Retinal receptive fields: balancing information transmission and metabolic cost B Vincent1, R Baddeley2 |
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1School of Psychology, University of Dundee, United Kingdom |
| The spatio-chromatic receptive field properties of retinal ganglion cells are well characterised, but why are they this way? Due to the high level of spatial and chromatic correlations between cone responses, direct transmission of their outputs would be an inefficient use of limited optic nerve bandwidth. It has been known for some time that luminance, blue/yellow- and red/green-opponent channels are effective at reducing this inefficiency, but this only accounts for chromatic (not spatial) aspects of retinal receptive fields. We applied statistical compression methods to a large dataset of human cone-calibrated images from a Kibali rainforest. We show that the chromatic and spatial coding can be understood as maximising information transmission while minimising metabolic costs incurred. We find i) large metabolic savings can be made for little loss of performance; ii) there is a point of optimal efficiency; and iii) at this optima, the system self organises into three spatio-chromatic opponent channels with properties closely matching those observed experimentally. In summary, the major retinal receptive field properties can be understood as being matched to the statistics of the natural environment, but only when the metabolic expenditure and information transmission are considered in conjunction. |
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