Table 2.
Summary of significant findings from studies using phase-locked methods to assess connectivity.
| 1. Mild cognitive impairment (MCI) v. Healthy control (HC) | ||||||
|---|---|---|---|---|---|---|
| Authors (Year) | Connectivity approach |
Analysis basis† |
Recording context† |
Significant bands† |
Group effects |
Ref. |
| Cantero et al. (2009a) | PSI | Source - swLORETA | Rest: EC | Alpha1 | MCI > HC | 16 |
| Gómez et al. (2018) | PSLI | Sensors - pairs | Rest: EC | Delta, theta, alpha, gamma | MCI < HC | 36 |
| Gonzalez-Escamilla et al. (2015) | PLI | Sensors - avg. regions | Rest: EC | Alpha | MCI < HC | 37 |
| Gonzalez-Escamilla et al. (2015) | PLI | Sensors - pairs | Rest: EC | Alpha | MCI < HC | 38 |
| Gurja et al. (2022) | LPS | Source - eLORETA | Rest: EC | Alpha1 | MCI < HC | 41 |
| Handayani et al. (2018) | PLV | Sensors - pairs | Rest: EC | Alpha, beta | MCI < HC | 43 |
| Li et al. (2021) | PSI | Sensors - NA | Rest: EC | Theta | MCI < HC | 67 |
| Pons et al. (2010) | PLI | Sensors - pairs | Rest: EC | Alpha1, alpha2 | MCI > HC | 82 |
| Požar et al. (2020) | PLI | Sensors - avg. regions | Rest: EC | Delta | MCI < HC | 83 |
| Ruiz-Gómez et al. (2019b) | PLI | Sensors - pairs | Rest: EC | Theta | MCI > HC | 86 |
| Spyrou et al. (2018) | PLI (tensor factorization) | Sensors - pairs | Task: memory | Theta, alpha, beta | MCI < HC | 94 |
| Cross-component synchronization | MCI > HC | |||||
| Su et al. (2021) | PLV | Sensors - pairs | Rest: EC | Alpha | MCI < HC | 95 |
| Sweeney-Reed et al. (2012) | PLV (EMDPL) | Sensors - avg. regions | Task: memory | Theta | MCI < HC | 96 |
| Tóth et al. (2014) | PLI | Sensors - avg. regions | Rest: EO | Delta | MCI < HC | 102 |
| Alpha1 | MCI > HC | |||||
| Yan et al. (2021) | WPLI | Sensors - pairs | Rest: EC | Delta | MCI < HC | 118 |
| Youssef et al. (2021) | Debiased WPLI | Sensors - avg. regions | Rest: EC | Theta | MCI < HC | 119 |
| Zhang et al., 2022 | PS | Source - DICOS | Rest: EC | Alpha | MCI < HC | 122 |
| 2. Alzheimer’s disease (AD) v. Healthy control (HC) | ||||||
|---|---|---|---|---|---|---|
| Authors (Year) | Connectivity approach |
Analysis basis† |
Recording context† |
Significant bands† |
Group effects |
Ref. |
| Cai et al. (2018) | PSI | Sensors - pairs | Rest: EC | Delta | AD > HC | 14 |
| Alpha | AD < HC | |||||
| Canuet et al. (2012) | LPS | Source - eLORETA | Rest: EC | Alpha 2 | AD < HC | 18 |
| Theta | AD > HC | |||||
| Engels et al. (2015) | PLI | Sensors - avg. regions | Rest: EC | Alpha1 | AD < HC | 28 |
| Frangopoulou and Alimardani (2022) | PLV | Sensors - pairs | Rest: EO | Theta; Homotopic pairs: theta, delta | AD > HC | 34 |
| Gurja et al. (2022) | LPS | Source - eLORETA | Rest: EC | Alpha1 | AD < HC | 41 |
| Han et al. (2017) | PLI | Sensors - avg. regions | Task: memory | Delta, theta, alpha, beta, gamma | AD > HC | 42 |
| Hata et al. (2016) | LPS | Source - eLORETA | Rest: EC, EO | Delta, theta | AD < HC | 44 |
| Kabbara et al. (2018) | PLV | Source - WMNE | Rest: EC | Theta, alpha2 (default mode network), beta (visual network) | AD < HC | 57 |
| Theta (salience attention network) | AD > HC | |||||
| Knyazeva et al. (2010) | PSI | Sensors - NA | Rest: EC | Left frontal-temporal: delta, theta, alpha1, alpha2, beta1, beta2 | AD < HC | 59 |
| Parietal: delta, theta, alpha1, alpha2, beta1, beta2 | AD > HC | |||||
| Li et al. (2019) | WPLI | Source - DBTN | Task: WM | Alpha1, alpha2, beta | AD < HC | 66 |
| Beta (temporal regions) | AD > HC | |||||
| Mehraram et al. (2020) | WPLI | Sensors - avg. regions | Rest: EC | Alpha, beta | AD < HC | 71 |
| Ruiz-Gómez et al. (2019b) | PLI | Sensors - pairs | Rest: EC | Alpha, beta2 | AD < HC | 86 |
| Theta | AD > HC | |||||
| Wang et al. (2022) | LPS | Source - eLORETA, sLORETA | Rest: EC | Gamma | AD < HC | 114 |
| Yan et al. (2021) | WPLI | Sensors - pairs | Rest: EC | Delta | AD < HC | 118 |
| Yu et al. (2021) | PSI | Sensors - pairs | Rest: EC, EO | Broadband | AD < HC | 121 |
Within-group effects are not shown. †see Supplementary Table S1 for study specifications and technical descriptions; avg = averaged; DBTN = Dynamic brain transition network; DICOS = Dynamic imaging of coherence sources; EC = eyes closed; EMDPL = empirical mode decomposition phase locking; EO = eyes open; LPS = Lagged phase synchronization; NA = not available/specified; PLI = phase lag index; PLV = phase locking value; PSLI = phase slope index; PSI = phase synchronization index; Ref = reference number; WPLI = weighted phase lag index; WMNE = Weighted minimum norm estimate; WM = working memory.