Tversky, B. Language and Space. MIT Press, Cambridge, MA, USA, 1996, ch. Spatial Perspective in Descriptions, pp. 463–491.

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Thaking other points of view is essential for a range of cognitive functions and social interactions, from recognizing an object from a novel point of view to navigating an environment to understand someone else’s position. This chapter tries at first to reconciliate different perspectives from different disciplines on spatial perspectives.

There are three bases for spatial reference: the viewer, other objects and external sources. These three bases seems to correspond to deictic, intrinsic and extrinsic uses of language. An interesting point is that deictic uses cannot be accounted for by the language alone. They require additional knowledge of the interactional situation in which they are produced.

Depending on the complexity of the task, the speaker can decide to take his own perspective, the perspective of the addressee or a neutral perspective, using a landmark, referent object, on the extrinsic system as a basis for the spatial reference.

The world is multidimensional but speech is linear. To describe the world linearly, it makes sense to choose an order. A natural way of conveying an environment is through a mental tour. These tours can differenciate between gaze tours and walking tours. In gaze tours the noun phrases are usually headed by objects and the verbs express states. In a walking tour, the noun phrases are headed by the addressee and the verbs express actions.

The choice of the perspective taken and the particular trategy chosed to encode the spatial situation will depend closely by the number of mental transformations required to produce or to understand an utterance. It stands to reason that speakers would avoid cognitively difficult tasks.

The chapter also report an interesting study on map descriptions. After learning a map, subjects were asked to describe them from memory. Two possible descriptions were found: a route description takes the reader on a mental tour. It uses a changing view and locates landmarks in respect to the addressee. A survey description, in contrast, takes a static view from above the environments and locates landmarks with respect to each other.

Going beyond perspective is critical to spatial cognition.