Theory 22/Population coding/High-density electrophysiology
Codes Are Distributed
The claim
The information a population carries about a stimulus is set by the ratio of correlated to independent noise, so adding neurons helps only while their noise remains partly independent.
01Mechanism
Correlated noise limits how much averaging can improve the estimate; the ratio sets the ceiling.
02Prediction
Decoding should saturate as noise correlation rises.
03Refutation
Decoding improving indefinitely with neuron count would remove the correlation limit.
04What makes it checkable
High-density probes now record thousands of neurons simultaneously, allowing noise correlations to be estimated rather than assumed.
05Why it was not testable before
Hundreds of simultaneous neurons were the practical ceiling a decade ago.