Being oriented in a new environment and finding and remembering the locations of resources are critical skills for human existence. When exploring a new city, tourists often wander through the streets, with the goal of visiting individual sites and taking in specific views. Through this wandering, they gain an understanding of the network of the city streets. When returning to their hotel, they are unlikely to retrace their steps. They also will not take a straight-line shortcut. Instead, they will draw on what they have learned about their environment to determine a path home using the city streets. How are tourists able to find their way back, based on experience alone, yet unable to determine a straight-line shortcut? This project addresses the challenging problem in the study of human navigation: What is the underlying geometric structure of our navigational knowledge? Is it truly a cognitive map, as is commonly assumed? Is it something coarser and more fluid? We propose that the underlying structure is a graph?a series of connections between places in a network, much like city streets. The overarching goal of this proposal is to test hypotheses about graph knowledge and its properties using walking virtual reality (VR) methods. Outcomes of this research have the potential to impact other fields, including robotics, neuroscience, mathematics, and geography. The interdisciplinary research proposed here will establish a deep understanding of the theory and cognitive mechanisms of spatial orientation, with far-reaching impacts. Greater knowledge of the basic properties of human navigational systems will lead to improved and more effective electronic navigation and GPS systems, self-driving vehicles, emergency response training, and transportation signage. Dr. Chrastil is committed to training the next generation of scientists and increasing the participation of underrepresented groups in STEM fields. As part of this proposal, Dr. Chrastil will develop a workshop on research methods for virtual reality to train researchers on this exciting technique. She actively participates as a teacher and mentor for programs that encourage participation of women and girls in science.
This project specifically tests the hypothesis that the most likely structure of navigational knowledge is a labeled graph, which incorporates local metric information but is not globally consistent across the environment. We have previously conducted an initial test of the idea of a cognitive graph, demonstrating that graph spatial knowledge is used preferentially rather than simply learning routes between locations (Chrastil & Warren, 2014). However, a systematic test of labeled graph knowledge has not been conducted. Little is known about how graph knowledge is constructed during learning or whether labeled graphs are used across all individuals and situations. Here, we propose a framework detailing the theoretical contributors to graph knowledge. We will also test the relationship between graph knowledge and other spatial knowledge taxonomies. In a series of experiments, we will use fully-immersive virtual reality to test hypotheses regarding the nature of spatial knowledge. First, we will characterize the nature of cognitive graphs by pitting labeled graph knowledge against other types of spatial knowledge and testing a primary prediction of labeled graph knowledge. Next, we will test the constraints on labeled graph knowledge, such as generalizability across contexts, its relationship to other taxonomies, and spatial preference. Finally, we will examine the mechanisms of learning labeled graph knowledge, in particular the deployment of attention and active decision making. This research cuts across levels of analysis by contrasting local and global levels of spatial understanding and by pitting labeled graphs against other spatial systems. The results of the proposed work will provide critical insight into the fundamental formation of human spatial knowledge and will contribute to the fields of robotics and neuroscience.
This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
