Efficient search benefits from persistent exposure to the statistical liklihoods that underpin object locations, such that time and energy expenditure tends be minimal. Inspections are made towards areas where objects are most likely to appear or have previously produced successful results. Experimentally, this phenomena has been named the ‘probability cueing effect’, and has predominantly been studied using visual search paradigms. In this context, participants bias their search towards locations where a target frequently appears, but they do not express any conscious awareness of doing so. However, in real-world tasks, it is much harder for spatial inferences to be made, with additional factors to be considered, such as consistency in where search is inititated. When the cue is learnt, it is instead consciously acknowledged. The research within this Thesis investigated search in an additional context: virtual, representational space. Probability cueing was successful but only when the environment was of minimal immersion. Parallel to visual search, participants did not express an awareness of the cue suggesting that physical movement is important for conscious awareness of learning. The transfer of probability cueing across virtual to real space was also examined, although an effect was not established. This finding has important applied implications, when considering that virtual environments are used throughout many industries as training tools. To conclude, three experiments investigated the underlying neural system that may support probability cueing, specifically the right parietal cortex. Much research has shown that this area plays a key role in allocating spatial attention across hemifields, but its input for probability cueing has not yet been investigated. These experiments used transcranial anodal (excitatory) and cathodal (inhibitory) stimulation to moduate this brain area. In a visual, 2D task and a 3D virtual environment task, search efficiency was modulated, with both stimulation types improving general search profiles. In a real-world task, search efficiency was again modulated, as well as probability cueing with stimulation interacting with the high-probability hemispace. Together these studies provide a comprehensive understanding of probability cueing under various environmental search constraints, and the role of the right parietal cortex in the guidance of this search strategy.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:728579 |
| Date | January 2017 |
| Creators | Holloway, Amy Louise |
| Publisher | University of Nottingham |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Source | http://eprints.nottingham.ac.uk/46839/ |
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