Baris Metin

Neural mirroring during the observation of live and video actions in infants

OBJECTIVE Previous infant studies investigated neural mirroring during the observation of live or video actions. However, both methods have their (dis)advantages and studies using one of these methods are not always directly comparable. Therefore, the present study directly compared neural mirroring activity in a video setting with a live setting in infants between 18 and 36 months old. METHODS Central mu rhythm suppression was measured through EEG recordings during the observation and imitation of the same goal-directed and mimicked actions presented either on video or live. RESULTS Results revealed significant mu suppression during action imitation in both settings but stronger mu suppression was observed in the live setting during this condition. Significant mu suppression during the observation of goal-directed actions and mimicked actions was only observed in the live setting. CONCLUSION This study revealed a different influence of video and live actions on neural mirroring activity in infants. SIGNIFICANCE It is recommended to use live actions to investigate neural mirroring in young children.

Current use of imaging and electromagnetic source localization procedures in epilepsy surgery centers across Europe

In 2014 the European Union–funded E‐PILEPSY project was launched to improve awareness of, and accessibility to, epilepsy surgery across Europe. We aimed to investigate the current use of neuroimaging, electromagnetic source localization, and imaging postprocessing procedures in participating centers.

Dysfunctional modulation of default mode network activity in attention-deficit/hyperactivity disorder.

The state regulation deficit model posits that individuals with attention-deficit/hyperactivity disorder (ADHD) have difficulty applying mental effort effectively under suboptimal conditions such as very fast and very slow event rates (ERs). ADHD is also associated with diminished suppression of default mode network (DMN) activity and related performance deficits on tasks requiring effortful engagement. The current study builds on these 2 literatures to test the hypothesis that failure to modulate DMN activity in ADHD might be especially pronounced at ER extremes. Nineteen adults with ADHD and 20 individuals without any neuropsychiatric condition successfully completed a simple target detection task under 3 ER conditions (2-, 4-, and 8-s interstimulus intervals) inside the scanner. Task-related DMN deactivations were compared between 2 groups. There was a differential effect of ER on DMN activity for individuals with ADHD compared to controls. Individuals with ADHD displayed excessive DMN activity at the fast and slow, but not at the moderate ER. The results indicate that DMN attenuation in ADHD is disrupted in suboptimal energetic states where additional effort is required to optimize task engagement. DMN dysregulation may be an important element of the neurobiological underpinnings of state regulation deficits in ADHD.

Treatment with group psychotherapy for chronic psychogenic nonepileptic seizures

Although there have been a number of psychotherapy trials for chronic psychogenic nonepileptic seizures, evidence-based treatment options are limited. We developed an eclectic group psychotherapy which combines psychoeducation and behavioral and psychoanalytic techniques. Nine patients completed 12 weeks of psychotherapy. Patients were interviewed with SCID-I. They also filled in the following measures at the beginning and end of the therapy: Beck Depression Inventory, Dissociative Experiences Scale, Spielberger State-Trait Anxiety Scale, SF-36 Life Quality Scale, and Toronto Alexithymia Scale. Seizure frequency was assessed before and after the therapy and on follow-up visits at the fourth, sixth, ninth, and twelfth months. After one year of follow-up, the decrease in seizure frequency was highly significant (p<0.001). In addition, we observed significant improvements in the mental health subscale of the SF-36 (p=0.03) and the state (p=0.006) and trait (p=0.02) subscales of the Spielberger State-Trait Anxiety Scale at the end of the therapy. These results suggest that group psychotherapy might be a treatment option for chronic psychogenic nonepileptic seizures.

Convulsive syncope: a condition to be differentiated from epilepsy

The clinical presentation of epilepsy and syncope can be confusingly similar. We present a patient with reflex syncopal episodes that mimic seizures using video-EEG recordings. During the episodes, head/eye deviations, automatisms and dystonic movements, suggesting an epileptic seizure, were observed. The EEG revealed diffuse slow waves when the patient lost consciousness and complete cessation of the cerebral activity occurred when the dystonic movements started. On ECG recordings, bradycardia, followed by complete asystolia lasting for 40 seconds, was observed. We conclude that the differential diagnosis of epilepsy and syncope can be quite misleading and clinical features may not always be reliable. In cases where diagnosis is uncertain, circulatory and cardiac causes should always be kept in mind and video-EEG with simultaneous cardiac recordings are mandatory for accuracy of diagnosis.

Thalamic and Cerebellar Gray Matter Volume Reduction in Synthetic Cannabinoids Users

Background: Synthetic cannabinoids are compounds that bind cannabinoid receptors with a high potency and have been used widely in Europe by young people. However, little is known about the pharmacology and morphological effects of this group of substances in the brain. This study is aimed at investigating the morphological differences among synthetic cannabinoids users and healthy controls. Methods: Voxel-based morphometry was used to investigate the differences in brain tissue composition in 20 patients with synthetic cannabinoids use and 20 healthy controls. All participants were male. Results: Compared to healthy controls, voxel of interest analyses showed that regional grey matter volume in both left and right thalamus and left cerebellum was significantly reduced in synthetic cannabinoids users (p < 0.05). No correlation has been found between the age of first cannabis use, duration of use, frequency of use and grey matter volume. Discussion: These preliminary results suggest an evidence of some structural differences in the brain of synthetic cannabinoids users, and point the need for further investigation of morphological effects of synthetic cannabinoids in the brain.

Event rate and reaction time performance in ADHD: testing predictions from the state regulation deficit hypothesis using an ex-Gaussian model

According to the state regulation deficit (SRD) account, ADHD is associated with a problem using effort to maintain an optimal activation state under demanding task settings such as very fast or very slow event rates. This leads to a prediction of disrupted performance at event rate extremes reflected in higher Gaussian response variability that is a putative marker of activation during motor preparation. In the current study, we tested this hypothesis using ex-Gaussian modeling, which distinguishes Gaussian from non-Gaussian variability. Twenty-five children with ADHD and 29 typically developing controls performed a simple Go/No-Go task under four different event-rate conditions. There was an accentuated quadratic relationship between event rate and Gaussian variability in the ADHD group compared to the controls. The children with ADHD had greater Gaussian variability at very fast and very slow event rates but not at moderate event rates. The results provide evidence for the SRD account of ADHD. However, given that this effect did not explain all group differences (some of which were independent of event rate) other cognitive and/or motivational processes are also likely implicated in ADHD performance deficits.

Volumetric brain abnormalities in polysubstance use disorder patients.

Aim Polysubstance users represent the largest group of patients seeking treatment at addiction and rehabilitation clinics in Turkey. There is little knowledge about the structural brain abnormalities seen in polysubstance users. This study was conducted to examine the structural brain differences between polysubstance use disorder patients and healthy control subjects using voxel-based morphometry. Methods Forty-six male polysubstance use disorder patients in the early abstinence period and 30 healthy male controls underwent structural magnetic resonance imaging scans. Voxel-based morphometry analysis was performed to examine gray matter (GM) abnormality differences. Results Polysubstance use disorder patients displayed significantly smaller GM volume in the thalamus, temporal pole, superior frontal gyrus, cerebellum, gyrus rectus, occipital lobe, anterior cingulate cortex, superior temporal gyrus, and postcentral gyrus. Conclusion A widespread and smaller GM volume has been found at different regions of the frontal, temporal, occipital, and parietal lobes, cerebellum, and anterior cingulate cortex in polysubstance users.

Environmental Stimulation Does Not Reduce Impulsive Choice in ADHD A “Pink Noise” Study

Objective: The preference for sooner smaller over larger later rewards is a prominent manifestation of impulsivity in ADHD. According to the State Regulation Deficit (SRD) model, this impulsive choice is the result of impaired regulation of arousal level and can be alleviated by adding environmental stimulation to increase levels of arousal. Method: To test this prediction, we studied the effects of adding background “pink noise” on impulsive choice using a classical and new adjusting choice delay task in a sample of 25 children with ADHD and 28 controls. Results: Children with ADHD made more impulsive choices than controls. Adding noise did not reduce impulsive choice in ADHD. Conclusion: The findings add to the existing evidence on impulsive choice in ADHD, but no evidence is found for the SRD model’s explanation of this behavioral style. Alternative explanations for impulsive choice in ADHD are discussed.

Reward Processing Deficits During a Spatial Attention Task in Patients With ADHD: An fMRI Study:

Objective: In this study, we aimed to explore how cues signaling rewards and feedbacks about rewards are processed in ADHD. Method: Inside the scanner, 16 healthy children and 19 children with ADHD completed a spatial attention paradigm where cues informed about the availability of reward and feedbacks were provided about the earned reward. Results: In ventral anterior thalamus (VA), the controls exhibited greater activation in response to reward-predicting cues, as compared with no-reward cues, whereby in the ADHD group, the reverse pattern was observed (nonreward > reward). For feedbacks; absence of rewards produced greater activation than presence in the left caudate and frontal eye field for the control group, whereas for the ADHD group, the reverse pattern was again observed (reward > nonreward). Discussion: The present findings indicate that ADHD is associated with difficulty integrating reward contingency information with the orienting and regulatory phases of attention.