The middle house or the middle floor: Bisecting horizontal and vertical mental number lines in neglect.
2989 - 3000.
This study explores the processing of mental number lines and physical lines in five patients with left unilateral neglect. Three tasks were used: mental number bisection ('report the middle number between two numbers'), physical line bisection ('mark the middle of a line'), and a landmark task ('is the mark on the line to the left/right or higher/lower than the middle of the line?'). We manipulated the number line orientation purely by task instruction: neglect patients were told that the number-pairs represented either houses on a street (horizontal condition) or floors in a building (vertical condition). We also manipulated physical line orientation for comparison. All five neglect patients showed a rightward bias for horizontally oriented physical and number lines (e.g. saying 'five' is the middle house number between 'two' and 'six'). Only three of these patients also showed an upward bias for vertically oriented number lines. The remaining two patients did not show any bias in processing vertical lines. Our results suggest that: (1) horizontal and vertical neglect can associate or dissociate among different patients; (2) bisecting number lines operates on internal horizontal and vertical representations possibly analogous to horizontal and vertical physical lines; (3) at least partially independent mechanisms may be involved in processing horizontal and vertical number lines. (C) 2007 Elsevier Ltd. All rights reserved.
|Title:||The middle house or the middle floor: Bisecting horizontal and vertical mental number lines in neglect|
|Open access status:||An open access publication|
|Keywords:||neglect, number line, physical line, bisection, number cognition, task-dependence, UNILATERAL NEGLECT, VISUAL NEGLECT, REPRESENTATIONAL SPACE, PSYCHOMETRIC FUNCTION, HEMISPATIAL NEGLECT, ALTITUDINAL NEGLECT, PARIETAL CORTEX, LANDMARK TASK, BRAIN-DAMAGE, ATTENTION|
|UCL classification:||UCL > School of Life and Medical Sciences > Faculty of Brain Sciences > Psychology and Language Sciences (Division of) > Institute of Cognitive Neuroscience
UCL > School of Life and Medical Sciences > Faculty of Brain Sciences > Institute of Neurology
UCL > School of Life and Medical Sciences > Faculty of Life Sciences
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