We have studied a patient with early D.A.T. who shows profound and selective impairment inthe perception of global spatial configuration. MRI scans show a mildly atrophic cortex, with a significant pronounced enlargement of the sulci at the level of the parieto-temporal junction in the right hemisphere. Both standard neuropsychological tests and quantitative neuropsychological measurements show severe impairment for all tasks requiring global synthesis from local elements. She is completely incapable of seeing 'hierarchical letters' (letters made up of smaller letters) , of seeing structure in the most obvious circular or radial glass pattern, of perceiving Kanitza figures of any kind, and has difficulties in perceiving single figures made from aligned Gabor patterns in noise. Where thresholds could be measured, they were at least more than one order of magnitude higher than the norm, while a series of tasks not requiring global integration were within standardized norms. Most interestingly, she could not see biological motion,even after extensive prompting, although thresholds for optic flow were within normal limits. The study suggests the existence of a specific neural substrate for perceiving global spatial structure, whether derived from static elements or from global motion.

A specific deficit for global processing of spatial structure / Piccini C.; Lauro-Grotto R.; Del Viva M.M.; Burr C.D.. - In: PERCEPTION. - ISSN 0301-0066. - STAMPA. - 28 Supplement:(1999), pp. 96-96.

A specific deficit for global processing of spatial structure

LAURO GROTTO, ROSAPIA;DEL VIVA, MARIA;BURR, DAVID CHARLES
1999

Abstract

We have studied a patient with early D.A.T. who shows profound and selective impairment inthe perception of global spatial configuration. MRI scans show a mildly atrophic cortex, with a significant pronounced enlargement of the sulci at the level of the parieto-temporal junction in the right hemisphere. Both standard neuropsychological tests and quantitative neuropsychological measurements show severe impairment for all tasks requiring global synthesis from local elements. She is completely incapable of seeing 'hierarchical letters' (letters made up of smaller letters) , of seeing structure in the most obvious circular or radial glass pattern, of perceiving Kanitza figures of any kind, and has difficulties in perceiving single figures made from aligned Gabor patterns in noise. Where thresholds could be measured, they were at least more than one order of magnitude higher than the norm, while a series of tasks not requiring global integration were within standardized norms. Most interestingly, she could not see biological motion,even after extensive prompting, although thresholds for optic flow were within normal limits. The study suggests the existence of a specific neural substrate for perceiving global spatial structure, whether derived from static elements or from global motion.
1999
Piccini C.; Lauro-Grotto R.; Del Viva M.M.; Burr C.D.
File in questo prodotto:
Non ci sono file associati a questo prodotto.

I documenti in FLORE sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificatore per citare o creare un link a questa risorsa: https://hdl.handle.net/2158/771283
Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus ND
  • ???jsp.display-item.citation.isi??? ND
social impact