title: Lateralized responses during covert attention are modulated by target eccentricity.
abstract: Various studies have demonstrated that covert attention to different locations in the visual field can be used as a control signal for brain computer interfacing. It is well known that when covert attention is directed to the left visual hemifield, posterior alpha activity decreases in the right hemisphere while simultaneously increasing in the left hemisphere and vice versa. However, it remains unknown if and how the classical lateralization pattern depends on the eccentricity of the locations to which one attends. In this paper we study the effect of target eccentricity on the performance of a brain computer interface system that is driven by covert attention. Results show that the lateralization pattern becomes more pronounced as target eccentricity increases and suggest that in the current design the minimum eccentricity for having an acceptable classification performance for two targets at equal distance from fixation in opposite hemifields is about 6° of visual angle.
authors.affiliation: Radboud University Nijmegen, Institute for Computing and Information Sciences, Nijmegen, The Netherlands. ali@cs.ru.nl
authors.forename: Ali
authors.initials: A
authors.lastname: Bahramisharif
authors.forename: Tom
authors.initials: T
authors.lastname: Heskes
authors.forename: Ole
authors.initials: O
authors.lastname: Jensen
authors.forename: Marcel A J
authors.initials: MA
authors.lastname: van Gerven
mesh_terms: D001288:Attention / Q000502:physiology*; D005133:Eye Movements / Q000502:physiology*; D005260:Female; D007839:Functional Laterality / Q000502:physiology*; D006801:Humans; D008297:Male; D013028:Space Perception / Q000502:physiology*; D014794:Visual Fields / Q000502:physiology*; D014796:Visual Perception / Q000502:physiology*