Attenuating the stress-induced bias towards habit memory through hippocampal self- neuromodulation

• Applicant: Professor Dr. Lars Schwabe
• Subject Area: Biological Psychology and Cognitive Neuroscience
• Term: since 2022
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 508413974

Stress may have a critical impact on our health and well-being, partly due to stress-induced changes in cognition. Stress effects on learning and memory processes are particularly well documented, showing that stress not only affects how much we learn and remember but also what and how we learn. In particular, stress promotes a shift from hippocampus-dependent ‘cognitive’ memory to dorsal striatum-dependent ‘habit’ memory. This shift is thought to play an important role in mental disorders in which both dysregulated stress systems and aberrant memory processes are prominent, such as post-traumatic stress disorder (PTSD) or addiction. The primary objective of the present project is to test whether hippocampus targeted neurofeedback (NF) aimed to upregulate self-control over its activity can be used to strengthen ‘cognitive’ memory processing under stress and hence attenuate the stress-induced shift towards striatum-dependent ‘habit’ memory. To this end, two experiments will be conducted in Hamburg and Tel Aviv, using state-of-the-art imaging techniques along with advanced computational methods of machine learning and modelling. In a first experiment, healthy participants will undergo a standardized stress or control procedure before they are trained via fMRI-NF (test or sham) to upregulate their hippocampus activity. Thereafter, they will complete a learning task, in the scanner, that can be acquired by the hippocampus or the dorsal striatum and thus reveals the relative engagement of multiple memory systems. In a second experiment, simultaneous fMRI/EEG recording will be used to develop an Electrical-Finger Print (EFP) of the fMRI hippocampal activity. The capacity of this EFP to modulate the engagement of multiple memory systems during probabilistic classification learning will be tested in an additional (pilot) experiment. This project will provide novel insights into the theoretical and clinical aspects of stress effects on learning and memory. From a theoretical perspective, it will provide causal inference to brain mechanisms underlying stress effects on learning and memory, in particular the engagement of multiple memory systems. From a clinical perspective, it will point to new avenues of how stress effects on cognition can be counteracted, while using a scalable novel computational approach for non-invasive localized neural modulation. The study may thus have critical implications for educational and/or work-related settings and, most importantly, for stress-related mental disorders. This will be a joint project of PIs from Hamburg and Tel Aviv who bring in unique capabilities in stress, memory and neuroimaging research, the combination of which is essential for the success of this ground-breaking project.

• DFG Programme: Research Grants
• International Connection: Israel
• International Co-Applicant: Professorin Dr. Talma Hendler