On the Rational Boundedness of Cognitive Control: Independent vs. Interactive Parallelism (Cosyne 2019)

On the Rational Boundedness of Cognitive Control: Independent vs. Interactive Parallelism (Cosyne 2019)

One of the most compelling characteristics of controlled processing is our limitation to exercise it. These limitations form one of the most basic and influential tenets of cognitive psychology: controlled processing relies on a central, limited capacity processing mechanism that imposes seriality on control-dependent processes. In the first part of this talk, I present a challenge to this view that distinguishes control-dependent and automatic processing by their reliance on shared vs. separated (task-dedicated) representations. Specifically, I propose that control functions to avert conflicting use of representations shared by multiple processes. That is, constraints on the use of control arise as a rational response to the shared use of representations, rather than from the control mechanism itself. I use graph-theoretic methods to formalize this theory, and show that multitasking capability of a network architecture drops precipitously with an increase in shared representations, and is virtually invariant to network size. This raises an important question: insofar as shared representation introduces the risk of cross-talk and thereby limitations in multitasking, why would the brain prefer shared task representations over separate ones? In computational simulations and behavioral experiments I demonstrate a tradeoff between learning efficiency, promoted by shared representations, and multitasking capability, best achieved via separated representations. The commonly-observed trajectory from controlled to automatic processing during learning may therefore reflect a rational optimization of this tradeoff: shared representations initially afford a bias toward efficient learning in novel task environments at the expense of seriality and control-dependence; but experience in environments where multitasking affords sufficient advantage ultimately promotes acquisition of separated, task-dedicated representations.


Sebastian Musslick

March 04, 2019