Table 5 Clinical, preprocessing and analysis factors potentially implicated in heterogeneity of findings for power spectra (patients vs controls).
Parameter | Studies with increased gamma power (N = 13) | Studies with decreased gamma power (N = 3) | Studies with mixed results (N = 2) | Studies with no group differences (N = 14) |
|---|---|---|---|---|
Total sample size | 716 | 92 | 55 | 652 |
Age | 35.8 [30 | 44.8] | 30 [25.5 | 30.6] | 32 [29.5 | 34.5] | 37 [27.7 | 42.4] |
Sex (F) | 29% [18.75 | 34.55] | 29% [14.5 | 42] | 27.5% [26.25 | 28.75] | 30.5% [19.25 | 56] |
Duration of illness (months) | 124.8 [61 | 244.75] | 12.7 | Na | 145 [101 | 196] |
Severity of disease (PANSS total score) | 84 [83 | 87.6] | 40 (Na: 2) | 61.6 [59 | 64.25] | 63.75 [56.4 | 71.4] |
Medication status | Medicated: 7 | Medicated: 2 | Medicated:1 | Medicated: 7 |
Unmedicated: 4 | Na: 1 | Unmedicated: 1 | Mixeda: 7 | |
Mixeda: 2 | ||||
Recording method | EEG: 11 | EEG: 2 | EEG: 0 | EEG: 12 |
MEG: 2 | MEG: 1 | MEG: 2 | MEG: 2 | |
Number of channels/sensors | 128 [40 | 192] | 192 [106 | 233] | 248 | 46 [27 | 69] |
Recording duration | 5 [3 | 5.5] | 10 [7 | 12] | 5 | 4.5 [3 | 6.5] |
Eyes open/eyes closed | Open: 4 | Open: 0 | Open: 2 | Open: 4 |
Closed: 9 | Closed: 3 | Closed: 0 | Closed: 8 | |
Na: 0 | Na: 0 | N: 0 | Na: 2 | |
Gamma subband | 30–50 hz: 5 | 30–50 hz: 1 | 30–50 hz: 0 | 30–50 hz: 10 |
30–70 hz: 5 | 30–70 hz: 0 | 30–70 hz: 0 | 30–70 hz: 2 | |
30–100 hz: 3 | 30–100 hz: 2 | 30–100 hz: 2 | 30–100 hz: 2 | |
Artifact correction method | ICA: 0 | ICA: 0 | ICA: 0 | ICA: 2 |
ICA+other: 7 | ICA+other: 0 | ICA+other: 2 | ICA+other: 6 | |
Other: 6 | Other: 3 | Other: 0 | Other: 6 | |
Absolute or relative power | Absolute: 9 | Absolute: 2 | Absolute: 2 | Absolute: 8 |
Relative: 1 | Relative: 0 | Relative: 0 | Relative: 4 | |
Na: 4 | Na: 1 | Na: 0 | Na: 2 | |
Sensor-level spectral power vs source estimates | Sensor: 7 | Sensor: 1 | Sensor: 0 | Sensor: 8 |
Source: 6 | Source: 2 | Source: 2 | Source: 5 | |
Both: 1 | ||||
Brain region | Whole brain: 3 | Whole brain: 0 | Whole brain: 0 | / |
Multiple: 7 | Multiple: 2 | Multiple: 2 | ||
Frontal: 1 | Frontal: 0 | Frontal: 1 | ||
Temporal: 1 | Temporal: 1 | Temporal: 0 | ||
Central: 1 | Central: 0 | Central: 0 | ||
Parietal: 0 | Parietal: 0 | Parietal: 0 | ||
Occipital:0 | Occipital: 0 | Occipital: 0 | ||
Source localization method | LORETA: 2 | LORETA: 1 | LORETA: 0 | LORETA: 2 |
Equivalent current dipole: 3 | Equivalent current dipole: 0 | Equivalent current dipole: 0 | Equivalent current dipole: 0 | |
Minimum norm estimates: 2 | Minimum norm estimates: 0 | Minimum norm estimates: 0 | Minimum norm estimates: 1 | |
DICS: 0 | DICS: 0 | DICS: 2 | DICS: 1 | |
BESA: 0 | BESA: 0 | BESA: 0 | BESA: 2 | |
Others: 0 | Others: 1 | Others: 0 | Others: 1 |
