Frontal Beta Research Articles

QEEG related changes following the treatment of anxiety disorders: Case series

Patients with anxiety spectrum disorders are a highly heterogeneous group, requiring new therapeutic strategies and individualized treatment monitoring. Today, there is a growing interest for implementing biological approaches to clinical practice in psychiatry. Quantitative EEG is an excellent tool in this regard, though it has been widely underestimated when compared to recent neuroimaging techniques. In this case series, we presented four cases with a different anxiety spectrum disorder and evaluated their qEEG changes before and after the treatment. In addition, we also calculated the so-called EEG cordance values as an index of cerebral perfusion and cingulate cortex activity. According to the results, there appears to be an increase in the frontal beta and theta band in our cases, which has responded to treatment. In regards to the cordance values, we found that there was a reduction in the prefrontal regions up to %38 percent following the treatment. Based on previous studies, this may also indirectly suggest reduction in the cingulate cortex activity. The possible implications of these findings were discussed. Taken together, this case series highlighted the potential use of qEEG power values, normative z-scores and cordance values in anxiety spectrum disorders.

The Neural Development of Response Inhibition in 5- and 6-Year-Old Preschoolers: An ERP and EEG Study

Many studies have used event-related potential and neural oscillations to probe the underlying neural mechanisms of inhibitory control in adults, but little has been done in typically developing preschoolers. In this study we tested healthy preschool children between the ages of 5 and 6, and observed better response inhibition in 6-year-olds compared to 5-year-olds. Importantly, this age-related difference could not be explained by the N2 component from event-related potential, but was reflected in an increase in right frontal beta power from electroencephalogram. These results suggest that frontal beta power during the preschool period may reflect neural development of inhibitory control.

The relation between electroencephalogram asymmetry and attention biases to threat at baseline and under stress

Electroencephalogram (EEG) asymmetry in the alpha frequency band has been implicated in emotion processing and broad approach-withdrawal motivation systems. Questions remain regarding the cognitive mechanisms that may help elucidate the observed links between EEG asymmetry and patterns of socioemotional functioning. The current study observed frontal EEG asymmetry patterns at rest and under social threat among young adults (N=45, M=21.1years). Asymmetries were, in turn, associated with performance on an emotion-face dot-probe attention bias task. Attention biases to threat have been implicated as potential causal mechanisms in anxiety and social withdrawal. Frontal EEG asymmetry at baseline did not predict attention bias patterns to angry or happy faces. However, increases in right frontal alpha asymmetry from baseline to the stressful speech condition were associated with vigilance to angry faces and avoidance of happy faces. The findings may reflect individual differences in the pattern of response (approach or withdrawal) with the introduction of a mild stressor. Comparison analyses with frontal beta asymmetry and parietal alpha asymmetry did not find similar patterns. Thus, the data may reflect the unique role of frontal regions, particularly the dorsolateral prefrontal cortex, in cognitive control and threat detection, coupled with ruminative processes associated with alpha activity.

Attentional dynamics during free picture viewing: Evidence from oculomotor behavior and electrocortical activity

Most empirical evidence on attentional control is based on brief presentations of rather abstract stimuli. Results revealed indications for a dynamic interplay between bottom-up and top-down attentional mechanisms. Here we used a more naturalistic task to examine temporal signatures of attentional mechanisms on fine and coarse time scales. Subjects had to inspect digitized copies of 60 paintings, each shown for 40 s. We simultaneously measured oculomotor behavior and electrophysiological correlates of brain activity to compare early and late intervals (1) of inspection time of each picture (picture viewing) and (2) of the full experiment (time on task). For picture viewing, we found an increase in fixation duration and a decrease of saccadic amplitude while these parameters did not change with time on task. Furthermore, early in picture viewing we observed higher spatial and temporal similarity of gaze behavior. Analyzing electrical brain activity revealed changes in three components (C1, N1 and P2) of the eye fixation-related potential (EFRP); during picture viewing; no variation was obtained for the power in the frontal beta- and in the theta activity. Time on task analyses demonstrated no effects on the EFRP amplitudes but an increase of power in the frontal theta and beta band activity. Thus, behavioral and electrophysiological measures similarly show characteristic changes during picture viewing, indicating a shifting balance of its underlying (bottom-up and top-down) attentional mechanisms. Time on task also modulated top-down attention but probably represents a different attentional mechanism.

Brief Cerebral Applications of Weak, Physiologically-patterned Magnetic Fields Decrease Psychometric Depression and Increase Frontal Beta Activity in Normal Subjects

Background: Brief (30 min to 60 min) applications of weak, physiologically-patterned magnetic fields have been demonstrated to produce analgesia in rodents and reduction of depression in patients who have sustained Traumatic Brain Injuries (TBI). To discern if the effects from one effective field pattern could be measured by quantitative electroencephalography (QEEG) and reflected in psychometric inferences of depressed mood, normal volunteers were measured. Methods: A total of 22 normal volunteers were exposed for 30 min to sham field conditions or to a burst-firing magnetic field (1 μT) that was applied across the temporal lobes during QEEG measurements. The Profile of Mood Scores short-form (POMS-sf) was administered before and after the exposures and correlations between these scores and bands of QEEG power were completed. Results: The subjects exposed to the burst-firing magnetic field displayed a significant decrease in depression scores compared to those exposed to the sham fields. The treatment effects accommodated about one-quarter of the variance in scores. Like previous studies the other components of the POMS-sf did not differ significantly between treatments. Field exposed subjects displayed significant increases in beta power over the prefrontal regions and left temporoparietal areas the magnitude of which was strongly correlated with the depression mood scores. Conclusion: Brief exposures to weak, physiologically-patterned magnetic fields that can be generated by contemporary computer systems produced reliable changes in QEEG activity and were even reflected in relatively insensitive psychometric indicators in normal individuals. The development of this technology for self-treatment of patients who have sustained TBIs may be a useful adjunctive therapeutic intervention.

Neural aftereffects of errors in a stop-signal task

In order to maintain goal-directed behavior in a changing and distractive environment, one needs to continuously monitor one's own performance and adjust it in case of unfavorable outcomes. One aspect of behavioral adjustment commonly observed in reaction time tasks is an increase in response time in trials following an error, referred to as post-error slowing (PES). Using a stop-signal task with a four-on-two stimulus–response mapping, we here investigated the neural aftereffects of stop-errors. We examined oscillatory activity in the inter-trial interval as well as event-related potentials (ERP) in the next trial. Behavioral results speak against general adjustments after stop-errors as post-error behavioral changes could be attributed to stimulus or response repetitions. This corresponded with ERP effects in the next trial with only the visual N1 showing an effect of previous trial type and both N2 and P3 showing an effect of stimulus repetition. During the inter-trial interval, we observed stronger and later occipital alpha power increase after stop-errors compared to go- or inhibited trials. Errors also elicited enhanced frontal beta power relative to stop-trials and by trend to correct go-trials, which largely returned to baseline before the onset of the next trial. These transient changes in the neural aftereffects of stop-errors might be related to previous behavioral observations of PES after short, but not long response–stimulus intervals.

Fetal cerebrovascular resistance and neonatal EEG predict 18‐month neurodevelopmental outcome in infants with congenital heart disease

The purpose of this study was to investigate early markers of risk for neurobehavioral compromise in survivors with congenital heart disease (CHD). Pregnant women in whom a fetal CHD had been diagnosed before 24 weeks' gestational age (GA) were enrolled in this prospective pilot study for serial Doppler ultrasound assessment of the fetal middle cerebral artery (MCA) and umbilical arteries. The cerebral-to-placental resistance ratio (CPR) and MCA pulsatility index (PI) Z-scores for GA were calculated. After birth, subjects underwent high-density (128-lead) electroencephalography (EEG), and beta frequency (12-24 Hz) band EEG power, a measure of local neural synchrony, was analyzed. Neurodevelopment was assessed at 18 months with the Bayley Scales of Infant Development (BSID)-III. Thirteen subjects were enrolled: four with hypoplastic left heart syndrome (HLHS), four with transposition of the great arteries (TGA) and five with tetralogy of Fallot (TOF). Compared with subjects with normal CPR, those with CPR < 1 (n = 7) had lower mean BSID cognitive scores (91.4 ± 4.8 vs. 99.2 ± 3.8, P = 0.008). Fetal MCA-PI Z-score also correlated with BSID cognitive score (r = 0.589, P = 0.03) as did neonatal EEG left frontal polar (r = 0.58, P = 0.037) and left frontal (r = 0.77, P = 0.002) beta power. Furthermore, fetal Doppler measures were associated with EEG power: fetuses with CPR < 1 had lower left frontal polar (t = 2.36, P = 0.038) and left frontal (t = 2.85, P = 0.016) beta power as newborns than did fetuses with normal CPR, and fetal MCA-PI Z-score correlated with neonatal EEG left frontal polar (r = 0.596, P = 0.04) and left frontal (r = 0.598, P = 0.04) beta power. In fetuses with HLHS, TGA and TOF, abnormal cerebrovascular resistance predicts decreased neonatal EEG left frontal beta power and lower 18-month cognitive development scores.

Enhanced frontoparietal synchronized activation during the wake-sleep transition in patients with primary insomnia.

Cognitive and brain hyperactivation have been associated with trouble falling asleep and sleep misperception in patients with primary insomnia (PI). Activation and synchronization/temporal coupling in frontal and frontoparietal regions involved in executive control and endogenous attention might be implicated in these symptoms. Standard polysomnography (PSG) and electroencephalogram (EEG) were recorded in 10 unmedicated young patients (age 19-34 yr) with PI with no other sleep/medical condition, and in 10 matched control subjects. Absolute power, temporal coupling, and topographic source distribution (variable resolution electromagnetic tomography or VARETA) were obtained for all time spent in waking, Stage 1 and Stage 2 of the wake-sleep transition period (WSTP), and the first 3 consecutive min of N3. Subjective sleep quality and continuity were evaluated. In comparison with control subjects, patients with PI exhibited significantly higher frontal beta power and current density, and beta and gamma frontoparietal temporal coupling during waking and Stage 1. These findings suggest that frontal deactivation and disengagement of brain regions involved in executive control, attention, and self-awareness are impaired in patients with PI. The persistence of this activated and coherent network during the wake-sleep transition period (WSTP) may contribute to a better understanding of underlying mechanisms involved in difficulty in falling asleep, in sleep misperception, and in the lighter, poorer, and nonrefreshing sleep experienced by some patients with PI.

Frontal theta and beta synchronizations for monetary reward increase visual working memory capacity

Visual working memory (VWM) capacity is affected by motivational influences; however, little is known about how reward-related brain activities facilitate the VWM systems. To investigate the dynamic relationship between VWM- and reward-related brain activities, we conducted time-frequency analyses using electroencephalograph (EEG) data obtained during a monetary-incentive delayed-response task that required participants to memorize the position of colored disks. In case of a correct answer, participants received a monetary reward (0, 10 or 50 Japanese yen) announced at the beginning of each trial. Behavioral results showed that VWM capacity under high-reward condition significantly increased compared with that under low- or no-reward condition. EEG results showed that frontal theta (6 Hz) amplitudes enhanced during delay periods and positively correlated with VWM capacity, indicating involvement of theta local synchronizations in VWM. Moreover, frontal beta activities (24 Hz) were identified as reward-related activities, because delay-period amplitudes correlated with increases in VWM capacity between high-reward and no-reward conditions. Interestingly, cross-frequency couplings between frontal theta and beta phases were observed only under high-reward conditions. These findings suggest that the functional dynamic linking between VWM-related theta and reward-related beta activities on the frontal regions plays an integral role in facilitating increases in VWM capacity.

In-vivo EEG Changes During A Panic Attack in A Patient With Specific Phobia

Since early adolescence a 47-year-old male suffers from specific phobia with panic disorder (PD) which is similar to agoraphobia. The panic starts when he crosses the borders of his domicile, regardless of the type of transport. On request of client and his GP, we recorded his EEG during a car trip from his house to a distant village. We aimed to explore underlying EEG changes that may accompany the initiation and the progression of his panic attacks. The panic attack took place during the car-ride where we detected an increase of frontal beta (β) activity (13-26 Hz) and a relatively sudden decrease of frontal-central theta (θ) activity (3-6 Hz). These findings suggest that EEG recordings can be useful to monitor the beginning and the end of a panic attack and may determine the exact EEG changes that initiate a panic attack.

In-vivo EEG Changes During A Panic Attack in A Patient With Specific Phobia

Since early adolescence a 47-year-old male suffers from specific phobia with panic disorder (PD) which is similar to agoraphobia. The panic starts when he crosses the borders of his domicile, regardless of the type of transport. On request of client and his GP, we recorded his EEG during a car trip from his house to a distant village. We aimed to explore underlying EEG changes that may accompany the initiation and the progression of his panic attacks. The panic attack took place during the car-ride where we detected an increase of frontal beta (β) activity (13-26 Hz) and a relatively sudden decrease of frontal-central theta (θ) activity (3-6 Hz). These findings suggest that EEG recordings can be useful to monitor the beginning and the end of a panic attack and may determine the exact EEG changes that initiate a panic attack. J Med Cases. 2012;3(1):34-38 doi: https://doi.org/10.4021/jmc403e

Individual visual working memory capacities and related brain oscillatory activities are modulated by color preferences

Subjective preferences affect many processes, including motivation, along with individual differences. Although incentive motivations are proposed to increase our limited visual working memory (VWM) capacity, much less is known about the effects of subjective preferences on VWM-related brain systems, such as the prefrontal and parietal cortices. Here, we investigate the differences in VWM capacities and brain activities during presentation of preferred and non-preferred colors. To this end, we used time-frequency (TF) analyses of electroencephalograph (EEG) data recorded during a delayed-response task. Behavioral results showed that the individual VWM capacities of preferred colors were significantly higher than those of non-preferred colors. The EEG results showed that the frontal theta and beta amplitudes for maintenance of preferred colors were higher than those of non-preferred colors. Interestingly, the frontal beta amplitudes were consistent with recent EEG recordings of the effects of reward on VWM systems, in that they were strongly and individually correlated with increasing VWM capacities from non-preferred to preferred colors. These results suggest that subjective preferences affect VWM systems in a similar manner to reward-incentive motivations.

Neuropsychological and neurophysiological effects of strengthening exercise for early dementia: A pilot study

ABSTRACT Research demonstrates a positive effect of aerobic exercise on cognitive functioning in older adults. Unfortunately, aerobic exercise is often contraindicated for older adults due to cardiovascular and functional limitations. Low-intensity strengthening exercise may offer a practical alternative, but the neuropsychological benefits and potential neurophysiological mechanisms are less well understood. The current study evaluated the effects of a 10-week strengthening exercise intervention on cognitive functioning and EEG in a sample of 13 older adults with early dementia, and 9 normative controls. Results revealed beneficial effects of strengthening exercise on verbal memory coupled with frontal beta and delta power asymmetries and N200 amplitude asymmetry. Results point to increased cognitive efficiency following 10 weeks of strengthening exercise. The findings suggest it is feasible to conduct a strengthening intervention with early dementia patients, and to gather neuropsychological and neurophysiological data to evaluate outcomes. Strengthening exercise may serve as a useful alternative to aerobic exercise.

Asymmetrical frontal resting-state beta oscillations predict trait aggressive tendencies and behavioral inhibition

Asymmetrical patterns of frontal cortical activity have been implicated in the development and expression of aggressive behavior. Along with individual motivational tendencies, the ability to restrain one's impulses might be a factor in aggressive behavior. Recently, a role for the inhibitory cortical beta rhythm was suggested. The present study investigated whether individual differences in resting state asymmetries in the beta frequency band were associated with trait aggression and behavioral inhibition. In addition, the selective contributions of the prefrontal and motor cortex areas to these associations were examined. Results showed that relative dominant right frontal beta frequency activity was associated with both heightened trait aggression, especially hostility, and reduced response inhibition. Moreover, asymmetries over the anterior electrode locations proved to be related most closely to trait aggression, while asymmetries over the central electrode locations were associated with response inhibition. Together these findings show that right-dominant frontal beta activity is positively associated with aggressive tendencies and reduced behavioral inhibition.

Correlation Between EEG Activity and Behavior in Children with Attention-Deficit/Hyperactivity Disorder

The aim of this study was to determine whether EEG activity in specific bands correlated with the core behavioral symptoms of children with attention-deficit/hyperactivity disorder (AD/HD). Sixty boys diagnosed with AD/HD Combined type and 60 age-matched male controls participated in this study. An EEG was recorded during an eyes-closed resting condition and relative power estimates in the delta, theta, alpha, and beta bands, and the theta/beta ratio, were calculated. The EEG measures of the AD/HD group were converted to z scores relative to the controls, and these were correlated with scores on the Conners' Rating Scale obtained from a parent. The AD/HD group had global increases in theta activity and the theta/beta ratio, increased frontal delta, with reduced global alpha and frontal beta activity. Frontal theta activity correlated with inattention, the theta/beta ratio correlated with hyperactivity-impulsivity, and both measures correlated with a Combined type diagnosis. EEG power anomalies in AD/HD ar...

P06.16 Clinical manifestations of the autoimmune process of central nervous system

Background: Pediatric infection triggered Autoimmune Neu¬ropsychiatric Disorders are described in the literature since 1.998. Autoimmune limbic encephalitis is recognized as a precipitating factor of onset temporallobe seizures. Aim: two case reports of children with autoimmune neuropsychiatric disorders. First case: K.L., 13 years old girl was hospitalized for the third cime because she had fever, ataxia, psychomotor seizures, bizarre gait and abnorrnai choreiforrn movements, catatonia, dysarthric speech and communication only in German .anguage with often changes in mood and hallucinations. Previous hospitalization was two weeks earlier because she had a painful right mastoid. First hospitalization was two years earlier because of right mastoids infection and right retrobulbar neuritis. Now the EEG showed the focus of the slow waves on the right temporal, and later on both sides in temporoparietal region ; oligodonal bands in CSF were positive ; MS CT of pyramids showed chronic inflammatory changes right and psychological testing showed deficits in cognitive functions. She was treated with antibiotics, steroids, benzodiazepines and carbamazepine. The patient underwent exploratory antrotomy of the right ear. After that she had started to recover. Second case: In l6-year-old girl non-paraneoplastic lim¬bic encefalitis was diagnosed. Immune thrombocytopenia manifested in chronic form had been diagnosed 11 years earlier. She had complex partial seizures and developed behavioral disturbances: anxiety, feeling of unreality, auditory hallucinations and insomnia. EEG showed frontal fast beta activity. MRI scans demonstrated a temporal swelling. Cere¬brospinal fluid showed pleocytosis and positive oligodonal bands. The serologycal tests for neurotropic viruse were negative. Immunomodulation therapy was followed by an improvement of clinical status.

Age- and performance related modulations in spectral event-related dynamics during a working memory task

Event Abstract Back to Event Age- and performance related modulations in spectral event-related dynamics during a working memory task Thomas Fischer1*, Alexander Strobel1 and Sergei Schapkin2 1 Technical University of Dresden, Germany 2 Federal Institute for Occupational Safety and Health, Germany Age-dependent changes in event-related spectral perturbations (ERSP) and decrements in performance have previously been reported for several cognitive paradigms. However, the relationship between ERSP modulations, performance and age has not been well documented until now. Using a 2-back working memory task, we compared ERSPs between 44 healthy younger subjects (aged 29±3 years) and 44 older subjects (aged 55±3 years). Based on the d’ scores in the 2-back condition participants of each age group were divided into high and low performers. For event-related beta synchronization (ERS; 800-1000 ms after target), the ANOVA showed significant main effects for the factor age and the factor performance in the left frontal cluster (F3, FC3). The beta ERS was significantly larger in the high-performer group (the younger and older subjects taken together) than in the low-performer group as well as larger in younger than in older adults. No interaction effects were obtained. Additionally, age differences in the alpha event-related desynchronisation (ERD; 600-800 ms after target) in the parietal cluster (P3; Pz, P4) were found: the alpha ERD increased in younger adults as compared to older adults. Moreover, alpha ERS was larger in low performers than in high performers.Our results show that working memory processes are associated with left frontal event-related beta-synchronization and suggest that frontal beta synchronization could be an informative indicator for age-related changes in neuronal processes underlying working memory. Keywords: Aging, ERSP Conference: XI International Conference on Cognitive Neuroscience (ICON XI), Palma, Mallorca, Spain, 25 Sep - 29 Sep, 2011. Presentation Type: Poster Presentation Topic: Poster Sessions: Cognitive Aging Citation: Fischer T, Strobel A and Schapkin S (2011). Age- and performance related modulations in spectral event-related dynamics during a working memory task. Conference Abstract: XI International Conference on Cognitive Neuroscience (ICON XI). doi: 10.3389/conf.fnhum.2011.207.00547 Copyright: The abstracts in this collection have not been subject to any Frontiers peer review or checks, and are not endorsed by Frontiers. They are made available through the Frontiers publishing platform as a service to conference organizers and presenters. The copyright in the individual abstracts is owned by the author of each abstract or his/her employer unless otherwise stated. Each abstract, as well as the collection of abstracts, are published under a Creative Commons CC-BY 4.0 (attribution) licence (https://creativecommons.org/licenses/by/4.0/) and may thus be reproduced, translated, adapted and be the subject of derivative works provided the authors and Frontiers are attributed. For Frontiers’ terms and conditions please see https://www.frontiersin.org/legal/terms-and-conditions. Received: 15 Nov 2011; Published Online: 28 Nov 2011. * Correspondence: Dr. Thomas Fischer, Technical University of Dresden, Dresden, Germany, fischer.tho@googlemail.com Login Required This action requires you to be registered with Frontiers and logged in. To register or login click here. Abstract Info Abstract The Authors in Frontiers Thomas Fischer Alexander Strobel Sergei Schapkin Google Thomas Fischer Alexander Strobel Sergei Schapkin Google Scholar Thomas Fischer Alexander Strobel Sergei Schapkin PubMed Thomas Fischer Alexander Strobel Sergei Schapkin Related Article in Frontiers Google Scholar PubMed Abstract Close Back to top Javascript is disabled. Please enable Javascript in your browser settings in order to see all the content on this page.

Transient changes in frontal alpha asymmetry as a measure of emotional and physical distress during sleep

The aim of this project was to identify measurable physiological responses linked to the human experience of distress in a non-communicative state. Since sleep is a state of sensory-motor detachment in which subjects cannot report how they feel or what they experience, it can be considered a suitable model of non communicative states. A transitory distress-related response has consistently been reported in healthy awake subjects in the form of power spectrum alpha band changes in frontal brain areas. Hence, changes in frontal alpha asymmetry (FAA) were analysed in 16 volunteers before and after administration of distressful aversive stimuli during sleep. Transient physical or emotional distress was achieved by presentation of conditioned (to electroshocks or affective images) or directly-applied aversive stimuli (electroshocks). Frontal beta asymmetry (FBA) was also evaluated for comparisons. Power spectrum data were assessed from frontal electroencephalographic (EEG) leads (F3/F4). Galvanic skin response (GSR) and heart rate (HR) were also simultaneously monitored. To test the possibility that the short lasting stimulations would have long-term physiological effects, we included saliva cortisol sampling, evaluation of dream emotional valence and a standard assessment of sleep quality measurements. Aversive stimulation of diverse nature, compared to neutral valence stimuli, produced measurable changes in FAA (left>right) and in GSR evoked responses in both stage 2 (S2) and rapid eye movement (REM) sleep suggesting implicit processing of experiences with negative valence. Noticeably, dream content evaluation showed a trend towards increased negative emotionality. No FBA was observed, confirming the specificity of FAA responses. Saliva cortisol, and sleep parameters were not significantly affected by the protocol. This is, to our knowledge, the first time that an aversive imaging conditioning protocol has been successfully applied during sleep.

Brain electrical activity during food presentation in obese binge‐eating women

Binge-eating (BE) subjects have shown altered brain activity at frontal regions during food presentation. The aim of this study was to examine the frontal brain electrical activity in obese BE women (n = 12) and in obese women without BE (non-BE, n = 13). Brain electrical activity was measured using a quantitative electroencephalography during a resting state (eyes-closed) and when the subjects focused (eyes-open) their attention on a picture of a landscape (control experiment) or on a meal (food experiment). The BE showed greater frontal beta activity (14-20 Hz) than the non-BE in both the eyes-closed (on average 52%) and the eyes-open situations and independently of the stimulus (control experiment: 57% and food experiment: 71%). No significant differences between the groups were found in alpha, delta or theta amplitudes. Increased beta activity correlated positively with the disinhibition factor of the Three-Factor Eating Questionnaire. Thus, our results suggest that elevated frontal beta activity may be a marker of dysfunctional disinhibition-inhibition mechanism, which could make the obese BE women more vulnerable or sensitive to food and the environmental cues.

Dysfunctional brain circuitry in obsessive–compulsive disorder: Source and coherence analysis of EEG rhythms

BackgroundMorphological and functional studies suggested involvement of several cortical and subcortical circuitries in patients with obsessive–compulsive disorder (OCD). The aim of the present study was to investigate networks involved in OCD pathophysiology, using power (coupling of EEG bands, low-resolution electromagnetic tomography—LORETA) and coherence analysis in drug naïve patients. MethodEEG was obtained from 37 drug-naïve patients with OCD and 37 age- and sex-matched controls. Resting EEG was recorded from 29 scalp channels. Coupling (ratio and correlation) between low and high frequencies was analyzed on Fz. For each frequency band, LORETA current density distribution, intra-hemispheric and inter-hemispheric coherence analysis were computed. ResultsOCD had increased current density for delta in the insula and for beta in frontal, parietal and limbic lobes. OCD also had decreased inter-hemispheric coherence and reduced coupling between delta and beta frequencies. ConclusionsIn OCD, increased frontal beta is consistent with previous evidence of frontal dysfunction. Hyperactivity of insular delta sources, together with rhythms decoupling and reduced interhemispheric alpha coherence are consistent with additional involvement of cortico-subcortical functional connections. Combined use of power and coherence analysis may provide functional measures on different levels of involvement of cortico-subcortical circuits in neuropsychiatric disorders.