Efficient coding hypothesis

The efficient coding hypothesis was proposed by Horace Barlow in 1961 as a theoretical model of sensory coding in the brain. The model treats the sensory pathway as a communications channel where neuronal spiking represents a code which maximizes channel capacity by minimizing the redundancy of the underlying code. The formal definition of channel capacity, redundancy, and information are based on information theory, which is the basis of the modern study of communications in electrical engineering.

A key prediction of the efficient coding hypothesis is that sensory processing in the brain should be adapted to natural stimuli. Neurons in the visual (auditory) system should be optimized for coding images (sounds) representative of those found in nature. Researchers have shown that filters optimized for coding natural images lead to filters which resemble the receptive fields of simple-cells in V1. In the auditory domain, optimizing a network for coding natural sounds lead to filters which resemble the impulse response of cochlear filters found in the inner ear.

References

• Barlow, H. (1961) 'Possible principles underlying the transformation of sensory messages' in Sensory Communication, MIT Press

• Lewicki, M.S. (2002) Efficient coding of natural sounds. Nature: Neuroscience, 5(4):356–363

• Olshausen, B. A. and Field, D.J. (1997) Sparse coding with an overcomplete basis set: A strategy employed by V1? Vision Research, 37(23):3311–3325