Inappropriate rightward saccades after right hemisphere damage: Oculomotor analysis and anatomical correlates.
Patients with right hemisphere damage and visual neglect have severe problems to orient attention towards left-sided objects, often associated with the tendency to produce inappropriate rightward saccades. In its most severe form, this tendency can assume the compulsive character of a rightward deviation of gaze as soon as the visual scene deploys (so-called "magnetic attraction of gaze"). However, little is known about the exact nature of inappropriate rightward saccades, their relation with impaired conscious perception of left-sided stimuli, and their lesional correlates. To explore these issues, we studied three groups of patients with right brain damage: patients with signs of left visual neglect associated to left homonymous hemianopia, neglect patients without hemianopia, and patients without neglect or hemianopia. Participants searched for a gap missing within a target, presented among distractors. Manual responses for target detection were required, while participants were encouraged to move their eyes during search. Endogenous attention could be summoned to the target location by a central cue. All the three groups of patients produced inappropriate rightward saccades, which could not be completely overcome by the endogenous orienting of attention induced by the cues. Anatomical analysis indicated a specific implication of damage to the right frontal eye field and to a long-range white matter tract, the fronto-parietal superior longitudinal fasciculus. Fronto-parietal networks in the right hemisphere appear thus to be essential to integrate covert and overt orienting of attention, and to thoroughly explore space in order to become aware of the multiple competing objects around us.
INSERM UMRS 1127, CNRS UMR 7225, Institut du Cerveau et de la Moelle Epinière (ICM) et Université Pierre et Marie Curie (UPMC), Groupe Hospitalier Pitié-Salpêtrière, Paris, France; Neuroscience Department, Laboratory for Behavioral Neurology and Imaging of Cognition, University of Geneva, Geneva, Switzerland. Electronic address: alx.bourgeois@gmail.com.
Alexia
A
Bourgeois
Department of Experimental Psychology, University of Granada, Spain; Brain, Mind, and Behaviour research center, Granada, Spain.
Ana B
AB
Chica
INSERM UMRS 1127, CNRS UMR 7225, Institut du Cerveau et de la Moelle Epinière (ICM) et Université Pierre et Marie Curie (UPMC), Groupe Hospitalier Pitié-Salpêtrière, Paris, France; AP-HP, Groupe Hospitalier Pitié-Salpêtrière, Fédération de Neurologie, Paris, France.
Raffaella
R
Migliaccio
INSERM UMRS 1127, CNRS UMR 7225, Institut du Cerveau et de la Moelle Epinière (ICM) et Université Pierre et Marie Curie (UPMC), Groupe Hospitalier Pitié-Salpêtrière, Paris, France; Centre de Recherche sur le Sport et le Mouvement (CeRSM, EA 2931), Université Paris Ouest-La Défense, Nanterre, France.
Dimitri J
DJ
Bayle
Service de Neurorééducation, Clinique Les Trois Soleils, Boissise le Roi, France.
Christophe
C
Duret
ER 06, UPMC, service de MPR, groupe hospitalier Pitié-Salpêtrière, AP-HP, 75013 Paris, France.
Pascale
P
Pradat-Diehl
INSERM UMRS 1127, CNRS UMR 7225, Institut du Cerveau et de la Moelle Epinière (ICM) et Université Pierre et Marie Curie (UPMC), Groupe Hospitalier Pitié-Salpêtrière, Paris, France.
Marine
M
Lunven
INSERM UMRS 1127, CNRS UMR 7225, Institut du Cerveau et de la Moelle Epinière (ICM) et Université Pierre et Marie Curie (UPMC), Groupe Hospitalier Pitié-Salpêtrière, Paris, France.
Pierre
P
Pouget
INSERM UMRS 1127, CNRS UMR 7225, Institut du Cerveau et de la Moelle Epinière (ICM) et Université Pierre et Marie Curie (UPMC), Groupe Hospitalier Pitié-Salpêtrière, Paris, France; Neuroscience Department, Laboratory for Behavioral Neurology and Imaging of Cognition, University of Geneva, Geneva, Switzerland; Department of Psychology, Catholic University, Milan, Italy.
Paolo
P
Bartolomeo
D000328:Adult; D000368:Aged; D001288:Attention / Q000502:physiology; D001921:Brain / Q000473:pathology / Q000503:physiopathology*; D002908:Chronic Disease; D056324:Diffusion Tensor Imaging; D053483:Eye Movement Measurements; D005260:Female; D007839:Functional Laterality / Q000502:physiology*; D006423:Hemianopsia / Q000473:pathology / Q000503:physiopathology; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009434:Neural Pathways / Q000473:pathology / Q000503:physiopathology; D009483:Neuropsychological Tests; D010468:Perceptual Disorders / Q000473:pathology / Q000503:physiopathology; D011930:Reaction Time; D012438:Saccades / Q000502:physiology*; D020521:Stroke / Q000473:pathology / Q000503:physiopathology* / Q000523:psychology
Attentional orienting; Fronto-parietal networks; Magnetic gaze attraction; Right hemisphere damage; Saccadic orienting; Visual neglect