Increased functional connectivity within alpha and theta frequency bands in dysphoria: A resting-state EEG study

Background: The understanding of neurophysiological correlates underlying the risk of developing depression may have a significant impact on its early and objective identification. Research has identified abnormal resting-state electroencephalography (EEG) power and functional connectivity patterns in major depression. However, the entity of dysfunctional EEG dynamics in dysphoria is yet unknown. Methods: 32-channel EEG was recorded in 26 female individuals with dysphoria and in 38 age-matched, female healthy controls. EEG power spectra and alpha asymmetry in frontal and posterior channels were calculated in a 4-minute resting condition. An EEG functional connectivity analysis was conducted through phase locking values, particularly mean phase coherence. Results: While individuals with dysphoria did not differ from controls in EEG spectra and asymmetry, they exhibited dysfunctional brain connectivity. Particularly, in the theta band (4-8 Hz), participants with dysphoria showed increased connectivity between right frontal and central areas and right temporal and left occipital areas. Moreover, in the alpha band (8-12 Hz), dysphoria was associated with increased connectivity between right and left prefrontal cortex and between frontal and central-occipital areas bilaterally. Limitations: All participants belonged to the female gender and were relatively young. Mean phase coherence did not allow to compute the causal and directional relation between brain areas. Conclusions: An increased EEG functional connectivity in the theta and alpha bands characterizes dysphoria. These patterns may be associated with the excessive self-focus and ruminative thinking that typifies depressive symptoms. EEG connectivity patterns may represent a promising measure to identify individuals with a higher risk of developing depression

Towards the mind of a humanoid: Does a cognitive robot need a self? - Lessons from neuroscience

As we endow cognitive robots with ever more human-like capacities, these have begun to resemble constituent aspects of the 'self' in humans (e.g., putative psychological constructs such as a narrative self, social self, somatic self and experiential self). Robot's capacity for body-mapping and social learning in turn facilitate skill acquisition and development, extending cognitive architectures to include temporal horizon by using autobiographical memory (own experience) and inter-personal space by mapping the observations and predictions on the experience of others (biographic reconstruction). This 'self-projection' into the past and future as well as other's mind can facilitate scaffolded development, social interaction and planning in humanoid robots. This temporally extended horizon and social capacities newly and increasingly available to cognitive roboticists have analogues in the function of the Default Mode Network (DMN) known from human neuroscience, activity of which is associated with self-referencing, including discursive narrative processes about present moment experience, 'self-projection' into past memories or future intentions, as well as the minds of others. Hyperactivity and overconnectivity of the DMN, as well as its co-activation with the brain networks related to affective and bodily states have been observed in different psychopathologies. Mindfulness practice, which entails reduction in narrative self-referential processing, has been shown to result in an attenuation of the DMN activity and its decoupling from other brain networks, resulting in more efficient brain dynamics, and associated gains in cognitive function and well-being. This suggests that there is a vast space of possibilities for orchestrating self-related processes in humanoids together with other cognitive activity, some less desirable or efficient than others. Just as for humans, relying on emergence and self-organization in humanoid scaffolded cognitive development might not always lead to the 'healthiest' and most efficient modes of cognitive dynamics. Rather, transient activations of self-related processes and their interplay dependent on and appropriate to the functional context may be better suited for the structuring of adaptive robot cognition and behaviour.This work was supported in part by the European Commission under projects ITALK ("Integration and Transfer of Action and Language in Robots") and BIOMICS (contract numbers FP7-214668 and FP7-318202, respectively) to Prof Nehaniv, and by the King’s Together Fund award (“Towards Experiential Neuroscience Paradigm”) to Dr Antonova

Multivariate analytical approaches for investigating brain-behavior relationships

BackgroundMany studies of brain-behavior relationships rely on univariate approaches where each variable of interest is tested independently, which does not allow for the simultaneous investigation of multiple correlated variables. Alternatively, multivariate approaches allow for examining relationships between psychopathology and neural substrates simultaneously. There are multiple multivariate methods to choose from that each have assumptions which can affect the results; however, many studies employ one method without a clear justification for its selection. Additionally, there are few studies illustrating how differences between methods manifest in examining brain-behavior relationships. The purpose of this study was to exemplify how the choice of multivariate approach can change brain-behavior interpretations.MethodWe used data from 9,027 9- to 10-year-old children from the Adolescent Brain Cognitive DevelopmentSM Study (ABCD Study®) to examine brain-behavior relationships with three commonly used multivariate approaches: canonical correlation analysis (CCA), partial least squares correlation (PLSC), and partial least squares regression (PLSR). We examined the associations between psychopathology dimensions including general psychopathology, attention-deficit/hyperactivity symptoms, conduct problems, and internalizing symptoms with regional brain volumes.ResultsThe results of CCA, PLSC, and PLSR showed both consistencies and differences in the relationship between psychopathology symptoms and brain structure. The leading significant component yielded by each method demonstrated similar patterns of associations between regional brain volumes and psychopathology symptoms. However, the additional significant components yielded by each method demonstrated differential brain-behavior patterns that were not consistent across methods.ConclusionHere we show that CCA, PLSC, and PLSR yield slightly different interpretations regarding the relationship between child psychopathology and brain volume. In demonstrating the divergence between these approaches, we exemplify the importance of carefully considering the method’s underlying assumptions when choosing a multivariate approach to delineate brain-behavior relationships

Neural Precursors of Apathy and Depressive Symptoms in Amnestic Mild Cognitive Impairment

Depressive symptoms and apathy are common in amnestic mild cognitive impairment (aMCI) and are associated with increased risk of conversion to Alzheimer’s disease (AD). The shared neuropathological model of neuropsychiatric symptoms (NPS) in AD suggests that symptoms of depression and anxiety represent noncognitive manifestations of neuropathological changes. Neurodegeneration in aMCI occurs in areas of the brain that support emotion regulation, including the limbic system and prefrontal control regions. Depression and apathy in aMCI have been linked to atrophy in the limbic system and prefrontal cortex and reduced connectivity in resting-state networks. However, it is not yet established whether neural changes in emotion centers in the brain predict symptoms of depression and apathy in persons with aMCI, or whether neural precursors in the limbic system and prefrontal cortex are associated with higher risk of conversion from aMCI to AD. The current study utilized longitudinal clinical and neuroimaging data from the Alzheimer’s Disease Neuroimaging Initiative (ADNI) to determine whether change in neural structure and function in emotion centers predicted symptoms of depression and apathy in aMCI and conversion to AD. Depressive symptoms and apathy increased over time, and cortical volume in emotion centers in the brain decreased over time, especially in the MCI group. The slope of change in neural markers was not correlated with the slope of change in depressive symptoms or with the presence versus absence of apathy. Presence of apathy, slope of change in depressive symptoms, and speed of atrophy in the amygdala and cingulate cortex predicted progression of disease. Overall, results provided limited support for the shared neuropathological model of NPS in aMCI, primarily related to amygdala atrophy. Future research is needed to further define the role of neurodegeneration in emotion centers in the brain in the development and/or worsening of NPS in aMCI

Neural Correlates of Cognitive-Attentional Syndrome: An fMRI Study on Repetitive Negative Thinking Induction and Resting State Functional Connectivity

AimCognitive-attentional syndrome (CAS) is the main factor underlying depressive and anxiety disorders in the metacognitive approach to psychopathology and psychotherapy. This study explore neural correlates of this syndrome during induced negative thinking, abstract thinking, and resting states.Methodsn = 25 people with high levels of CAS and n = 33 people with low levels of CAS were chosen from a population-based sample (N = 1225). These groups filled-in a series of measures of CAS, negative affect, and psychopathology; they also underwent a modified rumination induction procedure and a resting state fMRI session. Resonance imaging data were analyzed using static general linear model and functional connectivity approaches.ResultsThe two groups differed with large effect sizes on all used measures of CAS, negative affect, and psychopathology. We did not find any group differences in general linear model analyses. Functional connectivity analyses showed that high levels of CAS were related to disrupted patterns of connectivity within and between various brain networks: the default mode network, the salience network, and the central executive network.ConclusionWe showed that low- and high-CAS groups differed in functional connectivity during induced negative and abstract thinking and also in resting state fMRI. Overall, our results suggest that people with high levels of CAS tend to have disrupted neural processing related to self-referential processing, task-oriented processing, and emotional processing

Intrinsic Spirituality and Acute Stress: Neural Mechanisms Supporting the Relationship Between Spirituality and Reduced Stress Responsivity

Spirituality is a multidimensional construct that refers to the experience of self-transcendence and connection with a higher sacred reality. Previous research has demonstrated that spirituality represents a consistent resilience factor for stress and a range of stress-related mental disorders, but neural mechanisms by which spirituality confers resilience are unknown. This paper focuses on intrinsic spirituality, or the extent to which spirituality functions as a master motive in one’s life regardless of religious affiliation, and reviews the research literature on behaviors and brain structures and functions related to intrinsic spirituality. Additionally, literature is reviewed on adaptive and maladaptive functions of the stress response, its relationship to psychopathology, and its underlying neurobiology. To understand neural responses underlying the link between intrinsic spirituality and stress, the current study utilized a script-guided imagery task to assess brain activity during a stress exposure. Results showed that during a stressful experience higher intrinsic spirituality is associated with greater deactivation in the hippocampus, brain stem, ventral striatum, thalamus, extending to the orbitofrontal cortex (OFC) and ventromedial prefrontal cortex (vmPFC), as well as in another cluster comprising of the posterior cingulate cortex (PCC) and right inferior parietal lobule. These regions are implicated in stress responsiveness, emotional and cognitive processing, and self-referential processing. While preliminary, results provide a potential neural substrate for how spirituality may influence stress processing. Moreover, they suggest a role for spirituality in attenuating neural responses to stress responsivity, regulating emotion during exposure to stress, and preventing and treating stress-related psychopathology

Cognitive-attentional syndrome Neural correlates and relationships with psychopathology symptoms

Syndrom poznawczo-uwagowy (CAS) to kluczowy konstrukt w metapoznawczym modelu psychopatologii i psychoterapii. Składają się na niego nieadaptacyjne wzorce powtarzającego się negatywnego myślenia i dysfunkcjonalne przekonania metapoznawcze. W tym podejściu teoretycznym jest on konstruktem transdiagnostycznym, leżącym u podłożaróżnego rodzaju zaburzeń psychicznych.W poniższej pracy przedstawione zostały dwa artykuły naukowe. Głównym celem było potwierdzenie transdiagnostycznego statusu syndromu poznawczo-uwagowego. Pierwsza praca dotyczyła eksploracji związków nasilenia objawów CASu z objawami psychopatologicznymi i zaburzeniami psychicznymi. Druga objęła eksplorację różnic w funkcjonowaniu neuronalnym między osobami z wysokim i niskim nasileniem objawów CASu za pomocą indukcji ruminacji i pomiaru aktywności spoczynkowej mózgu podczas funkcjonalnego rezonansu magnetycznego.Nasilenie objawów CASu jest powiązane z wyższym nasileniem różnych rodzajów objawów psychopatologicznych oraz jest związane z kilkukrotnie większym ryzykiem względnym rozpoznania zaburzeń psychicznych w obecnym momencie i w ciągu całego życia. Osoby z wysokim nasileniem objawów CASu różnią się także istotnie w zakresie połączeń funkcjonalnych w mózgu w kilku istotnych sieciach neuronalnych – sieci spoczynkowej, sieci wykonawczej i sieci istotności. Uzyskane wyniki mogą wskazywać na istotną rolę wysokiego nasilenia objawów CASu w etiopatogenezie różnego rodzaju zaburzeń psychicznych, co potwierdza jedno z głównych założeń metapoznawczej teorii zaburzeń psychicznych i rozszerza je o dodatkową perspektywę różnic w funkcjonowaniu mózgu u osób z różnym nasileniem objawów CASu.Cognitive-attentional syndrome is a key construct in the metacognitive approach to psychopathology and psychotherapy. It consists of maladaptive patterns of repetitive negative thinking and dysfunctional metacognitive beliefs. In this approach CAS is a transdiagnostic construct, involved in etiopathology of various psychological disorders.Two scientific papers are presented in this dissertation. The main goal was to confirm the transdiagnostic status of cognitive-attentional syndrome. The first one concentrated on exploring the relationship between CAS and psychopathology symptoms and psychological disorders. The other one was concerned with the differences in neural functioning between people with high and low levels of CAS symptoms. This was done by means of rumination induction procedure and a resting state fMRI session. CAS symptoms are related to higher levels of various psychopathology symptoms and several times higher relative risk of diagnosing both current and lifetime psychological disorders. People reporting high levels of CAS also differ significantly in the brain functionalconnectivity in some prominent brain neural networks – default mode, central executive and salience networks. Results of this study indicate a prominent role that high levels of CAS symptoms mayhave in etiopathogenesis of various psychological disorders. This confirms one of the main assumptions of metacognitive theory of psychopathology. Plus to that, it provides an additional perspective of the differences in brain functioning between people reporting high and low levels of CAS symptoms

Aberrant brain activation and coupling in Depression – Links between Psychopathology and Neurophysiology

Major Depressive Disorder (MDD) is the most common mental disorder and ranging under the top three of the most disabling diseases worldwide. Although various treatments exist for MDD, about 30 to 40 % of the patients don’t respond. A better understanding of the neurobiological correlates of MDD might lead to the development of new and the improvement of existing treatments. The dissertation at hand is dedicated to the aim of a better understanding of aberrant brain functioning and coupling in MDD. Further, we sought to investigate the behavioral and cognitive-affective underpinnings that lead to aberrant brain functioning and coupling in MDD, in terms of depressive rumination. In total this work comprises four studies. In our first study, we investigated the functional connectivity (FC) during resting state (rsFC) and task performance of the Trail Making Test (TMT) in subjects with late-life depression (LLD) and healthy controls (HC). FC was assessed via functional near-infrared spectroscopy (fNIRS) in areas of the cognitive control network (CCN). While we observed an expected pattern of change in FC in the healthy controls with relatively low FC during resting-state and an increase during task-performance, subjects with LLD showed an opposite pattern, with relatively high FC during resting-state and decreases during task-performance. Further, depressed and non-depressed subjects differed significantly during resting-state (LLD>HC) and the executive demanding condition of the TMT (HC>LLD). While these results were interesting from a standpoint of pathophysiological changes in FC, we couldn’t give a final explanation for the observed FC patterns in LLD. As a possible explanation, we assumed that some kind of depressive cognitive process could lead to hyper-connectivity within the CCN during resting-state that further disturbs cortical coupling during task performance. As depressive rumination is such a cognitive process that is common in depression, we developed a resting-state questionnaire to assess state rumination for subsequent studies. In study two, we investigated rsFC within subjects with MDD and HC with a parietal probeset covering parts of the default mode network (DMN), CCN and dorsal attention network (DAN). Further, we investigated in how far state- and trait rumination explained the differences between depressed and non-depressed subjects in rsFC. In contrast to our first study, we observed an opposite pattern of FC differences between the groups: within the parietal cortex, depressed subjects showed reduced FC in comparison to HC in a widespread bilateral network. While state rumination showed rather restricted effects, the measures of trait rumination showed wide-spread effects. Further, FC was negatively correlated with state- and trait rumination. Since our results so far were restricted to non-experimental between-subject associations, that don’t allow the investigation of causal relationships, we further designed a study in which we sought to induce rumination with the Trier Social Stress Test (TSST). In study three, we investigated the hemodynamic changes during the TSST in high and low trait ruminators in the CCN, further, we examined in how far state rumination would be induced through the TSST. Relationships between hemodynamic responses and state rumination were examined with a mediation analysis. As expected, we found increases in state rumination through the TSST. Further, these increases were higher in the high-trait ruminators. On a cortical level, low ruminators showed higher cortical activation in the stress condition than the high ruminators in the right inferior frontal gyrus (IFG). Further, group differences in post-stress state rumination were mediated by the cortical reactivity in this region. Subject with high IFG reactivity showed less state-rumination following the TSST. In study four, we further investigated in the same study cohort, if rsFC before and after stress would show an expected pattern with higher baseline FC in the high trait ruminators and a higher reactivity in rsFC in subjects with high increases in state rumination. As expected, baseline levels of rsFC were increased in the high-ruminators like in our first study for the LDD group. However, although state rumination increased in the high trait ruminators more strongly than in the low trait ruminators, rsFC only increased in the latter group. Since we didn’t observe a co-variation of change scores between rsFC and state rumination, we concluded that the effect of rumination on FC changes would be an indirect one. In the general discussion of this dissertation, I propose a model of indirect prolonged stress effects in high ruminating subjects that lead to higher stress levels and subsequently to permanent changes in FC. This model would explain the observed effects in our study and is in line with current research of FC alterations in chronic stress. I further outline, in how far the presented results and the research of biological underpinnings could improve the current theory development of mental diseases as well as treatment planning