Task switching and shifting between stopping and going: Developmental change in between-trial control adjustments

This study set out to investigate developmental differences in the ability to switch between choice tasks and to shift between Go/NoGo and choice tasks. Three age groups (7-year-olds, 11-year-olds, and young adults) were asked to consider the shape or color of a bivalued target stimulus. The participants performed a switch task in which a cue signaled the task to be performed (i.e., respond to shape vs. respond to color) and a shift task in which a cue instructed them to make a choice reaction to the shape of the stimulus or to respond (Go) versus inhibit (NoGo) to the color of the stimulus. The ability to switch was examined by considering choice-choice switches versus choice-choice repeats. The ability to shift was examined by considering NoGo-to-choice shifts versus choice-choice repeats and NoGo-to-Go shifts versus Go-Go repeats. The results showed that responding on Go trials was delayed following response inhibition on a NoGo trial. This delay did not discriminate between age groups. Responding on choice trials was considerably slowed when following response inhibition on NoGo trials. This slowing decreased with advancing age. Finally, responses on switch trials were slower compared with repeat trials, and this slowing was disproportionately large in young children compared with the other two age groups. This pattern of findings was interpreted in terms of a generic mechanism involving between-trial control adjustments in the setting of response thresholds that are likely to be mediated by a complex neural network implicating the dorsolateral prefrontal cortex and the pre-supplementary motor cortex. (C) 2010 Elsevier Inc. All rights reserved.