KEYNOTE LECTURES
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Spatial Representation and Updating: Evidence from
Neuropsychological Investigations
Marlene Behrmann and John Philbeck
How spatial information is represented and updated over time and over
changes in the position of the stimulus and/or observer is considered in
the context of a population of patients who have impairment in spatial
perception. We present data both from our own research with patients suffering
from hemispatial neglect as well as from studies in the literature. Taken
together, these studies suggest that spatial information is coded in more
than one spatial frame of reference simultaneously and that the choice
of reference frame depends on the demands of the tasks. Once the stimulus
is located, however, the patients are able to update the position of the
stimulus dynamically when walking or when undergoing passive rotation.
The insights obtained from this neuropsychological population provides
converging evidence for the psychological and neural mechanisms which mediate
spatial representation and dovetail well with existing single unit recording
and functional imaging data.
A Geographer Looks at Spatial Information Theory
Michael F. Goodchild
Geographic information is defined as a subset of spatial information,
specific to the spatiotemporal frame of the Earth’s surface. Thus geographic
information theory inherits the results of spatial information theory,
but adds results that reflect the specific properties of geographic information.
I describe six general properties of geographic information, and show that
in some cases specialization has assumed other properties that are less
generally observed. A recognition of the distinction between geographic
and spatial would allow geographic information theory to achieve greater
depth and utility.
How Spoken Language and Signed Language Structure Space
Differently
Leonard Talmy
Linguistic research to date has determined many of the factors that
structure the spatial schemas found across spoken languages. It is now
feasible to integrate these factors and to determine the comprehensive
system they constitute for spatial structuring in spoken language. This
system is characterized by several features: It has a relatively closed
universally available inventory of fundamental spatial elements that are
combined to form whole schemas. It has a relatively closed set of categories
that these elements appear in. And it has a relatively closed small number
of particular elements in each category, hence, of spatial dis-tinctions
that each category can ever mark. An examination of signed language shows
that its structural representation of space systematically differs from
that in spoken language in the direction of what appear to be the structural
characteristics of scene parsing in visual perception. Such differences
include the following: Signed language can mark finer spatial distinctions
with its inventory of more structural elements, more categories, and more
elements per category. It represents many more of these distinctions in
any particular expression. It also represents these distinctions independently
in the expression, not bundled together into "pre-packaged" schemas. And
its spatial representations are largely iconic with visible spatial characteristics.
The findings suggest that instead of some discrete whole-language module,
spoken language and signed language are both based on some more limited
core linguistic system that then connects with different further subsystems
for the full functioning of the two different language modalities.