Brain, Vol. 122, No. 2, 339-350,
February 1999
© 1999 Oxford University Press
Selective horizontal dysmetropsia following prestriate lesion
1 Dipartimento di Patologia Neuropsicosensoriale, Università di Modena, 2 Dipartimento di Psicologia, Università di Bologna, Italy
Correspondence to:
Paolo Nichelli, MD, Dipartimento di Patologia Neuropsicosensoriale, Sezione di Neurologia, Università degli Studi di Modena, Largo del Pozzo 71, 41100 Modena, Italy. E-mail: nichelli{at}unimo.it
We describe a patient (P.S.) who, following a right prestriate lesion, reported that objects in the left visual field appeared distorted and smaller than those on the right. Other aspects of visual processing were remarkably unaffected. We carried out a series of size comparison tests using simple or complex stimuli and requiring different types of behavioural responses. We found that P.S. significantly underestimated the size of stimuli presented in her left visual field. When comparison tasks involved stimuli placed along the vertical axis or in the right visual field, P.S. performed well. The vertical and horizontal components of size distortion were found to be differentially affected. We conclude that size processing may be dissociated from other aspects of visual processing, such as form or colour processing, and depends critically on part of the occipital, prestriate areas (Brodmann areas 1819).
size perception; micropsia; dysmetropsia; visual perception
BA = Brodmann area; JND = just noticeable difference; PSE = point of subjective equality
![]()
CiteULike
Connotea
Del.icio.us What's this?
This article has been cited by other articles:
![]() |
M.-G. Park, K.-D. Choi, J. S. Kim, K.-P. Park, D.-S. Kim, H. J. Kim, and D. S. Jung Hemimacropsia after medial temporo-occipital infarction J. Neurol. Neurosurg. Psychiatry, May 1, 2007; 78(5): 546 - 548. [Full Text] [PDF] |
||||
![]() |
G. Rode, C. Michel, Y. Rossetti, D. Boisson, and G. Vallar Left size distortion (hyperschematia) after right brain damage Neurology, November 28, 2006; 67(10): 1801 - 1808. [Abstract] [Full Text] [PDF] |
||||
![]() |
S. Ferber and H.-O. Karnath Size perception in hemianopia and neglect Brain, March 1, 2001; 124(3): 527 - 536. [Abstract] [Full Text] [PDF] |
||||


