title: Cortical control of inhibition of return: evidence from patients with inferior parietal damage and visual neglect.
abstract: Inhibition of return (IOR) refers to slower reaction times to targets presented at previously stimulated or inspected locations. This phenomenon biases orienting towards novel locations and is functional to an effective exploration of the environment. Patients with right brain damage and left visual neglect explore their environment asymmetrically, with strong difficulties to orient attention to left-sided objects. We show for the first time a dissociation between manual and saccadic IOR in neglect. Our patients demonstrated facilitation, instead of inhibition, for repeated right-sided targets with manual responses, but normal IOR to right-sided targets with saccadic responses. All neglect patients had damage to the supramarginal gyrus in the right parietal lobe, or to its connections with the ipsilateral prefrontal cortex. We concluded that IOR with manual responses relies on fronto-parietal attentional networks in the right hemisphere, whose functioning is typically impaired in neglect patients. Saccadic IOR may instead depend on circuits less likely to be damaged in neglect, such as the retinotectal visual pathway.
authors.affiliation: INSERM UMRS 975, Centre de Recherche de l'Institut du Cerveau et de Moelle Epinière et Université Pierre et Marie Curie, Groupe Hospitalier Pitié-Salpêtrière, Paris, France. alx.bourgeois@gmail.com
authors.forename: Alexia
authors.initials: A
authors.lastname: Bourgeois
authors.forename: Ana B
authors.initials: AB
authors.lastname: Chica
authors.forename: Raffaella
authors.initials: R
authors.lastname: Migliaccio
authors.forename: Michel
authors.initials: M
authors.lastname: Thiebaut de Schotten
authors.forename: Paolo
authors.initials: P
authors.lastname: Bartolomeo
mesh_terms: D000704:Analysis of Variance; D001288:Attention / Q000502:physiology; D001930:Brain Injuries / Q000150:complications*; D001931:Brain Mapping; D056324:Diffusion Tensor Imaging; D007839:Functional Laterality; D006801:Humans; D007091:Image Processing, Computer-Assisted; D007266:Inhibition, Psychological; D008279:Magnetic Resonance Imaging; D010296:Parietal Lobe / Q000473:pathology / Q000503:physiopathology*; D010468:Perceptual Disorders / Q000209:etiology* / Q000473:pathology*; D010775:Photic Stimulation; D011930:Reaction Time / Q000502:physiology; D012438:Saccades; D013997:Time Factors