142 / 218
140
Chapter 7
y = 16
y = 6
y = - 6
reward - cognition - action
cognition - action
anterior
posterior
reward
cognition
action
reward - cognition
Figure 7.1
Hypothesized interactions between corticostriatal circuits
The red, green and blue vertical arrows between the cortical regions and the subparts of the striatum
indicate connections between parts of the frontal cortex involved in reward anticipation (motivation, in
red), task switching (cognition, in green) and response switching (action, in blue) and distinct regions
in the striatum. The additional arrows in the lower panel indicate directional information flow between
circuits, for example, from the reward circuit to the cognitive, and subsequently the action circuit (red
arrows). Stimulation with cTBS over the aPFC, dlPFC and PMC is indicated by the red, green and blue
thunderbolts, respectively. It is important to note that the arrows between the striatal regions indicate
information flow and do not reflect anatomical connections.
We aimed to investigate this functionally cascading architecture in humans by assessing the
consequences of manipulating distinct prefrontal regions for reward motivation, cognition
and action and associated signaling in distinct striatal subregions. To this end we used offline
inhibitory TMS, (continuous theta burst stimulation; cTBS) (Huang et al., 2005), aiming to
decrease neural signaling in three corticostriatal circuits (Ko et al., 2008; Volman et al., 2011;
Wischnewski and Schutter, 2015), combined with fMRI to measure the impact of stimulation
on task evoked activity in the striatum. Task-related processing was assessed using an
established paradigm that we have used extensively to investigate reward anticipation, task
switching and the effect of reward on task switching (Aarts et al., 2010; van Holstein et
al., 2011; Aarts et al., 2014a; Aarts et al., 2015). The cortical stimulation sites were selected