Space re-exploration in hemispatial neglect.
Exploration of the space around us is a fundamental part of human behaviour. When it breaks down there is an important opportunity to understand its underlying mechanisms. Here we show that many right-hemisphere patients with left neglect re-explore rightward locations, failing to keep track of them during search. Importantly, such re-exploration occurred despite leftward stimuli being indistinguishable in peripheral vision, so it is unlikely to result from implicit processing of neglected targets. Revisits generally occurred after visits to other targets and are therefore not immediate perseverations. Finally, manipulating the visual salience of found targets altered the degree of neglect, but not revisit rates. Space exploration appears to be modulated both by the ability to keep track of spatial locations and by stimulus salience.
Parton
Andrew
A
Centre for Cognition and Neuroimaging, Brunel University, Uxbridge, London, UK. andrew.parton@brunel.ac.uk
Malhotra
Paresh
P
Nachev
Parashkev
P
Ames
Diane
D
Ball
Joanna
J
Chataway
Jeremy
J
Husain
Masud
M
D000368:Aged; D001921:Brain / Q000503:physiopathology; D005106:Exploratory Behavior / Q000502:physiology*; D007839:Functional Laterality / Q000502:physiology*; D006801:Humans; D008875:Middle Aged; D008959:Models, Neurological; D009483:Neuropsychological Tests; D009949:Orientation / Q000502:physiology*; D010468:Perceptual Disorders / Q000175:diagnosis / Q000503:physiopathology* / Q000523:psychology; D010775:Photic Stimulation; D013028:Space Perception / Q000502:physiology*; D014795:Visual Pathways / Q000503:physiopathology