This thesis presents a series of human psychophysical experiments designed to
examine the interaction between the reliability of spatial form information and the
neural mechanisms responsible for the processing of sub-second durations. Duration
discrimination sensitivity was found to be lower when event durations were defined
by stimulus characteristics that caused reductions in spatial form sensitivity. This
form-duration sensitivity coupling persisted across stimuli defined both by crossed
and uncrossed retinal disparity and within monocularly visible texture-defined stimuli.
The interaction was also observed when spatial form was degraded by physical
instability within shape borders, and when physically stable borders became
perceptually unstable. These effects could not be attributed to artefacts of stimulus
visibility, temporal coherence or stimulus size. Adaptation experiments generated aftereffects of perceived duration within stimuli whose durations were defined solely
by retinal disparity, providing the first demonstration of duration selectivity within
exclusively cortical duration encoding mechanisms. The selectivity of these
aftereffects was then investigated using adapting and testing durations defined by
matching or opposing retinal disparities. Duration aftereffects were maximal when
adapt and test disparities were matched. However, there was partial transfer of
duration aftereffects across large changes in retinal disparity, implicating contributions
from higher-level extra-striate mechanisms. Collectively, these experiments provide
support for duration processing mechanisms that are inextricably linked to the
mechanisms underpinning spatial processing across multiple levels of the visuo-spatial hierarchy.
| Identifer | oai:union.ndltd.org:BRADFORD/oai:bradscholars.brad.ac.uk:10454/19063 |
| Date | January 2020 |
| Creators | Collins, Howard P. |
| Contributors | Heron, James |
| Publisher | University of Bradford, Department of Optometry and Vision Science, Faculty of Life Sciences |
| Source Sets | Bradford Scholars |
| Language | English |
| Detected Language | English |
| Type | Thesis, doctoral, PhD |
| Rights | <a rel="license" href="http://creativecommons.org/licenses/by-nc-nd/3.0/"><img alt="Creative Commons License" style="border-width:0" src="http://i.creativecommons.org/l/by-nc-nd/3.0/88x31.png" /></a><br />The University of Bradford theses are licenced under a <a rel="license" href="http://creativecommons.org/licenses/by-nc-nd/3.0/">Creative Commons Licence</a>. |
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