Neural activity in visual areas of marmosets during free-viewing

• Grant number: 23/08440-1
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• Start date: August 01, 2023
• End date: September 30, 2024
• Field of knowledge: Interdisciplinary Subjects
• Agreement: Max Planck Society for the Advancement of Science
• Principal Investigator: Gustavo Rohenkohl
• Grantee: Estêvão Carlos Lima
• Host Institution: Instituto de Biociências (IB). Universidade de São Paulo (USP). São Paulo , SP, Brazil
• Associated research grant: 17/10429-5 - Long-range brain connectivity during active visual behavior, AP.JP

Abstract

A main question in neuroscience is how the neural system access and processes information from the surrounding. To do so, visual information in primates is often obtained and processed around the timeframe of 250 ms. This time constraint is brought on by the eye-movements produced during natural vision. The main type of eye-movement used for sampling the environment is known as the saccade. Saccades are rapid eye-movements that constantly bring objects of interest to the center of the visual field. Although still not fully understood, it is known that neural activity in visual areas is modulated in anticipation of the onset of a saccade. It is believed that this perisaccadic modulation is involved in the smooth transition between the fixational targets. Diverse cortical and subcortical regions are involved in the processing of these brief instants of visual information. These neural activities are associated with primary sensory regions, such as V1 (primary visual cortex), as well as with higher visual processing regions, such as V6. Most studies' designs on perisaccadic processing are developed prioritizing the control of saccadic behavior, such as tasks with cue-oriented saccades. This kind of approach might limit the extrapolation of the obtained data into more naturalistic cognitive models. This project aims to investigate the impact of saccade preparation and execution in visual areas during a more naturalistic behavior. Here, marmosets are presented with short movies (urban and nature landscapes), that they can freely explore, while simultaneously recording eye-tracking data and neural activity in two visual cortical regions, V1 and V6. The experimental data was already collected from two marmosets (Callithrix jacchus) at the Ernst Strüngmann Institute (ESI) in cooperation with the Max Planck Society. Neural activity was obtained through implanted linear electrodes of 32 channels allowing the recording of single- (SUA) as well as multi-unit activity (MUA), and local field potentials (LFP). The main aim of this project is to investigate known findings described in studies using highly controlled but more artificial tasks, as well as explore possible novel mechanisms related to perisaccadic visual processing. The high complexity and unconstrained nature of the dataset pose both a challenge and an opportunity to explore the neural basis of perisaccadic perception. (AU)