervous system, they do not impede the fly to behave suitably over a wide range of conditions. We recorded responses from a motion-sensitive neuron, the H1-cell, to a time-varying stimulus at many different combinations of temperature and luminance. We found that the mean firing rate, but not firing precision, changes with temperature, while both were affected by mean luminance. Because we also found that information rate and coding efficiency are mainly set by the mean firing rate, our results suggest that, in the face of environmental perturbations, the coding efficiency is improved by an increase in the mean firing rate, rather than by an increased firing precision.

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Overview of the results.The mean coefficient of temperature (Q) for luminances up to 1 cd m are represented by black squares, and for luminances above 1 cd m, by gray squares. The shaded region correspond to coefficient of 1. Coefficients smaller than 1 were inverted, for sake of comparison. Similarly, the blue squares represent the mean amplitudes of the coefficient of luminance (K) for temperatures up to 22C, whereas red squares represent the mean amplitudes for higher temperatures.
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pcbi-1000860-g005: Overview of the results.The mean coefficient of temperature (Q) for luminances up to 1 cd m are represented by black squares, and for luminances above 1 cd m, by gray squares. The shaded region correspond to coefficient of 1. Coefficients smaller than 1 were inverted, for sake of comparison. Similarly, the blue squares represent the mean amplitudes of the coefficient of luminance (K) for temperatures up to 22C, whereas red squares represent the mean amplitudes for higher temperatures.

Mentions: In summary, the various response parameters can be grouped into three different classes according to whether or not they are affected by temperature and/or luminance (Fig. 5). The firing rate and the information rate are influenced by both temperature and luminance. The encoding window and the coding efficiency are barely affected by temperature and by luminance. Finally, the latency and spike jitter are mainly affected by luminance, but only weakly if at all by temperature.


Coding efficiency of fly motion processing is set by firing rate, not firing precision.

Spavieri DL, Eichner H, Borst A - PLoS Comput. Biol. (2010)

Overview of the results.The mean coefficient of temperature (Q) for luminances up to 1 cd m are represented by black squares, and for luminances above 1 cd m, by gray squares. The shaded region correspond to coefficient of 1. Coefficients smaller than 1 were inverted, for sake of comparison. Similarly, the blue squares represent the mean amplitudes of the coefficient of luminance (K) for temperatures up to 22C, whereas red squares represent the mean amplitudes for higher temperatures.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC2908696&req=5

pcbi-1000860-g005: Overview of the results.The mean coefficient of temperature (Q) for luminances up to 1 cd m are represented by black squares, and for luminances above 1 cd m, by gray squares. The shaded region correspond to coefficient of 1. Coefficients smaller than 1 were inverted, for sake of comparison. Similarly, the blue squares represent the mean amplitudes of the coefficient of luminance (K) for temperatures up to 22C, whereas red squares represent the mean amplitudes for higher temperatures.
Mentions: In summary, the various response parameters can be grouped into three different classes according to whether or not they are affected by temperature and/or luminance (Fig. 5). The firing rate and the information rate are influenced by both temperature and luminance. The encoding window and the coding efficiency are barely affected by temperature and by luminance. Finally, the latency and spike jitter are mainly affected by luminance, but only weakly if at all by temperature.

Bottom Line: Although these two environmental variables have a considerable impact on the fly's nervous system, they do not impede the fly to behave suitably over a wide range of conditions.We found that the mean firing rate, but not firing precision, changes with temperature, while both were affected by mean luminance.Because we also found that information rate and coding efficiency are mainly set by the mean firing rate, our results suggest that, in the face of environmental perturbations, the coding efficiency is improved by an increase in the mean firing rate, rather than by an increased firing precision.

View Article: PubMed Central - PubMed

Affiliation: Department of System and Computational Neurobiology, Max-Planck-Institute of Neurobiology, Martinsried, Germany.

ABSTRACT
To comprehend the principles underlying sensory information processing, it is important to understand how the nervous system deals with various sources of perturbation. Here, we analyze how the representation of motion information in the fly's nervous system changes with temperature and luminance. Although these two environmental variables have a considerable impact on the fly's nervous system, they do not impede the fly to behave suitably over a wide range of conditions. We recorded responses from a motion-sensitive neuron, the H1-cell, to a time-varying stimulus at many different combinations of temperature and luminance. We found that the mean firing rate, but not firing precision, changes with temperature, while both were affected by mean luminance. Because we also found that information rate and coding efficiency are mainly set by the mean firing rate, our results suggest that, in the face of environmental perturbations, the coding efficiency is improved by an increase in the mean firing rate, rather than by an increased firing precision.

Show MeSH