Low-frequency Alpha Research Articles

Notes on Neuroplasticity Investigation using Coupled Electrical and Electrochemical Sensing through Carbon Electrodes

Neuroplasticity, the ability of the brain to form new neural pathways and synaptic connections, is gaining renewed interest for therapeutic purposes in stroke or spinal cord injury patients. Earlier work in this area in animal models has shown that behavior modulation was associated with the release of serotonin that subsequently leads to changes in gene expression and new neural growth [1]. A separate work has also demonstrated that using serotonin 1A agonists in rats with respiratory dysfunction due spinal cord injury results in better respiratory function [2]. Taken together, these studies indicate that neurotransmitters such as serotonin are closely linked to neuroplasticity, suggesting that changes in levels of these neurotransmitters can be correlated to synaptic changes. Currently, there is growing interest in the use of electrical stimulation as a means for inducing neuroplasticity in stroke and spinal cord injury patients [3]. However, while the data suggests that plasticity could be induced by electrical stimulation, neither the mechanism nor the protocols of stimulation are understood. We submit that a possible path to understanding these mechanisms involves simultaneous real-time monitoring of neurotransmitters such as serotonin electrochemically and electrical signals during stimulation and finding a correlation between these electrical signals and neurotransmitters. In cases where detection of several key electroactive neurotransmitters like serotonin and dopamine is sought, fast scan cyclic voltammetry (FSCV) with its high temporal resolution is the preferred electrochemical method of obtaining real time data [4]. Now, to be able to simultaneously monitor these electrochemical signals along with electrical signals, new approaches in neural probe material and architecture selection are required, as almost all neural probes currently in use are capable of recording only electrical or chemical signals, but not both. Thus, implementation of electrochemical monitoring techniques in animal models requires an integrated electrode array with a size suitable for an animal containing a counter electrode, working electrodes and a reference electrode. Furthermore, electrode materials capable of electrochemically detecting the presence of neurotransmitters without undergoing non-reversible reactions are sought. To meet this need, we investigate and report on the use of glassy carbon, a form of carbon that has been demonstrated to possess ideal characteristics, such as a wide electrochemical window with no irreversible reactions as a coupled electrical and electrochemical sensing platform. In this particular study, we introduce a 12-channel glassy carbon (GC) microelectrode array fabricated on a flexible substrate. The specific design introduced here consists of electrodes supported on a polyimide substrate with penetrating probes at their edges that can penetrate up to 1.25 mm into an animal's cortex or spinal cord. Each probe contains a glassy carbon electrode that can be used to detect serotonin, stimulate a neuron, or read an electrophysiological signal. Our preliminary results show that serotonin can be detected using a polyimide-glassy carbon device down to at least 1 uM in vitro by stimulating through one portion of the device and reading through another (Figure 1). Furthermore, we have shown that our electrodes can read electrophysiological data in-vivo. Figure 2b shows the Fourier Transform of a few seconds of electrical brain signals from a song bird without stimulus. In this graph low frequency alpha waves are most prominent. Figure 2c, the stimulus graph, on the other hand, shows that the beta and gamma waves became more prominent under external, audio stimulation. We believe that the ability to couple this kind of electrical signal detection with electrochemical sensing through FSCV (fast-scan CV) in a single device for in-vivostudies give promise for the disambiguation behind the mechanisms involved in neuroplasticity. Figure 1: Background subtracted cyclic voltagramms for various concentrations of serotonin Figure2: In vivo ECoG signals recorded with carbon electrodes. (a) Time lapse of the audio stimulus (b) Amplitude spectra of the animal during quiet time (c) Amplitude spectra of the signal during the stimulus phase. [1] Kandel, Eric R. Science 294, no. 5544 (2001): 1030-1038. [2] Choi, Howard, Wei-Lee Liao, Kimberly M. Newton, Renna C. Onario, Allyson M. King, Federico C. Desilets, Eric J. Woodard et al. The Journal of neuroscience 25, no. 18 (2005): 4550-4559. [3] Dimyan, Michael A., and Leonardo G. Cohen. Nature Reviews Neurology 7, no. 2 (2011): 76-85. [4] Lama, Rinchen D., Karl Charlson, Arun Anantharam, and Parastoo Hashemi. Analytical chemistry 84, no. 19 (2012): 8096-8101. Figure 1

Cortical generation of on-going “Delta” and “Alpha” EEG rhythms in mouse models of Alzheimer’s disease and Alzheimer’s disease patients at prodromic stages

Background and aim In the framework of IMI PharmaCog project (Grant Agreement n°115009, www.pharmacog.org ), this study evaluated whether cortical sources of resting state EEG rhythms were related to cerebrospinal fluid A®42 level in amnesic mild cognitive impairment (MCI) subjects and have translational value in mouse model of AD. Methods The research data (including human biological samples) were sourced ethically and used in line with international ethical standards. EEG rhythms were recorded in 127 aMCI subjects. Cortical sources of global delta (2–4 Hz) and low-frequency alpha (8–10.5 Hz) EEG rhythms were estimated by LORETA package. Back translation was tested on on-going EEG rhythms in wild type and transgenic mouse models of AD developing accumulation of A®42 in the brain (i.e. PDAPP, TASTPM). Results and conclusions (1) delta (

Workshop “Individualized Neurofeedback”.

Workshop “Individualized Neurofeedback”.

Neurophysiological Assessment of Alzheimer’s Disease Individuals by a Single Electroencephalographic Marker

Here we presented a single electroencephalographic (EEG) marker for a neurophysiological assessment of Alzheimer's disease (AD) patients already diagnosed by current guidelines. The ability of the EEG marker to classify 127 AD individuals and 121 matched cognitively intact normal elderly (Nold) individuals was tested. Furthermore, its relationship to AD patients' cognitive status and structural brain integrity was examined. Low-resolution brain electromagnetic tomography (LORETA) freeware estimated cortical sources of resting state eyes-closed EEG rhythms. The EEG marker was defined as the ratio between the activity of parieto-occipital cortical sources of delta (2-4 Hz) and low-frequency alpha (8-10.5 Hz) rhythms. Results showed 77.2% of sensitivity in the recognition of the AD individuals; 65% of specificity in the recognition of the Nold individuals; and 0.75 of area under the receiver-operating characteristic curve. Compared to the AD subgroup with the EEG maker within one standard deviation of the Nold mean (EEG-), the AD subgroup with EEG+ showed lower global cognitive status, as revealed by Mini-Mental State Evaluation score, and more abnormal values of white-matter and cerebrospinal fluid normalized volumes, as revealed by structural magnetic resonance imaging. We posit that cognitive and functional status being equal, AD patients with EEG+ should receive special clinical attention due to a neurophysiological "frailty". EEG+ label can be also used in clinical trials (i) to form homogeneous groups of AD patients diagnosed by current guidelines and (ii) as end-point to evaluate intervention effects.

Expecting to See a Letter: Alpha Oscillations as Carriers of Top-Down Sensory Predictions.

Predictions strongly influence perception. However, the neurophysiological processes that implement predictions remain underexplored. It has been proposed that high- and low-frequency neuronal oscillations act as carriers of sensory evidence and top-down predictions, respectively (von Stein and Sarnthein 2000; Bastos et al. 2012). However, evidence for the latter hypothesis remains scarce. In particular, it remains to be shown whether slow prestimulus alpha oscillations in task-relevant brain regions are stronger in the presence of predictions, whether they influence early categorization processes, and whether this interplay indeed boosts perception. Here, we directly address these questions by manipulating subjects' prior expectations about the identity of visually presented letters while collecting magnetoencephalographic recordings. We find that predictions lead to increased prestimulus alpha oscillations in a multisensory network representing grapheme/phoneme associations. Furthermore, alpha power interacts with stimulus degradation and top-down expectations to predict visibility ratings, and correlates with the amplitude of early sensory components (P1/N1m complex), suggesting a role in the selective amplification of predicted information. Our results thus indicate that low-frequency alpha oscillations can serve as a mechanism to carry and test sensory predictions about letters.

The Neurotoxicity and Pharmacokinetics of Oral Ifosfamide

Purpose:Ifosfamide can cause an unexplained encephalopathy. The incidence after intravenous infusion is 10%, but is much higher after oral administration. This study assesses the pharmacokinetics of oral ifosfamide in relation to neurotoxicity. Patients and Methods:Eleven patients received oral ifosfamide 500 mg twice daily for 14 days, with concurrent oral mesna. The concentrations of ifosfamide, isophosphoramide mustard, 2-dechloroethylifosfamide, 3-dechloroethylifosfamide, carboxyifosfamide, ketoifosfamide, chloroethylamine and 3-oxazolidine-2-one were measured using GC-MS. Patients were evaluated clinically, and also with the EEG, psychometric testing, the national adult reading test, and the mini-mental state examination. Results:A decrease in the electroencephalogram alpha frequency was observed, with the development of pathological slow wave activity. Psychometric performance was also impaired. Neurotoxicity was progressive during treatment, and the incidence of grade 3 neurotoxicity was 22%. The mean day 14 / day 1 Cmax ratios for 2-dechloroethylifosfamide and 3-dechloroethylifosfamide were 2.73 (± 2.11) and 2.04 (± 1.32) respectively. The metabolite with the lowest ratio was isophosphoramide mustard 1.07 (± 0.39). High chloroethylamine Cmax values were associated with lower alpha frequencies, and increased clinical neurotoxicity. Conclusion:Oral ifosfamide 500 mg twice daily for 14 days causes unacceptable neurotoxicity. It was not possible to identify one particular metabolite responsible for the neurotoxicity, although the dechloroethyl metabolites and chloroethylamine are implicated.

The spatial synchronization and power of the alpha and theta rhythm after Go/NoGo signals

Conditioning Go/NoGo signals, which determine the triggering stimulus conditional value, were presented to healthy adult subjects (n = 35) in the pause between the target (facial expression) and triggering stimuli. The response of the low-frequency α rhythm to conditioning stimuli was more pronounced in the left hemisphere. The coherence of cortical low-frequency alpha potentials increased 5–7 s after presenting both positive and negative conditioning (Go/NoGo) stimuli (i.e., immediately before the triggering stimulus). These data confirm the assumption that the development of differentiation requires not less functional activity than the development of a positive conditional response. The modulation of cortical activity after presenting Go/NoGo stimuli is mediated primarily by the thalamocortical system of selective attention. The coherence of θ rhythm after the presentation of positive conditioning stimuli was more pronounced in the medial cortical areas, which was apparently determined by the emotional memory function.

Use of EEG Workload Indices for Diagnostic Monitoring of Vigilance Decrement

A study was run to test which of five electroencephalographic (EEG) indices was most diagnostic of loss of vigilance at two levels of workload. EEG indices of alertness include conventional spectral power measures as well as indices combining measures from multiple frequency bands, such as the Task Load Index (TLI) and the Engagement Index (El). However, it is unclear which indices are optimal for early detection of loss of vigilance. Ninety-two participants were assigned to one of two experimental conditions, cued (lower workload) and uncued (higher workload), and then performed a 40-min visual vigilance task. Performance on this task is believed to be limited by attentional resource availability. EEG was recorded continuously. Performance, subjective state, and workload were also assessed. The task showed a vigilance decrement in performance; cuing improved performance and reduced subjective workload. Lower-frequency alpha (8 to 10.9 Hz) and TLI were most sensitive to the task parameters. The magnitude of temporal change was larger for lower-frequency alpha. Surprisingly, higher TLI was associated with superior performance. Frontal theta and El were influenced by task workload only in the final period of work. Correlational data also suggested that the indices are distinct from one another. Lower-frequency alpha appears to be the optimal index for monitoring vigilance on the task used here, but further work is needed to test how diagnosticity of EEG indices varies with task demands. Lower-frequency alpha may be used to diagnose loss of operator alertness on tasks requiring vigilance.

Reduced variability of auditory alpha activity in chronic tinnitus.

Subjective tinnitus is characterized by the conscious perception of a phantom sound which is usually more prominent under silence. Resting state recordings without any auditory stimulation demonstrated a decrease of cortical alpha activity in temporal areas of subjects with an ongoing tinnitus perception. This is often interpreted as an indicator for enhanced excitability of the auditory cortex in tinnitus. In this study we want to further investigate this effect by analysing the moment-to-moment variability of the alpha activity in temporal areas. Magnetoencephalographic resting state recordings of 21 tinnitus subjects and 21 healthy controls were analysed with respect to the mean and the variability of spectral power in the alpha frequency band over temporal areas. A significant decrease of auditory alpha activity was detected for the low alpha frequency band (8–10 Hz) but not for the upper alpha band (10–12 Hz). Furthermore, we found a significant decrease of alpha variability for the tinnitus group. This result was significant for the lower alpha frequency range and not significant for the upper alpha frequencies. Tinnitus subjects with a longer history of tinnitus showed less variability of their auditory alpha activity which might be an indicator for reduced adaptability of the auditory cortex in chronic tinnitus.

Resting-state Modulation of Alpha Rhythms by Interference with Angular Gyrus Activity

The default mode network is active during restful wakefulness and suppressed during goal-driven behavior. We hypothesize that inhibitory interference with spontaneous ongoing, that is, not task-driven, activity in the angular gyrus (AG), one of the core regions of the default mode network, will enhance the dominant idling EEG alpha rhythms observed in the resting state. Fifteen right-handed healthy adult volunteers underwent to this study. Compared with sham stimulation, magnetic stimulation (1 Hz for 1 min) over both left and right AG, but not over FEF or intraparietal sulcus, core regions of the dorsal attention network, enhanced the dominant alpha power density (8-10 Hz) in occipitoparietal cortex. Furthermore, right AG-rTMS enhanced intrahemispheric alpha coherence (8-10 Hz). These results suggest that AG plays a causal role in the modulation of dominant low-frequency alpha rhythms in the resting-state condition.

Adolescent anxiety and aggression can be differentially predicted by electrocortical phase reset variables

Increasing evidence supports the notion that both internalizing (e.g., anxiety) and externalizing (e.g., aggression) behavioral dysregulation are associated with abnormal communication between brain regions. Electroencephalographic (EEG) signals across two electrode sites are said to be coherent with one another when they show consistent phase relations. However, periods of desynchrony with shifting of phase relations are a necessary aspect of information processing. The components of EEG phase reset (‘locking’ when two regions remain in synchrony, and ‘shifting’ when the two regions desynchronize momentarily) show dramatic changes across development. We collected resting EEG data from typically developing 12 to 15-year-olds and calculated phase shift and lock values in the alpha frequency band across 14 pairs of electrodes varying in inter-electrode distance. A composite measure of participants’ aggression levels was positively associated with phase shifting, particularly in the low alpha frequency range, most strongly over the left hemisphere, consistent with the relatively greater left-prefrontal activity reported in aggressive adults. A composite measure of anxiety levels was positively associated with alpha phase locking at sites over both hemispheres, consistent with changes in connectivity reported during anxious thinking in adults. Associations with anxiety could not be explained by traditional EEG coherence measures and suggest that phase shifting and locking might provide an important non-invasive associate of clinically problematic behavior.

INFLUENCE OF BIOFEEDBACK AND SELF-REGULATION PSYCHOTECHNIQUES ON THE COGNITIVE FUNCTIONS AND ALPHA ACTIVITY EEG

Comparison the influence of voluntary increasing alpha power and decreasing EMG by using biofeedback (BFB) and usual self-regulation techniques (SRT) on cognitive functions and alpha activity in 27 male subjects was provided. The results show that alpha-BFB improve cognitive task performance and enhance the alpha activity in participants with low alpha frequency. SRT without feedback has no such effect.

INFLUENCE OF ALPHAEEG/EMG BIOFEEDBACK AND SELF-REGULATION PSYCHO TECHNIQUES ON THE HEART RATE VARIABILITY INDICES

With the purpose to study the impact of the upper frequency alpha EEG power increasing neurofeedback training (ANFT) on the cognitive performance, EEG alpha-activity and heart rate variability (HRV) 27 healthy men aged 18–34 years in pre, post and follow up one month 10 sessions ANFT time were investigated. The AFNT enhanced the fluency in cognitive performance, alpha frequency and power in upper frequency range and HRV only in participants with low baseline alpha frequency. While mock AFNT did change neither cognitive performance, nor alpha-activity, nor HRV indices. ANT reduces activation in cognitive load, and this effect persists for a month.

Changes in Evoked Cortical Electrical Activity at Different Time Points after Warning and Target Stimuli

Experiments involving solution of a simple visuospatial task (identification of the position of a target letter in a matrix) in adult healthy subjects (n = 16) were performed to assess the dynamics of cortical electrical activity in the alpha range during the intervals between warning and target stimuli. Pauses between stimuli were of duration 2 sec in one series and 9 sec in the other. In both series, apart from evoked reactions consisting of desynchronization of the low-frequency alpha rhythm (8–10 Hz) during the first second after the warning signal, desynchronization of this rhythm also occurred during the period immediately preceding presentation of the target stimulus. In the series with the longer interstimulus pause, synchronization of the alpha rhythm occurred at 4–6 sec, this being particularly clear in the high-frequency range (10–12 Hz); this gradually decreased by the beginning of exposure to the target stimulus. We regard changes in alpha-rhythm power at particular stages in the interstimulus pause as evoked reactions in response to “internal stimuli,” whose source is the inner representation (set) of the sequence of stimuli and their time parameters. As a result of “cognitive control” during the interstimulus pause, activity in the frontothalamic selective attention system increased or decreased, which was apparent as changes in alpharhythm power. The dynamics of cortical activity, as shown by analysis of the theta rhythm, did not involve the corticohippocampal system.

Влияние тренинга произвольного увеличения альфа-мощности ЭЭГ на вариабельность сердечного ритма

In order to study the effect of the alpha EEG power increasing training at heart rate variability (HRV) as the index of the autonomic regulation of cognitive functions there were follow tasks: (1) to figure out the impact of biofeedback in the voluntary increasing the power in the individual high-frequency alpha-band effect on heart rate variability and related characteristics of cognitive and emotional spheres, (2) to determine the nature of the relationship between alpha activity indices and heart rate variability, depending on the alpha-frequency EEG pattern at rest (3) to examine how the individual alpha frequency EEG pattern is reflected in changes HRV as a result of biofeedback training. Psychometric indicators of cognitive performance, the characteristics of the alpha-EEG activity and heart rate variability (HRV) as LF/HF and pNN50 were recorded in 27 healthy men aged 18-34 years, before, during, and after 10 sessions of training of voluntary increase in alpha power in the individual high-frequency alpha band with eyes closed. To determine the biofeedback effect on the alpha power increasing training, data subjects are compared in 2 groups: experimental (14) with the real and the control group (13 people)--with mock biofeedback. The follow up effect of trainings was studied through month over the 10 training sessions. Results showed that alpha biofeedback training enhanced the fluency and accuracy in cognitive performance, decreased anxiety and frontal EMG, increased resting frequency, width and power in individual upper alpha range only in participants with low baseline alpha frequency. While mock biofeedback increased resting alpha power only in participants with high baseline resting alpha frequency and did change neither cognitive performance, nor HRV indices. Biofeedback training eliminated the alpha power decrease in response to arithmetic task in both with high and low alpha frequency participants and this effect was followed up over the month. Mock biofeedback training has no such effect. The positive correlation between the alpha-peak frequency and pNN50 in patients with initially low, but negative--those with high baseline alpha frequency explains the multidirectional biofeedback effects on HRV in low and high alpha frequency subjects. The individual alpha-frequency EEG pattern determines the effectiveness of the alpha EEG biofeedback training in changing heart rate variability, which provides a basis for predicting the results and develop individual approaches to the biofeedback technology implementation that can be used in clinical practice for treatment and rehabilitation of psychosomatic syndromes and in educational training.

Clinical utility of paced breathing as a concentration meditation practice

The present study examined changes in electroencephalogram (EEG) and heart rate variability (HRV) parameters during paced breathing (PB) and their relationships with self-reported personality traits. Fifty-eight meditation-naive subjects (36 men, 22 women) ranging in age from 20 to 30 years completed the Temperament and Character Inventory (TCI). After a spontaneous breathing session, participants were asked to breathe in 6-s cycles, guided by an acoustic stimulus. EEG, HRV, and respiratory data were recorded during spontaneous and paced breathing. We calculated the powers for the EEG and HRV parameters based on the most regular respiratory curve observed over a 5-min period. In terms of HRV parameters, the high-frequency power increased and the low frequency-to-high frequency ratio decreased during PB. The low-frequency power did not change. In terms of EEG parameters, low-frequency alpha power, a marker of internal attention, globally increased and theta power, a marker of an advanced meditative state, locally decreased. This indicates that parasympathetic activity and internal attention increased, whereas an advanced meditative state was inhibited during PB. Of the personality traits, harm avoidance, novelty seeking, persistence, self-directedness, and self-transcendence were related to changes in low- and high-frequency alpha powers. Our results suggest that PB can be utilized as a concentration meditation practice for novices, and that individual differences such as personality traits should be considered when PB is offered for clinical or experimental purposes.

Diagnostic Monitoring Of Vigilance Decrement Using EEG Workload Indices

The resource model of vigilance (Warm, Parasuraman, & Matthews, 2008) suggests that EEG-based indices of workload might be used to monitor the operator’s fitness to sustain signal detection. 92 participants performed a 40 minute vigilance task believed to be sensitive to resource availability. Half performed in a cued condition, half without cues. Findings confirmed that cueing reduces workload and enhances vigilance. EEG was recorded throughout performance. Of the various EEG indices analyzed, lower frequency alpha and the Task Load Index (TLI) corresponded most closely to changes in signal detection rates. Other indices, the Engagement Index (EI) and frontal theta, did not show systematic decrement but discriminated cued and uncued conditions towards the end of the task. Implications of the findings for using EEG to drive adaptive automation are discussed.

Developmental Trajectories of Resting EEG Power: An Endophenotype of Autism Spectrum Disorder

Current research suggests that autism spectrum disorder (ASD) is characterized by asynchronous neural oscillations. However, it is unclear whether changes in neural oscillations represent an index of the disorder or are shared more broadly among both affected and unaffected family members. Additionally, it remains unclear how early these differences emerge in development and whether they remain constant or change over time. In this study we examined developmental trajectories in spectral power in infants at high- or low-risk for ASD. Spectral power was extracted from resting EEG recorded over frontal regions of the scalp when infants were 6, 9, 12, 18 and 24 months of age. We used multilevel modeling to assess change over time between risk groups in the delta, theta, low alpha, high alpha, beta, and gamma frequency bands. The results indicated that across all bands, spectral power was lower in high-risk infants as compared to low-risk infants at 6-months of age. Furthermore high-risk infants showed different trajectories of change in spectral power in the subsequent developmental window indicating that not only are the patterns of change different, but that group differences are dynamic within the first two years of life. These findings remained the same after removing data from a subset of participants who displayed ASD related behaviors at 24 or 36 months. These differences in the nature of the trajectories of EEG power represent important endophenotypes of ASD.

The Role of the Context of Cognitive Activity in the Recognition of Facial Emotional Expressions

The effects of the types of additional cognitive tasks (visuospatial or semantic) added to the context of experiments with a set to recognition of an emotionally negative facial expression were studied in healthy human subjects. Loading on working memory decreased the plasticity of the set: changes in the situation increased the number of erroneous recognitions of the facial expression. Differences were seen in the nature of erroneous recognitions (assimilative and contrast illusions) depending on the additional task. Analysis of coherence functions of cortical electrical potentials in the low-frequency alpha (8–10 Hz) and beta (14–20 Hz) ranges supported the hypothesis that increases in the loading on working memory lead to decreases in the involvement of the frontal mechanisms of selective attention in the formation and actualization of the set. This leads to slowing of the process of set shifting. Loading on working memory induced hemisphere asymmetry in prestimulus electrical activity: spatial synchronization of theta potentials significantly decreased in the right hemisphere and increased in the left. The functional significance of coherence connections in the theta range between the dorsolateral part of the prefrontal cortex and the temporal area in the right hemisphere for the process of set substitution is discussed.

Reactivity of alpha rhythms to eyes opening is lower in athletes than non-athletes: A high-resolution EEG study

In the present study, we tested the hypothesis that compared with non-athletes, elite athletes are characterized by a reduction of reactivity of electroencephalographic (EEG) alpha rhythms (about 8–12 Hz) to eyes opening in the condition of resting state, as a possible index of spatially selective cortical activation (i.e. “neural efficiency”). EEG data (56 channels; Eb-Neuro©) were recorded in 18 elite karate athletes and 28 non-athletes during resting state eyes-closed and eyes-open conditions. The EEG data were spatially enhanced by surface Laplacian estimation. Cortical activity was indexed by task-related power decrease (TRPD), namely the alpha power during the eyes-open referenced to the eyes-closed resting condition. Low-frequency alpha TRPD (about 8–10 Hz) was lower in the elite karate athletes than in the non-athletes in frontal (p < 0.00002), central (p < 0.008) and right occipital (p < 0.02) areas. Similarly, high-frequency alpha TRPD (about 10–12 Hz) was lower in the elite karate athletes than in the non-athletes in frontal (p < 0.00009) and central (p < 0.01) areas. These results suggest that athletes' brain is characterized by reduced cortical reactivity to eyes opening in the condition of resting state, in line with the “neural efficiency” hypothesis. The present study motivates future research evaluating the extent to which this general functional brain feature is related to heritable trait or intensive visuo-motor training of elite athletes.