Brain meeting: Mark Stokes

Brain meeting 

Cognitive multitasking is limited by interference between component tasks. Neural substrates for such interference have previously been identified in the lateral prefrontal cortex (lPFC). However, lPFC processes information in a dynamic, context dependent manner, possibly enabling multitasking during complex behaviour. We recorded from lPFC during an overlapping spatial attention and working memory task (dual task). Monkeys learned to perform the dual task with a high success rate and over various levels of experimentally induced inter-task interference. Prefrontal neurons were tuned to unique task features as well as to complex mixtures of features from both tasks and time i.e. switching, linear-mixed and nonlinear-mixed selectivity. This heterogeneity in neural responses resulted in distinct patterns of activity across the population. Population activity patterns transitioned between distinct neural subspaces across task epochs, while protecting task specific representations from interference. This was characterised by orthogonal subspaces for attention and memory locations, as well a common subspace coding task-invariant spatial location. Our data suggests that lPFC multiplexes information within and across tasks as well as time to achieve concurrent but distinct processing on the level of the population.  

There will be coffee, tea and cake in the conservatory directly after the talk.