Table 1.
Characteristics of studies included in Meta-Analysis.
| References | Design | Sample | EEG-alpha NFT characteristics | Outcomes of interest | ||||
|---|---|---|---|---|---|---|---|---|
| Participants | Age (mean ± SD) | Electrode(s) | Modality | Sessions (min/session) | WM | EM | ||
| Alekseeva et al., 2012 | Two-arm trial (Control vs. α) | 27 (13 vs. 14) | (19.8 ± 0.6 vs. 19.5 ± 0.4) | Pz | Upper α | 8 (18) | MRT | |
| Escolano et al., 2011 | Two-arm trial (Control vs. α) | 16 (6 vs. 10) | (27.1 ± 3.9 vs. 24.7 ± 4.1) | P3, Pz, P4, O1, O2 | Upper α | 5 (25) | CST | |
| Escolano et al., 2012 | Two-arm RCT (Control vs. α) | 19 (9 vs. 10) | (24.3 ± 3.6 vs. 25.8 ± 4.0) | P3, Pz, P4, O1, O2 | Upper α | 1 (25) | PASAT | |
| Escolano et al., 2014 | Two-arm RCT (Control vs. α) | 19 (9 vs. 10) | (24.3 ± 3.7 vs. 25.8 ± 4.1) | P3, Pz, P4, O1, O2 | Upper α | 1 (25) | MRT | |
| Farnia et al., 2017 | Three-arm RCT (Control vs. low α/high α) | 30 (10 vs. 10) | (34.2 ± 5.7 vs. 31.7 ± 6.4) | FCz | Low α/high α | 10 (30) | WMS-R | |
| Gordon et al., 2019 | Six-arm RCT (Control vs. α) | 165 (40 vs. 20) | (21.9 ± 2.5 vs. 21.6 ± 2.4) | Pz | Upper α | 10 (21) | MRT | |
| Guez et al., 2014 | Three-arm RCT (Control vs. α) | 30 (10 vs. 10) | 23.6 ± 2.7 | C4, Pz | Upper α | 10 (30) | VMT | Word pair |
| Hsueh et al., 2016 | Two-arm RCT (Control vs. α) | 50 (25 vs. 25) | (21.6 ± 2.4 vs. 20.9 ± 2.8) | C3a, C3p, Cza, Czp, C4a, C4p | α | 12 (36) | BDST | Word pair |
| Lecomte and Juhel, 2011 | Three-arm RCT (Control vs. α) | 30 (10 vs. 10) | 75.25 | C3, C4, Cz | Upper α | 4 (30) | Word pair | |
| Nan et al., 2012 | Two-arm RCT (Control vs. α) | 32 (16 vs. 16) | 23.2 ± 3.1 | Cz | α | 20 (3.33) | BDST | |
| Naas et al., 2019 | Two-arm RCT (Control vs. α) | 33 (16 vs. 17) | 21.2 ± 1.4 | P7, P8, O1, O2 | Upper α | 4 (15) | FDST | |
| Pei et al., 2018 | Two-arm trial (Control vs. α) | 20 (10 vs. 10) | (21.2 ± 1.7 vs. 22.7 ± 1.9) | Fz, C4 | α | 5 (36) | BDST | Word pair |
| Reis et al., 2016 | Four-arm RCT (Control vs. α+ θ) | 34 (6 vs. 9) | 65.9 ± 6.6 | FCz, Cz | α + θ | 8 (30) | M. Rot. | |
| Wei et al., 2017 | Two-arm RCT (Control vs. α) | 30 (15 vs. 15) | 26 ± 3 | C3 | α | 12 (25) | BDST | Word pair |
| Xiong et al., 2014 | Four-arm RCT (Control vs. θ/α) | 48 (12 vs. 12) | NA (young adult) | Fz, FCz, Cz, C1, C2 | θ/α | 5 (2) | 2-back task | |
| Zoefel et al., 2011 | Two-arm trial (Control vs. α) | 24 (10 vs. 12) | (22.1 ± 3.8 vs. 23.7 ± 2.3) | P3, Pz, P4, O1, O2 | Upper α | 5 (25) | MRT | |
BDST, backward digital span task; CST, conceptual span test; EEG, electroencephalography; EM, episodic memory; FDST, forward digital span task; M. Rot, matrix rotation task; MRT, mental rotation task; NA, not available; NFT, neurofeedback training; PASAT, paced auditory serial addition task; RCT, randomized controlled trials; VMT, verbal memory test; WMS, Wechsler memory scale; WM, working memory.