Understanding and improving hippocampal neuroplasticity through allocentric spatial navigation training

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Enhancing everyday learning and memory capacity in healthy young adults has long been an elusive goal of academic research and commercial enterprise. Arguably, one of the most important aims of research in experience dependent plasticity is “far transfer”, referring to generalizable and flexible cognitive benefits of experience/training that extend beyond the training context and into the real world. A large body of literature on environmental enrichment (EE) shows that neurologically vulnerable animals and humans (e.g., brain injured, pre-mature) demonstrate experience-dependent neuroplastic change, with some studies showing concomitant behavioural improvements. But there is a notable gap when it comes to healthy young adults. The long-term vision of our research program is to understand mechanisms of EE on the HC and on far transfer, with a greater understanding of how the HC mechanistically supports far transfer. A small body of promising research points to allocentric spatial navigation to achieve this. Allocentric spatial navigation - navigation from a “bird's eye view” necessitating the creation of a mental map of one's environment - is known to robustly activate and enhance the hippocampi.(HC) Those who use this type of navigation have larger HC that are less vulnerable to accelerated aging processes. Combining allocentric spatial navigation with EE (i.e., intensive, continuously novel and engaging cognitive stimulation) has been found to offset normal HC decline in healthy young and older male adults and with modest memory increases. Therefore, the proposed program of research will entail the delivery of an allocentric spatial navigation paradigm to healthy young male adults harnessing the principles of EE. Comprehensive, highly sensitive and specific “far transfer' memory outcomes (including pattern generation and separation, location and declarative memory) will be administered along with comprehensive MRI imaging of the HC and related regions (including volumetric, DTI, MRS, CVR and ASL). In Project 1, performance will be compared to a generalized, non-targeted EE control protocol. It is hypothesized that intensive allocentric spatial navigation will result in structural and functional HC changes that will in turn give rise to generalizable enhancements to learning and memory. By augmenting the intensity of training (Project 2), it is hypothesized that these findings will be amplified, with more robust far transfer and HC-memory associations. Secondary sub-group analyses of the findings will permit exploration of factors known to affect the HC (e.g., age, education). Project 2 findings will provide groundwork for a next stage of research exploring the above mechanisms in a broader demographic sample, including older adults and females, and taking a more fine-grained approach to the impact of intensity of cognitive and neural changes.**