We examine the distributed nature of the neural code for faces represented by the firing of visual neurons in the superior temporal sulcus of monkeys. Both information theory and neural decoding techniques are applied to determine how the capacity to represent faces depends on the number of coding neurons. Using a combination of experimental data and Monte Carlo simulations, we show that the in...

Before examining neural interspike intervals to see how they might encode information, an essential question that has first to be answered is whether, under the unstimulated condition, the apparent randomness of the neural firing paltern renects deterministic chaos or a stochastic process. Here, we use short term predictability and the structure of the prediction residual to determine the dynam...

Neurons communicate primarily with spikes, but most theories of neural computation are based on firing rates. Yet, many experimental observations suggest that the temporal coordination of spikes plays a role in sensory processing. Among potential spike-based codes, synchrony appears as a good candidate because neural firing and plasticity are sensitive to fine input correlations. However, it is...

Circulating glucose levels significantly affect vagal neural activity, which is important in the regulation of pancreatic functions. Little is known about the mechanisms involved. This study investigates the neural pathways responsible for hypoglycemia-induced vagal efferent signaling to the pancreas and identifies the neurotransmitters involved. Vagal pancreatic efferent nerve activities were ...

Lee, Albert K. and Matthew A. Wilson. A combinatorial method for analyzing sequential firing patterns involving an arbitrary number of neurons based on relative time order. J Neurophysiol 92: 2555–2573, 2004. First published June 22, 2004; 10.1152/jn.01030.2003. Information processing in the brain is believed to require coordinated activity across many neurons. With the recent development of te...

In vivo cortical neurons exhibit highly irregular spike sequences. However, the computational implications of this irregular firing with respect to neural codings are not yet fully understood. Recently, we formulated neuronal firing as a stochastic process to translate the firing rate determined by synaptic input into an irregular sequence of inter-spike intervals (ISIs). We previously determin...

Neural field equations model population dynamics of large-scale networks of neurons. Wave propagation in neural fields is often studied by constructing traveling wave solutions in the wave coordinate frame. Nonequilibrium dynamics are more challenging to study, due to the nonlinearity and nonlocality of neural fields, whose interactions are described by the kernel of an integral term. Here, we ...

A brief review of oscillatory activity in neurons and networks is given. Conditions required for neural oscillations are provided. Three mathematical methods for studying the coupling between neural oscillators are described: (i) weak coupling, (ii) firing time maps, and (iii) leaky integrate-and-fire methods. Several applications from macroscopic motor behavior to slice phenomena are provided.

fMRI does not measure neural activity directly. Instead, it measures small and variable changes in the ratio of oxygenated to deoxygenated blood in the brain when a particular task is performed or stimulus presented—the so-called BOLD, or blood oxygen level-dependent, response. Firing neurons, like working muscles, require oxygen; follow the trail of oxygenated hemoglobin, and you find neural a...

The general objectives of our research, presented in this series of papers, were to develop a computational model of the brain stem respiratory neural network and to explore possible neural mechanisms that provide the genesis of respiratory oscillations and the specific firing patterns of respiratory neurons. The present paper describes models of single respiratory neurons that have been used a...