Mapping the functional anatomy of task preparation: Priming task‐appropriate brain networks

Abstract

The present study used functional magnetic resonance imaging (fMRI) and a cued version of a flanker paradigm to elucidate the effects of task preparation on subsequent brain activation patterns. A mixed block and event-related design was employed to examine activations associated with the cue periods themselves and the cued and un-cued correct responses to incongruent flankers. A number of areas were active during the cues, most notably left dorsolateral prefrontal cortex (DLPFC), which was interpreted as subserving a role in task-set maintenance. Widespread activity was noted for correct responses to incongruent flankers, including bilateral parietal and frontal regions, consistent with previous studies. Activation was increased in these regions for correct responses after cue periods. An overlapping network of regions was also noted for cues and correct responses, suggesting preparation of task-appropriate anatomical regions during the cue period. These results suggest that cue periods allow participants to prime task-relevant areas within the brain and highlight the importance of left DLPFC in top-down control.

Adjustments of Response Threshold during Task Switching: A Model-Based Functional Magnetic Resonance Imaging Study

“…This unexpected finding that pre-SMA is related to threshold setting regardless of cue type may be explained by previous anatomical tracing studies in monkeys showing projections between pre-SMA and dorsolateral prefrontal cortex (DLPFC) (Lu et al, 1994;Wang et al, 2005), a region coding for goaldirected behavior, including the maintenance and manipulation of action sets (Fassbender et al, 2006;Hester et al, 2007;Jamadar et al, 2010). The DLPFC is believed to increase baseline activity in motor-related and decision-related networks to control the speed-accuracy tradeoff (van Veen et al, 2008).…”

Dissociable mechanisms underlying individual differences in visual working memory capacity

“…The failure to find group differences in theta power might also be related to the relatively long (1-s) foreperiod used in this experiment. Having a foreperiod might have resulted in similar priming of task-related functional brain regions for both WMC groups (Fassbender et al, 2006), thereby resulting in similar levels of conflict and absence of group differences in theta power.…”

Dynamic Adjustments in Prefrontal, Hippocampal, and Inferior Temporal Interactions with Increasing Visual Working Memory Load

“…This suggests that communication between the MFG and FFA, while most likely polysynaptic (Petrides and Pandya 1999), may make a functional contribution to the task in a loadindependent manner. One speculative explanation is that top-down signals emanating from MFG regions tag face representations in the FFA as task relevant, regardless of the mnemonic load, which serves to facilitate task-set maintenance (Fassbender et al 2006). Load-dependent connectivity changes were also not observed in the FEF ROIs.…”