Joseph K. Jun

Learn More
We examined neural spike recordings from prefrontal cortex (PFC) while monkeys performed a delayed somatosensory discrimination task. In general, PFC neurons displayed great heterogeneity in response to the task. That is, although individual cells spiked reliably in response to task variables from trial-to-trial, each cell had idiosyncratic combinations of(More)
Temporally precise sequences of neuronal spikes that span hundreds of milliseconds are observed in many brain areas, including songbird premotor nucleus, cat visual cortex, and primary motor cortex. Synfire chains-networks in which groups of neurons are connected via excitatory synapses into a unidirectional chain-are thought to underlie the generation of(More)
We present findings in an experiment where we obtain stationary ramified transportation networks in a macroscopic nonbiological system. Our purpose here is to introduce the phenomenology of the experiment. We describe the dynamical formation of the network which consists of three growth stages: (I) strand formation, (II) boundary formation, and (III)(More)
The aggregation of individuals into colonies raises important questions about scaling of structure and function. We model the metabolic benefits and costs of two-dimensional, fractallike foraging trails, such as those used by ant colonies. Total area foraged by the colony and, consequently, resource flow to the nest and rate of colony metabolism, increase(More)
The primary mode of information transmission in neural networks is unknown: is it a rate code or a timing code? Assuming that presynaptic spike trains are stochastic and a rate code is used, probabilistic models of spiking can reveal properties of the neural computation performed at the level of single neurons. Here we show that depending on the(More)
We study the dynamical self–organization of conducting particles into ramified tree networks when subjected to strong electric fields. We find that for a general class of initial configurations of particles that the trees grow in three stages: (I) strand formation , (II) boundary connection, and (III) geometric expansion. We show that graph theoretical(More)
  • 1