Table 1.
Selected studies that reported IGF’s relationship with anatomical factors.
| Author and Year | Sample | Methods | IGF Measure | Relevant Findings |
|---|---|---|---|---|
| Robson et al., 2015 [22] | 34 healthy adults | MEG, MRS, visual gratings | Power | IGF: 52.5 ± 4.4 Hz, ~45–65 Hz. No correlation of IGF with V1 surface area and thickness |
| van Pelt et al., 2018 [23] | 158 healthy adults | MEG, MRI, visual gratings | Amplitude | IGF: 56.2 ± 5.4 Hz, 41.5–72.9 Hz. Positive correlation of IGF with occipital thickness (13.4 Hz per mm increase). Negative correlation of IGF with occipital surface area (−0.044 Hz per cm2 increase) and pericalcarine volume (−1.88 Hz per cm3 increase) |
| Proskovec et al., 2020 [26] | 94 healthy adults | MEG, MRI, electrical stimulation of the right median nerve | Power | IGF: ~30–100 Hz. Negative correlation of IGF with S1 thickness: 27.25 Hz decrease per 1 mm increase |
| Gregory et al., 2016 [44] | 10 healthy adults | MEG, fMRI, visual gratings | Power | IGF: 41.15–70.41 Hz. Positive correlation of IGF with V1 surface area (rho = 0.38) |
| Pinotsis et al., 2013 [45] | Simulated data | Dynamic causal modeling | Power | IGF: ~45–60 Hz. Positive correlation of IGF with V1 columnar width (r = 0.27) |
| Schwartzkopf et al., 2012 [46] | 16 healthy adults | MEG, MRI, visual gratings | Power | IGF: 44.6–57 Hz. Positive correlation of IGF with V1 (Rs = 0.63) and V2 (Rs = 0.54) surface area. No correlation of IGF with V1 thickness |
| Gaetz et al., 2012 [47] | 46 healthy adults, 13 healthy children |
MEG, MRI, visual gratings | Amplitude | IGF: ~35–70 Hz. Positive correlation of IGF with pericalcarine thickness (r2 = 0.059), cuneus thickness (r2 = 0.115) and cuneus volume (r2 = 0.13) |
| Kienitz et al., 2021 [48] | 2 macaque monkeys | In vivo LFP, V1 lesions, visual illusory stimuli | Power | After V1 lesion, IGF decreased by 5.73 ± 0.86 Hz in V4 in one monkey |
| Perry et al., 2013 [49] | 12 healthy adults | MEG, MRI, visual gratings | Amplitude | IGF: ~40–70 Hz. No correlation of IGF with V1 surface area, thickness or volume |
| Muthukumaraswamy et al., 2010 [50] | 30 healthy adults | MEG, MRI, visual gratings | Power | IGF: 51.4 ± 6.6 Hz, 42–64.5 Hz. Positive correlation of IGF with pericalcarine cortical thickness (R = 0.392) |
| Shaw et al., 2013 [51] | 37 healthy adults: 19 remitted depression (RD), 18 never depressed (ND) |
MEG, MRS, visual gratings | Power | IGF in RD: 57.64 Hz, IGF in ND: 55.83 Hz, non-significant difference. No correlation of IGF with pericalcarine surface area, positive correlation of IGF with pericalcarine thickness (r = 0.32) |
| Zaehle et al., 2011 [52] | 17 healthy adults | EEG, MRI, visual gratings | Amplitude | IGF: ~20–50 Hz. Positive correlation of IGF with corpus callosum white matter density (r = 0.44–0.65) |
Abbreviations: EEG—electroencephalogram; fMRI—functional magnetic resonance imaging; IGF—individual gamma frequency; LFP—local field potential; MEG—magnetoencephalogram; MRS—magnetic resonance spectroscopy; ND—never depressed; RD—remitted depression.