title: Neural representations of unfamiliar objects are modulated by sensorimotor experience.
abstract: Sensory/functional accounts of semantic memory organization emphasize that object representations in the brain reflect the modalities involved in object knowledge acquisition. The present study aimed to elucidate the impact of different types of object-related sensorimotor experience on the neural representations of novel objects. Sixteen subjects engaged in an object matching task while their brain activity was assessed with functional magnetic resonance imaging (fMRI), before and after they acquired knowledge about previously unfamiliar objects. In three training sessions subjects learned about object function, actively manipulating only one set of objects (manipulation training objects, MTO), and visually exploring a second set (visual training objects, VTO). A third object set served as control condition and was not part of the training (no training objects, NTO). While training-related activation increases were observed in the fronto-parietal cortex for both VTO and MTO, post training activity in the left inferior/middle frontal gyrus and the left posterior inferior parietal lobule was higher for MTO than VTO and NTO. As revealed by Dynamic Causal Modeling of effective connectivity between the regions with enhanced post training activity, these effects were likely caused, respectively, by a down-regulation of a fronto-parietal tool use network in response to VTO, and by an increased connectivity for MTO. This pattern of findings indicates that the modalities involved in sensorimotor experience influence the formation of neural representations of objects in semantic memory, with manipulation experience specifically yielding higher activity in regions of the fronto-parietal cortex.
authors.affiliation: Institute of Cognitive Neuroscience, Department of Neuropsychology, Ruhr University Bochum, Bochum, Germany. christian.bellebaum@rub.de
authors.forename: Christian
authors.initials: C
authors.lastname: Bellebaum
authors.forename: Marco
authors.initials: M
authors.lastname: Tettamanti
authors.forename: Elisa
authors.initials: E
authors.lastname: Marchetta
authors.forename: Pasquale
authors.initials: P
authors.lastname: Della Rosa
authors.forename: Giovanna
authors.initials: G
authors.lastname: Rizzo
authors.forename: Irene
authors.initials: I
authors.lastname: Daum
authors.forename: Stefano F
authors.initials: SF
authors.lastname: Cappa
mesh_terms: D000328:Adult; D001499:Bayes Theorem; D005260:Female; D005556:Form Perception / Q000502:physiology*; D007839:Functional Laterality / Q000502:physiology; D006801:Humans; D007091:Image Processing, Computer-Assisted; D007858:Learning / Q000502:physiology; D008279:Magnetic Resonance Imaging; D008297:Male; D008568:Memory / Q000502:physiology*; D008959:Models, Neurological; D009048:Motor Skills / Q000502:physiology; D010296:Parietal Lobe / Q000502:physiology; D017397:Prefrontal Cortex / Q000502:physiology; D011597:Psychomotor Performance / Q000502:physiology; D011930:Reaction Time / Q000502:physiology; D021641:Recognition, Psychology / Q000502:physiology*; D055815:Young Adult