title: Comprehension of Co-Speech Gestures in Aphasic Patients: An Eye Movement Study.
abstract: BACKGROUND
  Co-speech gestures are omnipresent and a crucial element of human interaction by facilitating language comprehension. However, it is unclear whether gestures also support language comprehension in aphasic patients. Using visual exploration behavior analysis, the present study aimed to investigate the influence of congruence between speech and co-speech gestures on comprehension in terms of accuracy in a decision task.
  
  
  METHODS
  Twenty aphasic patients and 30 healthy controls watched videos in which speech was either combined with meaningless (baseline condition), congruent, or incongruent gestures. Comprehension was assessed with a decision task, while remote eye-tracking allowed analysis of visual exploration.
  
  
  RESULTS
  In aphasic patients, the incongruent condition resulted in a significant decrease of accuracy, while the congruent condition led to a significant increase in accuracy compared to baseline accuracy. In the control group, the incongruent condition resulted in a decrease in accuracy, while the congruent condition did not significantly increase the accuracy. Visual exploration analysis showed that patients fixated significantly less on the face and tended to fixate more on the gesturing hands compared to controls.
  
  
  CONCLUSIONS
  Co-speech gestures play an important role for aphasic patients as they modulate comprehension. Incongruent gestures evoke significant interference and deteriorate patients' comprehension. In contrast, congruent gestures enhance comprehension in aphasic patients, which might be valuable for clinical and therapeutic purposes.
authors.affiliation: Perception and Eye Movement Laboratory, Departments of Neurology and Clinical Research, Inselspital, University Hospital Bern, and University of Bern, Bern, Switzerland.
authors.forename: Noëmi
authors.initials: N
authors.lastname: Eggenberger
authors.affiliation: Perception and Eye Movement Laboratory, Departments of Neurology and Clinical Research, Inselspital, University Hospital Bern, and University of Bern, Bern, Switzerland.
authors.forename: Basil C
authors.initials: BC
authors.lastname: Preisig
authors.affiliation: Perception and Eye Movement Laboratory, Departments of Neurology and Clinical Research, Inselspital, University Hospital Bern, and University of Bern, Bern, Switzerland.|Division of Cognitive and Restorative Neurology, Department of Neurology, Inselspital, Bern University Hospital, and University of Bern, Bern, Switzerland.
authors.forename: Rahel
authors.initials: R
authors.lastname: Schumacher
authors.affiliation: Perception and Eye Movement Laboratory, Departments of Neurology and Clinical Research, Inselspital, University Hospital Bern, and University of Bern, Bern, Switzerland.
authors.forename: Simone
authors.initials: S
authors.lastname: Hopfner
authors.affiliation: Perception and Eye Movement Laboratory, Departments of Neurology and Clinical Research, Inselspital, University Hospital Bern, and University of Bern, Bern, Switzerland.|Neurology and Neurorehabilitation Center, Department of Internal Medicine, Luzerner Kantonsspital, Luzern, Switzerland.
authors.forename: Tim
authors.initials: T
authors.lastname: Vanbellingen
authors.affiliation: Perception and Eye Movement Laboratory, Departments of Neurology and Clinical Research, Inselspital, University Hospital Bern, and University of Bern, Bern, Switzerland.|Neurology and Neurorehabilitation Center, Department of Internal Medicine, Luzerner Kantonsspital, Luzern, Switzerland.
authors.forename: Thomas
authors.initials: T
authors.lastname: Nyffeler
authors.affiliation: Division of Cognitive and Restorative Neurology, Department of Neurology, Inselspital, Bern University Hospital, and University of Bern, Bern, Switzerland.
authors.forename: Klemens
authors.initials: K
authors.lastname: Gutbrod
authors.affiliation: Neurology Unit, Laboratory for Cognitive and Neurological Sciences, Department of Medicine, Faculty of Science, University of Fribourg, Fribourg, Switzerland.
authors.forename: Jean-Marie
authors.initials: JM
authors.lastname: Annoni
authors.affiliation: Perception and Eye Movement Laboratory, Departments of Neurology and Clinical Research, Inselspital, University Hospital Bern, and University of Bern, Bern, Switzerland.|Neurology and Neurorehabilitation Center, Department of Internal Medicine, Luzerner Kantonsspital, Luzern, Switzerland.
authors.forename: Stephan
authors.initials: S
authors.lastname: Bohlhalter
authors.affiliation: Gerontechnology and Rehabilitation Group, University of Bern, Bern, Switzerland.
authors.forename: Dario
authors.initials: D
authors.lastname: Cazzoli
authors.affiliation: Perception and Eye Movement Laboratory, Departments of Neurology and Clinical Research, Inselspital, University Hospital Bern, and University of Bern, Bern, Switzerland.|Division of Cognitive and Restorative Neurology, Department of Neurology, Inselspital, Bern University Hospital, and University of Bern, Bern, Switzerland.
authors.forename: René M
authors.initials: RM
authors.lastname: Müri
mesh_terms: D000328:Adult; D000368:Aged; D001921:Brain / Q000000981:diagnostic imaging; D001931:Brain Mapping; D016022:Case-Control Studies; D032882:Comprehension / Q000502:physiology*; D003710:Demography; D005133:Eye Movements / Q000502:physiology*; D005260:Female; D005868:Gestures; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008402:Mass Media; D008875:Middle Aged; D010775:Photic Stimulation; D011859:Radiography; D013060:Speech; D020521:Stroke / Q000000981:diagnostic imaging / Q000503:physiopathology*