Changes in electroencephalographic activity associated with learning a novel motor task

The Effect of Aerobic Exercise on Visuospatial Attention in Young Adults

Our objective in this study was to investigate the effect of moderate-intensity aerobic exercise on visuospatial attention bias. We examined line bisection performance at rest before exercise and then immediately after exercise in 20 young adults. Pre-exercise, there was a larger leftward bias in subjective midpoint judgment of all participants than post-exercise (p < .001). Thus, leftward error magnitude decreased according to aerobic exercise, as there were rightward shifts after the exercise. The participants' performancse were modulated by the hand used to perform manual bisection tasks (p < .02). Participants erred to the left of the true midpoint with the non-dominant hand and to the right of the true midpoint with the dominant hand. The use of the non-dominant hand led to greater leftward error than the errors obtained using the dominant hand, though there was no interaction effect between hand use and effort. These findings suggest that moderate aerobic exercise can benefit visuospatial attention in adults.

Using EEG to study sensorimotor adaptation

Sensorimotor adaptation, or the capacity to flexibly adapt movements to changes in the body or the environment, is crucial to our ability to move efficiently in a dynamic world. The field of sensorimotor adaptation is replete with rigorous behavioural and computational methods, which support strong conceptual frameworks. An increasing number of studies have combined these methods with electroencephalography (EEG) to unveil insights into the neural mechanisms of adaptation. We review these studies: discussing EEG markers of adaptation in the frequency and the temporal domain, EEG predictors for successful adaptation and how EEG can be used to unmask latent processes resulting from adaptation, such as the modulation of spatial attention. With its high temporal resolution, EEG can be further exploited to deepen our understanding of sensorimotor adaptation.

Electroencephalography as a Biomarker for Functional Recovery in Spinal Cord Injury Patients

BACKGROUND

Functional changes after spinal cord injury (SCI) are related to changes in cortical plasticity. These changes can be measured with electroencephalography (EEG) and has potential to be used as a clinical biomarker.

METHOD

In this longitudinal study participants underwent a total of 30 sessions of robotic-assisted gait training (RAGT) over a course of 6 weeks. The duration of each session was 30 min. Resting state EEG was recorded before and after 30-session rehabilitation therapy. To measure gait, we used the Walking Index for Spinal Cord Injury Scale, 10-Meter- Walking Test, Timed-Up-and-Go, and 6-Min-Walking Test. Balance was measured using Berg Balance Scale.

RESULTS

Fifteen participants with incomplete SCI who had AIS C or D injuries based on American Spinal Cord Injury Association Impairment Scale classification were included in this study. Mean age was 35.7 years (range 17-51) and the mean time since injury was 17.08 (range 4-37) months. All participants showed clinical improvement with the rehabilitation program. EEG data revealed that high beta EEG activity in the central area had a negative correlation with gait (p = 0.049; β coefficient: -0.351; and adj-R 2: 0.23) and balance (p = 0.043; β coefficient: -0.158; and adj-R 2:0.24) measured at baseline, in a way that greater high beta EEG power was related to worse clinical function at baseline. Moreover, improvement in gait and balance had negative correlations with the change in alpha/theta ratio in the parietal area (Gait: p = 0.049; β coefficient: -0.351; adj-R 2: 0.23; Balance: p = 0.043; β coefficient: -0.158; and adj-R 2: 0.24).

CONCLUSION

In SCI, functional impairment and subsequent improvement following rehabilitation therapy with RAGT correlated with the change in cortical activity measured by EEG. Our results suggest that EEG alpha/theta ratio may be a potential surrogate marker of functional improvement during rehabilitation. Future studies are necessary to improve and validate these findings as a neurophysiological biomarker for SCI rehabilitation.

Quantification of Movement-Related EEG Correlates Associated with Motor Training: A Study on Movement-Related Cortical Potentials and Sensorimotor Rhythms

The ability to learn motor tasks is important in both healthy and pathological conditions. Measurement tools commonly used to quantify the neurophysiological changes associated with motor training such as transcranial magnetic stimulation and functional magnetic resonance imaging pose some challenges, including safety concerns, utility, and cost. EEG offers an attractive alternative as a quantification tool. Different EEG phenomena, movement-related cortical potentials (MRCPs) and sensorimotor rhythms (event-related desynchronization—ERD, and event-related synchronization—ERS), have been shown to change with motor training, but conflicting results have been reported. The aim of this study was to investigate how the EEG correlates (MRCP and ERD/ERS) from the motor cortex are modulated by short (single session in 14 subjects) and long (six sessions in 18 subjects) motor training. Ninety palmar grasps were performed before and after 1 × 45 (or 6 × 45) min of motor training with the non-dominant hand (laparoscopic surgery simulation). Four channels of EEG were recorded continuously during the experiments. The MRCP and ERD/ERS from the alpha/mu and beta bands were calculated and compared before and after the training. An increase in the MRCP amplitude was observed after a single session of training, and a decrease was observed after six sessions. For the ERD/ERS analysis, a significant change was observed only after the single training session in the beta ERD. In conclusion, the MRCP and ERD change as a result of motor training, but they are subject to a marked intra- and inter-subject variability.

Train the Brain: Novel Electroencephalography Data Indicate Links between Motor Learning and Brain Adaptations

EEG differences were examined between part and whole practice in the learning of a novel motor task. Recording was done at 4 sites (i.e., O1, O2, C3, and C4) on 30 participants who performed a novel mirror star tracer task. Individuals were randomly assigned to 3 groups: whole practice, part practice, and control (no practice). Whole practice is defined as practicing a skill in its entirety. Part practice is defined as practicing separate, independent parts of the skill, and gradually combining those parts with parts that are dependent on one another. Each group was assessed during a pretest and posttest. EEG data was analyzed using a 2×2×2×3 (trials×hemisphere×site×practice) repeated measures mixed model ANOVA for each of the wave bands (lower alpha, upper alpha, lower beta, upper beta). All participants performed the task faster as no practice effect was found across the three groups; however the part practice group exhibited a significant decrease in errors. Reduced activation in the occipital and central sites was observed for lower alpha in the posttest compared to the pretest, for all participants. Hemispheric differences were present for all wavebands, with greater activation in the left hemisphere independent of practice type. The results of our study indicate that task learning was likely associated with the observed changes in the lower alpha waveband. Further, a concomitant behavior between the hemispheric lateralization of alpha and beta waveforms was observed. These results have implications for athlete training and rehabilitation. They indicate the utility of EEG for learning assessment in athletes. They also indicate learning strategies with a partial movement focus may be a beneficial strategy to support the development of complex sport skills training and rehabilitation strategies focused on reacquisition of skills prior to sport reintegration.

UNCONSCIOUS OPERANT CONDITIONING IN THE PARADIGM OF BRAIN-COMPUTER INTERFACE BASED ON COLOR PERCEPTION

This study investigate the mutual fine-tuning of ongoing EEG rhythmic features with RGB values controlling color shades of computer screen during neuro-feedback training. Fifteen participants had not been informed about the existence of neurofeedback loop (NF), but were guided only to look at the computer screen. It was found that during such unconscious NF training, a variety of color shades on the screen gradually changed from rather various types to the main one within the framework of color palette specified for each individual. This phenomenon was not observed in control experiments with simulated neuro-feedback. Individual color patterns induced on the screen during NF did not depend on the schema of connection between of EEG rhythms and RGB controller. It is suggested that the basic neurophysiological mechanism of described NF training consists of the directed selection of EEG patterns reinforced by comfortable color shades without conscious control.

Improved sensorimotor adaptation after exhaustive exercise is accompanied by altered brain activity

Acute exercise has been shown to exhibit different effects on human sensorimotor behavior; however, the causes and mechanisms of the responses are often not clear. The primary aim of the present study was to determine the effects of incremental running until exhaustion on sensorimotor performance and adaptation in a tracking task. Subjects were randomly assigned to a running group (RG), a tracking group (TG), or a running followed by tracking group (RTG), with 10 subjects assigned to each group. Treadmill running velocity was initially set at 2.0 m s(-1), increasing by 0.5 m s(-1) every 5 min until exhaustion. Tracking consisted of 35 episodes (each 40 s) where the subjects' task was to track a visual target on a computer screen while the visual feedback was veridical (performance) or left-right reversed (adaptation). Resting electroencephalographic (EEG) activity was recorded before and after each experimental condition (running, tracking, rest). Tracking performance and the final amount of adaptation did not differ between groups. However, task adaptation was significantly faster in RTG compared to TG. In addition, increased alpha and beta power were observed following tracking in TG but not RTG although exhaustive running failed to induce significant changes in these frequency bands. Our results suggest that exhaustive running can facilitate adaptation processes in a manual tracking task. Attenuated cortical activation following tracking in the exercise condition was interpreted to indicate cortical efficiency and exercise-induced facilitation of selective central processes during actual task demands.

Changed cortical activity after anterior cruciate ligament reconstruction in a joint position paradigm: an EEG study

After reconstruction of the anterior cruciate ligament (ACL) afferent proprioceptive information from the knee joint may be altered. In order to examine changes in central activation patterns, spectral features of the electroencephalography (EEG) were measured. Patients after ACL reconstruction and healthy controls carried out an knee-angle reproduction task in a groups x limbs x trials design. Cortical activity was recorded using international standards. FFT were conducted to determine power at Theta, Alpha-1, Alpha-2 and Beta-1. Statistics show significantly larger aberrations in the reconstructed limbs compared with the controls whereas there are no differences between the uninvolved land controls. Brain activity demonstrates significantly higher frontal Theta-power (F3, F4, F8) in both limbs of the ACL group vs the controls and a significantly higher Alpha-2 power was shown in the ACL-reconstructed limb compared with controls at parietal positions (P3, P4). No such differences were found between the uninvolved side and the controls. The EEG was able to measure a change in joint position sense at the cortical level after the reconstruction of the ACL. The results of these findings might indicate differences in focused attention with involvement of the anterior cingulate cortex (frontal Theta) and sensory processing in the parietal somatosensory cortex (Alpha-2).

Electroencephalographic Studies of Skilled Psychomotor Performance

Measurements based on the EEG have featured prominently in shaping present-day concepts of the neurocognitive aspects of skilled performance. The techniques include measurements of spectral power, interelectrode coherence, event-related potential components such as the P300, slow potentials, and the method of cognitive inference. The advantages offered by EEG-based approaches lies in their spatiotemporal resolution (potentially 1 mm and less than 1 millisecond, respectively) and the potential to preserve ecological validity, i.e., to obtain measurements of cortical function under the same conditions that the task is normally performed. These studies indicate that activity is reduced in specific regions of the cerebral cortex of experts relative to that observed in novices. These changes occur over time as a result of practice. The authors argue that such cortical change results in less attentional demand and less cognitive interference with motor planning and execution. The findings attest to the plasticity of the central nervous system when one is engaged in goal-directed learning, and hold implications for understanding how the nervous system acquires voluntary skills, whether in the context of the training of an athlete or the rehabilitation of a patient who has lost motor skills due to a disease of the nervous system.

Line-bisecting performance in highly skilled athletes: Does preponderance of rightward error reflect unique cortical organization and functioning?

A line-bisecting test was administered to 250 highly skilled right-handed athletes and a control group of 60 right-handed age matched non-athletes. Results revealed that athletes made overwhelmingly more rightward errors than non-athletes, who predominantly bisected lines to the left of the veridical center. These findings were interpreted in the context of previous EEG research on athletes and brain localization studies of select personality traits. A preliminary theory (Group Cortical Organization and Activation Theory) that highly skilled athletes and other specific homogeneous populations may have developed a unique cortical organization or response system that mediates relative tendencies in cerebral activation was advanced. The potential utility of the line-bisecting test as an assessment and intervention tool in sports was discussed.

Spatial distribution of coefficients of asymmetry of brain bioelectrical activity during the experiencing of negative emotions

Significant differences in the spatial distribution of the coefficients of asymmetry of the power of bioelectrical activity were identified in negative emotions of different qualities (anger and grief). In the case of the sthenic (excitable) emotion anger, there was an increase over baseline in the positive value of the coefficient of asymmetry in the anterior areas and the beta2 range, while for the asthenic emotion grief, there was an increase in the negative value of the coefficient in the beta1 range and a generalized increase in slow-wave activity.

Motor performance and motor learning as a function of age and fitness

Past studies have shown that electroencephalographic alpha activity increases as people learn to perform a novel motor task. Additionally, it has been suggested that motor performance and learning decline as people age beyond 60 years, and it has been hypothesized that physical fitness may attenuate this decline through its impact on the cerebral environment. This study was designed to replicate past research by assessing changes in alpha activity as a function of learning and to extend past research by examining differences in motor performance, motor learning, and alpha activity as a function of age and fitness. VO2max was assessed in 41 older (ages 60-80 years) and 42 younger (ages 20-30 years) participants. Participants were randomly assigned to experimental or control conditions, which differed in the amount of practice received. Participants performed trials on the mirror star trace on both an acquisition and a retention day. Results indicated that younger participants performed better and had greater learning than older participants. Fitness was not found to impact either performance or learning. Participants in the experimental group improved more than those in the control group and maintained this difference at retention, which suggests that learning occurred. Associated with these improvements in performance capabilities was an increase in alpha power.