A High-Definition tDCS and EEG study on model-based and model-free reinforcement learning: Non-invasive brain stimulation of the dorsolateral prefrontal cortex alters reinforcement learning strategies in humans
Starting Date
Principal Investigator
Dr. ZHEN, Shanshan (Duration: 24 months)

Understanding the neurocomputational mechanisms underlying reinforcement learning is fundamental to decision neuroscience and human intelligence. Two basic learning strategies have been proposed: habitual, automatic, fast model-free learning and deliberative, effortful, slow model-based learning. An overreliance on one strategy may lead to suboptimal decisions and has been linked to psychiatric disorders. Brain imaging studies have explored brain regions implicated in two learning strategies, but causal effects remain to be established. In this project, we will use low-cost, simple and safe high-definition transcranial direct current stimulation (HD-tDCS) to stimulate the dorsolateral prefrontal cortex (DLPFC) to establish the causal links between brain regions and learning strategies. We further use electroencephalogram (EEG) to delineate the HD-tDCS effects on outcome processing during learning. Our project sheds light on the role of the prefrontal cortex in model-based learning and may pave the way for HD-tDCS-based interventions for patients with addiction and other cognitive control-related psychiatric disorders.

The PI's lab studies strategic learning and decision-making in different populations using neuroscience techniques (e.g., fMRI/EEG/tDCS) and behavioral modeling to better understand their underlying psychological and neural mechanisms.

EEG studies with adults

EEG studies with children

Brain scanner (Magnetic resonance imaging)

4×1 HD-tDCS (Picture from