Navigation through Spatial Layout

Psychological Aspects

Navigating over large distances is a complex process, sometimes requiring specialized instruments, maps, charts, or training. By contrast, navigating over smaller distances or in familiar territory may be accomplished without any specialized equipment or training. However, the basic requirements for successful navigation remain the same at large and small scales. At a minimum, navigators must first become oriented—that is, they must determine their current position and orientation with respect to a map of the environmental layout. The map could be physical (printed on paper, or perhaps displayed on a computer monitor), or it could be internalized (the navigator's memory of the environment). Then, navigators must plan a convenient route from the current location to the destination. Finally, navigators must keep track of, or update, their changing position and orientation while traveling in order to execute the planned route.

Most human navigation research has focused on situations in which the destination is not directly visible. These situations naturally fall into two types: landmark-based navigation (or piloting) and path integration (or dead reckoning).

In landmark-based navigation, we can see the immediate environment, but not the destination. This might happen because the destination is far away or hidden behind other objects. In this situation, we visually determine the distance and direction to prominent objects or locations in the environment (“landmarks”); if we can see a landmark in the real world that is represented in our map, we can use the landmark to determine our position and orientation with respect to the map. For example, when driving to a new restaurant, we might navigate by following a simple sketch map containing landmarks such as “green house on the left” and “second stop sign.” When we see the green house on the left while traveling, we can determine our current location and orientation on the map and use this information to guide our progress toward the destination.

In path integration, our body sends signals to the brain about how fast we are moving, and we use this to determine our position and orientation relative to our starting point. For example, if our muscles tell our brain that we are walking at 1 meter per second (m/s), and we have been walking for 5 s, integrating this rate over 5 s shows that we are now 5 m from the starting position. Although path integration can certainly be performed by consciously estimating one's velocity and using mathematical calculating to integrate velocity over time, our brain is also capable of performing path integration without our explicit awareness. When walking across the room in the dark, for example, we may not be explicitly aware of our speed and how long we have been walking, but nevertheless we continue to feel oriented with respect to the room, despite having changed our location. This sense of orientation is based upon path integration. In real-world navigation, path integration might be used along with landmark-based navigation as we move about with our eyes open. However, most research focusing on path integration excludes the possibility of landmark-based navigation by asking people to navigate to a nearby destination with their eyes and ears covered.

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