The Relationship between Inclination for Conscious Movement Monitoring and Control and Stopping a Golf Stroke.

Increased conscious movement monitoring and control can impair sports performance. Recent evidence indicates it might facilitate stopping motor actions. To further investigate, we asked novices to putt balls, but they needed to stop promptly while an auditory cue appeared during the downswing. They also completed the Movement Specific Reinvestment Scale, which measures movement self-consciousness (MS-C) and conscious motor processing, indicating the degree of inclination for conscious movement monitoring and control, respectively. Individuals with high MS-C displayed higher stopping rates but longer stopping time. Further exploration suggests that they were more likely to make slow downswings, allowing successful but late stops. We conclude that increased conscious movement monitoring may affect movement execution in such a way that it affords better stopping of ongoing motor actions.

The effects of conscious movement investment on inhibiting a golf stroke.

Previous studies have suggested an association between conscious movement investment and inhibiting motor actions. However, no within-designs were used in which conscious movement investment was manipulated. The current study compared changes in inhibition after instruction interventions that aimed to expand and limit conscious investment in the execution of a golf putting task. During a baseline and post-intervention test, participants were asked to putt balls in a hole. Randomly, an auditory stop-signal appeared 50 ms after reaching the end of backswing on some trials, signalling them to stop the downswing as quickly as possible. Between the two tests, the participants practiced under different instructions, without the stop-signal. One group (i.e., expanded conscious investment, ECIG) received multiple explicit movement-related instructions along with the internal focus of attention instructions, while the second group (i.e., limited conscious investment, LCIG) received a single analogy instruction paired with external focus of attention instructions. The results did not reveal significant differences in stopping rate and stopping time between the baseline and post-intervention tests and the two groups. However, a mediation analysis highlighted that the ECIG exhibited a greater change in downswing time compared to the LCIG. This change was correlated with a larger increase in stopping rate and stopping time. We conclude that conscious movement investment did not directly influence inhibition. Instead, we discuss how conscious movement investment may indirectly influence inhibition dependent on the putting kinematics.

No training effects of top-down controlled response inhibition by practicing on the stop-signal task.

The aim of the current study is to examine if the top-down controlled response inhibition on a stop-signal task (SST) can be trained. Results from previous studies have been equivocal, possibly because signal-response combinations are often not varied across training and test phases, allowing bottom-up signal-response associations to be formed that may improve response inhibition. The current study compared the response inhibition on the SST in a pre-test and post-test in an experimental group (EG) and control group (CG). In between tests, the EG received ten training sessions on the SST with varying signal-response combinations that were also different from the combinations in the test phase. The CG received ten training sessions on the choice reaction time task. Results failed to reveal a decrease in stop-signal reaction time (SSRT) during and after training, with Bayesian analyses revealing anecdotal and substantial evidence for the null hypothesis during and after training, respectively. Yet, the EG did show smaller go reaction times (Go_RT) and stop signal delays (SSD) after training. The results indicate that the top-down controlled response inhibition is difficult or impossible to improve.

Effects of an Arbuscular Mycorrhizal Fungus on the Growth of and Cadmium Uptake in Maize Grown on Polluted Wasteland, Farmland and Slopeland Soils in a Lead-Zinc Mining Area.

Arbuscular mycorrhizal fungi (AMF) exist widely in soil polluted by heavy metals and have significant effects on plant growth and cadmium (Cd) uptake. Cd contents differ among wasteland, farmland and slopeland soils in a lead-zinc mining area in Yunnan Province, Southwest China. The effects of AMF on maize growth, root morphology, low-molecular-weight organic acid (LMWOA) concentrations and Cd uptake were investigated via a root-bag experiment. The results show that AMF increased maize growth on Cd-polluted soils, resulting in increases in root length, surface area, volume and branch number, with the effects being stronger in farmland than in wasteland and slopeland soils; increased malic acid and succinic acid secretion 1.3-fold and 1.1-fold, respectively, in roots on farmland soil; enhanced the iron- and manganese-oxidized Cd concentration by 22.6%, and decreased the organic-bound Cd concentration by 12.9% in the maize rhizosphere on farmland soil; and increased Cd uptake 12.5-fold and 1.7-fold in shoots and by 25.7% and 86.6% in roots grown on farmland and slopeland soils, respectively. Moreover, shoot Cd uptake presented significant positive correlations with root surface area and volume and LMWOA concentrations. Thus, these results indicated the possible mechanism that the increased maize Cd uptake induced by AMF was closely related to their effect on root morphology and LMWOA secretion, with the effects varying under different Cd pollution levels.

Motor expertise modulates unconscious rather than conscious executive control.

BACKGROUND: Executive control, the ability to regulate the execution of a goal-directed task, is an important element in an athlete's skill set. Although previous studies have shown that executive control in athletes is better than that in non-athletes, those studies were mainly confined to conscious executive control. Many recent studies have suggested that executive control can be triggered by the presentation of visual stimuli without participant's conscious awareness. However, few studies have examined unconscious executive control in sports. Thus, the present study investigated whether, similar to conscious executive control, unconscious executive control in table tennis athletes is superior to that in non-athletes. METHODS: In total, 42 age-matched undergraduate students were recruited for this study; 22 nonathletic students lacking practical athletic experience comprised one group, and 20 table tennis athletes with many years of training in this sport comprised a second group. Each participant first completed an unconscious response priming task, the unconscious processing of visual-spatial information, and then completed a conscious version of this same response priming task. RESULTS: Table tennis athletes showed a significant response priming effect, whereas non-athletes did not, when participants were unable to consciously perceive the visual-spatial priming stimuli. In addition, the number of years the table tennis athletes had trained in this sport (a measure of their motor expertise) was positively correlated with the strength of the unconscious response priming effect. However, both table tennis athletes and non-athletes showed a response priming effect when the primes were unmasked and the participants were able to consciously perceive the visual-spatial priming stimuli. CONCLUSION: Our results suggest that motor expertise modulates unconscious, rather than conscious, executive control and that motor expertise is positively correlated with unconscious executive control in table tennis athletes.

Unconscious response inhibition differences between table tennis athletes and non-athletes.

BACKGROUND: Response inhibition is associated with successful sporting performance. However, research on response inhibition in athletes from open-skill sports has mainly focused on a consciously triggered variety; little is known about open-skill athletes' response inhibition elicited by unconscious stimuli. METHODS: Here, we explored unconscious response inhibition differences between table tennis athletes (n = 20) and non-athletes (n = 19) using the masked go/no-go task and event-related potentials technique (ERPs). RESULTS: At the behavioral level, table tennis athletes displayed shorter go-response times (RTs) than non-athletes in the conscious condition. Furthermore, table tennis athletes exhibited longer response time-slowing (RT-slowing) than non-athletes in the unconscious condition. At the neural level, table tennis athletes displayed shorter event-related potential N2 component latencies than non-athletes for all conditions. More importantly, athletes displayed larger no-go event-related potential P3 component amplitudes than non-athletes at both the conscious and unconscious levels. DISCUSSION: The present study results suggested that table tennis athletes have superior conscious and unconscious response inhibition compared to non-athletes.

The benefits of Tai Chi and brisk walking for cognitive function and fitness in older adults.

The purpose of this study was to investigate the benefits of exercises with different cognitive demands for cognitive functions (Executive and non-Executive) in healthy older adults. A cross-sectional design was adopted. In total, 84 healthy older adults were enrolled in the study. They were categorized into the Tai Chi group (TG), the brisk walking group (BG) or the control group (CG). Each participant performed the Stroop task and a digit comparison task. The Stroop task included the following three conditions: a naming condition, an inhibition condition and an executive condition. There were two experimental conditions in the digit comparison task: the non-delay condition and the delay condition. The results indicated that participants of the TG and BG revealed significant better performance than the CG in the executive condition of cognitive tasks and fitness. There was no significant difference of reaction time (RT) and accuracy rate in the inhibition and delay conditions of cognitive tasks and fitness between the TG and BG. The TG showed shorter reaction time in the naming and the executive conditions, and more accurate in the inhibition conditions than the BG. These findings demonstrated that regular participation in brisk walking and Tai Chi have significant beneficial effects on executive function and fitness. However, due to the high cognitive demands of the exercise, Tai Chi benefit cognitive functions (Executive and non-Executive) in older adults more than brisk walking does. Further studies should research the underlying mechanisms at the behavioural and neuroelectric levels, providing more evidence to explain the effect of high-cognitive demands exercise on different processing levels of cognition.