Kang, Jing, Ph.D. (2009) Discrimination and control in stochastic neuron models. PhD thesis, University of Warwick.

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Abstract

Major topics of great interest in neuroscience involve understanding the
brain function in stimuli coding, perceptive discrimination, and movement
control through neuronal activities. Many researchers are designing biophysical
and psychological experiments to study the activities of neurons in the
presence of various stimuli. People have also been trying to link the neural responses
to human perceptual and behavioral level. In addition, mathematical
models and neural networks have been developed to investigate how neurons
respond and communicate with each other.
In this thesis, my aim is to understand how the central nervous system performs
discrimination tasks and achieves precise control of movement, using
noisy neural signals. I have studied, both through experimental and modelling
approaches, how neurons respond to external stimuli. I worked in three aspects
in details. The first is the neuronal coding mechanism of input stimuli
with different temporal frequencies. Intracellular recordings of single neurons
were performed with patch-clamp techniques to study the neural activities
in rats somatosensory cortices in vitro, and the simplest possible neural model—integrate-and-fire model—was used to simulate the observations.
The results obtained from the simulation were very consistent with that in the
experiments. Another focus of this work is the link between the psychophysical
response and its simultaneous neural discharges. I derived that under a
widely accepted psychophysical law (Weber’s law), the neural activities were
less variable than a Poisson process (which is often used to describe the neuron
spiking process). My work shows how psychophysical behaviour reflects
intrinsic neural activities quantitatively. Finally, the focus is on the control
of movements by neural signals. A generalized approach to solve optimal
movement control problems is proposed in my work, where pulses are used
as neural signals to achieve a precise control. The simulation results clearly
illustrate the advantage of this generalized control.
In this thesis, I have raised novel, insightful yet simple approaches to study
and explain the underlying mechanism behind the complexity of neural system,
from three examples on sensory discrimination and neural movement
control.

Item Type:	Thesis or Dissertation (PhD)
Subjects:	R Medicine > RC Internal medicine > RC0321 Neuroscience. Biological psychiatry. Neuropsychiatry Q Science > QL Zoology
Library of Congress Subject Headings (LCSH):	Rats -- Physiology -- Research, Neurons -- Physiology, Evoked potentials (Electrophysiology), Poisson processes
Official Date:	July 2009
Dates:	Date Event July 2009 Submitted
Institution:	University of Warwick
Theses Department:	Molecular Organisation and Assembly in Cells
Thesis Type:	PhD
Publication Status:	Unpublished
Supervisor(s)/Advisor:	Robinson, Hugh P. C. ; Feng, Jianfeng
Sponsors:	University of Warwick (UoW)
Format of File:	pdf
Extent:	200 leaves : ill., charts
Language:	eng

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