Effects of the Mood Induction Paradigm on the Binocular Rivalry mix percept

• ¹ The University of Melbourne, Melbourne School of Psychological Sciences, Australia

Background: Binocular rivalry occurs when two different images are presented simultaneously to each eye, respectively. Despite a constant visual input, the perceptual experience is characterized by a spontaneous alternation of the two images and period of “mix percept”, where both images are visible. Previous researchers have reported longer mix percept in children, and in adults after consumption of hallucinogenic drugs. We previous showed that people more susceptible to engage with sensorial stimulation or with unusual perceptual experience perceive longer mix percept. High scores on Openness (a Big Five trait), characterized by high engagement with sensory and perceptual information, and in Unusual Experiences (a facet of schizotypy related to the subclinical positive symptoms of schizophrenia), were strong predictors of mix percept duration. In this study, to consolidate our findings, we used a mood induction procedure that influenced individuals particularly susceptible to perceptually pleasant stimuli/situations (Positive-Pleasant mood induction). We predicted that individuals high in Openness and Unusual Experience traits would report an increase of mix percept, following this procedure. Method: Participants (n. 90). Mood Induction: Participants randomly assigned to one of three mood induction procedures (Control n.30, Positive-Pleasant n.30, Positive-Appetitive n.30). Task: Binocular Rivalry with orthogonal stationary gratings (tilted left/right). Participants reported gratings orientations and mix percept. Personality Traits: Openness, Unusual Experience. Result: Moderated Multiple Regression was employed showing that Openness and mood conditions were not directly associated with mix percept, but Positive-Pleasant mood induction and Openness interacted to predict reports of mix percept, β = 3.68, t (89) = 2.3, p = 0.02 Discussion: Our findings showed how Positive-Pleasant mood Induction increased overall mix percept report and strengthen further the relationship between Openness and mix percept. Unusual Experiences did not show a similar trend, suggesting that schizotypy are not susceptible to positive pleasant sensorial stimulation in a similar way.