We’re very excited to see this paper out! How does SC contribute to executive control? Our data suggests that the SC can be at the very heart of executive control, responsible for combining cognitive control signals with sensory inputs to compute context-appropriate responses. Remarkably, the fully context-appropriate responses can be decoded from SC neurons almost 200 ms faster than from cortical neurons (wow!), suggesting the computation may be led, and happen, in the SC itself. Circuit modeling supports this idea, with large-scale searches revealing a wide variety of possible SC circuits that would achieve this and that are compatible with the experimental data.
- Chunyu A Duan, Marino Pagan, Alex T Piet, Charles D Kopec, Athena Akrami, Alexander J Riordan, Jeffrey C Erlich, Carlos D Brody, “Collicular Circuits for Flexible Sensorimotor Routing“, Nature Neuroscience 2021.
Abstract: Context-based sensorimotor routing is a hallmark of executive control. Pharmacological inactivations in rats have implicated the midbrain superior colliculus (SC) in this process. But what specific role is this, and what circuit mechanisms support it? Here we report a subset of rat SC neurons that instantiate a specific link between the representations of context and motor choice. Moreover, these neurons encode animals’ choice far earlier than other neurons in the SC or in the frontal cortex, suggesting that their neural dynamics lead choice computation. Optogenetic inactivations revealed that SC activity during context encoding is necessary for choice behavior, even while that choice behavior is robust to inactivations during choice formation. Searches for SC circuit models matching our experimental results identified key circuit predictions while revealing some a priori expected features as unnecessary. Our results reveal circuit mechanisms within the SC that implement response inhibition and context-based vector inversion during executive control.