Objective: To investigate the effects of dual task balance training in the elderly on standing postural control while performing a cognitive task.
Design: A randomized two-group parallel controlled ...trial.
Participants: Forty-three subjects (all >65 years old) were enrolled in the study and were assigned randomly to either an experimental group (n = 21) or a control group (n = 22).
Interventions: Subjects in the experimental group were given strength and balance training while performing cognitive tasks simultaneously. Subjects in the control group were given strength and balance training only. The training was administered twice a week for three months.
Measurements: The Chair Stand Test, Functional Reach Test, Timed Up and Go Test and Trail Making Test were measured. The sway length of the centre of gravity was measured during standing while performing the Stroop task. The rate of Stroop task was also measured. All measurements were collected at baseline and after the training period.
Results: There were no significant differences in Functional Reach Test, Timed Up and Go Test and sway length at baseline and after training between the two groups. However, the rate of Stroop task (P < 0.05) was significantly higher after training in the experimental group than in the control group.
Conclusions: These results suggest that dual task balance training in elderly people improves their dual task performance during standing postural control.
► We evaluate the effects of tDCS on emotional pain in light of cerebral activity. ► Anodal tDCS of the left DLPFC improves subjective reports of an emotional pain. ► Anodal tDCS of the left DLPFC ...causes alterations of cerebral activity. ► Activity in DLPFC may facilitate activation of descending pain inhibitory system. ► Anodal tDCS of the left DLPFC reduce emotional pain efficiently.
Pain is a multidimensional experience with sensory-discriminative, cognitive-evaluative and affective-motivational components. Emotional factors such as unpleasantness or anxiety are known to have influence on pain in humans. The aim of this single-blinded, cross over study was to evaluate the effects of transcranial direct current stimulation (tDCS) on emotional aspects of pain in pain alleviation. Fifteen subjects (5 females, 10 males) volunteered to participate in this study. In an oddball paradigm, three categories of 20 pictures (unpleasant, neutral, and pleasant) served as rare target pictures from the International Affective Picture System (IAPS). The power of the delta (1–4Hz), theta (4–8Hz), alpha (8–12Hz), beta (12–25Hz), and gamma (30–40Hz) frequency bands in the three categories were measured using electroencephalography during an oddball paradigm at pre- and post-anodal or sham tDCS above the left dorsolateral prefrontal cortex (DLPFC). Results showed that the beta band power was significantly increased, and the alpha band power was significantly decreased during unpleasant pictures after anodal tDCS compared with sham tDCS. Furthermore, regarding unpleasant pictures, subjective reports of Self Assessment Manikin (SAM) for emotional valence after anodal tDCS showed a significant decrease of unpleasantness. Therefore, emotional aspects of pain may be effectively alleviated by tDCS of the left DLPFC as was shown not only by subjective evaluation, but also by objective observation of cerebral neural activity. This processing may be mediated by facilitation of the descending pain inhibitory system through enhancing neural activity of the left DLPFC.
Posture control during a dual-task involves changing the distribution of attention resources between the cognitive and motor tasks and involves the frontal cortex working memory (WM). The present ...study aimed to better understand the impact of frontal lobe activity and WM capacity in postural control during a dual-task. High and low WM-span groups were compared using their reading span test scores. High and low WM capacity were compared based on cognitive and balance performance and hemoglobin oxygenation (oxyHb) levels during standing during single (S-S), standing during dual (S-D), one leg standing during single (O-S), and one leg standing during dual (O-D) tasks. For sway pass length, significant difference in only the O-D task was observed between both groups. oxyHb levels were markedly increased in the right dorsolateral prefrontal cortex and supplementary motor area in the high-span group during a dual-task. Therefore, WM capacity influenced the allocation of attentional resources and motor performance.
Smooth social communication consists of both verbal and non-verbal information. However, when presented with incongruence between verbal information and nonverbal information, the relationship ...between an individual judging trustworthiness in those who present the verbal-nonverbal incongruence and the brain activities observed during judgment for trustworthiness are not clear. In the present study, we attempted to identify the impact of incongruencies between verbal information and facial expression on the value of trustworthiness and brain activity using event-related potentials (ERP). Combinations of verbal information positive/negative and facial expressions smile/angry expressions were presented randomly on a computer screen to 17 healthy volunteers. The value of trustworthiness of the presented facial expression was evaluated by the amount of donation offered by the observer to the person depicted on the computer screen. In addition, the time required to judge the value of trustworthiness was recorded for each trial. Using electroencephalography, ERP were obtained by averaging the wave patterns recorded while the participants judged the value of trustworthiness. The amount of donation offered was significantly lower when the verbal information and facial expression were incongruent, particularly for negative × smile. The amplitude of the early posterior negativity (EPN) at the temporal lobe showed no significant difference between all conditions. However, the amplitude of the late positive potential (LPP) at the parietal electrodes for the incongruent condition negative × smile was higher than that for the congruent condition positive × smile. These results suggest that the LPP amplitude observed from the parietal cortex is involved in the processing of incongruence between verbal information and facial expression.
Studies suggest that the observation of others' actions leads to enhanced motor skill learning.
We examined whether others' or self-action observation is effective for standing balance learning. In ...addition, we examined cortical activation during action observation using functional near-infrared spectroscopy.
Thirty-nine healthy young subjects were assigned randomly to the Control, Other-Observation (O-O), and Self-Observation (S-O) groups. The subjects learned to stand on a tilting platform while maintaining a horizontal position. The Control group alternated each trial with a rest period. The O-O and S-O groups were provided with information related to their performance during the rest period: the O-O group observed another person, while the S-O group observed their previous performance. Cortical activation was assessed by changes of hemoglobin oxygenation (oxyHb).
A 2-way analysis of variance with repeated measures on balance performance revealed a significant difference in post-training (p < 0.05) and retention (p < 0.01) only in the S-O group. And an increase of oxyHb levels at post-training in the S-O group was observed in the supplementary motor area.
Self-action observation improved standing balance and brain activity during training and at 24 h after training.
The effect of transcranial direct current stimulation (tDCS) on the precise nondominant hand movement was investigated by applying anodal stimulation over the right primary motor cortex. We recruited ...14 healthy participants for this single-blind, sham-controlled crossover trial. A circle-drawing task was performed before, immediately after, and at 30 min after 20 min of 1 mA anodal or sham tDCS. Anodal tDCS, compared with sham stimulation, significantly improved the circle-drawing task compared with sham stimulation. The deviation area and path length of the task were significantly decreased after anodal tDCS application and were further enhanced at 30 min after stimulation. These results suggest that anodal tDCS over the primary motor cortex enhances the precise movement of the nondominant hand for 30 min in healthy participants.
Pain is a multidimensional experience with sensory-discriminative, cognitive-evaluative, and affective-motivational components. Emotional factors, such as unpleasantness or anxiety, are known to have ...influence on pain in humans. Repeated painful stimulation has been reported to reduce subjective pain intensity. Nevertheless, there is little evidence of the influence of such stimulation on the emotional factors of pain. The aim of this study was to evaluate the influence of repeated painful stimulation on the experience of unpleasantness and anxiety.
Eight subjects (six females, two males) volunteered to participate in this study. Subjects received repeated painful stimulation for 3 consecutive days each instance lasting 6 seconds, 60 times per day, on the medial side of the forearm of the nondominant hand. We examined the following items to evaluate changes of responses to painful stimulation: pain thresholds, pain tolerance levels, pain intensities, unpleasantness, and anxiety. Furthermore, pain thresholds and pain tolerance levels were compared between different sites on the ipsilateral and contralateral forearms.
No immediate or chronological changes in pain thresholds or pain tolerance levels were observed. Pain intensities were reduced significantly over the 3-day experimental period (P<0.05). On the other hand, there was no great change in unpleasantness during the 3-day period. Anxiety was increased significantly after the painful stimulation compared with that without the painful stimulation and before day 1 of the stimulation (P<0.05).
These results suggest that repeated painful stimulation may result in habituation to pain intensities but not habituation to emotional factors.
Objective: To determine whether plantar perception training using a hardness discrimination task efficiently improves stabilization of standing posture balance in the old old as well as the very old.
...Design: A randomized two-group parallel controlled trial.
Setting: Nursing homes.
Participants: Forty-six elderly persons 75 years of age or older living in nursing facilities were randomly assigned evenly to either an intervention or a control group.
Intervention: The intervention group was given a task to discriminate hardness differences while standing on foam rubber of different levels of hardness, while the control group was given the task to simply remain standing on foam rubber. The tasks were imposed for 10 successive days.
Outcome measures: Outcome assessment was made by determinations of centre-of-gravity sway in the standing position and the Functional Reach Test.
Results: Planter perception was significantly improved and centre-of-gravity sway in the standing position was also significantly reduced in the intervention group after the intervention. In the control group, however, there were no significant changes in perception or in sway (P < 0.01) There was a significant difference in the Functional Reach Test values between the two groups: an increment of 12.3 ± 10.1 cm in the intervention group vs. 2.3 ± 5.8 cm in the control group (P < 0.001).
Conclusion: These results suggested that plantar perception exercises might efficiently stabilize standing postural balance in the old old as well as the very old.
Objective: To investigate the effects of sensory perception exercises for discrimination of surface hardness by the soles of the feet on standing postural balance in the elderly.
Design: A randomized ...two-group parallel controlled trial.
Subjects: Twenty-four healthy people aged from 61 to 71 years were enrolled and randomly assigned to a perception exercise group (n = 12) or a control group (n = 12).
Intervention: The perception exercise group were given a task designed to train ability to discriminate different degrees of hardness of foam rubber. The training period was 10 days. Control group subjects were instructed to maintain a standing posture on foam rubber for 10 seconds for a total of 10 days.
Measurements: Before and after training we measured centre-of-gravity sway with the subject standing, obtaining sway path length and area of ellipse. The Functional Reach Test was used to measure the forward displacement distance of the centre of gravity.
Results: Our data revealed a significant reduction in centre-of-gravity sway post training in the perception exercise group as well as a significant increase in forward displacement of the centre of gravity. These parameters were unchanged in the control group. As to change values (difference between pre- and post-training values), the perception exercise group had significantly better values than the control group, indicating the efficacy of sensory perception exercises.
Conclusions: We demonstrated that standing postural balance was improved by sensory perception exercises involving the soles of the feet. Used in addition to balance training, such training for hardness discrimination could be effective in the clinical setting to improve balance in the elderly.
The ability to maintain a one-leg standing position and the relation between plantar two-point discrimination and standing time on one leg were assessed. Participants were 1,241 apparently healthy ...people aged 2–92 years. Participants were asked to stand on one leg with eyes open (EO group) or closed (EC group) for up to 120 seconds. Coefficients of determination (COD) between subjects’ ages and results for both groups were calculated by quadratic and cubic functions. The slope of the tangent line drawn against the resultant curve was calculated by a differential formula. COD for the quadratic function were 0.65 (EO) and 0.33 (EC); age at maximum values in both groups was 37 years. COD for the cubic function were 0.77 (EO) and 0.52 (EC); maximum values were at ages 30 (EO) and 28 (EC) and minimum values at ages 88 (EO) and 77 (EC). The ability to remain standing on one leg with eyes closed appears to begin deteriorating in the late 20s. Age and plantar two-point discrimination distance had a significant positive correlation, and the two-point discrimination distance and standing time on one leg had a significant negative correlation. Decreased plantar sensation appears to be related to the decline in duration of one-leg standing.
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