Task-Switching Performance Improvements After Tai Chi Chuan Training Are Associated With Greater Prefrontal Activation in Older Adults

Abstract

Studies have shown that Tai Chi Chuan (TCC) training has benefits on task-switching ability. However, the neural correlates underlying the effects of TCC training on task-switching ability remain unclear. Using task-related functional magnetic resonance imaging (fMRI) with a numerical Stroop paradigm, we investigated changes of prefrontal brain activation and behavioral performance during task-switching before and after TCC training and examined the relationships between changes in brain activation and task-switching behavioral performance. Cognitively normal older adults were randomly assigned to either the TCC or control (CON) group. Over a 12-week period, the TCC group received three 60-min sessions of Yang-style TCC training weekly, whereas the CON group only received one telephone consultation biweekly and did not alter their life style. All participants underwent assessments of physical functions and neuropsychological functions of task-switching, and fMRI scans, before and after the intervention. Twenty-six (TCC, N = 16; CON, N = 10) participants completed the entire experimental procedure. We found significant group by time interaction effects on behavioral and brain activation measures. Specifically, the TCC group showed improved physical function, decreased errors on task-switching performance, and increased left superior frontal activation for Switch > Non-switch contrast from pre- to post-intervention, that were not seen in the CON group. Intriguingly, TCC participants with greater prefrontal activation increases in the switch condition from pre- to post-intervention presented greater reductions in task-switching errors. These findings suggest that TCC training could potentially provide benefits to some, although not all, older adults to enhance the function of their prefrontal activations during task-switching.

The Effect of Exercise Training on Brain Structure and Function in Older Adults: A Systematic Review Based on Evidence from Randomized Control Trials

“…Nine of the 13 studies (69%) reported that older adults were assigned to a moderate frequency (three to four times weekly) intervention [38,[49][50][51][52][53][54][55][56], three studies (23%) reported older adults were assigned to a high frequency (five to seven times weekly) intervention [57][58][59], and one study (8%) reported older adults were assigned to a low frequency (one to two times weekly) intervention [45].…”

“…Of the included studies in the review, five studies (46%) used vigorous intensity exercise training [38,50,[54][55][56], three studies (15%) used moderate intensity [45,49,53], and one study (8%) used moderate-to-vigorous intensity [52]. Four studies (31%) did not report the intensity of exercise training [51,[57][58][59].…”

“…Seven studies (50%) indicated that the exercise intervention occurred for a short-term length of time ( 12 weeks) [38,49,52,[56][57][58][59], three studies (25%) indicated a mid-term length of time (13-24 weeks) [45,50,51], three studies (25%) indicated a long-term length of time (25-48 weeks) [53][54][55], and none of the included studies employed a very long-term length of time (> 48 weeks).…”

“…Six studies (46%) reported exercise training for a short-time exercise ( 45 min) per session [38,45,50,[54][55][56], six studies (46%) used a moderate session time (45-60-min) [49,52,53,[57][58][59], and one study (8%) did not report the specific session time of exercise training [51]. None of the included studies used a long session time (> 60 min).…”

“…Eight studies (62%) reported an intervention using aerobic exercise training [38,45,[49][50][51][52]54,55], four studies (31%) used Tai Chi [56][57][58][59], and one study (7%) used coordination exercise compared to aerobic exercise and no exercise training (Voelcker-Rehage et al, 2011). None of the included studies used resistance exercise and combined exercise for examining brain function.…”