Information processing in a neuron ensemble with the multiplicative correlation structure.

The present study investigates the performance of population codes when the fluctuations in neural activity have mutual correlation with strength being proportional to the neuronal firing rate (multiplicative noise). The neural field is used to calculate the Fisher information, which is decomposed in two parts, one due to the tuning function and spatial correlation, and the other due to the multiplicative structure. Their different characteristics are studied. The paper also investigates three types of maximum likelihood method, namely, decoding by using faithful and unfaithful models and the Center of Mass strategy, and compares their performances in terms of decoding accuracy and computational complexity.