Peripheral Vision in Matching-to-Sample Procedures

In an on-screen matching-to-sample task, participants have to visually search for the stimuli on the screen. Peripheral vision plays an essential role in visual search. In this presentation, we will show results from three experiments investigating peripheral visions in a matching to sample procedure and to what extent participants can attend to stimuli that vary in size and positions in the periphery. Participants learned eight conditional discriminations. In the test trials, participants had to fixate their gaze on the sample while selecting a comparison stimulus. Participants were exposed to 12 test condition were stimuli size and position varied. Eye movements were measured with a head-mounted eye-tracker. In Experiment 1, arbitrary relations were trained and tested. In Experiment, 2 participants were exposed to identity matching of abstract stimuli, and in Experiment 3 participants were exposed to identity matching of simple shapes. Initial results show that participants in Experiments 1 and 2, discriminate between abstract stimuli in the periphery when stimuli were 0.7 cm or larger. When stimuli were 0.7 cm and more than 12 cm from the fixation point, discrimination ceased. Participants were unable to discriminate stimuli that were 0.3 cm regardless of position. When stimuli were simple shapes, participants discriminated stimuli as small as 0.3 cm when they were 6 cm from the sample position but when the distance was 12 cm and 18 cm discrimination decrease.