Evidence integration in the human brain through active visual sampling

• Grant number: 23/03177-0
• Support Opportunities: Scholarships abroad - Research Internship - Doctorate
• Start date: August 30, 2023
• End date: February 28, 2024
• Field of knowledge: Interdisciplinary Subjects
• Principal Investigator: Gustavo Rohenkohl
• Grantee: Gabriela Mueller de Melo
• Supervisor: Valentin Wyart
• Host Institution: Instituto de Biociências (IB). Universidade de São Paulo (USP). São Paulo , SP, Brazil
• Institution abroad: Laboratoire de Neurosciences Cognitives Computationnelles (LNC), France
• Associated to the scholarship: 20/09284-5 - Predictive signals in the fovea during saccade planning, BP.DR

Abstract

In most natural situations, we are constantly making decisions to infer the perceptual properties of the world around us. To generate these inferences, we first need to sample relevant evidence by directing our senses to specific sources in the environment. For example, we seek visual evidence by repeatedly shifting our eyes specifically to the most informative locations in a scene. Crucially, these shifts are not random, rather, we are in control of what is sampled, and can actively guide the sampling process to match our current goals. In contrast to these active strategies, the majority of experiments on perceptual decision-making are based on passive paradigms, wherein participants have no control over the sampling strategy, and the evidence is provided to them passively. Recent findings have shed some light on the differences between active and passive inference strategies, suggesting that they can be subserved by distinct neural mechanisms and behavioral patterns, likely impacting how information is integrated when making decisions under the two circumstances. However, it has not yet been elucidated how the perceptual, decision, and motor components of decision-making operate when visual evidence is actively sampled through eye movements. Thus, in this project we propose a study based on a novel paradigm for visual decision-making associated with magnetoencephalography (MEG) recordings of brain activity. In this paradigm, participants are required to estimate the predominant orientation of a visual array by either actively seeking evidence with their eyes, or merely sample a predefined sequence of locations. The findings of this project can help to elucidate the behavioral consequences, and neural correlates of accumulating perceptual evidence under active vision. (AU)