332 research outputs found
Functional cerebral asymmetries of emotional processes in the healthy and bipolar brain
Get PDFThe perception and processing of emotions are of primary importance for social interaction, which confers faculties such as inferring what another person’s feels. Brain organisation of emotion perception has shown to primarily involve right hemisphere functioning. However, the brain may be functionally organised according to fundamental aspects of emotion such as valence, rather than involving processing of emotions in general. It should be noted, however, that emotion perception is not merely a perceptual process consisting in the input of emotional information, but also involves one’s emotional response. Therefore, the functional brain organisation of emotional processing may also be influenced by emotional experience. An experimental model for testing functional cerebral asymmetries (FCAs) of valenced emotional experience is uniquely found in bipolar disorder (BD) involving impaired ability to regulate emotions and eventually leading to depressive or manic episodes. Previous models have only explained hemispheric asymmetries for manic and depressive mood episodes, but not for BD euthymia.
The present thesis sought to investigate FCAs in emotional processing in two major ways. First, FCAs underlying facial emotion perception under normal functioning was examined in healthy controls. Secondly, functional brain organisation in emotional processing was further investigated by assessing FCAs in the bipolarity continuum, used as an experimental model for studying the processing of emotions. In contrast with previous asymmetry models, results suggested a right hemisphere involvement in emotional experience regardless of valence. Atypical FCAs were found in euthymic BD patients reflecting inherent aspects of BD functional brain organisation that are free of symptomatic influence. Also, BD patients exhibited atypical connectivity in a default amygdala network particularly affecting the right hemisphere, suggesting intrinsic mechanisms associated with internal emotional states. Last, BD patients were associated with a reduced right hemisphere specialisation in visuospatial attention, therefore suggesting that right hemisphere dysfunction can also affect non-emotional processes. Taken together, the findings emphasize a BD continuum model relying on euthymia as a bridging state between usual mood and acute mood phases
Recommended from our members
The role of HG in the analysis of temporal iteration and interaural correlation
Get PDFThe neuropsychological correlates of individuals at risk for bipolar I disorder
Full text linkBipolar disorder is now recognized as a severe psychiatric disorder characterized by extreme mood swings and cognitive deficits, most notably in the domains of verbal learning, executive function, and sustained attention. Neurocognitive deficits have been proposed as vulnerability markers or endophenotypes for the development of bipolar disorder. However, few research studies have examined whether neurocognitive deficits also exist in individuals at risk for bipolar disorder or first-degree relatives. This study examined neurocognitive function in individuals with bipolar disorder, their first-degree relatives, and a normal control group. Results indicated that individuals with bipolar disorder and their unaffected relatives demonstrated neuropsychological deficits in comparison to the normal control group in the domains of visuospatial/constructional abilities, executive function, and visual learning and memory. In general, the unaffected relatives demonstrated an intermediate level of performance in comparison to the normal control and bipolar group. After adjustment for mood symptomotology, significant differences remained only in the visuospatial/constructional and executive function domains. Individuals with bipolar disorder also demonstrated a differential right versus left hemisphere deficit with respect to neurocognitive tasks, providing support for the theory of right hemisphere dysfunction in bipolar affective disorder. Deficits on specific neuropsychological tests, most notably Digit Symbol, Block Design, and Judgment of Line Orientation may be indicative of cognitive endophenotypes for bipolar disorder. Replication studies are needed to identify these deficits as neurocognitive phenotypes and to further examine hemispheric functioning in bipolar affective disorder
Psychometric Properties of a Multichannel Battery for the Assessment of Emotional Perception
Full text linkPerceiving the emotions of others is an important, even critical, skill for success in social interactions. The lack of this skill has been associated with decreased social competence and poor interpersonal relationships (Shimokawa et al., 2001). It frequently co-occurs with psychopathology.
Furthermore, there is a large and rapidly growing literature examining the neural substrates of emotional processing. Studies have examined the processing of particular emotions, as well as how emotions conveyed through different modalities are processed.
The New York Emotion Battery (NYEB; Borod, Welkowitz, & Obler, 1992) includes tests for the perception of eight discrete emotions across three communication channels: facial, prosodic, and lexical. The NYEB has been used to study psychiatric and neurological conditions, as well as normal aging.
For the current study, data were collected from 122 healthy, right-handed adults, ages 20-89. Participants completed emotion perception and nonemotional control tasks from the NYEB. Perceptual tasks included both identification and discrimination of emotion. All participants completed a screening battery which included measures of cognitive, perceptual, and affective functioning.
The aims of the current study were:
1) To establish the internal consistency reliability and construct validity of the NYEB.
2) To examine the structure of its observed and latent variables and compare those structures to theory.
3) To describe any demographic or response biases of the NYEB.
Results indicated that the NYEB has very good internal consistency for identification tasks, but lower internal consistency for discrimination tasks. Performance on the NYEB (both overall and in its identification subtests) is strongly determined by a general factor of emotion perception ability. Individual identification subtests often display a moderately strong second factor, but are still good measures of general emotional perception ability. Analysis of hierarchical grouping of the battery\u27s emotions provides support for the approach/withdrawal classification of emotions (as it relates to perceived emotions). Individual emotions varied in how accurately they were perceived and how frequently they were named in responses.
Overall, the NYEB has good psychometric properties, should be a valid and useful instrument for assessing emotion perception deficits in psychopathology, and has potential to be adapted into an abbreviated form
Emotional Prosody Processing in the Schizophrenia Spectrum.
Get PDFTHESIS ABSTRACT
Emotional prosody processing impairment is proposed to be a main contributing factor for the formation of auditory verbal hallucinations in patients with schizophrenia. In order to evaluate such assumption, five experiments in healthy, highly schizotypal and schizophrenia populations are presented. The first part of the thesis seeks to reveal the neural underpinnings of emotional prosody comprehension (EPC) in a non-clinical population as well as the modulation of prosodic abilities by hallucination traits. By revealing the brain representation of EPC, an overlap at the neural level between EPC and auditory verbal hallucinations (AVH) was strongly suggested. By assessing the influence of hallucinatory traits on EPC abilities, a continuum in the schizophrenia spectrum in which high schizotypal population mirrors the neurocognitive profile of schizophrenia patients was established. Moreover, by studying the relation between AVH and EPC in non-clinical population, potential confounding effects of medication influencing the findings were minimized. The second part of the thesis assessed two EPC related abilities in schizophrenia patients with and without hallucinations. Firstly, voice identity recognition, a skill which relies on the analysis of some of the same acoustical features as EPC, has been evaluated in patients and controls. Finally, the last study presented in the current thesis, assessed the influence that implicit processing of emotional prosody has on selective attention in patients and controls. Both patients studies demonstrate that voice identity recognition deficits as well as abnormal modulation of selective attention by implicit emotion prosody are related to hallucinations exclusively and not to schizophrenia in general. In the final discussion, a model in which EPC deficits are a crucial factor in the formation of AVH is evaluated. Experimental findings presented in the previous chapters strongly suggests that the perception of prosodic features is impaired in patients with AVH, resulting in aberrant perception of irrelevant auditory objects with emotional prosody salience which captures the attention of the hearer and which sources (speaker identity) cannot be recognized. Such impairments may be due to structural and functional abnormalities in a network which comprises the superior temporal gyrus as a central element
Positive emotion processing deficits in schizophrenia
Full text linkAffective impairments were examined in patients with and without deficit syndrome schizophrenia. A battery of tests designed to measure emotional experience, emotional information processing, and emotional perception were administered to deficit (n = 15) and non-deficit syndrome (n = 26) schizophrenia patients classified according to the Schedule for the Deficit Syndrome, and matched non-patient control subjects (n = 22). As predicted, in comparison to non-deficit patients and controls, deficit syndrome patients reported less frequent and intense experience of positive emotion, recalled significantly fewer positive words, and displayed an impaired ability to accurately identify and judge the valence of pleasant odors. Additionally, deficit patients demonstrated a unique failure to have their attention captured by positive information, as well as less accurate and efficient labeling of positive faces than non-deficit patients or controls. Abnormalities were also associated with negative emotions, such that deficit syndrome patients demonstrated impairment at identifying fearful faces, were less accurate at judging negative smells, had a bias toward recalling anger words, and displayed an elevated attentional lingering effect for negative information. These findings indicate that the deficit syndrome is associated with affective disturbances that impact a number of cognitive and sensory domains, and provide support for the notion that abnormalities may be most severe in relation to the experience and processing of positive emotions. These abnormalities may be due to a mood-congruent processing abnormality, and are consistent with the notion that frontal and limbic system dysfunction may be core to deficit syndrome schizophrenia
Facial Affect Recognition and Social Functioning in Individuals at Risk for Schizophrenia Spectrum Disorders
Full text linkFacial affect recognition (FAR) is impaired in schizophrenia patients and to a lesser extent in individuals at familial/genetic, clinical, and psychometric risk for psychosis. Reduced FAR reaction time and negative bias are present in patients; however, their role is less clear in at-risk samples. Impaired social functioning, a hallmark of schizophrenia, is also impaired in at-risk individuals and is associated with FAR impairment. Given FAR deficits in schizophrenia, the current study aimed to elucidate the nature of FAR and social functioning impairments among individuals at high psychometric risk for psychosis and to examine whether FAR acts as a mediator in the relationship between schizotypal traits and social functioning. Nine-hundred and sixty-five (653 Female/312 Male) young adults were recruited from across CUNY campuses and asked to complete self-report measures assessing schizotypal traits (to determine psychometric risk status) and social functioning. Participants were also administered a computerized measure of FAR remotely via the Internet. Individuals at high psychometric risk performed significantly worse on total accuracy and neutral accuracy and were significantly more likely to misattribute negative emotions and sadness to neutral faces when compared to low-risk individuals. However, when adjusting for depressive symptoms, schizotypal traits were no longer associated with negative bias. Aspects of FAR performance were differentially associated with schizotypal traits in the total, high-risk, and low-risk samples. High-risk individuals reported significantly worse social functioning than individuals at low risk, and FAR accuracy was a partial mediator of the relationship between schizotypal traits and social functioning in the total sample. Results demonstrating attenuated FAR deficits in psychometrically at-risk individuals suggest that FAR may be an important endophenotype of schizophrenia spectrum disorders and has implications for understanding etiology of these disorders. Furthermore, results demonstrating that FAR deficits were related to poor social functioning in at-risk individuals have important clinical implications for improving ways of identifying those at risk and potential treatment strategies
From autism to eating disorders and more: the role of oxytocin in neuropsychiatric disorders
Get PDFOxytocin (oxy) is a pituitary neuropeptide hormone synthesized from the paraventricular and supraoptic nuclei within the hypothalamus. Like other neuropeptides, oxy can modulate a wide range of neurotransmitter and neuromodulator activities. Additionally, through the neurohypophysis, oxy is secreted into the systemic circulation to act as a hormone, thereby influencing several body functions. Oxy plays a pivotal role in parturition, milk let-down and maternal behavior and has been demonstrated to be important in the formation of pair bonding between mother and infants as well as in mating pairs. Furthermore, oxy has been proven to play a key role in the regulation of several behaviors associated with neuropsychiatric disorders, including social interactions, social memory response to social stimuli, decision-making in the context of social interactions, feeding behavior, emotional reactivity, etc. An increasing body of evidence suggests that deregulations of the oxytocinergic system might be involved in the pathophysiology of certain neuropsychiatric disorders such as autism, eating disorders, schizophrenia, mood, and anxiety disorders. The potential use of oxy in these mental health disorders is attracting growing interest since numerous beneficial properties are ascribed to this neuropeptide. The present manuscript will review the existing findings on the role played by oxy in a variety of distinct physiological and behavioral functions (Figure 1) and on its role and impact in different psychiatric disorders. The aim of this review is to highlight the need of further investigations on this target that might contribute to the development of novel more efficacious therapies. Figure 1Oxytocin regulatory control of different and complex processes
Hypomethylation of MB-COMT promoter is a major risk factor for schizophrenia and bipolar disorder
Get PDFThe variability in phenotypic presentations and the lack of consistency of genetic associations in mental illnesses remain a major challenge in molecular psychiatry. Recently, it has become increasingly clear that altered promoter DNA methylation could play a critical role in mediating differential regulation of genes and in facilitating short-term adaptation in response to the environment. Here, we report the investigation of the differential activity of membrane-bound catechol-O-methyltransferase (MB - COMT) due to altered promoter methylation and the nature of the contribution of COMT Val158Met polymorphism as risk factors for schizophrenia and bipolar disorder by analyzing 115 post-mortem brain samples from the frontal lobe. These studies are the first to reveal that the MB - COMT promoter DNA is frequently hypomethylated in schizophrenia and bipolar disorder patients, compared with the controls (methylation rate: 26 and 29 versus 60; P = 0.004 and 0.008, respectively), particularly in the left frontal lobes (methylation rate: 29 and 30 versus 81; P = 0.003 and 0.002, respectively). Quantitative gene-expression analyses showed a corresponding increase in transcript levels of MB - COMT in schizophrenia and bipolar disorder patients compared with the controls (P = 0.02) with an accompanying inverse correlation between MB - COMT and DRD1 expression. Furthermore, there was a tendency for the enrichment of the Val allele of the COMT Val158Met polymorphism with MB - COMT hypomethylation in the patients. These findings suggest that MB - COMT over-expression due to promoter hypomethylation and/or hyperactive allele of COMT may increase dopamine degradation in the frontal lobe providing a molecular basis for the shared symptoms of schizophrenia and bipolar disorder. © Copyright 2006 Oxford University Press
- …
