 |
||
Coding of natural visual stimuli in the thalamus: What exactly is optimized? |
||
Pamela Reinagel |
||
|
||
Given the task of representing natural stimuli, some coding strategies can be shown to be "better" than others by various different criteria. If efficiency of information transfer has been an important constraint in the evolution of sensory neurons, we should be able to see evidence of this in the structure of neural codes. In the mammalian visual system, there is an information transmission channel between the retina and the visual cortex, passing through a relay in the thalamus, the Lateral Geniculate Nucleus (LGN). At the level of this relay, the neural code is optimized for natural scenes in at least one respect: natural scenes are represented with less redundancy than matched artificial stimuli. Other things being equal, less redundancy is better because redundancy limits the total amount of information that can be carried over a channel. However it does not follow that the LGN actually encodes more information about natural scenes, and I will present and discuss experiments showing that the opposite is true. |
||