Current models of visual spatial attention are based on the extent to which attention can
be allocated in 2-dimensional displays. The distribution of attention in 3-dimensional
space has received little consideration. A series of experiments were devised to explore
the apparent inconsistencies in the literature pertaining to the allocation of spatial
attention in the third dimension. A review of the literature attributed these
inconsistencies to differences and limitations in the various methodologies employed, in
addition to the use of differing attentional paradigms. An initial aim of this thesis was
to develop a highly controlled novel adaptation of the conventional robust covert
orienting of visual attention task (COVAT) in depth defined by either binocular
(stereoscopic) or monocular cues. The results indicated that attentional selection in the
COVAT is not allocated within a 3-dimensional representation of space. Consequently,
an alternative measure of spatial attention in depth, the overlay interference task, was
successfully validated in a different stereoscopic depth environment and then
manipulated to further examine the allocation of attention in depth. Findings from the
overlay interference experiments indicated that attentional selection is based on a
representation that includes depth information, but only when an additional feature can
aid 3D selection. Collectively, the results suggest a dissociation between two paradigms
that are both purported to be measures of spatial attention. There appears to be a further
dissociation between 2-dimensional and 3-dimensional attentional selection in both
paradigms for different reasons. These behavioural results, combined with recent
electrophysiological evidence suggest that the temporal constraints of the 3D COVAT
paradigm result in early selection based predominantly on retinotopic spatial
coordinates prior to the complete construction of a 3-dimensional representation. Task
requirements of the 3D overlay interference paradigm, on the other hand, while not
being restricted by temporal constraints, demand that attentional selection occurs later,
after the construction of a 3-dimensional representation, but only with the guidance of a
secondary feature. Regardless of whether attentional selection occurs early or late,
however, some component of selection appears to be based on viewer-centred spatial
coordinates.
| Identifer | oai:union.ndltd.org:ADTP/216623 |
| Date | January 2006 |
| Creators | Tucker, Andrew James, n/a |
| Publisher | Swinburne University of Technology. |
| Source Sets | Australiasian Digital Theses Program |
| Language | English |
| Detected Language | English |
| Rights | http://www.swin.edu.au/), Copyright Andrew James Tucker |
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