Table 5.
Selected studies that reported IGF’s relationship with age.
| Author and Year | Sample | Methods | IGF Measure | Relevant Findings |
|---|---|---|---|---|
| Duygun et al., 2022 [20] | 60 healthy young (HY) adults, 60 healthy elderly (HE) and 26 healthy children (HC) | rsEEG | Power | IGF in HC: ~34 Hz; IGF in HY: ~37 Hz; IGF in HE: ~35 Hz |
| Güntekin et al. [21] | 60 healthy young (HY) adults, 60 healthy elderly (HE) and 59 Alzheimer’s patients (AD) | rsEEG | Power | IGF: ~30–43 Hz. IGF in AD: ~33 ± 3 Hz; IGF in HE: ~35 ± 2 Hz; IGF in HY: ~37 ± 1 Hz |
| Robson et al., 2015 [22] | 34 healthy adults | MEG, MRS, visual gratings | Power | IGF: 52.5 ± 4.4 Hz, ~45–65 Hz. Negative correlation of IGF (r = −0.69) with age (Mage = 33.7 ± 11.9) |
| 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. Negative correlation of IGF with age (−0.52Hz per year; F age: 23.2 ± 3.9, Mage: 24.3 ± 5.4) |
| Wyss et al., 2017 [24] | 15 healthy adults | EEG, MRS, auditory stimulation | Power | IGF: ~30–160 Hz. No correlation of IGF with age (19–31 years) |
| Proskovec et al., 2020 [26] | 94 healthy adults | MEG, MRI, electrical stimulation of the right median nerve | Power | No correlation of IGF with age (22–72 years) |
| Purcell et al., 2004 [31] | 38 healthy adults | EEG, auditory steady-state stimulation, gap detection task | Amplitude | IGF in young (18–43 years): 41 ± 5 Hz; IGF in old (60–78 years): 37 ± 4 Hz |
| Insel et al., 2012 [37] | 12 rats | In vivo LFP, decision-making task | Power | IGF: 50–60Hz. IGF in younger rats: 56.4 Hz; IGF in older rats: 53.5 Hz |
| Schwartzkopf et al., 2012 [46] | 16 healthy adults | MEG, MRI, visual gratings | Power | IGF: 44.6–57 Hz. No correlation of IGF with age (19–34 years) |
| Gaetz et al., 2012 [47] | 46 healthy adults, 13 healthy children |
MEG, MRI, visual gratings | Amplitude | IGF: ~35–70 Hz. Negative correlation of IGF with age (8.7–45.3 years): r2 = 0.46 |
| Muthukumaraswamy et al., 2010 [50] | 30 healthy adults | MEG, MRI, visual gratings | Power | IGF: 51.4 ± 6.6 Hz, 42–64.5 Hz. Negative correlation of IGF (r = −0.47) with age (19–44 years) |
| 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 age (19–35 years) |
| Gaetz et al., 2011 [59] | 9 healthy adults | MEG, MRI, MRS, visual stimuli and motor responses | Amplitude | IGF: ~70–80 Hz. Negative correlation of IGF with age (22.7–42.7 years): R2 = 0.40; 4.8 Hz decrease per 10 years |
| Kahlbrock et al., 2012 [89] | 26 adults with liver cirrhosis, 8 healthy adults |
MEG, MRI, selective attention task with visual and auditory stimulation | Power | IGF: ~35–65 Hz. IGF in low age (≤59 years) group: 52 Hz; IGF in high age (>59 years) group: 46 Hz |
| Murty et al., 2020 [90] | 236 healthy elderly, 47 younger adults |
EEG, visual gratings | Power | Negative correlation of IGF with age (50–88 years): β = −0.08 for fast gamma; β = −0.16 for slow gamma |
| Orekhova et al., 2015 [91] | 27 healthy children | EEG, MEG, visual gratings | Power | IGF: 50–97.5 Hz. Negative correlation of IGF with age (8–15 years): rho = −0.58–0.8 |
| Orekhova et al., 2018 [92] | 27 healthy adults, 50 healthy children |
MEG, visual gratings | Power | Negative correlation of IGF with age: −1.71 Hz/year for children, −0.64 Hz/year for adults |
| Wiesman and Wilson 2019 [93] | 77 healthy adults | MEG, MRI, visual grid stimuli | Amplitude | IGF: ~48–70 Hz. Negative correlation of IGF (r = −0.29) with age (22–72 years) |
| Stroganova et al., 2015 [94] | 21 children with autism (ASD), 26 healthy children |
MEG, visual gratings | Power | IGF: 57.5–92.3 Hz. Negative correlation of IGF with age (7–15 years), rho = −0.6. Positive correlation of IGF modulation with age in healthy group (r = 0.45), but not ASD group |
| Poulsen et al., 2007 [95] | 33 healthy adults | EEG, auditory steady-state stimulation | Amplitude | IGF: 41 ± 4.7 Hz, 32–52 Hz. Positive correlation of IGF with age (19–45 years): 38 Hz at 19 years, 46 Hz at 45 years |
| Poulsen et al., 2009 [96] | 65 healthy children, 23 healthy adults |
EEG, auditory steady-state stimulation | Amplitude | IGF at 10 years: 35.3 ± 5.76 Hz, 25–52 Hz; IGF at 11.5 years: 36.5 ± 5.55 Hz, 27–55 Hz; IGF in adults (19–45 years): 41.2 ± 4.7 Hz |
Abbreviations: AD—Alzheimer’s disease; ASD—autism spectrum disorder; EEG—electroencephalogram; HC—healthy children; HE—healthy elderly; HY—healthy adults; IGF—individual gamma frequency; MEG—magnetoencephalogram; MRI—magnetic resonance imaging; MRS—magnetic resonance spectroscopy; ND—never depressed; RD—remitted depression; rsEEG—resting-state electroencephalogram.