Table 11.
Comparison of findings using different methodologiesa
| Measure | Change in methodology |
||
|---|---|---|---|
| Group partition based on young + elderly at baseline, individual gamma = 2, Group gamma = 2 | 389 nodes, individual gamma = 2, Group gamma = 2 | No global regression | |
| Cross-sectional analysis | |||
| Global measures | |||
| Global efficiency | NA | Young > Elderly (trend; uncorrected p = 0.25) | Young > Elderly |
| Local efficiency | NA | Young > Elderly (trend; uncorrected p = 0.06) | Young > Elderly |
| Mean participation coefficient | Elderly > Young | Elderly > Young | Elderly > Young |
| System segregation | Young > Elderly | Young > Elderly | Young > Elderly |
| Modular measures | |||
| Participation coefficient | Elderly > Young in all modules | Elderly > Young in all modules, except DorsAttn/Control A | Elderly > Young in all modules, except SalVentAttn |
| Proportion of node types | Elderly > Young in connector hubs and satellite connectors of most modules | Elderly > Young in connector hubs and satellite connectors of most modules | Inconsistent differences in node types; elderly showed both increases and decreases in all node types relative to young adults |
| Young > Elderly in provincial hubs and peripheral nodes of most modules | Young > Elderly in provincial hubs and peripheral nodes of most modules | ||
| Association with cognition in elderly | Worse attention performance associated with | Worse attention performance associated with | Worse attention performance associated with |
| · Lower local efficiency | · Lower local efficiency | · Lower local efficiency (trend; uncorrected p = 0.06) | |
| · Higher mean participation coefficient | · Higher mean participation coefficient | · Higher mean participation coefficient (trend; uncorrected p = 0.16) | |
| Worse global cognitive performance associated with higher participation coefficient in Control/DorsAttn B (trend; uncorrected p = 0.08) | Worse global cognitive performance associated with higher participation coefficient in Control (uncorrected p < 0.05) | ||
| Longitudinal analysis | |||
| Global measures | |||
| Global efficiency | NA | Decrease with time | NA |
| Local efficiency | NA | Decrease with time | NA |
| Mean participation coefficient | Increase with time | Increase with time | NA |
| System segregation | Decrease with time | Decrease with time | NA |
| Modular measures | |||
| Participation coefficient | Increase with time in | Increase with time in | NA |
| · SalVentAttn | · SalVentAttn | ||
| · Default | · Default | ||
| · Control | · Control (uncorrected p < 0.05) | ||
| Proportion of node types | Increased connector hubs and satellite connectors and decreased provincial hubs and peripheral nodes with time in | Increased satellite connectors and decreased provincial hubs with time in | NA |
| · Default | · Default (uncorrected p < 0.05) | ||
| · Control | · Control (uncorrected p < 0.05) | ||
aDorsAttn, Dorsal attention; SomMot, somatomotor; SalVentAttn, salience/ventral attention; TempPar, temporoparietal. The original analyses were performed on functional images with global regression done and using a functional parcellation scheme comprising 114 nodes. For the original cross-sectional analysis, the group-level partition was obtained using individual and group gamma of 2 and was based on all young participants. For the original longitudinal analysis, the group-level partition was obtained using individual and group gamma of 2 and was based on all elderly participants at baseline. Findings described in this table are significant effects (global measures: p < 0.05; modular measures: FDR-adjusted p < 0.05) unless otherwise stated.