A review of Mind and MazeAnn Sloan Devlin, 2001Preetha Lakshmi & Chris Mueller CSCI 8715Devlin presents a wide-ranging overview of topics and research in spatial cognition. She explores the development of spatial cognition, gender differences, physiological causes, map-making and route-finding, and urban planning. Combined, these explorations present a coherent and interesting understanding of human spatial abilities. Devlin makes effort to provide advice to designers, map-makers, and urban planners when the research indicates this would be appropriate, in particular: the division of memory into hierarchical chunks; the importance of landmarks; issues of scale; and assumptions about age as a predictive factor in spatial cognition.The selection of source material for Mind and Maze is mostly from psychology, though Devlin makes aconscious effort to include research on urban planning and map-making as well.The exploration of spatial cognition begins with theories of cognitive development. In general, childrenare less spatially aware than adults, and it's possible to categorize this development into distinct stages. Several models exist. Most literature suggests young children tend to be egocentric and unable to place themselves in another person's shoes. More recent studies suggest egocentrism is a naïve assumption, and that young children perform spatial tasks better when presented with objects and characters they are familiar with, such as their mothers or characters from Sesame Street. The “mother as landmark” theory is very powerful, and suggests that landmarks are critical for spatial cognition from a very young age.Another prominent theme in the literature of cognitive spatial development is the necessity of movement for understanding space. In way-finding exercises, people presented with films or slides of places perform significantly worse in real-world route-finding than people who have received guided tours of the environment. Some studies suggest that virtual tours of places are as effective as real-worldtours for developing a useful mental model of space. Devlin's review of the neurophysiological foundations of spatial cognition misses key points in work by O'Keefe (1978) as well as more recent research concerning the mapping of spatial directions and motion directly into neuronal structure. McNaughton, et. al (2006) provide a more complete survey of this research. Current cognitive models indicate that two types of neuronal networks directly map to directional motion and translational motion, respectively. Head direction cells can be thought of as a ring of cells corresponding to viewer-centric directions: when the animal turns, activity in the ring becomes greater at the new directional heading. Similarly, place cells provide a mapping of translational motion: neuronal topology is toroidal, and activity looping around this topology during movement produces a grid of activity maxima over time. The grid can be at many different scales depending on the environment. The hippocampus helps to encode memories of specific events and landmarks with respect to places by interacting with this grid of place cells. Encoding of place cells is almost completely dependent on self-motion (locomotion). This model suggests that place cells are located in a region called the medial entorhial cortex, rather than the hippocampus as first suggested by O'Keefe. Further studies have indicated that new environments produce unique grids not dependent or related to previous grid behavior; however, any time an animal enters an environment it has encountered before, regardless of its initial starting location in that environment, the grid structure seen previously is duplicated exactly. The implications of such a powerful and direct mapping of physicalspace into neuronal space are astounding. Landmarks are crucial to the development of mental models of space. One model of cognitive development suggests three kinds of learning systems: landmark knowledge, route learning (paired associations of landmarks), and configurational networks of landmarks. Other studies have shown that a Euclidean understanding of an environment is not nearly as important for way-finding tasks, unless the test subject has been presented with a map prior to attempting any tasks. In general, people with a lot of experience navigating an environment tend to not understand that environment in terms of its Euclidean properties, unless they have also seen a map of the space; instead, these people rely on landmarks and networks of landmarks to navigate. Furthermore, when giving or receiving directions, natural language is an effective mechanism for route navigation. Modern GPS systems take this into account when giving directions, e.g. a speech synthesizer produces phrases such as, “Turn left in 200 yards.” This correlation between language and spatial cognition is perhaps related to brain-hemispherical mappings of cognitive tasks. The left brain has been shown to be better suited for complex spatial tasks, such as mental rotation of objects and perception of complex scenes; whereas the right brain is often used for purer tasks such as determining line orientation. The overlap between hemispheres is significant, but it's worth considering that human brains are capable of both verbal and spatial