Perceptual versus motoric attention : an fMRI investigation of the speed-accuracy tradeoff in decision-making

Abstract

Selectively attending to either the sensory qualities of a stimulus or the response required by a task can influence the speed and accuracy of performance. Prior fMRI studies have identified medial and lateral prefrontal regions to play a critical role in accommodating speed instructions; however, no neural regions that accommodate improvements in accuracy have been identified. Here event-related fMRI was used to investigate when brain regions respond to speed-accuracy tradeoff manipulations and whether there are distinct brain regions for achieving greater accuracy or greater speed. First, visual-attention regions had greater activation when emphasizing accuracy rather than speed. Secondly, the pre-supplementary motor area increased activation during response preparation when emphasizing speed over accuracy. Lastly, the lentiform nucleus increased activation just prior to the execution of a response when emphasizing speed. Trading speed for accuracy may involve shifting the balance of neural activation between systems that prepare for action and those involved with visuo-spatial attention.