The hippocampus (HPC) is a labile structure capable of neurogenesis and synaptic plasticity throughout the lifespan, which is thought to underlie its role in learning and memory, particularly of autobiographical and spatial events. Numerous studies have associated the integrity of the hippocampus with performance in way-finding. In fact, it has been demonstrated that individuals who acquired a cognitive representation of an environment with greater ease possessed more hippocampal gray matter, which was positively correlated with experience. These and other similar studies have suggested that the hippocampus' ability to process spatial memory can be modulated by experience or practice.
Studies have demonstrated increased grey matter in the HPC of both young and older human adults as a function of memory training. Interestingly, the HPC shows signs of neurogenesis across the entire lifespan and, in adult primates, this HPC neurogenesis can be stimulated through learning and memory programs that increase HPC cellular survival. Similar training programs may thus enhance HPC cellular survival in Mild Cognitive Impairment (MCI) patients by focusing on the region where the pathology first emerges. While several memory intervention studies have shown success in alleviating memory impairments in participants with subjective cognitive impairment, MCI, and in patients with Alzheimer's disease by presumably affecting the HPC, this has not yet been supported by brain imaging or assessment. By contrast, using virtual reality-based tools, the investigators have developed an innovative learning and memory program. In previous research with healthy older adults, the investigators have shown that spatial memory intervention program (SMIP) improves cognition and hippocampal-based spatial memory compared to controls. In addition, the investigators have shown a positive impact of such training on HPC grey matter. These grey matter changes in the HPC were beneficial to healthy cognition as they correlated to improvements in memory.
In the current study, the investigators propose a randomized controlled trial comparing the effects of a 12-week spatial memory intervention to an active control condition. The design will be stratified according to age, education, and sex. After an eligibility assessment at baseline, participants meeting inclusion criteria will be randomly allocated to one of the two groups with a 50% probability of being enrolled in either a spatial memory intervention or an active placebo condition. In addition, participants will be given a pre-training psychometric battery, which will be repeated twice during two post-training sessions (at one- and 26 weeks post-training) to assess cognition, daily functioning, stress, health, physical activity, quality of life, and self-esteem. The battery will also include independent computerized spatial memory tests assessing the generalization of cognitive improvement in the spatial domain, as well as paper and pencil memory tests described below.