The effect of transcranial direct current stimulation on perception of effort in an isolated isometric elbow flexion task

This is the author's manuscript as accepted for publication in Motor Control. The final published article is available from the link below, copyright @ 2013 Human Kinetics.The purported ergogenic actions of transcranial direct current stimulation (tDCS) applied to motor cortex (M1) on force production and perception of effort were investigated using a 10-item numerical rating scale (0–10 NRS) in nonfatiguing bouts of a force-matching task utilizing isometric elbow flexion. Using a crossover design, 12 healthy volunteers received sham, anodal, and cathodal tDCS randomly for 10 min (1.5 mA, 62 ìA/cm2) to the left M1 in a double-blind manner. Cor- ticospinal excitability changes were also monitored using transcranial magnetic stimulation (TMS) with surface electromyography (sEMG) to monitor both motor evoked potentials (MEPs) and force-EMG from right m. biceps brachii and m. brachioradialis brachii. No significant differences between the verum and sham stimulation were obtained for elbow flexion maximum voluntary force, perception of effort, or sEMG. There were also no significant differences in MEP changes for the types of tDCS, which is consistent with reports that tDCS excitability effects are diminished during ongoing cognitive and motor activities.Brunel Universit

Evaluation of the numeric rating scale for perception of effort during isometric elbow flexion exercise

This is the author's accepted manuscript. The final publication is available at Springer via http://dx.doi.org/10.1007/s00421-011-2074-1.The aim of the study was to examine the reliability and validity of the numerical rating scale (0-10 NRS) for rating perception of effort during isometric elbow flexion in healthy people. 33 individuals (32 ± 8 years) participated in the study. Three re-test measurements within one session and three weekly sessions were undertaken to determine the reliability of the scale. The sensitivity of the scale following 10 min isometric fatiguing exercise of the elbow flexors as well as the correlation of the effort with the electromyographic (EMG) activity of the flexor muscles were tested. Perception of effort was tested during isometric elbow flexion at 10, 30, 50, 70, 90, and 100% MVC. The 0-10 NRS demonstrated an excellent test–retest reliability [intra class correlation (ICC) = 0.99 between measurements taken within a session and 0.96 between 3 consecutive weekly sessions]. Exploratory curve fitting for the relationship between effort ratings and voluntary force, and underlying EMG showed that both are best described by power functions (y = ax b ). There were also strong correlations (range 0.89–0.95) between effort ratings and EMG recordings of all flexor muscles supporting the concurrent criterion validity of the measure. The 0-10 NRS was sensitive enough to detect changes in the perceived effort following fatigue and significantly increased at the level of voluntary contraction used in its assessment (p < 0.001). These findings suggest the 0-10 NRS is a valid and reliable scale for rating perception of effort in healthy individuals. Future research should seek to establish the validity of the 0-10 NRS in clinical settings.School of Health Science and Social Care, Brunel Universit

Hemispheric lateralisation and immune function: A systematic review of human research

This is the post-print version of the final paper published in Journal of Neuroimmunology. The published article is available from the link below. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. Copyright @ 2011 Elsevier B.V.Past studies examined relationships between hemispheric lateralisation (HL) and immune system functioning. However, there has been no up-dated systematic review of this research area. This article reviews relevant published studies, evaluates study quality and effect sizes. Eleven studies were selected: three revealing a relationship between weaker left hemisphere function and poorer immune function, three describing a relationship between weaker right hemisphere function and stronger immune functioning, and five describing both relationships. Mean effect-size of the studies was r = 0.536 (range 0.280–0.866). Collectively, studies point at left-HL and stronger immunity relationships. Limitations, mechanisms and clinical implications are discussed

The relation between hemispheric lateralisation and measures of immune competence and adherence in Human Immunodeficiency Virus Type 1 (HIV-1)

This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited - Copyright © 2012 Sumner et al

Cerebral effects of music during isometric exercise: An fMRI study.

© 2018 The Authors. A block-design experiment was conducted using fMRI to examine the brain regions that activate during the execution of an isometric handgrip exercise performed at light-to- moderate-intensity in the presence of music. Nineteen healthy adults (7 women and 12 men; Mage = 24.2, SD = 4.9 years) were exposed to an experimental condition (music [MU]) and a no-music control condition (CO) in a randomized order within a single session. Each condition lasted for 10 min and participants were required to execute 30 exercise trials (i.e., 1 trial = 10 s exercise + 10 s rest). Attention allocation, exertional responses, and affective changes were assessed immediately after each condition. The BOLD response was compared between conditions to identify the combined effects of music and exercise on neural activity. The findings indicate that music reallocated attention toward task-unrelated thoughts (d = .52) and upregulated affective arousal (d = .72) to a greater degree when compared to a no- music condition. The activity of the left inferior frontal gyrus (lIFG) also increased when participants executed the motor task in the presence of music (F = 24.65), and a significant negative correlation was identified between lIFG activity and perceived exertion for MU (limb discomfort: r = -.54; overall exertion: r = -.62). The authors hypothesize that the lIFG activates in response to motor tasks that are executed in the presence of environmental sensory stimuli. Activation of this region might also moderate processing of interoceptive signals – a neurophysiological mechanism responsible for reducing exercise consciousness and ameliorating fatigue-related symptoms.Coordination for the Improvement of Higher Education Personnel (99999.010090/2013-04) (CAPES), Brazil

Ready Exerciser One: Effects of Music and Virtual Reality on Cycle Ergometer Exercise

© 2020 The Authors. Objectives Physical inactivity remains a major global health concern, and researchers have been encouraged to explore the role of technology in the promotion of physical activity. Technologies that deliver audio‐visual stimuli are frequently applied in the exercise domain. However, there is a paucity of research that examines the efficacy of modern virtual reality (VR) technology in this context. We investigated the effects of VR and music on affective, perceptual, enjoyment, and cardiac responses to aerobic‐type exercise. Design A fully counterbalanced, within‐subjects design was employed. Methods A convenience sample of recreationally active adult volunteers (N = 24) completed a 12‐min protocol during which they exercised under music, VR, VR‐with‐music, and control conditions. Results Analyses indicated a Condition × Time interaction for affective valence and perceived activation. Moreover, a main effect of condition emerged for state attention and perceived enjoyment. The VR and VR‐with‐music conditions elicited the most positive affective valence, highest levels of perceived activation, greatest number of dissociative thoughts, and most exercise enjoyment. Differences between these two conditions were negligible across the breadth of dependent variables. Conclusions The present findings illustrate the efficacy of modern VR technology in the exercise context, applied both with and without musical accompaniment. Additional research is required to assess the degree to which the findings are replicable among sedentary or ageing segments of the population. Given the emerging support pertaining to a positive relationship between affective responses and exercise adherence, VR technology should be considered as a means by which to promote an enjoyable exercise experience

Dynamic task observation: A gaze-mediated complement to traditional action observation treatment?

Action observation elicits changes in primary motor cortex known as motor resonance, a phenomenon thought to underpin several functions, including our ability to understand and imitate others’ actions. Motor resonance is modulated not only by the observer’s motor expertise, but also their gaze behaviour. The aim of the present study was to investigate motor resonance and eye movements during observation of a dynamic goal-directed action, relative to an everyday one – a reach-grasp-lift (RGL) action, commonly used in action-observation-based neurorehabilitation protocols. Skilled and novice golfers watched videos of a golf swing and an RGL action as we recorded MEPs from three forearm muscles; gaze behaviour was concurrently monitored. Corticospinal excitability increased during golf swing observation, but it was not modulated by expertise, relative to baseline; no such changes were observed for the RGL task. MEP amplitudes were related to participants’ gaze behaviour: in the RGL condition, target viewing was associated with lower MEP amplitudes; in the golf condition, MEP amplitudes were positively correlated with time spent looking at the effector or neighbouring regions. Viewing of a dynamic action such as the golf swing may enhance action observation treatment, especially when concurrent physical practice is not possible

Effects of Transcranial Direct Current Stimulation (tDCS) on Chronic Pain in Spinal Cord Injured Patients

Introduction: Pain following spinal cord injury (SCI) is notoriously difficult to manage and often refractory to treatment. Novel approaches, such as non-invasive brain stimulation, targeting central mechanisms associated with chronic pain, have shown early promise as a safe treatment in various patient groups, including spinal cord injury. To date the number of small clinical trials using non-invasive brain stimulation to treat chronic pain in SCI have produced mixed results (1). We report here the findings of a UK based trial examining the effects of anodal Transcranial Direct Current Stimulation (tDCS) administration on pain in spinal injury patients. Methods: Sixteen spinal injury patients from the National Spinal Injury Centre, Stoke Mandeville Hospital, Aylesbury, UK participated in a single centre, double blind randomized control trial. Patients were randomly allocated to either the active (n=8) or sham (n=8) treatment groups. tDCS was administered by electrodes with anode placement over the dominant M1 and the cathode electrode over the contralateral supra-orbit scalp area. Subjects received either active (2mA anodal current) or sham tDCS for 20 minutes daily treatment for 5 consecutive days with the dose based on previously reported chronic pain studies in spinal cord injury patients. A mixed ANOVA was used to evaluate both tDCS treatment and time effects on validated assessment measures for pain and depression up to 2 weeks following treatment intervention. Results: No adverse effects of the treatment were observed in this study, nor were there any significant differences between groups in rating perception of stimulation. While treatment appeared to have reduced group pain scores on a visual analogue scale (VAS), there were no statistically significant differences between active and sham treatment groups when re-examined at the two week follow up. Conclusions: There was a reduction in self-assessed VAS pain score in our small group of SCI patients during treatment in both the sham and active tDCS and at two weeks post treatment. However, our study appears to indicate only a placebo-like effect of tDCS on chronic pain in SCI and no effect attributable to the active anodal stimulation over motor cortex. We also did not observe any significant effects over time or treatment on neuropathic pain when assessed with validated measures. We observed trends of non-significant reduction in some of self-assessed pain scores of measures, however, these are inconclusive. Studies of clinical efficacy of pain treatment by tDCS in spinal cord injury should therefore be conducted on a larger scale, and with a longer follow up period to address the limited evidence available

Cerebral mechanisms underlying music use during exhaustive exercise

The brain mechanisms by which music-related interventions ameliorate fatigue-related symptoms and enhance exercise performance during the execution of fatiguing motor tasks are hitherto under-researched. The objective of the present study was to investigate the effects of music on electrical activity in the brain and psychophysiological responses during the execution of a fatiguing isometric ankle-dorsiflexion task that was performed to the point of volitional exhaustion. Nineteen healthy participants (10 men and 9 women; Mage = 26.4 years, SD = 3.6 years) performed two fatigue tests at 40% of maximal voluntary contraction while administered a musical excerpt or a no-music control condition. The well-known track Eye Of The Tiger by Survivor (109 bpm) was used as a distractive auditory stimulus. Electrical activity in the brain was assessed by use of a 64-channel EEG. Fast Fourier Transform was used to decompose the 1 s asynchronous samples into three wave frequencies (theta [3–8 Hz], alpha [8–12.5 Hz], and beta [12.5–35 Hz] bands); these were selected to facilitate investigation of how a musical excerpt might influence performance of a motor task. Attentional focus was assessed every 30 s during the motor task. Limb discomfort, situational motivation, affective valence, and felt arousal were assessed prior to and immediately after the motor task. The results indicated that, during the task, music down-regulated theta waves in the frontal, central, and parietal regions of the brain. Music also elicited a partial attentional switching from internal, task-related cues to external task-unrelated cues during exercise, which was associated with improvements in task performance. Moreover, participants experienced more positive affect while performing the isometric task in the music condition. In conclusion, music elicited a change in the predominance of low-frequency waves throughout the cortex and suppressed exercise-related afferent cues (e.g., limb discomfort) in such a way that they remained outside of focal awareness over a broader range of exercise intensity

Cross cultural adaptation of Berg balance scale in Greek for various balance impairments

Rationale, Aim & Objectives: The Berg Balance Scale (BBS) although widely used for assessing balance, it has not been officially adapted into Greek. The aim therefore, of this research is to translate and validate the cross cultural adaptation of the Greek BBS (BBS-GR). Method: The BBS-GR was adapted according to international guidelines, (forward & backward translation, by four bilingual independent translators). The pre-final BBS-GR was piloted by 6 physiotherapists (1-5 years of experience) and 12 patients (5 men & 7 women, age 76±7 years) in the 1st pilot study and by 10 patients (7 men & 3 women, age 57±20 years) during the 2nd pilot study with balance impairments. After modifications, the final BBS-GR was undertaken to 112 patients (43 men, 69 women, age 67±19 years) for its psychometric testing. It was administered by two raters, twice over a 10 day period, to assess both inter- and test-retest reliability correspondingly. Bland-Altman analysis presented the levels of agreement between measurements. Validity was assessed by correlation of the BBS-GR with the Greek mini-Balance Evaluation Systems Test (mini-BESTest), the Functional Reach Test (FRT), the Timed Up and Go test (TUG) and the questionnaire of Falls Efficacy Scale-International (FES-I). Results: Minor modifications to one item were required for the final BBS-GR version, and showed: excellent inter-rater reliability (ICC=0.998), test-retest (ICC=0.976) reliability and internal consistency (Cronbach's alpha=0.830). Measurements showed a level of agreement (meandif=0.126±0.7, p>0.05). Spearman’s correlations coefficient (rs) were strong between the BBS-GR and the Greek mini-BESTest (rs=0.844, p<0.001), the TUG (rs=-0.781, p<0.001), the FRT (rs=0.650, p<0.001) and FES-I (rs=-0.501, p<0.001), indicating good validity properties. Responsiveness across fallers and non fallers showed a moderate effect size (0.54). Conclusion: The excellent psychometric characteristics of the Greek BBS highly recommend its utility to the Greek clinical setting. Further research should be undertaken to evaluate responsiveness over treatment conditions