Persistent operational synchrony within brain default-mode network and self-processing operations in healthy subjects

Based on the theoretical analysis of self-consciousness concepts, we hypothesized that the spatio-temporal pattern of functional connectivity within the default-mode network (DMN) should persist unchanged across a variety of different cognitive tasks or acts, thus being task-unrelated. This supposition is in contrast with current understanding that DMN activated when the subjects are resting and deactivated during any attention-demanding cognitive tasks. To test our proposal, we used, in retrospect, the results from our two early studies (Fingelkurts, 1998; Fingelkurts et al., 2003). In both studies for the majority of experimental trails we indeed found a constellation of operationally synchronized cortical areas (indexed as DMN) that was persistent across all studied experimental conditions in all subjects. Furthermore, we found three major elements comprising this DMN: two symmetrical occipito-parieto-temporal and one frontal spatio-temporal patterns. This new data directly supports the notion that DMN has a specific functional connotation - it provides neurophysiologic basis for self-processing operations, namely first-person perspective taking and an experience of agency.     

What has fMRI told us about the Development of Cognitive Control through Adolescence?

Cognitive control, the ability to voluntarily guide our behavior, continues to improve throughout adolescence. Below we review the literature on age-related changes in brain function related to response inhibition and working memory, which support cognitive control. Findings from studies using functional magnetic resonance imaging (fMRI) indicate that processing errors, sustaining a cognitive control state, and reaching adult levels of precision, persist through adolescence. Developmental changes in patterns of brain function suggest that core regions of the circuitry underlying cognitive control are on-line early in development. However, age-related changes in localized processes across the brain, and in establishing long range connections that support top-down modulation of behavior, more effective neural processing for optimal mature executive function. While great progress has been made in understanding the age-related changes in brain processes underlying cognitive development, there are still important challenges in developmental neuroimaging methods and the interpretation of data that need to be addressed.     

Electrophysiological changes during adolescence: A review

While psychological research has long shown that adolescence is a period of major cognitive and affective transition, recent neurophysiological research has shown that adolescence is also accompanied by observable maturational changes in the brain, both in terms of structure and neurotransmitter function. Given this situation, we would expect that there should be observable and perhaps major changes in electrocortical activity and responses. In this review, we discuss developmental reductions in EEG power and alterations in the dominant band of EEG oscillation frequency, moderated by developmental factors such as growth-related changes in grey and white matter, and in the developmental history of cognitive and sociocultural stressors. Similarly, we summarize alterations in event-related potential components reflecting stimulus processing, response monitoring, and response anticipation. We review the literature on such changes in EEG and event-related potentials during the adolescent period and summarize some of the new developments in the field as well as interpretative difficulties.     

White matter development during adolescence as shown by diffusion MRI

Previous volumetric developmental MRI studies of the brain have shown white matter development continuing through adolescence and into adulthood. This review presents current findings regarding white matter development and organization from diffusion MRI studies. The general trend during adolescence (age 12–18 years) is towards increasing fractional anisotropy (FA) with age and decreasing mean diffusivity (MD) with age, findings primarily due to decreasing radial diffusivity with age. However, results of studies vary as to the regional specificity of such age-related changes, likely due in part to methodological issues. Another general trend is for FA to positively correlate and MD to negatively correlate with cognitive function. This trend is however region-specific, task-specific, and population-specific; some studies have in fact found negative correlations of FA and positive correlations of MD in specific regions with specific measures of cognitive performance. There are also published reports of sexual dimorphism in white matter development, indicating differing developmental trajectories between males and females as well as differing relationships developmentally between white matter architecture and cognitive function. There is a need for more research to further elucidate the development of white matter and its relation to cognitive function during this critical developmental period.     

Managing Frustration for Children (MFC) Group Intervention for ADHD: An Open Trial of a Novel Group Intervention for Deficient Emotion Regulation

Deficient emotion regulation is a common and impairing area of difficulty among children with ADHD. Few interventions specifically address deficient emotion regulation. The Managing Frustration for Children With ADHD (MFC) group treatment was developed to specifically target deficient emotion regulation deficits common to children with ADHD. The MFC was developed as a 12-week multisystemic intervention for emotion regulation deficits among children with ADHD. An open trial assessed the effectiveness of the MFC as an adjunctive treatment for deficient emotion regulation among children with ADHD. Fifty-two children with ADHD ages 9–11 (42 boys, 10 girls) were enrolled in the MFC, with 44 completing treatment. The majority (71.2%) of participants had at least one comorbid internalizing, externalizing, or learning disorder. Intent-to-treat repeated-measures ANCOVA suggested significant decreases in emotion regulation deficits, mood difficulties, and externalizing difficulties following completion of treatment. More than half (53%) of children who completed treatment experienced reliable and clinically significant improvement in at least one area of functioning. The MFC demonstrated promising initial effectiveness in addressing the emotion regulation deficits of children with ADHD.     

Application of deep transfer learning for automated brain abnormality classification using MR images

Magnetic resonance imaging (MRI) is the most common imaging technique used to detect abnormal brain tumors. Traditionally, MRI images are analyzed manually by radiologists to detect the abnormal conditions in the brain. Manual interpretation of huge volume of images is time consuming and difficult. Hence, computer-based detection helps in accurate and fast diagnosis. In this study, we proposed an approach that uses deep transfer learning to automatically classify normal and abnormal brain MR images. Convolutional neural network (CNN) based ResNet34 model is used as a deep learning model. We have used current deep learning techniques such as data augmentation, optimal learning rate finder and fine-tuning to train the model. The proposed model achieved 5-fold classification accuracy of 100% on 613 MR images. Our developed system is ready to test on huge database and can assist the radiologists in their daily screening of MR images.     

Does experienced pain affects local brain volumes? Insights from a clinical acute pain model

Background/Objective:To study pain-brain morphometry associations as a function of post-surgery stages (anesthesia, pain and analgesia) in an acute pain model. Method:Impacted mandible third molar were extracted. Before surgery, an anatomical T1 scan was obtained. Regional brain volumen and subcortical nuclei shapes were obtained. Statistical analyses were done using multiple regression, being pain scores the predictors and voxel volumes, subcortical nuclei volumes and subcortical nuclei shapes, the outcomes. Results:Pain was significantly larger at pain than at anesthesia and analgesia stages, and was higher during anesthesia than during analgesia. Pain intensity was related to grey matter in several cortical (Insula, Mid Frontal and Temporal Gyruses, Precuneus, Anterior Cingulate), and subcortical nuclei (Hippocampus, Thalamus, Putamen, Amygdala), depending of the post-surgical stage. A larger number of brain areas showed significance at pain that at anesthesia and analgesia stages. Conclusions:The relationships of regional brain volumes and subcortical nuclei shapes with pain scores seemed to be unsteady, as they changed with the patient's actual pain stage.     

Examining the link between adolescent brain development and risk taking from a social–developmental perspective

The adolescent age period is often characterized as a health paradox because it is a time of extensive increases in physical and mental capabilities, yet overall mortality/morbidity rates increase significantly from childhood to adolescence, often due to preventable causes such as risk taking. Asynchrony in developmental time courses between the affective/approach and cognitive control brain systems, as well as the ongoing maturation of neural connectivity are thought to lead to increased vulnerability for risk taking in adolescence. A critical analysis of the frequency of risk taking behaviors, as well as mortality and morbidity rates across the lifespan, however, challenges the hypothesis that the peak of risk taking occurs in middle adolescence when the asynchrony between the different developmental time courses of the affective/approach and cognitive control systems is the largest. In fact, the highest levels of risk taking behaviors, such as alcohol and drug use, often occur among emerging adults (e.g., university/college students), and highlight the role of the social context in predicting risk taking behavior. Moreover, risk taking is not always unregulated or impulsive. Future research should broaden the scope of risk taking to include risks that are relevant to older adults, such as risky financial investing, gambling, and marital infidelity. In addition, a lifespan perspective, with a focus on how associations between neural systems and behavior are moderated by context and trait-level characteristics, and which includes diverse samples (e.g., divorced individuals), will help to address some important limitations in the adolescent brain development and risk taking literature.     

Cerebral lateralization and general intelligence: gender differences in a transcranial Doppler study

The present study evaluated cerebral lateralization during Raven's progressive matrices (RPM) paradigm in female and male subjects. Bilateral simultaneous transcranial Doppler (TCD) ultrasound was used to measure mean blood flow velocities (MBFV) in the right and left middle cerebral arteries (MCAs) in 24 (15 females and 9 males) right-handed normal subjects. The female subjects used a left hemisphere strategy, while males used a right hemisphere strategy to successfully solve RPM tasks. This implies that general intelligence is associated with neural systems within one hemisphere that are accessible to a variety of cognitive processes.     

Cognitive therapy for irritable bowel syndrome is associated with reduced limbic activity, GI symptoms, and anxiety

This study sought to identify brain regions that underlie symptom changes in severely affected IBS patients undergoing cognitive therapy (CT). Five healthy controls and 6 Rome II diagnosed IBS patients underwent psychological testing followed by rectal balloon distention while brain neural activity was measured with O-15 water positron emission tomography (PET) before and after a brief regimen of CT. Pre-treatment resting state scans, without distention, were compared to post-treatment scans using statistical parametric mapping (SPM). Neural activity in the parahippocampal gyrus and inferior portion of the right cortex cingulate were reduced in the post-treatment scan, compared to pre-treatment (x, y, z coordinates in MNI standard space were -30, -12, -30, P=0.017; 6, 34, -8, P=0.023, respectively). Blood flow values at these two sites in the controls were intermediate between those in the pre- and post-treatment IBS patients. Limbic activity changes were accompanied by significant improvements in GI symptoms (e.g., pain, bowel dysfunction) and psychological functioning (e.g., anxiety, worry). The left pons (-2, -26, -28, P=0.04) showed decreased neural activity which was correlated with post-treatment anxiety scores. Changes in neural activity of cortical-limbic regions that subserve hypervigilance and emotion regulation may represent biologically oriented change mechanisms that mediate symptom improvement of CT for IBS.