Student Project: Using brain stimulation to modify decision-making in learned helplessness.

This is a project suitable for MSc or Forskerlinje students. It is also possible to participate in the research in the form of a BSc or semester project.

Summary:

Learned helplessness (LH) is closely related to disorders such as depression and chronic pain, characterized by behavioral passivity in response to uncontrollable aversive events. LH seems to be associated with dysfunctional interactions between the brain’s three valuation systems that mediate behavioral choices when facing rewarding or punishing stimuli. Here, we will investigate how LH affects value-based decision-making in healthy adults, and if non-invasive stimulation of the prefrontal cortex can restore the detrimental effects of LH on task performance.

Supervisors

Gabor Csifcsak, PhD, Cognitive Neuroscience Research Group.
Morten Øvervoll, University lecturer, Cognitive Neuroscience Research Group.
Matthias Mittner, PhD, Associate Professor, Cognitive Neuroscience Research Group.

 

Theoretical background
In our daily lives, we are constantly making decisions in order to maximize positive outcomes or to minimize negative events. This process is referred to as value-based decision-making (VBDM), which is mediated by three valuation systems: The Pavlovian, the habitual, and the goal-directed systems. Each system is characterized by different computational principles and by distinct neural mechanisms. It was suggested that altered activity within the Pavlovian system can be causally related to pathologically enhanced harm avoidance and reduced pleasure-seeking in patients with depression or chronic pain. This phenomenon seems to be linked to impaired interaction between prefrontal-limbic circuits in the brain. Moreover, the Pavlovian system has been implicated in learned helplessness (LH), which is closely related to both disorders. Therefore, we will investigate if experimentally-induced LH changes the degree of Pavlovian influences on VBDM, and if performance during LH can be normalized with transcranial direct current stimulation (tDCS).

Research question/ research hypothesis

  1. If LH is associated with worse task performance and increased Pavlovian influences in healthy adults.
  2. If tDCS of different regions of the prefrontal cortex can influence task performance in participants without LH-induction.
  3. If tDCS can improve task performance in participants with LH induction.

Design, Procedure, and Method
To study VBDM, we will use a special card game that has been designed to enable assessment of the interaction between the Pavlovian, goal-directed, and habitual systems. Participants will be randomized to four experimental groups: in two groups, we will induce LH by manipulating task difficulty, while the other two groups will serve as behavioral controls. In addition, half of the participants will receive real tDCS (http://www.neuroelectrics.com/products/starstim/starstim-8/) above the prefrontal cortex, while the other half will receive placebo stimulation. We will also collect data from questionnaires that ask about mood and personality traits, and use cognitive tests to measure working memory capacity.

Our main (dependent) variables will be overall task performance and behavioral indices that measure the degree of Pavlovian influences during the card game. We will compare these across the four experimental groups to assess if LH, tDCS, or both had an effect on VBDM. Scores from the questionnaires and cognitive tests will be used to control for latent factors (covariates) that might also influence task performance. We will use both conventional frequentist statistics and Bayesian approaches.

Student’s tasks and learning outcomes
The student will be responsible for recruiting participants, conducting data collection (setting up the brain stimulation protocol, supervising the card game, assessing questionnaires and cognitive tests), and contributing to data analysis. She/he will learn about the psychological and neurobiological background of VBDM and the main characteristics of the experimental protocol (including all practical aspects of tDCS). The student will be also named as a co-author on all publications related to this project.

Research environment and research group
The study will be performed within the Research Group for Cognitive Neuroscience at IPS. This research group has a good track record of conducting high-quality research (both in the field of tDCS and VBDM) and publishing in international peer-reviewed journals. The project will be supervised by Morten Øvervoll and co-supervised by Matthias Mittner. All technical aspects of the study (i.e., lab equipment) are already available at IPS. Our group has already conducted two studies using similar stimuli and tasks and we are therefore confident about its suitability as a productive student project.

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