title: Magnetoencephalographic signatures of visual form and motion binding.
abstract: This study investigates neural magneto-encephalographic (MEG) correlates of visual form and motion binding. Steady-state visual evoked fields (SSVEF) were recorded in MEG while observers reported their bound or unbound perception of moving bars arranged in a square shape. By using pairs of oscillating vertical and horizontal bars, "frequency-tagged" at f1 and f2, we identified a region with enhanced sustained power at 2f1+2f2 intermodulation frequency correlated with perceptual reports. Intermodulation power is more important during perceptual form/motion integration than during the perceptual segmentation of the stimulus into individual component motions, indicating that intermodulation frequency power is a neuromarker of form/motion integration. Source reconstruction of cortical activities at the relevant frequencies further reveals well segregated activity in the occipital lobe at the fundamental of the stimulation, f1 and f2, widely spread activity at 2f1 and 2f2 and a focal activity in the medial part of the right precentral sulcus region at the intermodulation component, 2f1+2f2. The present findings indicate that motion tagging provides a powerful way of investigating the processes underlying visual form/motion binding non-invasively in humans.
authors.affiliation: CRICM, Cogimage, Université Pierre and Marie Curie, UMR 7225, CNRS, INSERM, 47 Bd de l'Hôpital, 75013 Paris, France.
authors.forename: Charles
authors.initials: C
authors.lastname: Aissani
authors.forename: Benoit
authors.initials: B
authors.lastname: Cottereau
authors.forename: Guillaume
authors.initials: G
authors.lastname: Dumas
authors.forename: Anne-Lise
authors.initials: AL
authors.lastname: Paradis
authors.forename: Jean
authors.initials: J
authors.lastname: Lorenceau
mesh_terms: D000328:Adult; D000513:Alpha Rhythm / Q000502:physiology; D003627:Data Interpretation, Statistical; D004569:Electroencephalography; D005074:Evoked Potentials, Visual / Q000502:physiology; D005260:Female; D005403:Fixation, Ocular; D006801:Humans; D015225:Magnetoencephalography; D008297:Male; D009039:Motion Perception / Q000502:physiology*; D009778:Occipital Lobe / Q000502:physiology; D009801:Oculomotor Muscles / Q000502:physiology; D010775:Photic Stimulation; D014796:Visual Perception / Q000502:physiology*; D058067:Wavelet Analysis