Hyperschematia after right brain damage: a meaningful entity?
In recent years we reported three right-brain-damaged patients, who exhibited a left-sided disprortionate expansion of drawings, both by copying and from memory, contralateral to the side of the hemispheric lesion (Neurology, 67: 1801, 2006, Neurocase 14: 369, 2008). We proposed the term "hyperschematia" for such an expansion, with reference to an interpretation in terms of a lateral leftward distortion of the representation of extra-personal space, with a leftward anisometric expansion (relaxation) of the spatial medium. The symptom-complex shown by right-brain-damaged patients with "hyperschematia" includes: (1) a disproportionate leftward expansion of drawings (with possible addition of details), by copy and from memory (also in clay modeling, in one patient); (2) an overestimation of left lateral extent, when a leftward movement is required, associated in some patients with a perceptual underestimation; (3) unawareness of the disorder; (4) no unilateral spatial neglect. In most right-brain-damaged patients, left "hyperschematia" involves extra-personal space. In one patient the deficit was confined to a body part (left half-face: personal "hyperschematia"). The neural underpinnings of the disorder include damage to the fronto-temporo-parietal cortices, and subcortical structures in the right cerebral hemisphere, in the vascular territory of the middle cerebral artery. Here, four novel additional patients are reported. Finally, "hypeschematia" is reconsidered, in its clinical components, the underlying pathological mechanisms, as well as its neural underpinnings.
INSERM U1028, CNRS UMR5292, Centre de Recherche en Neurosciences de Lyon, Equipe ImpAct Bron, France ; Service de Médecine Physique et Réadaptation, Hôpital Henry Gabrielle, Hospices Civils de Lyon Saint Genis Laval, France.
Gilles
G
Rode
Laboratory of Cognitive Neuroscience, School of Life Sciences, Brain Mind Institute, Ecole Polytechnique Fédérale de Lausanne Lausanne, Switzerland.
Roberta
R
Ronchi
INSERM U1028, CNRS UMR5292, Centre de Recherche en Neurosciences de Lyon, Equipe ImpAct Bron, France.
Patrice
P
Revol
INSERM U1028, CNRS UMR5292, Centre de Recherche en Neurosciences de Lyon, Equipe ImpAct Bron, France.
Yves
Y
Rossetti
INSERM U1028, CNRS UMR5292, Centre de Recherche en Neurosciences de Lyon, Equipe ImpAct Bron, France ; Service de Médecine Physique et Réadaptation, Hôpital Henry Gabrielle, Hospices Civils de Lyon Saint Genis Laval, France.
Sophie
S
Jacquin-Courtois
Dipartimento di Psicologia, Università degli studi di Milano-Bicocca Milano, Italy.
Irene
I
Rossi
Dipartimento di Psicologia, Università degli studi di Milano-Bicocca Milano, Italy ; Neuropsychological Laboratory, IRCCS Istituto Auxologico Italiano Milano, Italy.
Giuseppe
G
Vallar
anisometry; extra-personal space; hyperschematia; representation