Repetitive transcranial magnetic stimulation over dorsolateral prefrontal cortex modulates value-based learning during sequential decision-making

Abstract

Adaptive behavior in daily life often requires the ability to acquire and represent sequential contingencies between actions and the associated outcomes. Although accumulating evidence implicates the role of dorsolateral prefrontal cortex (dlPFC) in complex value-based learning and decision-making, direct evidence for involvements of this region in integrating information across sequential decision states is still scarce. Using a 3-stage deterministic Markov decision task, here we applied offline, inhibitory low-frequency 1-Hz repetitive transcranial magnetic stimulation (rTMS) over the left dlPFC in young male adults (n = 31, mean age = 23.8 years, SD = 2.5 years) in a within-subject cross-over design to study the roles of this region in influencing value-based sequential decision-making. In two separate sessions, each participant received 1-Hz rTMS stimulation either over the left dlPFC or over the vertex. The results showed that transiently inhibiting the left dlPFC impaired choice accuracy, particularly in situations in which the acquisition of sequential transitions between decision states and temporally lagged action-outcome contingencies played a greater role. Estimating parameters of a diffusion model from behavioral choices, we found that the diffusion drift rate, which reflects the efficiency of information integration, was attenuated by the stimulation. Moreover, the effects of rTMS interacted with session: individuals who could not efficiently integrate information across sequential states in the first session due to disrupted dlPFC function also could not catch up in performance during the second session with those individuals who could learn sequential transitions with intact dlPFC function in the first session. Taken together, our findings suggest that the left dlPFC is crucially involved in the acquisition of complex sequential relations and in the potential of such learning.

Metacontrol of decision-making strategies in human aging

“…Indeed, underrecruitment of prefrontal brain regions in older adults is linked to impaired learning of task contingencies (Eppinger et al, 2015). Moreover, the importance of prefrontal brain regions for the representation of task structure is also in line with findings that transient inhibition of prefrontal areas leads to a reduction in model-based control and in the learning of sequential relations during value-based decision making (Smittenaar, FitzGerald, Romei, Wright, & Dolan, 2013;Wittkuhn et al, 2017). Future research should attempt to link aging-related neurobiological changes more directly to differences in modelbased decision making.…”

Effects of a Multi-Session Cognitive Training Combined With Brain Stimulation (TrainStim-Cog) on Age-Associated Cognitive Decline – Study Protocol for a Randomized Controlled Phase IIb (Monocenter) Trial

“…We designed a cognitive training with two cognitive tasks that are mediated by the prefrontal cortex, vulnerable to the effects of aging, and well suited to examine effects of practice over multiple sessions in older adults (Dahlin et al, 2008; Eppinger et al, 2015; Wittkuhn et al, 2018). The primary task (letter updating) has shown good applicability and training-induced plasticity in older adults (Dahlin et al, 2008).…”

“…The second training task will be a three-stage Markov decision-making task (Eppinger et al, 2015; cf. Tanaka et al, 2016; Wittkuhn et al, 2018), presented on a laptop computer. Participants will be instructed to choose between two actions, i.e., pressure of left or right key, which results in an action-related reward (monetary gain or loss).…”

Cognitive training and brain stimulation in prodromal Alzheimer’s disease (AD-Stim)—study protocol for a double-blind randomized controlled phase IIb (monocenter) trial

“…Second, participants will be presented with a three-stage Markov decision-making task on a laptop computer (cf. [ 24 , 35 , 36 ]), where they have to choose between two actions, i.e., pressure of left or right key, which results in an action-related reward (monetary gain or loss). The underlying Markov probability defines that a decision at a given state determines not only the reward, but also the transition into the next out of three decisional stages.…”