Unsupervised Learning of Temporal Features for Word Categorization in a Spiking Neural Network Model of the Auditory Brain. The nature of the code used in the auditory cortex to represent complex auditory stimuli, such as naturally spoken words, remains a matter of debate. Here we argue that such representations are encoded by stable spatio-temporal patterns of firing within cell assemblies known as polychronous groups, or PGs. We develop a physiologically grounded, unsupervised spiking neura...

Auditory Nerve Stochasticity Impedes Category Learning: the Role of Cochlear Nucleus and Inferior Colliculus in Stabilising Auditory Nerve Firing. It is well known that auditory nerve (AN) fibers overcome bandwidth limitations through the "volley principle", a form of multiplexing. What is less well known is that the volley principle introduces a degree of unpredictability into AN neural firing patterns which makes even simple stimulus categorization tasks difficult. We use a physiologically ...