- Trait anxiety and the neural efficiency of cognitive processing (2011)
- The current work investigated the association of trait anxiety and the neural efficiency of cognitive processing for affectively neutral (not threat-related) information. In a sample of 46 healthy volunteers, three fMRI experiments were conducted to test the prediction derived from attentional control theory (Eysenck et al., 2007) that high as compared to low trait-anxious individuals expend more neural effort on tasks requiring the top-down control of attention to reach a given level of performance. In a colour-word Stroop task requiring the inhibition of irrelevant stimulus information and associated responses as well as in a working-memorymanipulation task requiring the shifting of attention between items in working memory, trait anxiety (as measured with the State-Trait Anxiety Inventory; Spielberger et al., 1970) was positively associated with task-related increases in the activation of two adjacent regions in the right dorsolateral prefrontal cortex (DLPFC). The finding that along with a stronger activation of this brain region commonly implicated in top-down control processes, the high-anxious subjects showed equal (working memory manipulation) or worse (Stroop) performance when compared to low-anxious subjects, does support the assumption that processing is less efficient in the high anxious. However, in contrast to the predictions, trait anxiety did not show a significant association with task-related brain activation in a task-switching paradigm requiring shifting between task sets. It is discussed how different attentional control demands of the task may account for differences in the effects of trait anxiety on overt behavioural performance and underlying neural processes. In addition to DLPFC activation, trait anxiety modulated the functional connectivity of distributed regions involved in processing of the Stroop and the working-memory-manipulation task. It is discussed how the observed differences in regional DLPFC activation and network connectivity relate to each other. A possible interpretation suggests that activation increases in the DLPFC reflect an attempt to compensate for suboptimal connectivity by investing more effort in prefrontally supported control processes. Overall, the current work shows an association of trait anxiety with the neural efficiency of cognitive processing in affectively neutral tasks involving attentional control. Furthermore, it suggests that investigations of neural efficiency should take into account difference in functional integration in addition to regional activation.