Neural Basis of Mental Scanning of a Topographic Representation Built from a Text

Mellet E(1), Bricogne S, Crivello F, Mazoyer B, Denis M, Tzourio-Mazoyer N.

Author information:
(1)CNRS UMR 6995, Université de Caen and Université Paris V, BP 5227, 14074 Caen
Cedex, France.

Humans have the ability to build and to inspect an internal visual image of an
environment built from a verbal description. We used positron emission
tomography (PET) to investigate the brain areas engaged in the mental scanning
of a map that subjects built from the reading of a descriptive text. This task
engaged a parieto-frontal network known to deal with spatial representations.
Additional activations were evidenced in the angular gyrus and in Broca’s and
Wernicke’s areas. In order to examine the neural impact of the learning
modality, these PET results were compared to those obtained in another group of
six subjects who performed a similar mental scanning task on a topographic
representation built from visual inspection of a map. Both scanning tasks
engaged the parieto-frontal network. However, the bilateral activation of the
angular gyrus as well as the involvement of language areas appeared specific to
the mental scanning of the topographic representation built from textual
information. On the other hand, the right medial temporal lobe was activated
only when a map had been visually learned. These results suggest that although
both tasks involved visuo-spatial internal representation, a trace of the
learning modality remained present in the brain.

DOI: 10.1093/cercor/12.12.1322
PMID: 12427682 [Indexed for MEDLINE]

Auteurs Bordeaux Neurocampus