Table 8.

Selected studies that reported IGF’s relationship with somatosensory processing.

Author and Year	Sample	Methods	IGF Measure	Relevant Findings
Liu et al., 2018 [25]	19 adults with paroxysmal kinesigenic dyskinesia (PKD), 18 healthy adults	MEG, genetic analysis, electric stimulation of the wrist	Power	IGF in PKD: ~40 Hz, ~30–50 Hz; IGF in controls: ~60 Hz, ~45–90 Hz. Lower IGF in PRRT2 gene-related PKD (~35 Hz) vs. non-PRRT2 PKD (~44 Hz)
Spooner et al., 2018 [110]	43 HIV-infected, 28 healthy adults	MEG, electrical stimulation of the right median nerve	Power	IGF: ~30–90 Hz. Higher IGF for second stimulus vs. first stimulus in a sequence, stronger effect in HIV group
Cheng et al., 2016 [111]	22 healthy adults	MEG, somatosensory and auditory Go–Nogo tasks	Power	IGF: ~73 Hz, 40–89 Hz. Negative correlation of IGF with the ratio of responses to the second stimulus vs. the first stimulus (r = −0.57) in P35m component of somatosensory-evoked magnetic fields

Abbreviations: IGF—individual gamma frequency; MEG—magnetoencephalogram; PKD—paroxysmal kinesigenic dyskinesia.