Mark Nelson

AAMAS Conference 2006 Conference Paper

Reinforcement Learning for Declarative Optimization-Based Drama Management

• Mark Nelson
• David Roberts
• Charles Isbell
• Michael Mateas

NeurIPS Conference 1992 Conference Paper

A Neural Model of Descending Gain Control in the Electrosensory System

• Mark Nelson

In the electrosensory system of weakly electric fish, descending pathways to a first-order sensory nucleus have been shown to influ(cid: 173) ence the gain of its output neurons. The underlying neural mecha(cid: 173) nisms that subserve this descending gain control capability are not yet fully understood. We suggest that one possible gain control mechanism could involve the regulation of total membrane conduc(cid: 173) tance of the output neurons. In this paper, a neural model based on this idea is used to demonstrate how activity levels on descend(cid: 173) ing pathways could control both the gain and baseline excitation of a target neuron.

NeurIPS Conference 1989 Conference Paper

Computational Efficiency: A Common Organizing Principle for Parallel Computer Maps and Brain Maps?

• Mark Nelson
• James Bower

It is well-known that neural responses in particular brain regions are spatially organized, but no general principles have been de(cid: 173) veloped that relate the structure of a brain map to the nature of the associated computation. On parallel computers, maps of a sort quite similar to brain maps arise when a computation is distributed across multiple processors. In this paper we will discuss the rela(cid: 173) tionship between maps and computations on these computers and suggest how similar considerations might also apply to maps in the brain.

NeurIPS Conference 1988 Conference Paper

Neural Control of Sensory Acquisition: The Vestibulo-Ocular Reflex

• Michael Paulin
• Mark Nelson
• James Bower

We present a new hypothesis that the cerebellum plays a key role in ac(cid: 173) tively controlling the acquisition of sensory infonnation by the nervous system. In this paper we explore this idea by examining the function of a simple cerebellar-related behavior, the vestibula-ocular reflex or VOR, in which eye movements are generated to minimize image slip on the retina during rapid head movements. Considering this system from the point of view of statistical estimation theory, our results sug(cid: 173) gest that the transfer function of the VOR, often regarded as a static or slowly modifiable feature of the system, should actually be continu(cid: 173) ously and rapidly changed during head movements. We further suggest that these changes are under the direct control of the cerebellar cortex and propose experiments to test this hypothesis.

NeurIPS Conference 1988 Conference Paper

Simulation and Measurement of the Electric Fields Generated by Weakly Electric Fish

• Brian Rasnow
• Christopher Assad
• Mark Nelson
• James Bower

The weakly electric fish, Gnathonemus peters; ;, explores its environment by gener(cid: 173) ating pulsed elecbic fields and detecting small pertwbations in the fields resulting from nearby objects. Accordingly, the fISh detects and discriminates objects on the basis of a sequence of elecbic "images" whose temporal and spatial properties depend on the tim(cid: 173) ing of the fish's electric organ discharge and its body position relative to objects in its en(cid: 173) vironmenl We are interested in investigating how these fish utilize timing and body-po(cid: 173) sition during exploration to aid in object discrimination. We have developed a fmite-ele(cid: 173) ment simulation of the fish's self-generated electric fields so as to reconstruct the elec(cid: 173) trosensory consequences of body position and electric organ discharge timing in the fish. This paper describes this finite-element simulation system and presents preliminary elec(cid: 173) tric field measurements which are being used to tune the simulation.