title: A high density ERP comparison of mental rotation and mental size transformation.
abstract: To compare mental rotation and mental size transformation, 128-channel EEG was recorded while subjects performed both tasks using random two-dimensional shapes as stimuli. Behavioural results showed significant linear effects of both size transformation and mental rotation on reaction times. Rotation ERPs showed experimental effects at two latencies: a bilateral component distributed over posterior parietal electrodes at a latency of approximately 232-300ms and a second component at approximately 424-492ms distributed over right anterior parietal electrodes. The latency and spatial distribution of this second effect is consistent with previous research indicating a functional connection between this component and mental rotation. ERPs for the size-transformation task showed an effect at 180-228ms distributed bilaterally over occipital-temporal electrodes. These results are consistent with previous hemodynamic imaging studies that show involvement of parietal cortex in mental rotation and also the involvement of BA 19 in size-transformation tasks. However, the superior temporal resolution of the present data indicates that BA 19 activation may occur at a latency that is more likely related to apparent motion than to the size-transformation operation per se.
authors.affiliation: Research Centre for Cognitive Neuroscience, Department of Psychology, University of Auckland, Auckland, New Zealand. smut008@psynov1.auckland.ac.nz
authors.forename: Suresh D
authors.initials: SD
authors.lastname: Muthukumaraswamy
authors.forename: Blake W
authors.initials: BW
authors.lastname: Johnson
authors.forename: Jeff P
authors.initials: JP
authors.lastname: Hamm
mesh_terms: D000328:Adult; D001931:Brain Mapping / Q000379:methods; D004569:Electroencephalography; D005071:Evoked Potentials / Q000502:physiology; D005260:Female; D005556:Form Perception; D006801:Humans; D008297:Male; D009039:Motion Perception; D009778:Occipital Lobe / Q000502:physiology; D010296:Parietal Lobe / Q000502:physiology; D011930:Reaction Time / Q000502:physiology; D012399:Rotation; D013702:Temporal Lobe / Q000502:physiology; D014796:Visual Perception / Q000502:physiology