The model suggests that the frontal cortex can represent multiple parts of a sequence at the same time while using sensory evidence and goals to guide action.
Researchers used a hierarchical model in which sequential actions are inferred from sensory evidence and goals. The model reproduced neural patterns reported in the frontal cortex of primates, where multiple parts of an action sequence can be represented simultaneously in partly separate patterns of activity.
The model also produced nearly separate memory-related activity patterns and reused those patterns when sequences were carried out or considered in forward and backward order. The framework links planning, working memory and preparation for movement, while making predictions about how uncertainty may affect sequence processing.
How the model builds plans
The model reproduced several findings from studies of primate frontal cortex. Multiple elements of an action sequence became active at the same time rather than appearing only in a strictly serial order. The model also produced almost orthogonal memory subspaces—largely separate patterns of neural activity associated with different parts of a plan—and reused them across forward and backward sequence tasks.
These results arose when the model inferred control states from sensory evidence and goals. The framework also generates testable predictions about the changing activity involved in this inference, the role of sensory-related activity patterns and the effects of uncertainty on processing action sequences.
