Cognitive Aspects: How People Perceive, Memorize, Think and Talk About Landmarks - Landmarks: GIScience for Intelligent Services - page 94

3.4.5 What We Have Learned About Landmarks

from Externalizations of Mental Spatial Representations

All externalizations of mental spatial representations, such as maps, sketches,
and verbal descriptions, show rich use of landmarks. Triggered by at least two
filtering processes—first the selection, aggregation and abstraction process related
to maintaining or recalling the mental spatial representation of the speaker, and
secondly the filtering by the transformation into the language of the communication
medium—the externalizations tend to show what is relevant in a given communica-
tion context, and neglect the rest. For the same reasons externalizations tend to be
context-dependent and are by no means a representative image of the mental spatial
representation.
Landmarks provide the spatial reference frame for locating other objects in
an environment. Means for locating are spatial relationships, such as distances,
directions or orientations, projections, or containment. While graphical languages
preserve some ability to represent these relationships in a quantitative manner,
verbal descriptions, written or spoken, show a strong preference for qualitative
expressions. We remember Lynch's observation that people familiar with a city
show a tendency to rely more on landmarks in their sketches, which means they
rely on uniqueness, distinctness or local contrast rather than continuity. For route
directions, Michon and Denis [ 142 ] concluded that these references to landmarks
are intended to facilitate the construction of a mental spatial representation by the
recipient.

3.5 Summary

In summary, landmarks have a prominent role in spatial cognition, more specifically,
as points of reference in forming, maintaining, analysing and communicating spatial
mental representations. People equipped with this spatial mental representation
interact with their environments that are the subject of their mental spatial represen-
tations, but also with mediated experiences of these environments through external
spatial representations.
This complex system of physical environment, persons perceiving and interact-
ing with the environment, and (more and more electronic) information about this
environment has a classical form in the semiotic triangle [ 157 ] between a referent
(the object in the environment), the reference (a word or symbol for the object),
and an idea (a thought or knowledge about the object). Kuhn adopted the triangle
already to explore the interplay between language and landscape [ 107 ] , and our
version is shown in Fig. 3.9 . The 'knowledge in the mind' consists of the mental
spatial representation of the world, which is descriptive (the landmark, route or
survey knowledge described above), and strategies to utilize this representation,
the heuristics. The 'knowledge in the world' is the shape of the environment as