Biography

Dr. Nick Steinmetz is an Associate Professor in the Department of Neurobiology & Biophysics at the University of Washington in Seattle and a member of the International Brain Laboratory. Prior to starting his own lab, he completed a PhD in Neuroscience at Stanford University studying visual attention with Dr. Tirin Moore and Dr. Kwabena Boahen. As a postdoc, he worked on Neuropixels probe development and distributed coding in the mouse brain at University College London with Dr. Kenneth Harris and Dr. Matteo Carandini.

The Steinmetz Lab focuses on understanding the neural circuits and systems that underlie perception and cognition across the brain, and on developing tools and technologies to enable that understanding. The lab approaches these problems with a combination of large-scale electrophysiology with Neuropixels probes, calcium imaging across neocortical areas, and systematic optogenetic manipulations, all in combination with visual decision-making tasks for mice. Dr. Steinmetz’s work has been recognized with the Pew Biomedical Scholar award, the Klingenstein-Simons Fellowship in Neuroscience, and an NSF CAREER award.

Talk Title: The midbrain reticular formation in contextual control of perceptual decisions

Flexibly responding to sensory cues is fundamental to animal behavior. However, growing evidence suggests that the relevant neural circuits have been incompletely resolved. We trained mice to apply an abstract rule that maps identical visual stimuli to opposing actions across contexts and investigated the role of the midbrain reticular formation (MRF) in this process. Large-scale recordings revealed that neurons in the MRF, along with several canonical decision-making areas, maintained persistent representations of task context in pre-stimulus activity. These representations predicted divergent population dynamics, putatively routing stimuli toward context-appropriate actions. The MRF was the only recorded region containing neuronal populations that both predicted lapses in contextual control pre-stimulus and exhibited contextually modulated premotor responses. The MRF also showed task-specific sensory plasticity. Context-coding neurons were aligned with cortical inputs, suggesting a spatial organization. These findings support the hypothesis that the MRF is a key node for setting and implementing abstract contextual states within the distributed circuitry for flexible perceptual decisions.