Formation and Maintenance of Equivalence Classes with Stimuli Presented in Peripheral Vision

• Grant number: 25/22532-1
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: November 01, 2025
• End date: October 31, 2026
• Field of knowledge: Humanities - Psychology - Experimental Psychology
• Principal Investigator: Gerson Aparecido Yukio Tomanari
• Grantee: Adriel Lourenço
• Host Institution: Instituto de Psicologia (IP). Universidade de São Paulo (USP). São Paulo , SP, Brazil
• Associated research grant: 25/13239-9 - Formation and Maintenance of Equivalence Classes with Stimuli Presented in Peripheral Vision, AP.R

Abstract

The project proposes to investigate the role of peripheral vision in the establishment and demonstration of symbolic behavior arising from the formation of stimulus equivalence classes. Traditionally, the field studies the formation of equivalence classes, a phenomenon where relationships between stimuli emerge without direct training, through the matching-to-sample (MTS) procedure, attending almost exclusively on focal vision and neglecting the role of peripheral vision. Previous studies that attempted to explore peripheral vision in this context had limitations, such as the lack of rigorous gaze control, or obtained inconsistent results, possibly due to the crowding effect resulting from the use of stimuli made of complex features. To address this gap, the present project proposes two experiments that will use simple visual stimuli (colored geometric shapes) to mitigate crowding and apply strict control of ocular fixation on the sample stimulus through eye-tracking. Experiment 1 will investigate whether the formation of equivalence classes is possible when comparison stimuli are presented exclusively in the peripheral vision throughout the entire process of training and testing. To achieve this, an eye-tracking contingency will ensure the participant maintains a fixed gaze on the central sample stimulus, removing the comparison stimuli if their gaze deviates. Experiment 2 will test the maintenance of stimulus functions: participants will learn the relationships using focal vision during training but will be tested for emergent relations with the eye-tracking contingency activated, forcing the use of peripheral vision. The study, involving twelve adult participants, will train conditional relations (AB and AC) and test for emergent ones (BC and CB). Together, the results will allow for an assessment of the role of focal and peripheral vision in stimulus control, with implications for understanding symbolic learning and developing teaching technologies. (AU)