Abstract
Purpose :
We asked the question will one look reflexively towards a familiar target or to a novel target when no instructions are given? We studied this by priming participants with a target and analyzing their reflexive looking behavior. Such a test paradigm can then be developed to help study visual functions of non-verbal individuals including children and those with cognitive impairment who may not process instructions.
Methods :
Thirty-one normally sighted adults participated. No instructions were given to these participants other than to look at a monitor. One of the four LEA symbols (50’ of visual angle, white color) was presented for 2s on a black computer screen in a dark room. Post this priming, two white LEA symbols, one of which was the primed target (familiar) were flashed. The direction of the first saccadic eye movement of the participant to the flashed targets was analyzed. EyeLink 1000 plus eye tracker (sampling rate: 500 Hz) was used for recording the binocular eye movements. A total of 108 trials [4 LEA symbols x 3 sizes (25’,20’,15’) x 3 flash durations (0.2, 0.4, 0.6s) x 3 repetitions] were presented. The mean proportion of eye movements made to the familiar and unfamiliar target was calculated for each subject.
Results :
More than half the participants (58%) looked towards the familiar target (FT), 39% of the paritcipants looked towards the unfamiliar target (p<0.03). One participant was equivocal in their looking behavior. Repeated measures ANOVA showed reflexive eye movements were neither influenced by the target size (p=0.9) nor by the flashed duration (p=0.08). However the overall mean proportion of eye movements towards FT was 50% (±5.5 SD) and towards the unfamiliar was 40% (±5.5 SD). When asked for feedback, it was found that most of the participants (n=26) were unaware that a FT was flashed after the primed stimuli.
Conclusions :
Our study demonstrated that in the absence of any instructions, individuals have a propensity to first reflexively look towards the primed target rather than to an unfamiliar target. However such a reflexive preference is still at a chance level of 50%. Further modification to the test paradigm is needed to look for a stronger preference.
This abstract was presented at the 2019 ARVO Annual Meeting, held in Vancouver, Canada, April 28 - May 2, 2019.