I do not see it, but my brain knows what it means
New study published in Cortex
Milan, Italy, 29 May 2008 - Patients suffering from “hemineglect” cannot attend to, and hence cannot see, things presented to their left side. However, sometimes these ignored stimuli may be processed without awareness. In a paper published in the May 2008 issue of Cortex, Jerome Sackur and colleagues at Unité de Neuroimagerie Cognitive, Paris France, reported that unconscious processing in hemineglect is not limited to low level features of the stimuli.
The research was carried out on 4 right-handed female patients (40-56 years old), suffering from left unilateral neglect secondary to right hemispheric stroke and 14 neurologically normal, right handed patients (6 females, 9 males, 19-32 years old). An additional group of 4 neurologically normal age-matched control subjects was separately tested on the main experiment.
By analyzing the results of their experiment, the authors showed that the brain may extract the meaning of symbols that the patient has not consciously perceived. Thus, digits or number words presented on the left side were not detected by hemineglect patients, but still their numerical value influenced the way these patients performed on a numerical task presented shortly thereafter.
“This study demonstrates that in hemineglect the left part of the world is not a ''blind'' region: in a way, patients read and understand unconsciously what is there” says Dr. Sackur, coordinator of the study. “However, the patients cannot make conscious use of this information”.
# # #
Notes to Editors:
The article is “Semantic processing of neglected numbers” by Jerome Sackur, Lionel Naccache, Pascale Pradat-Diehl, Philippe Azouvi, Dominique Mazevet, Rose Katz, Laurent Cohen and Stanislas Dehaene, and it appears in Cortex, Volume 44, Issue 6, 2008, pp 673-682, published by Elsevier Masson, in Italy. Full text of the article featured above is available upon request. Contact firstname.lastname@example.org to obtain a copy. To schedule an interview contact Dr. Jerome Sackur, Jerome.email@example.com
Cortex is an international journal devoted to the study of cognition and of the relationship between the nervous system and mental processes, particularly as these are reflected in the behaviour of patients with acquired brain lesions, normal volunteers, children with typical and atypical development, and in the activation of brain regions and systems as recorded by functional neuroimaging techniques. It was founded in 1964 by Ennio De Renzi. The Editor in-chief of Cortex is Sergio Della Sala, Professor of Human Cognitive Neuroscience at the University of Edinburgh. Fax: 0131 6513230, e-mail: firstname.lastname@example.org. Cortex is available online at http://www.sciencedirect.com/science/journal/00109452
Elsevier is a global information analytics business that helps scientists and clinicians to find new answers, reshape human knowledge, and tackle the most urgent human crises. For 140 years, we have partnered with the research world to curate and verify scientific knowledge. Today, we’re committed to bringing that rigor to a new generation of platforms. Elsevier provides digital solutions and tools in the areas of strategic research management, R&D performance, clinical decision support, and professional education; including ScienceDirect, Scopus, SciVal, ClinicalKey and Sherpath. Elsevier publishes over 2,500 digitized journals, including The Lancet and Cell, 39,000 e-book titles and many iconic reference works, including Gray's Anatomy. Elsevier is part of RELX Group, a global provider of information and analytics for professionals and business customers across industries. www.elsevier.com
Elsevier Masson, Italy
+39 02 88184 260