Learning and consolidation of salient information: The causal role of theta oscillations

• Applicant: Dr. Matthias Gruber, Ph.D.
• Subject Area: General, Cognitive and Mathematical Psychology
• Term: from 2014 to 2016
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 264626455

Our memories are selective. Despite our best efforts, we can only remember a fraction of the events that we experience. Motivational salience is an important factor that determines the encoding and persistence of memories. Two disparate lines of research have shown that motivational salience is strongly associated with frontal neural oscillations in the theta band (4-8 Hz) and by activity in the dopaminergic circuit linking dopaminergic regions with prefrontal regions and the hippocampus. To date, however, the relationship between frontal theta and the dopaminergic circuit in support of learning remains largely unknown in humans. This project will test the crucial questions (i) whether theta oscillations have a causal role in learning and (ii) how frontal theta states influence the neural mechanisms that support learning. To address these questions, we will use non-invasive transcranial Alternate Current Stimulation (tACS) to directly entrain theta oscillations during learning of motivationally salient and neutral information and measure its effects on behavior and the neural mechanisms involved by using electroencephalography (EEG) and functional magnetic resonance imaging (fMRI). Experiment 1 (a combined tACS-EEG study) will ask how theta entrainment during learning benefits memory for motivationally salient and neutral information. Experiment 2 (a combined tACS-fMRI study) will ask how the boosting of theta oscillations will enhance (i) learning via the cortico-mesolimbic dopaminergic circuit and (ii) memory retention via increased neural replay of information. Importantly, this project not only has the potential to advance our knowledge about the causal role of theta oscillations in learning and memory consolidation, but could also lead to important benefits for applied settings (e.g. how to improve learning in education or to rehabilitate memory in clinical settings). Moreover, this project will greatly extend my expertise in the field of cognitive neuroscience by learning tACS and advanced multivariate pattern analyses for fMRI data, thereby equipping the applicant with a variety of complex tools to be an independent memory researcher.

• DFG Programme: Research Fellowships
• International Connection: USA
• Host: Professor Dr. Charan Ranganath