Table 3.
Selected studies that reported IGF’s relationship with neuropsychiatric disorders.
| Author and Year | Sample | Methods | IGF Measure | Relevant Findings |
|---|---|---|---|---|
| Rufener et al., 2021 [5] | 32 children with developmental dyslexia (DD), 26 healthy children |
EEG, auditory steady-state stimulation, phonological awareness task | Power | IGF in DD: 40.63 ± 5.76 Hz; IGF in controls: 45.69 ± 5.85 Hz |
| Griskova-Bulanova et al., 2020 [9] | 18 adults with schizophrenia (SZ), 18 healthy adults | EEG, auditory steady-state stimulation | Phase-locking | IGF in SZ: 44 ± 7 Hz; IGF in controls: 49 ± 8 Hz |
| Dickinson et al., 2015 [18] | 33 healthy adults | EEG, visual gratings, Autism Spectrum Quotient (AQ) | Power | IGF: 59.37 ± 15.66 Hz, 30.27–89.66 Hz. Positive correlation of IGF with AQ score (r = 0.58) |
| Güntekin et al., 2022 [21] | 60 healthy young (HY) adults, 60 healthy elderly (HE), 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 |
| Chen et al., 2014 [29] | 12 adults with schizophrenia; 12 healthy adults | EEG, MRS, working memory assessment | Amplitude | IGF: ~30–50 Hz. Positive correlation of IGF with prefrontal GABA (r = 0.58) |
| Dickinson et al., 2016 [72] | 28 adults with autism (ASD), 39 healthy adults | EEG, visual gratings | Power | IGF in ASD: 62.19 ± 10.04 Hz; IGF in controls: 51.61 ± 10.75 Hz |
| Perry et al., 2014 [73] | 12 adults with photosensitive epilepsy, 9 with non-photosensitive epilepsy; 12 healthy adults | MEG, visual gratings | Amplitude | No differences between groups |
| Hepschke et al., 2021 [74] | 18 adults with visual snow syndrome (VSS), 16 healthy adults | MEG, MRI, visual gratings | Power | No difference in IGF between groups. IGF in VSS: 53.17 Hz; IGF in controls: 52.63 Hz |
| Brealy et al., 2015 [75] | 15 adults with schizoaffective bipolar disorder (SABP), 22 healthy adults | MEG, visual gratings | Amplitude | IGF in SABP: ~45 Hz transient, ~40 Hz sustained; IGF in controls: ~50 Hz transient, ~45 Hz sustained; no significant difference |
| Arnfred et al., 2015 [76] | 16 adults with schizophrenia spectrum (SZS) | EEG, proprioceptive stimulation, SZS symptoms examination | Amplitude | IGF: ~25–38 Hz. Negative correlation of IGF with SZS symptom scores (r = −0.76) |
| Arrondo et al., 2009 [77] | 27 adults with multiple sclerosis (MS), 22 healthy adults | EEG, auditory steady-state stimulation, cognitive assessment | Amplitude | IGF in cognitively impaired MS: 39.79 Hz; IGF in cognitively unimpaired MS: 43.85 Hz; IGF in controls: 43.84 Hz |
Abbreviations: AD—Alzheimer’s disease; ASD—autism spectrum disorder; AQ—Autism Spectrum Quotient; DD—developmental dyslexia; EEG—electroencephalogram; HE—healthy elderly; HY—healthy young; IGF—individual gamma frequency; MEG—magnetoencephalogram; MRI—magnetic resonance imaging; MRS—magnetic resonance spectroscopy; MS—multiple sclerosis; rsEEG—resting-state electroencephalogram; SABP—schizoaffective bipolar disorder; SZ—schizophrenia; SZS—schizophrenia spectrum; VSS—visual snow syndrome.