title: Focusing narrowly or broadly attention when judging categorical and coordinate spatial relations: a MEG study.
abstract: We measured activity in the dorsal system of the human cortex with magnetoencephalography (MEG) during a matching-to-sample plus cueing paradigm, where participants judged the occurrence of changes in either categorical or coordinate spatial relations (e.g., exchanges of left versus right positions or changes in the relative distances) between images of pairs of animals. The attention window was primed in each trial to be either small or large by using cues that immediately preceded the matching image. In this manner, we could assess the modulatory effects of the scope of attention on the activity of the dorsal system of the human cortex during spatial relations processing. The MEG measurements revealed that large spatial cues yielded greater activations and longer peak latencies in the right inferior parietal lobe for coordinate trials, whereas small cues yielded greater activations and longer peak latencies in the left inferior parietal lobe for categorical trials. The activity in the superior parietal lobe, middle frontal gyrus, and visual cortex, was also modulated by the size of the spatial cues and by the type of spatial relation change. The present results support the theory that the lateralization of each kind of spatial processing hinges on differences in the sizes of regions of space attended to by the two hemispheres. In addition, the present findings are inconsistent with the idea of a right-hemispheric dominance for all kinds of challenging spatial tasks, since response times and accuracy rates showed that the categorical spatial relation task was more difficult than the coordinate task and the cortical activations were overall greater in the left hemisphere than in the right hemisphere.
authors.affiliation: Department of Neuroscience and Imaging, G. d'Annunzio University, Chieti, Italy ; ITAB, "G. d'Annunzio" University Foundation, Chieti, Italy.
authors.forename: Raffaella
authors.initials: R
authors.lastname: Franciotti
authors.affiliation: Department of Neuroscience and Imaging, G. d'Annunzio University, Chieti, Italy.
authors.forename: Stefania
authors.initials: S
authors.lastname: D'Ascenzo
authors.affiliation: Department of Neuroscience and Imaging, G. d'Annunzio University, Chieti, Italy.
authors.forename: Alberto
authors.initials: A
authors.lastname: Di Domenico
authors.affiliation: Department of Neuroscience and Imaging, G. d'Annunzio University, Chieti, Italy.
authors.forename: Marco
authors.initials: M
authors.lastname: Onofrj
authors.affiliation: Department of Psychology, Humanities and Territory, G. d'Annunzio University, Chieti, Italy.
authors.forename: Luca
authors.initials: L
authors.lastname: Tommasi
authors.affiliation: Department of Psychology, University of Oslo, Oslo, Norway.
authors.forename: Bruno
authors.initials: B
authors.lastname: Laeng
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D001288:Attention / Q000502:physiology*; D002540:Cerebral Cortex / Q000502:physiology*; D005260:Female; D007839:Functional Laterality; D006801:Humans; D015225:Magnetoencephalography / Q000379:methods; D008297:Male; D010775:Photic Stimulation; D011930:Reaction Time; D013028:Space Perception / Q000502:physiology*; D055815:Young Adult