Differential recruitment of brain networks following route and cartographic map learning of spatial environments.

An extensive neuroimaging literature has helped characterize the brain regions involved in navigating a spatial environment. Far less is known, however, about the brain networks involved when learning a spatial layout from a cartographic map. To compare the two means of acquiring a spatial representation, participants learned spatial environments either by directly navigating them or learning them from an aerial-view map. While undergoing functional magnetic resonance imaging (fMRI), participants then performed two different tasks to assess knowledge of the spatial environment: a scene and orientation dependent perceptual (SOP) pointing task and a judgment of relative direction (JRD) of landmarks pointing task. We found three brain regions showing significant effects of route vs. map learning during the two tasks. Parahippocampal and retrosplenial cortex showed greater activation following route compared to map learning during the JRD but not SOP task while inferior frontal gyrus showed greater activation following map compared to route learning during the SOP but not JRD task. We interpret our results to suggest that parahippocampal and retrosplenial cortex were involved in translating scene and orientation dependent coordinate information acquired during route learning to a landmark-referenced representation while inferior frontal gyrus played a role in converting primarily landmark-referenced coordinates acquired during map learning to a scene and orientation dependent coordinate system. Together, our results provide novel insight into the different brain networks underlying spatial representations formed during navigation vs. cartographic map learning and provide additional constraints on theoretical models of the neural basis of human spatial representation

Learning Deployable Navigation Policies at Kilometer Scale from a Single Traversal

Model-free reinforcement learning has recently been shown to be effective at learning navigation policies from complex image input. However, these algorithms tend to require large amounts of interaction with the environment, which can be prohibitively costly to obtain on robots in the real world. We present an approach for efficiently learning goal-directed navigation policies on a mobile robot, from only a single coverage traversal of recorded data. The navigation agent learns an effective policy over a diverse action space in a large heterogeneous environment consisting of more than 2km of travel, through buildings and outdoor regions that collectively exhibit large variations in visual appearance, self-similarity, and connectivity. We compare pretrained visual encoders that enable precomputation of visual embeddings to achieve a throughput of tens of thousands of transitions per second at training time on a commodity desktop computer, allowing agents to learn from millions of trajectories of experience in a matter of hours. We propose multiple forms of computationally efficient stochastic augmentation to enable the learned policy to generalise beyond these precomputed embeddings, and demonstrate successful deployment of the learned policy on the real robot without fine tuning, despite environmental appearance differences at test time. The dataset and code required to reproduce these results and apply the technique to other datasets and robots is made publicly available at rl-navigation.github.io/deployable

Increasing Food Safety Compliance With Online Resources

Presented to the Faculty of the University of Alaska Anchorage in Partial Fulfillment of the Requirements for the Degree of MASTER OF SCIENCEFood-borne illness is a top concern for public policy and public health in the U.S., causing nearly 48 million incidents yearly. The number of confirmed food-borne illness outbreaks has declined over recent years as regulation and control measures of the Food and Drug Administration have increased. However, despite increased regulations and decreased outbreaks, there are still a large number of food safety violations, and it is imperative that food service employers continue to encourage good food safety practices. Mandated training has produced varying results on the improved inspection scores of restaurant establishments, but understanding the barriers to food safety and employing food safety intervention measures has had positive results on improving the employees’ food safety compliance behaviors. There is an opportunity to explore new interventions and mediums to increase safe food handling behaviors. This project describes the development of a food safety resource, FoodSafetyKmowledge.org. The site exists as a singular location for managers to find all of the necessary safety and sanitation resources in one accessible and convenient place. The discussion and analysis includes feedback from other food service professionals, and I offer recommendations to improve the site for future use.Signature Page / Title Page / Abstract / List of Figures / Acknowledgements / Introduction / Literature Review / Method / Discussion / Conclusion / Reference

Ponte Las Pilas: Hidden Narratives and Latinidad at Macalester College

Latinxs in higher education, while numerous, still lag behind all major racial groups in terms of graduation. Why is that? It is society’s hope that education will provide equal opportunity and a path out of poverty, but are schools really providing equal opportunities for attainment or are they simply reproducing inequalities in society? To what extent does this idea, if at all, exist even at liberal and multiculturally focused institutions like Macalester? I ask first generation Latinx alumni to recount their college experiences at Mac in order understand how their narratives compared to those promoted in college advertisements on the official website and Youtube account. What emerges from interviews with alumni are intense feelings of isolation based on not only racial but also class differences. It seems that colleges and universities do a lot to bring racial and economic minorities onto their campuses but often lack a community to support them. Now the question is, what needs to change in order for higher education to become truly accessible

Barriers and Solutions to Advance Care Planning among Homeless-Experienced Older Adults.

Background/Objectives: Older homeless-experienced adults have low rates of advance care planning (ACP) engagement despite high rates of morbidity and mortality. To inform intervention development, we examined potential barriers and solutions to ACP engagement. Design: Cross-sectional qualitative study. Setting: We recruited adults who were homeless in the prior three years and ≥50 years of age in the San Francisco Bay Area, and recruited clinical stakeholders from a national meeting of homeless providers. We analyzed qualitative data using thematic analysis. Measurements: We conducted semistructured interviews with homeless-experienced older adults (n = 20) and focus groups with clinical stakeholders (n = 24) about perceived barriers and solutions to ACP engagement. Results: Participants considered ACP important, reflecting on deaths of people in their networks who had died. Participant-identified barriers to ACP included poor ACP knowledge, lack of familial ties and social isolation, competing priorities, avoidance and lack of readiness, fatalism and mistrust, and lack of ACP training for clinical and nonclinical staff. They identified solutions that included framing ACP as a way to provide meaning and assert choice, providing easy-to-read written documents focused on the populations' unique needs, tailoring content and delivery, initiating ACP in nonclinical settings, such as permanent supportive housing, and providing incentives. Conclusions: Both older homeless-experienced adults and clinical stakeholders believe that ACP is important, but acknowledge multiple barriers that impede engagement. By focusing on potential solutions, including capitalizing on opportunities outside of health care settings, focusing on the period after housing, and tailoring content, there are opportunities to improve ACP uptake

Lost in spatial translation - A novel tool to objectively assess spatial disorientation in Alzheimer's disease and frontotemporal dementia

Spatial disorientation is a prominent feature of early Alzheimer's disease (AD) attributed to degeneration of medial temporal and parietal brain regions, including the retrosplenial cortex (RSC). By contrast, frontotemporal dementia (FTD) syndromes show generally intact spatial orientation at presentation. However, currently no clinical tasks are routinely administered to objectively assess spatial orientation in these neurodegenerative conditions. In this study we investigated spatial orientation in 58 dementia patients and 23 healthy controls using a novel virtual supermarket task as well as voxel-based morphometry (VBM). We compared performance on this task with visual and verbal memory function, which has traditionally been used to discriminate between AD and FTD. Participants viewed a series of videos from a first person perspective travelling through a virtual supermarket and were required to maintain orientation to a starting location. Analyses revealed significantly impaired spatial orientation in AD, compared to FTD patient groups. Spatial orientation performance was found to discriminate AD and FTD patient groups to a very high degree at presentation. More importantly, integrity of the RSC was identified as a key neural correlate of orientation performance. These findings confirm the notion that i) it is feasible to assess spatial orientation objectively via our novel Supermarket task; ii) impaired orientation is a prominent feature that can be applied clinically to discriminate between AD and FTD and iii) the RSC emerges as a critical biomarker to assess spatial orientation deficits in these neurodegenerative conditions