title: New variations of intrahemispheric and interhemispheric processing indexed by the dimond paradigm.
abstract: We report 2 experiments designed to demonstrate that unilateral tachistoscopic stimulation would yield a response time (RT) advantage over bilateral stimulation in a simple experiment, whereas the opposite pattern would occur in a complex version of the same task, as predicted by the intrahemispheric resource limitation model of Banich and colleagues. Experiment 1 was a go/no-go task in which participants had to press a key when two shapes (circles or squares) were identical on the computer screen. A unilateral field advantage was obtained that was accentuated in several task conditions that yielded overall longer RTs, mostly in the bilateral condition. Experiment 2 was similar but required a more complex judgment: The go trials were to 2 stimuli identical on 1 dimension (shape or color) but not both or neither. The RTs were significantly and substantially longer than in Experiment 1 and exhibited a nonsignificant bilateral field advantage, which differed significantly from the unilateral field advantage obtained in Experiment 1. These results support the intrahemispheric resource limitation model of Banich and colleagues. However, several within-experiment effects are in direct opposition to this model and are best explained as limitations of commissural relay of perceptual information.
authors.affiliation: Département de Psychologie, Université du Québec à Montréal, Canada. Braun.Claude@uqam.ca
authors.forename: Claude M J
authors.initials: CM
authors.lastname: Braun
authors.forename: André
authors.initials: A
authors.lastname: Achim
authors.forename: Geoffrey
authors.initials: G
authors.lastname: Gauvin
authors.forename: Samuel
authors.initials: S
authors.lastname: Desjardins
authors.forename: Carl
authors.initials: C
authors.lastname: Roberge
authors.forename: Sabrina
authors.initials: S
authors.lastname: Suffren
mesh_terms: D000328:Adult; D001288:Attention / Q000502:physiology; D001921:Brain / Q000502:physiology*; D005260:Female; D007839:Functional Laterality / Q000502:physiology*; D006801:Humans; D008297:Male; D009483:Neuropsychological Tests; D010775:Photic Stimulation; D011930:Reaction Time / Q000502:physiology*; D014796:Visual Perception / Q000502:physiology