Influence of Motivation on Control Hierarchy in the Human Frontal Cortex

Abstract

The frontal cortex mediates cognitive control and motivation to shape human behavior. It is generally observed that medial frontal areas are involved in motivational aspects of behavior, whereas lateral frontal regions are involved in cognitive control. Recent models of cognitive control suggest a rostro-caudal gradient in lateral frontal regions, such that progressively more rostral (anterior) regions process more complex aspects of cognitive control. How motivation influences such a control hierarchy is still under debate. Although some researchers argue that both systems work in parallel, others argue in favor of an interaction between motivation and cognitive control. In the latter case it is yet unclear how motivation would affect the different levels of the control hierarchy. This was investigated in the present functional MRI study applying different levels of cognitive control under different motivational states (low vs high reward anticipation). Three levels of cognitive control were tested by varying rule complexity: stimulus-response mapping (low-level), flexible task updating (mid-level), and sustained cue-task associations (high-level). We found an interaction between levels of cognitive control and motivation in medial and lateral frontal subregions. Specifically, flexible updating (mid-level of control) showed the strongest beneficial effect of reward and only this level exhibited functional coupling between dopamine-rich midbrain regions and the lateral frontal cortex. These findings suggest that motivation differentially affects the levels of a control hierarchy, influencing recruitment of frontal cortical control regions depending on specific task demands.Key words: cognitive control; control hierarchy; fMRI; lateral frontal cortex; motivation; reward IntroductionOur decisions are driven by multiple factors, such as attention, motivation, emotion, and cognitive control. However, how these factors interact is not well understood. In particular, it is still under debate whether motivation and cognitive control operate independently to influence decision making (Kouneiher et al., 2009) or if these cognitive systems can also interact (Dreisbach and Goschke, 2004; Pessoa and Engelmann, 2010;Aarts et al., 2011).The lateral frontal cortex is a critical node in brain networks involved in cognitive control (Miller and Cohen, 2001; Fuster, 2004;Petrides, 2005;Duncan, 2010). Recent models of goaldirected behavior propose a hierarchical organization of the lateral frontal cortex as a function of different levels of cognitive control (Koechlin et al., 2003; Fuster, 2004; Badre and D'Esposito, 2009; Bahlmann et al., 2014). These models suggest that lower levels of cognitive control, such as choosing a specific motor response, are integrated within higher levels of cognitive control that guide behavior over longer time lags and at more complex levels of action contingency. Importantly, different levels of cognitive control are proposed to be represented in lateral frontal cortex along a rostro-caudal gradi...

Dopamine Does Double Duty in Motivating Cognitive Effort

“…This particular study showed that incentives yielded an additive increase in BOLD signal, on top of demand-driven control signals. However, more recent work has shown that incentive information is not merely additive, but interactive: with increasing incentive-related activity under high task-demand conditions, thus more directly implicating incentives in the enhancement of cognitive control (Bahlmann et al, 2015), cf. (Krebs et al, 2012).…”

Lifetime use of cannabis from longitudinal assessments, cannabinoid receptor (CNR1) variation, and reduced volume of the right anterior cingulate

“…Non-human primate studies using both lesions of the ACC and neuronal recording have demonstrated that ACC is critical for learning the value of actions (Kennerley et al, 2006; Amemori et al, 2015). An fMRI study examining the influence of motivation on the control hierarchy in the human frontal cortex found that the right anterior cingulate was one of the regions with the most significant Z max further supporting the importance of this region in motivation (Bahlmann et al, 2015). If long-term use of cannabis is associated with reduction in volume of the right anterior cingulum, the potential for changes in motivated behaviors appears to be a possibility.…”

Neural mechanisms underlying the reward‐related enhancement of motivation when remembering episodic memories with high difficulty

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