title: fMRI Adaptation between Action Observation and Action Execution Reveals Cortical Areas with Mirror Neuron Properties in Human BA 44/45.
abstract: Mirror neurons (MNs) are considered to be the supporting neural mechanism for action understanding. MNs have been identified in monkey's area F5. The identification of MNs in the human homolog of monkeys' area F5 Broadmann Area 44/45 (BA 44/45) has been proven methodologically difficult. Cross-modal functional MRI (fMRI) adaptation studies supporting the existence of MNs restricted their analysis to a priori candidate regions, whereas studies that failed to find evidence used non-object-directed (NDA) actions. We tackled these limitations by using object-directed actions (ODAs) differing only in terms of their object directedness in combination with a cross-modal adaptation paradigm and a whole-brain analysis. Additionally, we tested voxels' blood oxygenation level-dependent (BOLD) response patterns for several properties previously reported as typical MN response properties. Our results revealed 52 voxels in left inferior frontal gyrus (IFG; particularly BA 44/45), which respond to both motor and visual stimulation and exhibit cross-modal adaptation between the execution and observation of the same action. These results demonstrate that part of human IFG, specifically BA 44/45, has BOLD response characteristics very similar to monkey's area F5.
authors.affiliation: Department of Human Perception, Cognition and Action, Max Planck Institute for Biological Cybernetics Tübingen, Germany.
authors.forename: Stephan
authors.initials: S
authors.lastname: de la Rosa
authors.affiliation: Department of Human Perception, Cognition and Action, Max Planck Institute for Biological CyberneticsTübingen, Germany; Georg-Elias-Müller-Institute of Psychology, University of GöttingenGöttingen, Germany; Institute of Psychology, University of GrazGraz, Austria.
authors.forename: Frieder L
authors.initials: FL
authors.lastname: Schillinger
authors.affiliation: Department of Human Perception, Cognition and Action, Max Planck Institute for Biological Cybernetics Tübingen, Germany.
authors.forename: Heinrich H
authors.initials: HH
authors.lastname: Bülthoff
authors.affiliation: Department of Human Perception, Cognition and Action, Max Planck Institute for Biological CyberneticsTübingen, Germany; Medical Psychology Division, University of BonnBonn, Germany.
authors.forename: Johannes
authors.initials: J
authors.lastname: Schultz
authors.affiliation: Department of Human Perception, Cognition and Action, Max Planck Institute for Biological CyberneticsTübingen, Germany; Department of Cognitive Neuroscience, Maastricht UniversityMaastricht, Netherlands.
authors.forename: Kamil
authors.initials: K
authors.lastname: Uludag
keywords: BA 44; BA 45; action recognition; adaptation; fMRI; mirror neurons; object-directed actions; repetition suppression