V-046 | Exploring the neural correlates of working memory and visual search: MEG and eye-tracking recordings

Cognition, Behavior, and Memory
Author: Joaquin Gonzalez | Email: joaquin.gonzalez6693@gmail.com

Joaquín Ezequiel Gonzalez^1°, Damian Care^1°,Anthony J. Ries^2°, Juan Esteban Kamienkowski^1°3°4°, Matias Julián Ison^5°

^1° Laboratorio de Inteligencia Artificial Aplicada, Instituto de Ciencias de la Computación, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires – CONICET, Buenos Aires, Argentina
^2° DEVCOM, ARL, United States
^3° Departamento de Computación, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires – CONICET, Buenos Aires, Argentina
^4° Maestría de Explotación de Datos y Descubrimiento del Conocimiento, Facultad de Ciencias Exactas y Naturales – Facultad de Ingeniería, Universidad de Buenos Aires, Argentina
^5° School of Psychology, University of Nottingham, Nottingham, United Kingdom

Eye movements are essential for most daily tasks, from reading to driving. While a lot is known about eye movement patterns during real-world tasks, the understanding of the underlying neural mechanisms is much more limited. In this project we combine non-invasive MEG brain recordings with eye movement recordings, in a task where participants engage in visual and memory search across different realistic backgrounds. By applying source modeling to saccade and fixation aligned data, we found a strong lambda response localized in the V1, appearing around 100ms after fixation onset, and a robust target-related component consistent with the EEG-related P3, frequently observed in target-detection tasks. A whole-task time-frequency analysis allowed us to study the power changes when memorizing, retaining, and searching for an object. We found a significant occipito-parietal decrease in the Alpha band (8-12 Hz) activity, which was modulated by memory load in memorization and retention, whereas the activity during visual search presented a significant increase in High Gamma band (50-100Hz) originating in the V2 bilateral region. Finally, we found that this power increase was not originated merely by eye movements suggesting that it is possibly task-related or induced by the visual features from the image. Altogether, this work sheds light on the neural basis and processes involved in working memory and visual search under conditions that are close to real-world situations.