June 12, 2018 – INT – 2h30 pm
Meeting at 13h00 for the students of the ICN PhD program
Richard Krauzlis works at the National Eyes Institute.
What is the “parts list” for selective attention?
Selective attention is widely attributed to a network of areas in the cerebral neocortex, with frontal and parietal cortex regulating limited resources available in the sensory areas of cortex. Evolutionarily older subcortical structures like the superior colliculus in the midbrain also play a role in selective attention, and in this talk I will explain how our investigation of these subcortical structures has led us to a different view of how attention is controlled.
In previous work, we demonstrated that the superior colliculus plays a crucial role in the control of selective attention, but surprisingly, the mechanisms used by the superior colliculus appear to be independent of the well-known signatures of attention in visual cortex. We are now pursuing two lines of work aimed at understanding these counter-intuitive results. First, using mice to study visual selective attention, we are testing the idea that subcortical circuits through the basal ganglia known to be important for regulating actions are also important for governing how sensory signals are used. Our results provide evidence that the basal ganglia contribute to attention by adjusting the decision criterion based on the expected location of the upcoming sensory event (i.e., spatial priors). Second, using fMRI and electrophysiology in monkeys, combined with transient inactivation of the superior colliculus, we have identified a novel area in the temporal lobe of the cortex with attention-related activity uniquely dependent on the superior colliculus, and found that inactivation of this area itself causes deficits in attention. These results show that the networks for attention include a node in the temporal cortex that may provide a bridge between cortical and subcortical circuits – perhaps linking “where” signals from the superior colliculus with “what” information dependent on cortical processing.
Together, our findings illustrate that selective attention is not a unitary function achieved de novo with the emergence of the neocortex, but instead is an amalgam of several functions, implemented by circuits accrued and modified over hundreds of millions of years, beginning well before the forebrain contained a neocortex. Determining how older subcortical circuits interact with the more recently evolved components in the neocortex will likely be crucial for understanding the complex properties of selective attention in primates and other mammals, and for identifying the etiology of attention disorders.
Register on Ametice before June 5th, 2018.