Effect of Video Observation and Motor Imagery on Simple Reaction Time in Cadet Pilots

Neuromotor training can improve motor performance in athletes and patients. However, few data are available about their effect on reaction time (RT). We investigated the influence of video observation/motor imagery (VO/MI) on simple RT to visual and auditory stimuli. The experimental group comprised 21 cadets who performed VO/MI training over 4 weeks. Nineteen cadets completed a sham intervention as control. The main outcome measure was RT to auditory and visual stimuli for the upper and lower limbs. The RT to auditory stimuli improved significantly post-intervention in both groups (control vs. experimental mean change for upper limbs: -40 ms vs. -40 ms, p = 0.0008; for lower limbs: -50 ms vs. -30 ms, p = 0.0174). A trend towards reduced RT to visual stimuli was observed (for upper limbs: -30 ms vs. -20 ms, p = 0.0876; for lower limbs: -30 ms vs. -20 ms, p = 0.0675). The interaction term was not significant. Only the specific VO/MI training produced a linear correlation between the improvement in the RT to auditory and visual stimuli for the upper (r = 0.703) and lower limbs (r = 0.473). In conclusion, VO/MI training does not improve RT when compared to control, but it may be useful in individuals who need to simultaneously develop a fast response to different types of stimuli.

The Impact of a Motor Imagery-Based Training Program on Agility, Speed, and Reaction Time in a Sample of Young Tennis Athletes during Ramadan Fasting: Insights and Implications from a Randomized, Controlled Experimental Trial

The objective of this study was to explore whether a training program incorporating motor imagery could have an effect on physical performance outcomes in terms of agility, speed, and reaction time in a sample of tennis athletes who fasted during the month of Ramadan. Recruited subjects were 27 young male tennis players, randomly allocated to two groups: the imaging training group (n = 13) and a control group (n = 14). The study was designed as a randomized, controlled experimental study. The control group was engaged in watching videos concerning the history of the Olympic Games, whereas the motor imagery group followed a motor imagery-based training program. Physical performance outcomes were assessed during four sessions (one before Ramadan and three during Ramadan) by means of field tests. Our results revealed a drop in all performance outcomes measured in the middle and at the end of Ramadan for both groups (p < 0.01). The effect of the group × time interaction (p < 0.01) was reported for all physical performance outcomes measured for the two groups. This drop in performance was greater for the control group compared to the motor imagery group in the middle and at the end of Ramadan. This study showed that fasting during Ramadan reduced agility, speed, and reaction time performance for tennis players. A motor imagery-based training program could be an effective approach to reduce the effect of fasting during Ramadan and stabilize physical performance outcomes in terms of agility, speed, and reaction time for male tennis players.

Effects of Motor Mental Imagery Training on Tennis Service Performance during the Ramadan Fasting: a Randomized, Controlled Trial

The objective of the present study is to analyze the effects of motor mental imagery training on tennis service performance among tennis athletes who fast during Ramadan. Participants were 38 young male tennis players, randomly divided into two groups: Imaging Training (IMG, n = 18) and control group (CG, n = 20). The CG has watched videos on the history of the Olympic Games, while IMG has followed a training program in motor imagery. The performance of the tennis service was obtained by the product between accuracy and speed of typing (accuracy × average speed of all shots (km/h)). The effect of group/time interaction (p < 0.01) was identified for all performance indicators (accuracy, running speed and performance (speed × precision)), with improvement only in IMG (p = 0.01). The results showed that motor imagery training could be an effective strategy for mitigating/counteracting the negative effects of Ramadan on the tennis service performance.

Effects of motor imagery combined with action observation training on the lateral specificity of muscle strength in healthy subjects

Unilateral training of both lateral limbs increases unilateral muscle strength, whereas bilateral training increases bilateral muscle strength, a phenomenon known as lateral specificity in resistance training. Although motor imagery (MI) combined with action observation (AO) (i.e., MI + AO) training increases muscle strength, it is not completely understood whether such training increases the lateral specificity of muscle strength in a way resistance training does. To investigate whether MI + AO induces lateral specificity of muscle strength increase, 18 healthy subjects were divided into groups: MI + AO and the control groups. The control group watched a movie of natural sceneries for ten minutes per day five times a week for three weeks, whereas the MI + AO group imagined bilateral shoulder flexion while watching a movie of athletes performing bilateral shoulder flexion with barbells or dumbbells, with the same time schedule. The MI + AO group alone showed a significant increase in bilateral shoulder strength at three weeks after the intervention compared with the baseline. Unilateral shoulder strength was not significantly altered. These results suggest that MI + AO training increases muscle strength, providing evidence that similar to resistance training, lateral specificity also exists in MI + AO training.

Immediate effects of adding mental practice to physical practice on the gait of individuals with Parkinson's disease: Randomized clinical trial

BACKGROUND

Mental practice has shown benefits in the rehabilitation of neurological patients, however, there is no evidence of immediate effects on gait of individuals with Parkinson's disease.

OBJECTIVE

Determine the effects of mental practice activity added to physical practice on the gait of individuals with Idiopathic Parkinson's Disease (IPD).

METHODS

20 patients classified with stage 2 and 3, according to the Hoehn and Yahr scale were randomized into 2 groups. The experimental group (N = 10) was submitted to a single session of mental practice and physical practice gait protocol and the control group (N = 10) only to physical practice. The primary outcomes were stride length and total stance and swing time. Secondary outcomes were hip range of motion, velocity and mobility. Subjects were reassessed 10 minutes, 1 day and 7 days after the end of the session.

RESULTS

There was no statistically significant difference between the groups. An intragroup difference was observed in velocity, stride length, hip range of motion, and mobility, as well as total stance and swing time. These results were also observed on follow-ups.

CONCLUSIONS

Mental practice did not have a greater effect on the gait of individuals with IPD than physical practice, after a single session.

Neural processes mediating the preparation and release of focal motor output are suppressed or absent during imagined movement

Movements that are executed or imagined activate a similar subset of cortical regions, but the extent to which this activity represents functionally equivalent neural processes is unclear. During preparation for an executed movement, presentation of a startling acoustic stimulus (SAS) evokes a premature release of the planned movement with the spatial and temporal features of the tasks essentially intact. If imagined movement incorporates the same preparatory processes as executed movement, then a SAS should release the planned movement during preparation. This hypothesis was tested using an instructed-delay cueing paradigm during which subjects were required to rapidly release a handheld weight while maintaining the posture of the arm or to perform first-person imagery of the same task while holding the weight. In a subset of trials, a SAS was presented at 1500, 500, or 200 ms prior to the release cue. Task-appropriate preparation during executed and imagined movements was confirmed by electroencephalographic recording of a contingent negative variation waveform. During preparation for executed movement, a SAS often resulted in premature release of the weight with the probability of release progressively increasing from 24 % at -1500 ms to 80 % at -200 ms. In contrast, the SAS rarely (<2 % of trials) triggered a release of the weight during imagined movement. However, the SAS frequently evoked the planned postural response (suppression of bicep brachii muscle activity) irrespective of the task or timing of stimulation (even during periods of postural hold without preparation). These findings provide evidence that neural processes mediating the preparation and release of the focal motor task (release of the weight) are markedly attenuated or absent during imagined movement and that postural and focal components of the task are prepared independently.

Stress training for the surgical resident

BACKGROUND

Much effort in surgical education is placed on the development of clinical judgment and technical proficiency. However, little focus is placed on the management of stress associated with surgical performance. The inability to manage stress may lead to poor patient care, attrition from residency, and surgeon burnout.

METHODS

A blinded, matched, comparison group study to evaluate the efficacy of an educational program designed to improve surgical resident performance during stressful scenarios was conducted. The experimental group (n = 11) participated in stress training sessions, whereas the control group (n = 15) did not. Both groups then completed a simulation during which stress was evaluated using objective and subjective measures, and resident performance was graded using a standardized checklist.

RESULTS

Performance checklist scores were 5% higher in the experimental group than the control group (P = .54). No change existed in anxiety state according to the State Trait Anxiety Inventory (P = .34) or in heart rate under stress (P = .17) between groups.

CONCLUSIONS

There was a trend toward improved performance scoring but no difference in anxiety levels after stress training. However, 91% of residents rated the stress training as valuable.

Using touch or imagined touch to compensate for loss of proprioception: a case study

Proprioception is the sense of the position of one's own body. Here, we present a case study of an individual with proprioceptive loss in one limb consequent to stroke. The patient indicated that merely touching his impaired arm with his unimpaired arm temporarily restored his proprioception. We examined this claim and the effects of imagined touch by the unimpaired arm. Assessments were made using three-dimensional tracking of reaching trajectories towards targets in conditions of light and darkness. Both actual and imagined touching significantly reduced movement error and jerk, specifically for targets located in regions that both hands would be able to reach.

Befunde aus EEG-Untersuchungen zum Mentalen Training

Mentales Training (MT) im Sinne der planmäßig wiederholten Vorstellung eines Bewegungsablaufes ist ein zentraler Gegenstand sportpsychologischer Forschung. Im Hochleistungssport und in der Rehabilitation wird es zur Optimierung von Bewegungen eingesetzt. Einen Erklärungsansatz der Trainingswirkung bietet die Simulationstheorie mit dem zentralen Postulat, dass Bewegungsausführung und -vorstellung gleiche neuronale Strukturen aktivieren (funktionale Äquivalenz). Diese Annahme wurde mittels verschiedener neurophysiologischer Methoden geprüft, die teils zu widersprüchlichen Befunden führten. Die Elektroenzephalographie (EEG) kann unserer Ansicht nach dabei helfen, Lücken im theoretischen Erkenntnisprozess zu schließen. In diesem Artikel geben wir einen Überblick über die aktuelle Befundlage zum Mentalen Training mittels EEG. Es sollen drei wesentliche Vorteile der Methode aufgezeigt werden: (a) das EEG liefert Maße der neurophysiologischen Aktivität mit hoher zeitlicher Auflösung, (b) technische Weiterentwicklungen (drahtlose Hardware, tragbare Ausrüstung) erlauben die notwendige Bewegungsfreiheit für eine Anwendung im Sportkontext und (c) in der Rehabilitation kann die Vorstellung von Bewegungen als mentale Strategie dienen, um eine Neuroprothese auf Basis von Hirnsignalen zu steuern.

Motor imagery in patients with a right hemisphere stroke and unilateral neglect

INTRODUCTION

In the last decade new treatments based on mental imagery have been developed for patients with stroke. Whether this therapy works for patients with neglect is currently unclear.

OBJECTIVE

To investigate whether patients with a right hemisphere stoke complicated with unilateral neglect were less capable of performing motor imagery as compared to patients with a right hemisphere stroke without unilateral neglect.

METHODS

In a patient-control study, 20 patients with a right hemisphere stroke were included. Twelve patients were diagnosed on admission with neglect and eight without neglect. The ability to perform motor imagery was tested using mental rotation tasks, based on either a visual (CMIA 'Hand Rotation' test) or a verbal (Questionnaire d'Imagerie Mentale: Rotation des Mains) instruction. In both tasks subjects were instructed to generate a mental image of their hand.

RESULTS

Patients with neglect scored significantly less (p=0.02) as compared to patients without neglect on the visual mental rotation task, but not on the mental rotation task with verbal instruction.

CONCLUSION

Patients with a right-hemisphere stroke and neglect seem less capable of performing visual mental rotation tasks in comparison to patients with a stroke without neglect.

Lower limb muscle pre-motor time measures during a choice reaction task associate with knee abduction loads during dynamic single leg landings

BACKGROUND

Female neuromuscular control during dynamic landings is considered central to their increased ACL injury risk relative to males. There is limited insight, however, into the neuromuscular parameters governing this risk, which may hinder prevention success. This study targeted a new screenable and potentially trainable neuromuscular risk factor. Specifically, we examined whether lower limb muscle pre-motor times, being the time between stimulus presentation and initiation of the muscle EMG burst, elicited during a simple choice reaction task correlated with knee abduction loads during separate single leg landings.

METHODS

Twenty female NCAA athletes had muscle (n=8) pre-motor time and knee biomechanics data recorded bilaterally during a choice reaction task. Knee biomechanics were also quantified during anticipated and unanticipated single (dominant and non-dominant) leg landings. Mean peak knee abduction loads during landings were submitted to a two-way ANOVA to test for limb and decision effects. Individual regression coefficients were initially computed between-limb-based muscle pre-motor times and peak abduction moments elicited during both the choice reaction and landing tasks. Limb-based linear stepwise regression coefficients were also computed between muscle PMT's demonstrating significant (P<0.05) individual associations and peak knee abduction moments during landings.

FINDINGS

Peak knee abduction moments were significantly (P=0.0001) larger during unanticipated (51.25 (7.41) Nm) compared to anticipated (38.93 (9.32) Nm) landings. Peak abduction moments were significantly (P<0.05) correlated with bilateral medial gastrocnemius (r=0.62 dominant; r=0.63 non-dominant) and medial hamstring (r=0.77 dominant; r=0.79 non-dominant) pre-motor times elicited within the choice reaction task. Peak abduction moments during anticipated landings were significantly (P<0.05) correlated with both dominant (r=0.60) and non-dominant (r=0.59) medial hamstring pre-motor times. For unanticipated landings, non-dominant and dominant peak knee abduction moments were significantly correlated with medial hamstring pre-motor time (r=0.78) and combined medial gastroc and medial hamstring pre-motor times (r=0.94) respectively.

INTERPRETATION

Medial muscle pre-motor times during a specific choice reaction task are associated with peak knee abduction loads during separate single leg landings. These muscles appear critical in stabilizing the knee against the extreme dynamic load states associated with such tasks. Targeted screening and training of supraspinal processes governing these muscle pre-motor times may ultimately enable external knee loads associated with landings to be more effectively countered by the overarching neuromuscular strategy.