Cognitive Aspects: How People Perceive, Memorize, Think and Talk About Landmarks - Landmarks: GIScience for Intelligent Services - page 65

external to the infant's or young child's body). A significant portion is about
vista, environmental and (later) geographic scale [ 146 ] , and thus about localization,
orientation and navigation.
Piaget and Inhelder [ 166 ] observed that children at certain ages approach
spatial problems systematically different from adults. They postulate stages in
the development of spatial abilities. The first stage, from birth to age two, is
a sensorimotor stage where children form first notions of space based on their
visual, aural, gustatory, olfactory or tactile perception, and their sense of movement
(proprioception and equilibrioception) in a strictly egocentric frame of reference.
Later, at the age of two to seven (the pre-operational stage), children note the
topological properties of objects in the environment, and consider properties such
as separation, continuity and connectedness, closure, containment, and proximity
(the latter is, strictly speaking, not a topological property). Children at this age
can make qualitative judgements. A child can recognize which one of two lines
is longer at an age long before it can estimate or measure a quantitative value of
length [ 166 ] . Also at this stage transitions from egocentric to allocentric frames
of reference can be observed. This transition is facilitated by landmarks. When
Acredolo [ 1 ] led children of this age group into a room and asked them to search
for a trinket they learned the room in an egocentric manner, but once landmarks
were present in a room, these children did no longer rely on an egocentric search
heuristic but considered the location of the landmarks as well. But much earlier
than that, demonstrated at the age of 6 month already, infants can associate markers
(landmarks) with an expected location of an event [ 179 ] .
Only after this phase, at the age of seven to eleven (the concrete operational
stage), children develop an understanding of projective properties of space, of
distances and angles, and start thinking logically. From the age of eleven onwards
(the formal operational stage) children develop abstract thinking, learn Euclidean
properties of space, and order along dimensions of space.
Piaget and Inhelder's observations underscore that the notion of topology is
sufficient for forming spatial schemata and solving many spatial problems including
navigation. Metric notions, in this regard, are mostly needed for refinement, for
example, for navigating the shortest route. Accordingly, mental spatial repre-
sentations develop notions of topology long before, or treat topology as more
fundamental than metric notions. We will see later a reflection of this order in
communication about space.
Research has also investigated how children develop skills in reading maps, i.e.,
external spatial representations. Liben and Myers provide a review [ 122 ] . Children
have to learn that maps are representations: “the child must first have the basic
understanding that one thing can be used to stand for something else” (p. 198), and
“abasicchallenge[...] isforchildrentolearn todifferentiatewhichqualities of the
symbols carry meaning and which are simply incidental objects of the symbols”
(p. 199). The child's interpretation of the map is linked to their developmental
stage or age. Correspondences between the environment and the map have to be
established, and some of them are of topological nature, some of them metric. The
metric ones are understood only by older children. Age differences show also in