Table 2.
Neuromarker meta-analysis.
| Neuromarker | Peak frequency | Topography | Task dependence | |
|---|---|---|---|---|
| Only in synchronic tasks (Tognoli et al., 2007a, b, 2011; Tognoli, 2008) | Mu medial | 9.1 Hz (1.1) | FCz | - recruited during spontaneous coordination |
| - suppressed during social interaction | ||||
| - rebounds during intrinsic, self-produced movement | ||||
| Phi complex | 10.9 Hz (0.9) | CP4 | - phi 1 increases in spontaneous coordination when subjectsdo not synchronize with each other | |
| - phi 2 increases when subjects synchronize with each other | ||||
| - phi complex recruitment and modulation is strongest during intentional social coordination | ||||
| Both task types | Alpha | 9.9 Hz (0.9) | PO7 (left), PO8 (right), POz (midline aggregate) | - increased by drowsiness |
| - decreased by visual input | ||||
| - decreased further by vision of the partner’s movement (larger decrease than with non-social stimuli) | ||||
| - further decreased if partner’s movement is more variable | ||||
| Only in diachronic tasks(Suutari et al., 2010; Tognoli et al., 2011) | Left and right central mu | Left: 10.6 Hz (0.9) Right: 11.4 Hz (0.8) | C3 (left), and C4 (right) | - left and right mu depressed during self movement; rebound at self-movement arrest |
| - no systematical decrease during social observation | ||||
| - exhibit dynamic aftereffects (suppression, rebound) atcessation of observed movement | ||||
| - right mu vanishes tonically when people memorize observed behavior (right hand movement) | ||||
| Nu | 10.1 Hz (1.1) | CPz | - decreases during self-movement | |
| - increases when self-movement is performedin view of another person | ||||
| Kappa | 11.2 Hz (0.7) | FC2 | - tendency to decrease any time either partner performsa movement in view of the other |
Summary of spatial, spectral and functional properties of neuromarkers involved in synchronic and diachronic social behavior (see also Figure 6 for topographical maps and colorimetric spectra). The data presented are group results obtained from the samples of subjects that have participated in our studies. Peak frequency (measured from high-resolution spectra) describes the arithmetic mean of the samples with standard deviation in parenthesis. The electrode reported in column topography refers to the mode (electrodes most frequently observed across subjects that bear largest spectral energy, named according to the 10 percent system, Chatrian et al., 1985). All recordings were performed with linked-mastoid reference. “Task dependence” refers to conditions in which power is modulated, a precursor to inferences about function.