Thalamic contributions to working memory

Poster Session B - Sunday, April 14, 2024, 8:00 – 10:00 am EDT, Sheraton Hall ABC

Pedro M. Paz-Alonso¹ (kepa.pazalonso@gmail.com), Liu Mengxing², Ane Gurtubay-Antolin¹; ¹BCBL. Basque Center on Cognition, Brain and Language, ²School of Medicine, Tufts University, United States

The cortical substrates of working memory (WM) have been extensively investigated. However, less research has investigated the role of the thalamus and thalamocortical pathways in WM in humans. This could be due to the lack of detailed probabilistic atlases of the human thalamus or the small size of the thalamic nuclei as compared to regular voxel sizes. In the present MRI study, twenty participants performed a variation of a standard WM task with maintenance and manipulation components. In this task, participants were presented with a sequence of three images and were asked to remember them either in ‘forward’ or in ‘backward’ order. Using individual-subject analysis, we investigated the involvement of thalamic nuclei and to what extent thalamocortical functional and structural connections were related to WM abilities. Our results revealed mediodorsal and pulvinar thalamic nuclei engagement during encoding and maintenance. Moreover, results of a hierarchical regression analysis showed that thalamocortical-related indexes explained a significant proportion of the variance in WM abilities, beyond that explained by cortical (functional/structural) neuroimaging indexes alone. These findings highlight the relevance of the thalamus and thalamocortical connectivity in models of human WM.

Topic Area: EXECUTIVE PROCESSES: Working memory