The aim of the present study was to characterize participants’ abilities to answer binary yes/no questions by mentally manipulating imagery to produce imagined changes in luminance, which would in turn cause reflexive perturbations in pupil diameter. First, a paired association was established with participants, linking “yes” responses with imagining a “sunny sky” and “no” responses with imagining a “dark room”. Participants (N=20) then answered 16 yes/no questions using this response method, in place of providing verbal or gestural (e.g., head nod) answers. Pupil diameters were recorded for a period of 8000 ms following each stimulus question while participants maintained the mental image that corresponded with their answer. We hypothesized that on average, “no” responses would yield a pupil dilation and increased diameter relative to baseline, while “yes” responses would instead result in constrictions and smaller pupil diameters compared to baseline. A 2-factor repeated measures analysis of variance (ANOVA), where time was one factor and response type (i.e., yes or no) was the other, revealed a statistically significant interaction of time and response type, a significant main effect of time, and a trend toward significance for response type in aggregated group data. Item level discrimination consisted of comparing the mean pupil diameter in response to a single item for a single participant (e.g., “yes” response on one trial) to the mean pupil diameter of all contrasting responses for that same participant (e.g., all “no” response trials). This method achieved a 64.5% discrimination accuracy. This investigation affirmed the plausibility of leveraging pupillometry and luminance-based mental imagery in favor of an alternative communication system for individuals who are locked-in, as well as its potential as a screening tool. However, further investigation is warranted prior to its implementation. / Communication Sciences
| Identifer | oai:union.ndltd.org:TEMPLE/oai:scholarshare.temple.edu:20.500.12613/2780 |
| Date | January 2015 |
| Creators | Diedrichs, Victoria Anne |
| Contributors | Reilly, Jamie, Martin, Nadine, 1952- |
| Publisher | Temple University. Libraries |
| Source Sets | Temple University |
| Language | English |
| Detected Language | English |
| Type | Thesis/Dissertation, Text |
| Format | 37 pages |
| Rights | IN COPYRIGHT- This Rights Statement can be used for an Item that is in copyright. Using this statement implies that the organization making this Item available has determined that the Item is in copyright and either is the rights-holder, has obtained permission from the rights-holder(s) to make their Work(s) available, or makes the Item available under an exception or limitation to copyright (including Fair Use) that entitles it to make the Item available., http://rightsstatements.org/vocab/InC/1.0/ |
| Relation | http://dx.doi.org/10.34944/dspace/2762, Theses and Dissertations |
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