Corticokinematic coherence mainly reflects movement-induced proprioceptive feedback.
Bottom Line: The afferent rPDC was 37% higher when tactile input was present, and it was at highest at F1 of the passive conditions; the efferent rPDC level did not differ between conditions.The apparent latency for the afferent input, estimated within the framework of the rPDC analysis, was 50-100 ms.The higher directional coupling between hand kinematics and SM1 activity in afferent than efferent direction strongly supports the view that CKC mainly reflects movement-related somatosensory proprioceptive afferent input to the contralateral SM1 cortex.
Affiliation: Brain Research Unit and MEG Core, O.V. Lounasmaa Laboratory, Aalto University School of Science, PO BOX 15100, FI-00076-AALTO Espoo, Finland. Electronic address: email@example.com.Show MeSH
Mentions: Fig. 1B illustrates the rPDC results and Fig. 2 (left panel) gives the rPDC values for all conditions. Similarly to CKC spectra, the afferent rPDC spectra displayed clear peaks at F0 and F1 in most subjects. The afferent coupling was statistically significant either at F0 or F1 in 13–15 subjects (14 active–touch, 13 active–no-touch, 14 passive–touch, 15 passive–no-touch). The strength of the afferent coupling was affected by the tactile input (touch vs. no-touch, F1,14 = 7.17, p = 0.018), task (active vs. passive, F1,14 = 7.12 p = 0.018) and frequency (F0 vs. F1, F1,14 = 5.62, p = 0.033), with an interaction between task and frequency (F1,14 = 10.22, p < 0.01). In the rPDC averaged across subjects and conditions, the value was 37% higher in touch (4.8 × 10−3) than in no-touch (3.5 × 10−3), and the interaction between task and frequency was due to higher rPDC in passive at F1 (6.4 × 10−3) than in the other conditions (active at F0: 3.7 × 10−3; active at F1: 3.5 × 10−3; passive at F0: 3.1 × 10−3; p(s) < 0.01); these other conditions showing a similar level of rPDC (p(s) > 0.3). The efferent rPDC was clearly weaker, being statistically significant only in 2–4 subjects (2 active–touch, 3 active–no-touch, 3 passive–touch, 4 passive–no-touch), with no differences between conditions. Paired t-tests demonstrated that the rPDC was 2.7–15.5 times stronger in the afferent direction than in the efferent direction for all conditions, at F0 and F1 (p < 0.05 for all 8 comparisons, see Fig. 2 for exact p-values).
Affiliation: Brain Research Unit and MEG Core, O.V. Lounasmaa Laboratory, Aalto University School of Science, PO BOX 15100, FI-00076-AALTO Espoo, Finland. Electronic address: firstname.lastname@example.org.