Browsing Australian Research Council (ARC) by Subject "Attention"
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ItemAsymmetries in attention as revealed by fixations and saccades(Springer Verlag, 2014-06-21) Thomas, Nicole A; Loetscher, Tobias; Nicholls, Michael Elmo RichardNeurologically normal individuals devote more attention to the left side; an asymmetry known as pseudoneglect, which reflects right hemisphere involvement in visuospatial attention. The role of eye movements in attentional asymmetries has received little consideration, particularly in terms of the greyscales task. Stimulus length, elevation, and presentation duration were manipulated, while monitoring eye movements during the greyscales task. Region of interest analyses compared time spent examining each quadrant of the stimulus. Further, saccades were examined in conjunction with fixations to gain an understanding of overall eye movement patterns. Scatterplots combining x-and y-coordinates illustrate mean eye position. Results demonstrated a comparison strategy was used, where the dark portions of each rectangle were fixated. Mean eye position was within the lower left quadrant. The left visual field was inspected most for the baseline condition. Interestingly, the lower visual field was examined most when duration, length, or elevation was manipulated. Eye movement patterns provide a possible explanation for why correlations are y not observed between visuospatial tasks. Different strategies, based on specific-task demands, are likely to be used, which in turn, engage separate aspects of visuospatial attention. ItemClose to me: the effect of asymmetrical environments on spatial attention(Taylor & Francis, 2014-03-26) Nicholls, Michael Elmo Richard; Roden, Sally; Thomas, Nicole A; Loetscher, Tobias; Spence, Charles J; Forte, Jason DAttention can be captured by distractors and can affect performance. To examine whether asymmetrical distractors, such as a wall, affect spatial attention, Experiment 1 required participants (n = 20) to determine the relative length of pre-bisected lines when a temporary barrier was placed close to the left or right sides of the display. Post-hoc tests showed that attention was drawn towards left, but not right, walls. Experiment 2 (n = 18) sought to increase this effect using a solid brick wall rather than a temporary barrier. Instead of strengthening the result, no effect of barrier was observed. A non-effect was also observed in Experiment 3 (n = 18) when participants moved a cursor to the line's middle. Finally, Experiment 4 (n = 26) showed that asymmetrical barriers had no effect on visual search. While the data showed some evidence that attention is distracted by walls placed to the left, this effect is weak and task-specific. ItemKeeping your distance: attentional withdrawal in individuals who show physiological signs of social discomfort(Elsevier BV, 2014-10-16) Szpak, Ancret; Loetscher, Tobias; Churches, Owen; Thomas, Nicole A; Spence, Charles J; Nicholls, Michael Elmo RichardBeing in close social proximity to a stranger is generally perceived to be an uncomfortable experience, which most people seek to avoid. In circumstances where crowding is unavoidable, however, people may seek to withdraw their attention from the other person. This study examined whether social discomfort, as indexed by electrodermal activity, is related to a withdrawal of attention in 28 (m=8, f=20) university students. Students performed a radial line bisection task while alone or together with a stranger facing them. Physiological arousal was indexed by a wrist monitor, which recorded electrodermal activity. Correlational analyses showed that individuals who displayed physiological discomfort when together showed a withdrawal of the perceived midpoint of the line towards them (and away from the stranger). Conversely, individuals who showed no discomfort exhibited an expansion of the perceived midpoint away from them. We propose that participants shift their attention away from the stranger to increase interpersonal distance and reduce anxiety/arousal. ItemUpper visual field distractors preferentially bias attention to the left(Elsevier BV, 2014-11-11) Thomas, Nicole A; Castine, Benjamin R; Loetscher, Tobias; Nicholls, Michael Elmo RichardPseudoneglect is influenced by vertical visual field stimulation, such that attentional biases are stronger for upper space distractors. Leftward biases result from right hemisphere visuospatial processing, and may be accentuated by additional right hemisphere activation during upper space distraction. Three experiments examined potential explanations for this finding. Experiment 1 controlled for perceptual grouping and leftward biases remained stronger in upper space. Experiment 2 used peripheral distractors to eliminate two further potential explanations: centre-of-mass and framing effects. Eye tracking was included to compare overt and covert attention. Findings supported the occurrence of a stronger leftward attentional bias during upper space distraction. Distractors were rarely fixated, suggesting covert attentional mechanisms are preferentially drawn toward upper space distractors. Experiment 3 employed a cueing paradigm that purposefully directed attention away from centre to determine whether pseudoneglect was influenced by overt attentional orienting. Results indicated that when attention was overtly directed away from centre, the strength of pseudoneglect did not differ based on visual field. It is concluded that covert attention toward upper space distractors recruits additional right hemisphere activation, leading existing leftward biases to be accentuated.