Phase-locking Index Research Articles

Gamma music: a new acoustic stimulus for gamma-frequency auditory steady-state response.

A frequency range exceeding approximately 30 Hz, denoted as the gamma frequency range, is associated with various cognitive functions, consciousness, sensory integration, short-term memory, working memory, encoding and maintenance of episodic memory, and retrieval processes. In this study, we proposed a new form of gamma stimulation, called gamma music, combining 40 Hz auditory stimuli and music. This gamma music consists of drums, bass, and keyboard sounds, each containing a 40 Hz frequency oscillation. Since 40 Hz stimuli are known to induce an auditory steady-state response (ASSR), we used the 40 Hz power and phase locking index (PLI) as indices of neural activity during sound stimulation. We also recorded subjective ratings of each sound through a questionnaire using a visual analog scale. The gamma music, gamma drums, gamma bass, and gamma keyboard sounds showed significantly higher values in 40 Hz power and PLI compared to the control music without a 40 Hz oscillation. Particularly, the gamma keyboard sound showed a potential to induce strong ASSR, showing high values in these indices. In the subjective ratings, the gamma music, especially the gamma keyboard sound, received more relaxed, comfortable, preferred, pleasant, and natural impressions compared to the control music with conventional gamma stimulation. These results indicate that our proposed gamma music has potential as a new method for inducing ASSR. Particularly, the gamma keyboard sound proved to be an effective acoustic source for inducing a strong ASSR while preserving the comfortable and pleasant sensation of listening to music. Our developed gamma music, characterized by its pleasantness to the human ear, offers a significant advantage for the long-term use of gamma stimulation. The utilization of this music could potentially reduce the physical and psychological burden on participants compared to conventional 40 Hz stimuli. This music is not only expected to contribute to fundamental neuroscience research utilizing ASSR but also to facilitate the implementation of gamma music-based interventions aimed at enhancing human cognitive functions in everyday life.

Direct input of monitoring data into a mechanistic ecological model as a way to identify the phytoplankton growth-rate response to temperature variations

We present an approach (knowledge-and-data-driven, KDD, modeling) that allows us to get closer to understanding the processes that affect the dynamics of plankton communities. This approach, based on the use of time series obtained as a result of ecosystem monitoring, combines the key features of both the knowledge-driven modeling (mechanistic models) and data-driven (DD) modeling. Using a KDD model, we reveal the phytoplankton growth-rate fluctuations in the ecosystem of the Naroch Lakes and determine the degree of phase synchronization between fluctuations in the phytoplankton growth rate and temperature variations. More specifically, we estimate a numerical value of the phase locking index (PLI), which allows us to assess how temperature fluctuations affect the dynamics of phytoplankton growth rates. Since, within the framework of KDD modeling, we directly include the time series obtained as a result of field measurements in the model equations, the dynamics of the phytoplankton growth rate obtained from the KDD model reflect the behavior of the lake ecosystem as a whole, and PLI can be considered as a holistic parameter.

Cognitive Reorganization Due to Mental Workload: A Functional Connectivity Analysis Based on Working Memory Paradigms

Mental workload has a major effect on the individual’s performance in most real-world tasks, which can lead to significant errors in critical operations. On this premise, the analysis and assessment of mental workload attain high research interest in both the fields of Neuroergonomics and Neuroscience. In this work, we implemented an EEG experimental design consisting of two distinct mental tasks (mental arithmetic task, n-back task), each with two conditions of complexity (low and high) to investigate the task-related and task-unrelated workload effects. Since mental workload is an intricate phenomenon involving multiple brain areas, we performed a graph theoretical analysis estimating the Phase Locking Index (PLI) in four frequency bands (delta, theta, alpha, beta). The brainwave-dependent network results show statistically significant reductions in clustering coefficient, characteristic path length, and small-worldness metrics with higher workload in both tasks across several bands. Moreover, functional connectivity analysis indicates a task-independent fashion of the brain topological re-organization with increasing mental load. These results revealed how the brain network is re-organized with increasing mental workload in a task-independent way. Finally, the network metrics were used as classification features, leading to high performance in workload level discrimination.

Responses at Individual Gamma Frequencies Are Related to the Processing Speed but Not the Inhibitory Control.

The link between the state of networks underlying the generation of periodic responses at gamma ranges and cognitive outcomes is still poorly understood. In this study, we tested the idea that the individual differences in the ability to generate responses to auditory stimulation at gamma frequencies may underlie the individual differences in the inhibitory control. We focused on the processing speed and accuracy in the Bivalent Shape Task (a cognitive inhibition task assessing attentional interference) and explored the relationship with responses at 40 Hz and at individual gamma frequencies (IGFs, assessed utilizing auditory envelope-following responses in 30-60 Hz range). In a sample of 70 subjects, we show that individual measures (phase-locking index and event-related spectral perturbation) of the ability to generate gamma-range activity are not related to the individual differences in inhibitory control but rather reflect basic information processing speed in healthy young subjects. With the individualized approach (at IGFs), the observed associations were found to be somewhat stronger. These findings have important implications for the interpretation of gamma activity in neuropsychiatric disorders.

Phase synchronization of chlorophyll and total phosphorus oscillations as an indicator of the transformation of a lake ecosystem

The ecosystem of the Naroch Lakes (Belarus) includes three water bodies, Lake Batorino, Lake Myastro and Lake Naroch. These lakes have a common catchment area. At the end of the 80 s, the ecosystem of the Naroch Lakes underwent a transformation, during which the nutrient load on the catchment area decreased, and the concentration of phosphorus as a limiting factor in these water bodies decreased significantly. At the same time, the Naroch Lakes were exposed to zebra mussel (Dreissena polymorpha Pallas) invasion. In the mid-90 s, the biological and hydrochemical characteristics of the ecosystem of the Naroch Lakes stabilized. We show here that complex processes associated with the transformation of the lake ecosystem and affecting both trophic interactions in the Naroch Lakes and the influence of environmental factors on them can be represented using a single parameter, the phase-locking index, PLI. In this case, a statistically significant numerical value of PLI characterizes the phase synchronization of two processes, oscillations of the concentration of total phosphorus, TP, and oscillations of the concentration of chlorophyll, Chl. We show that the phase synchronization of these processes occurs only after the stabilization of the ecosystem of the Naroch Lakes. In the period preceding the transformation of the lake ecosystem, there was no synchronization. Numerical evaluation of PLI as a holistic parameter allows us to characterize the transformation of the lake ecosystem as a whole without resorting to study of complex interactions of various factors involved in this transformation.

Psilocybin-Mediated Attenuation of Gamma Band Auditory Steady-State Responses (ASSR) Is Driven by the Intensity of Cognitive and Emotional Domains of Psychedelic Experience.

Psilocybin is a classical serotoninergic psychedelic that induces cognitive disruptions similar to psychosis. Gamma activity is affected in psychosis and is tightly related to cognitive processing. The 40 Hz auditory steady-state responses (ASSR) are frequently used as indicators to test the ability to generate gamma activity. Based on previous literature, we studied the impact of psilocybin on 40 Hz ASSR in healthy volunteers. The study was double blind and placebo controlled with a crossover design. A sample of 20 healthy subjects (10M/10F) received psilocybin orally 0.26 mg/kg or placebo. Participants were measured four times in total, one time before ingestion of psilocybin/placebo and one time after ingestion, during the peak of intoxication. A series of 500 ms click trains were used for stimulation. Psilocybin induced a psychedelic effect and decreased 40 Hz ASSR phase-locking index compared to placebo. The extent of the attenuation was related to Cognition and Affect on the Hallucinogen Rating Scale. The current study shows that psilocybin lowers the synchronization level and the amplitude of 40 Hz auditory steady-state responses, which yields further support for the role of gamma oscillations in cognitive processing and its disturbance.

Power Spectrum and Connectivity Analysis in EEG Recording during Attention and Creativity Performance in Children

The present research aims at examining the power spectrum and exploring functional brain connectivity/disconnectivity during concentration performance, as measured by the d2 test of attention and creativity as measured by the CREA test in typically developing children. To this end, we examined brain connectivity by using phase synchrony (i.e., phase locking index (PLI) over the EEG signals acquired by the Emotiv EPOC neuroheadset in 15 children aged 9- to 12-years. Besides, as a complement, a power spectrum analysis of the acquired signals was performed. Our results indicated that, during d2 Test performance there was an increase in global gamma phase synchronization and there was a global alpha and theta band desynchronization. Conversely, during CREA task, power spectrum analysis showed a significant increase in the delta, beta, theta, and gamma bands. Connectivity analysis revealed marked synchronization in theta, alpha, and gamma. These findings are consistent with other neuroscience research indicating that multiple brain mechanisms are indeed involved in creativity. In addition, these results have important implications for the assessment of attention functions and creativity in clinical and research settings, as well as for neurofeedback interventions in children with typical and atypical development.

A systematic data-driven approach to analyze sensor-level EEG connectivity: Identifying robust phase-synchronized network components using surface Laplacian with spectral-spatial PCA.

Although conventional averaging across predefined frequency bands reduces the complexity of EEG functional connectivity (FC), it obscures the identification of resting-state brain networks (RSN) and impedes accurate estimation of FC reliability. Extending prior work, we combined scalp current source density (CSD; spherical spline surface Laplacian) and spectral-spatial PCA to identify FC components. Phase-based FC was estimated via debiased-weighted phase-locking index from CSD-transformed resting EEGs (71 sensors, 8min, eyes open/closed, 35 healthy adults, 1-week retest). Spectral PCA extracted six robust alpha and theta components (86.6% variance). Subsequent spatial PCA for each spectral component revealed seven robust regionally focused (posterior, central, and frontal) and long-range (posterior-anterior) alpha components (peaks at 8, 10, and 13 Hz) and a midfrontal theta (6Hz) component, accounting for 37.0% of FC variance. These spatial FC components were consistent with well-known networks (e.g., default mode, visual, and sensorimotor), and four were sensitive to eyes open/closed conditions. Most FC components had good-to-excellent internal consistency (odd/even epochs, eyes open/closed) and test-retest reliability (ICCs ≥ .8). Moreover, the FC component structure was generally present in subsamples (session × odd/even epoch, or smaller subgroups [n= 7-10]), as indicated by high similarity of component loadings across PCA solutions. Apart from systematically reducing FC dimensionality, our approach avoids arbitrary thresholds and allows quantification of meaningful and reliable network components that may prove to be of high relevance for basic and clinical research applications.

Tracking Brain Development From Neonates to the Elderly by Hemoglobin Phase Measurement Using Functional Near-Infrared Spectroscopy.

The biological and neurological processes during the lifespan are dynamic with significant alterations associated with different stages of life. The phase and coupling of oxy-hemoglobin (Δ[HbO]) and deoxy-hemoglobin concentration changes (Δ[Hb]) measured by functional near-infrared spectroscopy (fNIRS) are shown to characterize the neurovascular and metabolic development of infants. However, the changes in phase and coupling across the human lifespan remain mostly unknown. Here, fNIRS measurements of Δ[HbO] and Δ[Hb] conducted at two sites on different age populations (from newborns to elderly) were combined. Firstly, we assessed the influence of random noise on the calculation of the phase difference and phase-locking index (PLI) in fNIRS measurement. The results showed that the phase difference is close to π as the noise intensity approaches -8 dB, and the coupling strength (i.e., PLI) presents a u-shape curve as the noise increase. Secondly, phase difference and PLI in the frequency range 0.01-0.10 Hz were calculated after denoising. It showed that the phase difference increases from newborns to 3-4-month-olds babies. This phase difference persists throughout adulthood until finally being disrupted in the old age. The children's PLI is the highest, followed by that of adults. These two groups' PLI are significantly higher than those of infants and the elderly (p < 0.001). Lastly, a hemodynamic model was used to explain the observations and found close associations with cerebral autoregulation and speed of blood flow. These results demonstrate that the phase-related parameters measured by fNIRS can be used to study the brain and assess brain health throughout the lifespan.

Envelope Following Response to 440 Hz Carrier Chirp-Modulated Tones Show Clinically Relevant Changes in Schizophrenia.

The 40 Hz auditory steady-state response (ASSR) impairment is suggested as an electrophysiological biomarker of schizophrenia; however, existing data also points to the deficiency of low and high frequency ASSR responses. In order to obtain the full picture of potential impairment in schizophrenia, it is important to test responses at different frequencies. The current study aims to evaluate a wide frequency range (1–120 Hz) in response to brief low-frequency carrier chirp-modulated tones in a group of patients with schizophrenia. The EEG-derived envelope following responses (EFRs) were obtained in a group of male patients with schizophrenia (N = 18) and matched controls (N = 18). While subjects were watching silent movies, 440 Hz carrier chirp-modulated at 1–120 Hz tones were presented. Phase-locking index and evoked amplitude in response to stimulation were assessed and compared on point-to-point basis. The peak frequency of the low gamma response was estimated. Measures were correlated with psychopathology—positive, negative, total scores of the Positive and Negative Syndrome Scale (PANSS), and hallucination subscale scores. In comparison to controls, patients showed (1) reduced power of theta-beta (4–18 Hz) responses, (2) intact but slower low gamma (30–60 Hz), and (3) reduced high gamma (95–120 Hz) responses. No correlation survived the Bonferroni correction, but a sign of positive association between low gamma phase-locking and the prevalence of hallucinations, and a sign of negative association between high gamma phase-locking and the total PANSS scores were observed. Brain networks showed impaired capabilities to generate EFRs at different frequencies in schizophrenia; moreover, even when responses of patients did not significantly differ from controls on the group level, they still showed potentially clinically relevant variability.

Emergency detection during car driving using phase-locking index of EEG

Emergency detection during car driving using phase-locking index of EEG

Auditory steady-state response to chirp-modulated tones: A pilot study in patients with disorders of consciousness.

Due to the problems with behavioral diagnosis of patients with prolonged DOC (disorders of consciousness), complementary approaches based on objective measurement of neural function are necessary. In this pilot study, we assessed the sensitivity of auditory chirp-evoked responses to the state of patients with severe brain injury as measured with CRS-R (Coma Recovery Scale - Revised). A convenience sample of fifteen DOC patients was included in the study. Auditory stimuli, chirp-modulated at 1-120 Hz were used to evoke auditory steady-state response (ASSR). Phase-locking index (PLI) estimates within low gamma and high gamma windows were evaluated. The PLI estimates within a narrow low gamma 38-42 Hz window positively correlated with the CRS-R total score and with the scores of the Auditory and Visual Function subscales. In the same low gamma window, significant difference in the PLIs was found between minimally conscious (MCS) and vegetative state (VS) patients. We did not observe any between-group differences nor any significant correlations with CRS-R scores in the high gamma window (80-110 Hz). Our results support the notion that the activity around 40 Hz may serve as a possible marker of the integrity of thalamocortical networks in prolonged DOC patients. Auditory steady-state responses at gamma-band frequencies highlight the role of upper parts of auditory system in evaluation of the level of consciousness in DOC patients.

40-Hz auditory steady-state responses and the complex information processing: An exploratory study in healthy young males.

Electroencephalographic (EEG) activity in the gamma (30–80 Hz) range is related to a variety of sensory and cognitive processes which are frequently impaired in schizophrenia. Auditory steady-state response at 40-Hz (40-Hz ASSR) is utilized as an index of gamma activity and is proposed as a biomarker of schizophrenia. Nevertheless, the link between ASSRs and cognitive functions is not clear. This study explores a possible relationship between the performance on cognitive tasks and the 40-Hz ASSRs in a controlled uniform sample of young healthy males, as age and sex may have complex influence on ASSRs. Twenty-eight young healthy male volunteers participated (mean age ± SD 25.8±3.3) in the study. The 40-Hz click trains (500 ms) were presented 150 times with an inter-stimulus interval set at 700–1000 ms. The phase-locking index (PLI) and event-related power perturbation (ERSP) of the ASSR were calculated in the 200–500 ms latency range, which corresponds to the steady part of the response. The Psychology Experiment Building Language (PEBL) task battery was used to assess five cognitive subdomains: the Choice response time task, the Stroop test, the Tower of London test, the Lexical decision task and the Semantic categorisation task. Pearson‘s correlation coefficients were calculated to access the relationships; no multiple-test correction was applied as the tests were explorative in nature. A significant positive correlation was observed for the late-latency gamma and the mean number of steps in the Tower of London task reflecting planning and problem-solving abilities. These findings support the concept that 40-Hz ASSR might highlight top-down mechanisms which are related to cognitive functioning. Therefore, 40-Hz ASSRs can be used to explore the relationship between cognitive functioning and neurophysiological indices of brain activity.

Supervised piecewise network connectivity analysis for enhanced confidence of auditory oddball tasks

We present a network connectivity analysis to assess a relevant vector, valuing the contribution of connection node sets in distinguishing between labeled response stimuli. To this end, the piecewise computation of Phase Locking Index is performed, suggesting a combination procedure to reflect the whole recording span with a single relevance value. Further, we use a supervised, statistical thresholding algorithm to reduce the connectivity matrix dimension, holding the links that mostly differentiate the brain responses to each evoked stimulus. Obtained results in an auditory oddball task show that the developed analysis yields a relevant node set for δ and θ waves that becomes more coherent, connected with improved consistency of performed group-level connectivity graphs.

A broadband method of quantifying phase synchronization for discriminating seizure EEG signals

The nonlinear nature of phase coupling enables rich and context-sensitive interactions that characterize real brain dynamics, playing an important role in brain dysfunction such as epileptic disorders. Numerous phase synchronization (PS) measurements have been developed for seizure detection and prediction. However, the performance remains low for minor seizures in epileptic patients with an intellectual disability (ID), who are characterized by complex EEG signals associated with brain development disorders. The traditional PS measurements, e.g., phase locking index (PLI), are limited by the inability in detecting the nonlinear coupling of EEG signals and are sensitive to the background noise. This study focuses on developing a new EEG feature that can measure the nonlinear coupling, which thus would help improve seizure detection performance. We employ the correlation between probabilities of recurrence (CPR) to measure the PS on broadband EEG signals. CPR can capture the underlying nonlinear coupling of EEG signals and is robust to signal frequency and amplitude variance. The effectiveness of CPR-based features on identifying seizure EEG was evaluated on 26 epileptic patients with ID. Results show that the PS changes in seizures depend on the EEG discharge patterns including fast spike (SP), spike-wave (SPWA), wave (WA) and discharge with EMG activity (EMG). CPR-based PS decreased significantly in seizures with SP and EMG, (-0.1845 and -0.4278, with 95% CI [-0.1850, -0.1839] and [-0.4283, -0.4273], respectively), while it increases significantly in the SPWA seizures (+0.0746, with 95% CI [0.0744, 0.0749]). In addition, CPR-based PS shows potential for predicting SPWA and EMG seizures in an early manner. We conclude that CPR measurement is promising to improve seizure detection in ID patients and provides a promising method for modeling epilepsy-related brain functional networks.

Symbolic time series analysis of fNIRS signals in brain development assessment

Objective. Assessing an infant’s brain development remains a challenge for neuroscientists and pediatricians despite great technological advances. As a non-invasive neuroimaging tool, functional near-infrared spectroscopy (fNIRS) has great advantages in monitoring an infant’s brain activity. To explore the dynamic features of hemodynamic changes in infants, in-pattern exponent (IPE), anti-pattern exponent (APE), as well as permutation cross-mutual information (PCMI) based on symbolic dynamics are proposed to measure the phase differences and coupling strength in oxyhemoglobin (HbO) and deoxyhemoglobin (Hb) signals from fNIRS. Approach. First, simulated sinusoidal oscillation signals and four coupled nonlinear systems were employed for performance assessments. Hilbert transform based measurements of hemoglobin phase oxygenation and deoxygenation (hPod) and phase-locking index of hPod (hPodL) were calculated for comparison. Then, the IPE, APE and PCMI indices from resting state fNIRS data of preterm, term infants and adults were calculated to estimate the phase difference and coupling of HbO and Hb. All indices’ performance was assessed by the degree of monotonicity (DoM). The box plots and coefficients of variation (CV) were employed to assess the measurements and robustness in the results. Main results. In the simulation analysis, IPE and APE can distinguish the phase difference of two sinusoidal oscillation signals. Both hPodL and PCMI can track the strength of two coupled nonlinear systems. Compared to hPodL, the PCMI had higher DoM indices in measuring the coupling of two nonlinear systems. In the fNIRS data analysis, similar to hPod, the IPE and APE can distinguish preterm, term infants, and adults in 0.01–0.05 Hz, 0.05–0.1 Hz, and 0.01–0.1 Hz frequency bands, respectively. PCMI more effectively distinguished the term and preterm infants than hPodL in the 0.05–0.1 Hz frequency band. As symbolic time series measures, the IPE and APE were able to detect the brain developmental changes in subjects of different ages. PCMI can assess the resting-state HbO and Hb coupling changes across different developmental ages, which may reflect the metabolic and neurovascular development. Significance. The symbolic-based methodologies are promising measures for fNIRS in estimating the brain development, especially in assessing newborns’ brain developmental status.

Results Obtained by Combining Different Estimators of EEG Connectivity Become Uninterpretable If the Underlying Models Are Incompatible.

We comment on a recent article published in Brain Connectivity (Hatz et al., 2016 ) that combined electroencephalography (EEG) microstate analysis with the phase-locking index (PLI) and found that the test-retest reliability of connectivity patterns as obtained by the PLI increased when the data had been previously parcellated into microstates. Although we acknowledge the need to parcellate the continuous data into periods that supposedly correspond to transiently stable patterns of connectivity, we believe that the approach chosen by the authors is seriously mistaken. In particular, their approach disregards the particular a priori assumptions contained in each of the two methods that define connectivity in specific terms. Unfortunately, for microstate analyses and the PLI, these definitions are mutually exclusive, which makes attempts to draw any coherent conclusion in terms of comprehensibly interlinked biological processes meaningless. The occurrence of this type of problems should draw the attention to the importance of the particular methodological and conceptual features and limitations that come with the specific a priori assumptions contained in any quantifier of brain functional connectivity.

40Hz auditory steady-state response in schizophrenia: Sensitivity to stimulation type (clicks versus flutter amplitude-modulated tones).

Auditory steady-state response (ASSR) at 40Hz has been proposed as a potential biomarker for schizophrenia. The ASSR studies in patients have used click stimulation or amplitude-modulated tones. However, the sensitivity of 40Hz ASSRs to different stimulation types in the same group of patients has not been previously evaluated. Two stimulation types for ASSRs were tested in this study: (1) 40Hz clicks and (2) flutter-amplitude modulated tones. The mean phase-locking index, evoked amplitude and event-related spectral perturbation values were compared between schizophrenia patients (n=26) and healthy controls (n=20). Both stimulation types resulted in the observation of impaired phase-locking and power measures of late (200-500ms) 40Hz ASSR in patients compared to healthy controls. The early-latency (0-100ms) 40Hz ASSR part was diminished in the schizophrenia group in response to clicks only. The late-latency 40Hz ASSR parameters obtained through different stimulation types correlated in healthy subjects but not in patients. We conclude that flutter amplitude-modulated tone stimulation, due to its potential to reveal late-latency entrainment deficits, is suitable for use in clinical populations. Careful consideration of experimental stimulation settings can contribute to the interpretation of ASSR deficits and utilization as a potential biomarker.

Spatial variation in the hemoglobin phase of oxygenation and deoxygenation in the developing cortex of infants.

Spontaneous low-frequency oscillatory changes in oxygenated hemoglobin (oxy-Hb) and deoxygenated hemoglobin (deoxy-Hb) are observed using functional near-infrared spectroscopy (fNIRS). A previous study showed that the time-averaged phase difference between oxy-Hb and deoxy-Hb changes, referred to as hemoglobin phase of oxygenation and deoxygenation (hPod), is sensitive to the development of the cortex. We examined phase-locking index of hPod, referred to as [Formula: see text], in addition to hPod, in neonates and 3- and 6-month-old infants using the 94-channel fNIRS data, which covered large lateral regions of the cortex. The results showed that (1)developmental changes in hPod exhibited spatial dependency; (2)[Formula: see text] increased between the neonate group and 3-month-old infant group over the posterior, but not anterior, regions of the cortex; and (3) the cortical regions of each age group were clustered in several domains with specific characteristics of hPod and [Formula: see text]. This study indicates that the neonatal cortex is composed of regions with specific characteristics of hPod and [Formula: see text], and drastic changes occur between the neonatal period and 3 months of age. This study suggests that hPod and [Formula: see text] are sensitive to the cortical region-specific development of the circulatory, blood flow, metabolic, and neurovascular functions in young infants.

S.34.01 - Iatrogenic hyperprolactinaemia, antipsychotics and sexual dysfunction

Phase synchronization of neuronal oscillations is a fundamental mechanism underlying cognitive processing and behavior, including context-dependent response production and inhibition. Abnormalities in neural synchrony can lead to abnormal information processing and contribute to cognitive and behavioral deficits in neuropsychiatric disorders. However, little is known about genetic and environmental contributions to individual differences in cortical oscillatory dynamics underlying response inhibition. This study examined heritability of event-related phase synchronization of brain oscillations in 302 young female twins including 94 MZ and 57 DZ pairs performing a cued Go/No-Go version of the Continuous Performance Test (CPT). We used the Phase Locking Index (PLI) to assess inter-trial phase clustering (synchrony) in several frequency bands in two time intervals after stimulus onset (0–300 and 301–600 ms). Response inhibition (i.e., successful response suppression in No-Go trials) was characterized by a transient increase in phase synchronization of delta- and theta-band oscillations in the fronto-central midline region. Genetic analysis showed significant heritability of the phase locking measures related to response inhibition, with 30 to 49% of inter-individual variability being accounted for by genetic factors. This is the first study providing evidence for heritability of task-related neural synchrony. The present results suggest that PLI can serve as an indicator of genetically transmitted individual differences in neural substrates of response inhibition.