A gated prefrontal cortex model of dynamic task switching (original) (raw)

Free PDF

Challenging A Decade of Brain Research on Task Switching: Brain Activation in the Task-Switching Paradigm Reflects Adaptation Rather Than Reconfiguration of Task Sets

In daily life, we permanently need to adapt our behavior to new task situations, requiring cognitive control. Such adaptive processes are commonly investigated with the task-switching para- digm. Many fMRI studies have interpreted stronger activation for switch than repeat trials in fronto- parietal brain areas as reflecting an active reconfiguration process in switch trials, tuning the cognitive system for proper task execution. From the single cell literature, however, one could deduce the alter- native interpretation that switch-specific activity reflects reduced brain activity in repeat trials due to adaptation. These alternative explanations cannot be distinguished by simply comparing brain activity in switch and repeat trials. Therefore, we used a parametric approach to examine which interpretation is more powerful to account for the data. In all areas of the fronto-parietal network, adaptation explained the data better than reconfiguration. Therefore, our results call the classical reconfiguration interpretation into question and provide first evidence for adaptation of abstract task representations.

Free PDF

Common and Distinct Mechanisms of Cognitive Flexibility in Prefrontal Cortex

The Journal of Neuroscience, 2011

The human ability to flexibly alternate between tasks represents a central component of cognitive control. Neuroimaging studies have linked task switching with a diverse set of prefrontal cortex (PFC) regions, but the contributions of these regions to various forms of cognitive flexibility remain largely unknown. Here, subjects underwent functional brain imaging while they completed a paradigm that selectively induced stimulus, response, or cognitive set switches in the context of a single task decision performed on a common set of stimuli. Behavioral results indicated comparable reaction time costs associated with each switch type. Domain-general task-switching activation was observed in the inferior frontal junction and posterior parietal cortex, suggesting core roles for these regions in switching such as updating and representing task sets. In contrast, multiple domain-preferential PFC activations were observed across lateral and medial PFC, with progressively more rostral regio...

Free PDF

A gated prefrontal cortex model of dynamic task switching (original) (raw)

Free related PDFsRelated papers