title: Bringing the real world into the fMRI scanner: repetition effects for pictures versus real objects.
abstract: Our understanding of the neural underpinnings of perception is largely built upon studies employing 2-dimensional (2D) planar images. Here we used slow event-related functional imaging in humans to examine whether neural populations show a characteristic repetition-related change in haemodynamic response for real-world 3-dimensional (3D) objects, an effect commonly observed using 2D images. As expected, trials involving 2D pictures of objects produced robust repetition effects within classic object-selective cortical regions along the ventral and dorsal visual processing streams. Surprisingly, however, repetition effects were weak, if not absent on trials involving the 3D objects. These results suggest that the neural mechanisms involved in processing real objects may therefore be distinct from those that arise when we encounter a 2D representation of the same items. These preliminary results suggest the need for further research with ecologically valid stimuli in other imaging designs to broaden our understanding of the neural mechanisms underlying human vision.
authors.affiliation: Department of Psychology, The University of Western Ontario, London, ON, Canada, N6A 5C2. jacqueline.c.snow@gmail.com
authors.forename: Jacqueline C
authors.initials: JC
authors.lastname: Snow
authors.forename: Charles E
authors.initials: CE
authors.lastname: Pettypiece
authors.forename: Teresa D
authors.initials: TD
authors.lastname: McAdam
authors.forename: Adam D
authors.initials: AD
authors.lastname: McLean
authors.forename: Patrick W
authors.initials: PW
authors.lastname: Stroman
authors.forename: Melvyn A
authors.initials: MA
authors.lastname: Goodale
authors.forename: Jody C
authors.initials: JC
authors.lastname: Culham
mesh_terms: D002560:Cerebrovascular Circulation / Q000502:physiology; D005074:Evoked Potentials, Visual / Q000502:physiology*; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D010100:Oxygen / Q000097:blood; D010775:Photic Stimulation; D014793:Visual Cortex / Q000098:blood supply / Q000502:physiology*; D014796:Visual Perception / Q000502:physiology*
chemical_list: D010100:Oxygen