Task context load induces reactive cognitive control: An fMRI study on cortical and brain stem activity

Abstract

Cognitive control is a highly dynamic process that relies on flexible engagement of prefrontal areas and of neuromodulatory systems in order to adapt to changing demands. A range of internal and external factors come into play when individuals engage in a task requiring cognitive control. Here we investigated whether increased working memory (WM) demands would induce a flexible change in cognitive control mode in young healthy individuals. We developed a novel variant of the well-known AX–continuous performance task (AX-CPT). We manipulated the cognitive demands of maintaining task-relevant contextual information and studied the impact of this manipulation on behavior and brain activity. We expected that low WM load would allow for a more effortful, proactive strategy, while high WM load would induce a strategy of less effortful, stimulus-driven reactive control. In line with our hypothesis, a web-based experiment revealed that increased load was associated with more reactive behavioral responses, and this finding was independently replicated in behavioral data acquired in the MRI scanner. The results from brain activity showed that the right dorsolateral prefrontal cortex was activated by cues in the proactive mode and by probes in the reactive mode. The analysis of task-induced brain stem activity indicated that both the dopaminergic and noradrenergic systems are involved in updating context representations, and that, respectively, these systems mediate a gating signal to the control network and are involved in the dynamic regulation of task engagement. Electronic supplementary material The online version of this article (10.3758/s13415-019-00691-6) contains supplementary material, which is available to authorized users.

Pupil-based states of brain integration across cognitive states

“…In addition, we observed some specificity in the different tasks. Although overall brain patterns ( Figure 2) did not entirely match the activation patterns associated to these tasks (Fox et al, 2005;Mäki-Marttunen et al, 2019;Mäki-Marttunen et al, 2020b), the inferior frontal gyrus in AX-CPT (i.e. a cognitive control task), and frontal-eyes fields in MOT (i.e.…”

“…In addition, participants performed two runs of the AX-continuous performance task (AX-CPT). This task is commonly used to study cognitive control (Mäki-Marttunen et al, 2019;Servan-Schreiber et al, 1996). Each trial of the standard AX-CPT consisted of two displays: first, a contextual cue was presented, and after a delay, the probe followed.…”

Uncovering the locus coeruleus: comparison of localization methods for functional analysis

“…The purpose of these studies was to compare LC integrity across age or neurological conditions. In functional studies, LC segmentation was mainly done through manual drawing (Clewett et al, 2018;Krebs et al, 2018;Mäki-Marttunen et al, 2019b;Mäki-Marttunen et al, 2020). Functional analyses benefit from regions that cover the whole area of interest where BOLD signal is averaged, while structural studies often rely on the identification of the voxels with highest intensity in different slices or even in a single slice.…”

“…measured peak intensity of neuromelanin scan). A few functional studies used this method for individualized LC localization to test hypotheses regarding LC activity during different cognitive tasks (Clewett et al, 2018;Krebs et al, 2018), including our own work (Mäki-Marttunen et al, 2019b;Mäki-Marttunen et al, 2020). Recent studies have aimed for improved manual delineation of LC in neuromelanin scans by using a semi-automatic segmentation of LC (Betts et al, 2017;Dahl et al, 2019).…”

Adaptiveness in proactive control engagement in children and adults

“…As they grow up, children increasingly engage proactive control (e.g., Chatham et al, 2009 ). However, unlike older children and adults, who adaptively engage either control mode as a function of task demands ( Braver, 2012 ; Lewis-Peacock et al, 2016 ; Mäki-Marttunen et al, 2019 ), children around 5 and 6 years of age tend to rely mostly on reactive control, even though they are already capable of proactive control (e.g., Chevalier and Blaye, 2016 ; Chevalier et al, 2015 ; Hadley et al, 2020 ; Troller-Renfree et al, 2020 ). For example, when switching between colour- and shape-matching rules as a function of task cues, one can proactively prepare to process either the colour or shape of the upcoming target when the task cue is presented early.…”