title: Repetition suppression for visual actions in the macaque superior temporal sulcus.
abstract: In many brain areas, repetition of a stimulus usually weakens the neural response. This "adaptation" or repetition suppression effect has been observed with mass potential measures such as event-related potentials (ERPs), in fMRI BOLD responses, and locally with local field potentials (LFPs) and spiking activity. Recently, it has been reported that macaque F5 mirror neurons do not show repetition suppression of their spiking activity for single repetitions of hand actions, which disagrees with human fMRI adaptation studies. This finding also contrasts with numerous studies showing repetition suppression in macaque inferior temporal cortex, including the rostral superior temporal sulcus (STS). Since the latter studies employed static stimuli, we assessed here whether the use of dynamic action stimuli abolishes repetition suppression in the awake macaque STS. To assess adaptation effects in the STS, we employed the same hand action movies as used when examining adaptation in F5. The upper bank STS neurons showed repetition suppression during the approaching phase of the hand action, which corresponded to the phase of the action for which these neurons responded overall the strongest. The repetition suppression was present for the spiking activity measured in independent single-unit and multiunit recordings as well as for the LFP power at frequencies > 50 Hz. Together with previous data in F5, these findings suggest that adaptation effects differ between F5 mirror neurons and the STS neurons.
authors.affiliation: Laboratorium voor Neuro- en Psychofysiologie, Department of Neurosciences, KU Leuven, Campus Gasthuisberg, Leuven, Belgium;
authors.forename: Pradeep
authors.initials: P
authors.lastname: Kuravi
authors.affiliation: McGovern Institute for Brain Research, Massachusetts Institute of Technology, Cambridge, Massachusetts; and.
authors.forename: Vittorio
authors.initials: V
authors.lastname: Caggiano
authors.affiliation: Section on Computational Sensomotorics, Hertie Institute for Clinical Brain Research and Werner-Reichardt Center for Integrative Neuroscience (CIN), University of Tuebingen, Tuebingen, Germany.
authors.forename: Martin
authors.initials: M
authors.lastname: Giese
authors.affiliation: Laboratorium voor Neuro- en Psychofysiologie, Department of Neurosciences, KU Leuven, Campus Gasthuisberg, Leuven, Belgium; rufin.vogels@med.kuleuven.be.
authors.forename: Rufin
authors.initials: R
authors.lastname: Vogels
mesh_terms: D000222:Adaptation, Physiological; D000818:Animals; D005071:Evoked Potentials; D005260:Female; D006225:Hand / Q000294:innervation / Q000502:physiology; D008253:Macaca mulatta; D008297:Male; D009474:Neurons / Q000502:physiology; D011597:Psychomotor Performance; D060865:Repetition Priming; D013702:Temporal Lobe / Q000166:cytology / Q000502:physiology*; D014796:Visual Perception
keywords: adaptation; hand action stimuli; inferior temporal cortex; multiunit activity; single-unit activity