Schedule of Events | Symposia

Postdoctorial Fellowship Award Winner

Cerebellum causally influences spatial working memory tuning in frontoparietal and visual cortex

Poster Session B - Sunday, March 30, 2025, 8:00 – 10:00 am EDT, Back Bay Ballroom/Republic Ballroom

James Brissenden¹ (brissend@umich.edu), Rupsha Panda¹, Jacob Sellers¹, Taraz Lee¹; ¹University of Michigan

Despite extensive research focused on identifying the specific brain structures and mechanisms involved in working memory (WM), much of the prior literature has relied on correlational methods to explore the neural substrates of WM. We sought to investigate the causal role of brain areas spanning the cerebral cortex and cerebellum in WM using a combination of functional magnetic resonance imaging (fMRI) and transcranial magnetic stimulation. Across multiple sessions, we applied continuous theta-burst stimulation to perturb activity in intraparietal sulcus (IPS), frontal eye fields, cerebellar lobule VIIb, and a somatosensory control site immediately prior to the performance of a continuous report spatial working memory task both inside and outside of the fMRI scanner. A baseline fMRI session collected structural MRI, resting-state, and population receptive field (pRF) mapping scans. We examined the effect of stimulation on parameters of a variable precision mixture model for each session. We also investigated how stimulation impacted delay-period spatial tuning properties across a network of spatial WM areas. Information-theoretic analyses investigated how spatial tuning changes affected the fidelity of spatial population coding across the brain. Cerebellar and frontal stimulation resulted in reduced recall precision relative to control stimulation, while IPS stimulation increased precision variability. We also demonstrated a causal influence of cerebellum on neural response variability in higher-order visual cortex, IPS, and frontal cortex to repeated presentations of the same stimulus. Further analysis revealed that this change in variability resulted in reduced Fisher information throughout the delay period across this spatial WM network.

Topic Area: EXECUTIVE PROCESSES: Working memory