Organisation of executive functions: Hemispheric asymmetries

Abstract

This address provides a review of evidence for a deconstruction of executive functions, the set of cognitive operations which allow goal-directed behaviour. The underlying working hypothesis is that some complementary and computationally diverse executive functions are dissociable not only functionally but also temporally and anatomically, along the left-right axis of prefrontal cortex and related neural networks. In particular, criterion setting—the capacity to flexibly set up and select task rules—is more left-lateralised; monitoring—the process of continuously evaluating the internal or external contingencies to optimise behaviour—is more right-lateralised; finally, superior medial prefrontal regions, including dorsal anterior cingulate cortex, play a role in energising weakly activated but relevant processes. Several lines of empirical evidence, including neuroimaging and neuropsychological findings, are presented to support this tripartite model of executive functions. Evidence which is difficult to explain with this model and some future directions are also discussed.

Keywords:

• Criterion setting
• Energisation
• Executive functions
• Monitoring
• Prefrontal cortex fractionation

Acknowledgements

To receive the 2011 Bertelson Award from the European Society for Cognitive Psychology was definitely a great honour that I want to share with all the invaluable people with whom I have fruitfully collaborated in a number of works reviewed in this address. These works were partially funded by a Canadian Institute of Health Research Postdoctoral Fellowship to me, and a grant from Friuli Venezia Giulia to SISSA. A special thank goes to my previous mentors, Tim Shallice and Don Stuss, who inspired many of the ideas detailed here.