Table 2.
A summary of fNIRS studies on the effects of chronic exercise intervention on executive function in older adults.
| Study ID | Sample characteristics | fNIRS parameters | Experimental protocol | Activation tasks | Main findings |
|---|---|---|---|---|---|
| Wang et al. (2013) | Old: n = 12 (4 M, 8F); M = 64.25, SD = 3.14,range: 60–68 | 3-cm separation; 10 Hz; 24 bilateral frontal channels (Hitachi ETG-l00, Hitachi Medical Corporation, Tokyo, Japan) | T:60 min of Taichi I: NR D: 6 months F:1 time/week |
Color-word matching Stroop | No significant alterations were noted in the prefrontal hemoglobin concentration during the task. |
| Yang et al. (2019) | Old: n = 26F; M = 66.12, SD = 3.81 | 3-cm separation; 10 Hz; 44 bilateral frontal channels (ETG4000; Hitachi Medical Co., Kashiwa, Japan) | T:45 min of Taichi I: NR D: 6 months F: 3 days per week |
Flanker task (4 blocks, each block 30 trials) | Increase in (oxyHb) in the prefrontal cortex during the incongruent flankers after the Taichi intervention. |
| Eggenberger et al. (2016) | Old: n = 33 (12 M, 21F); M = 74.9, SD = 6.9, range: > 65 | Four different separations; 10 Hz; 2 bilateral prefrontal channels (Oxiplex TS Tissue Spectrometer; ISS Inc., Champaign, IL, USA) | T: 30 min of dance I: NR D: 6 months Fr: 3 days per week |
Treadmill walking (preferred or fast walking; 30-s walking periods; four blocks per condition) | The increase in bilateral prefrontal (oxyHb) during the acceleration phase of self-paced walking was generally lower after training. Dance training resulted in a smaller increase in left (oxyHb) compared to balance training during the deceleration phase of fast-paced walking. |
| Coetsee and Terblanche (2017) | Old: n = 72 (21 M, 46F); M = 62.7, SD = 5.7, range: > 65 | 4-cm separation; 5HZ; 2 bilateral prefrontal channels (NIRO 200NX, Hamamatsu, Japan | T: 30 min of RT or MCT or HIIT I: RT: 10RM; MCT:70–75% HRmax; HIIT:90-95%HRmax D: 16 weeks Fr: 3 days per week |
Color-word matching Stroop (simple task: 24 trials, complex task: 24 trials) | At post-test, the control group showed increased brain activation with significantly higher relative (oxyHb) values during the naming Stroop condition compared to pre-test and a trend towards significance for their increased relative (oxyHb) in the complex condition. MCT and HIIT participants demonstrated decreased brain activation during the Stroop task, with MCT showing a significant increase in relative (deoxyHb) compared to pre-test during both naming and executive Stroop conditions. |
| Guo (2020) | Old: n = 39 F; M = 60, SD = 5.1 | 2.5-cm separation; 2 bilateral prefrontal channels (Glen Head, NY, USA) | T:40 min of Flexi-bar exercise I: moderate D: 8 weeks Fr:3 days per week |
Color-word matching Stroop | The study revealed significant differences in activation levels between the left and right ventrolateral prefrontal cortex, as well as the right frontal pole region, during Stroop tasks following intervention. |
| Cai et al. (2024) | Old: n = 52 (20 M, 31 F); M = 83.6, SD = 6.8 | 3-cm separation; 10 Hz; 24 bilateral frontal channels (Brite24, Artinis Medical Systems, Netherlands) | T:40 min of elastic exercise I: low to moderate D: 16 weeks Fr:3 days per week |
N-back (0, 1, 2 back) | Prefrontal activation was not significant under low memory load conditions. However, significant activation was observed in the bilateral ventrolateral prefrontal cortex, left dorsolateral prefrontal cortex, and left frontal pole regions under medium and high memory load conditions. |
PFC, prefrontal cortex; (deoxyHb) = deoxyhemoglobin concentration; (oxyHb) = oxyhemoglobin concentration; (total-Hb) = total hemoglobin concentration. HIIT, high-intensity interval training; MCT, moderate-intensity continuous training; RT, resistance training; RM, repeated maximal; NR, no report; T, time; I, intensity; D, duration; Fr, frequency.