eprintid: 10104412
rev_number: 8
eprint_status: archive
userid: 695
dir: disk0/10/10/44/12
datestamp: 2020-07-08 13:01:52
lastmod: 2020-07-08 13:01:52
status_changed: 2020-07-08 13:01:52
type: thesis
metadata_visibility: show
creators_name: Harwood, Mark Richard
title: The Fourier analysis of saccadic eye movements
ispublished: unpub
keywords: Health and environmental sciences; Saccadic eye movements
note: Thesis digitised by ProQuest.
abstract: This thesis examines saccadic eye movements in the frequency domain and develops sensitive tools for characterising their dynamics. It tests a variety of saccade models and provides the first strong empirical evidence that saccades are time-optimal. By enabling inferences on the neural command, it also allows for better clinical differentiation of abnormalities and the evaluation of putative mechanisms for the development of congenital nystagmus. Chapters 3 and 4 show how Fourier transforms reveal sharp minima in saccade frequency spectra, which are robust to instrument noise. The minima allow models based purely on the output trajectory, purely on the neural input, or both, to be directly compared and distinguished. The standard, most commonly accepted model based on bang-bang control theory is discounted. Chapter 5 provides the first empirical evidence that saccades are time-optimal by demonstrating that saccade bandwidths overlap across amplitude onto a single slope at high frequencies. In Chapter 6, the overlap also allows optimal (Wiener) filtering in the frequency domain without a priori assumptions. Deconvolution of the aggregate neural driving signal is then possible for current models of the oculomotor plant. The final two chapters apply these Fourier techniques to the quick phases of physiological (optokinetic) nystagmus and of pathological (congenital) nystagmus. These quick phases are commonly assumed to be saccadic in origin. This assumption is thoroughly tested and found to hold, but with subtle differences implying that the smooth pursuit system interacts with the saccade system during the movement. This interaction is taken into account in Chapter 8 in the assessment of congenital nystagmus quick phases, which are found to be essentially normal. Congenital nystagmus models based on saccadic abnormalities are appraised.
date: 2003
oa_status: green
full_text_type: other
thesis_class: doctoral_open
thesis_award: Ph.D
language: eng
thesis_view: UCL_Thesis
primo: open
primo_central: open_green
verified: verified_manual
full_text_status: public
pages: 301
institution: UCL (University College London)
thesis_type: Doctoral
citation:        Harwood, Mark Richard;      (2003)    The Fourier analysis of saccadic eye movements.                   Doctoral thesis  (Ph.D), UCL (University College London).     Green open access   
 
document_url: https://discovery-pp.ucl.ac.uk/id/eprint/10104412/1/The_Fourier_analysis_of_saccad.pdf