Volker Backes

Gender differences in the cognitive control of emotion: An fMRI study.

The interaction of emotion and cognition has become a topic of major interest. However, the influence of gender on the interplay between the two processes, along with its neural correlates have not been fully analysed so far. In this functional magnetic resonance imaging (fMRI) study we induced negative emotion using negative olfactory stimulation while male (n=21) and female (n=19) participants performed an n-back verbal working memory task. Based on findings indicating increased emotional reactivity in women, we expected the female participants to exhibit stronger activation in characteristically emotion-associated areas during the interaction of emotional and cognitive processing in comparison to the male participants. Both groups were found to be significantly impaired in their working memory performance by negative emotion induction. However, fMRI analysis revealed distinct differences in neuronal activation between groups. In men, cognitive performance under negative emotion induction was associated with extended activation patterns in mainly prefrontal and superior parietal regions. In women, the interaction between emotion and working memory yielded a significantly stronger response in the amygdala and the orbitofrontal cortex (OFC) compared to their male counterparts. Our data suggest that in women the interaction of verbal working memory and negative emotion is associated with relative hyperactivation in more emotion-associated areas whereas in men regions commonly regarded as important for cognition and cognitive control are activated. These results provide new insights in gender-specific cerebral mechanisms.

Negative bias in fast emotion discrimination in borderline personality disorder

BACKGROUND The ability to decode emotional information from facial expressions is crucial for successful social interaction. Borderline personality disorder (BPD) is characterized by serious problems in interpersonal relationships and emotional functioning. Empirical research on facial emotion recognition in BPD has been sparsely published and results are inconsistent. To specify emotion recognition deficits in BPD more closely, the present study implemented two emotion recognition tasks differing in response format. METHOD Nineteen patients with BPD and 19 healthy subjects were asked to evaluate the emotional content of visually presented stimuli (emotional and neutral faces). The first task, the Fear Anger Neutral (FAN) Test, required a rapid discrimination between negative or neutral facial expressions whereas in the second task, the Emotion Recognition (ER) Test, a precise decision regarding default emotions (sadness, happiness, anger, fear and neutral) had to be achieved without a time limit. RESULTS In comparison to healthy subjects, BPD patients showed a deficit in emotion recognition only in the fast discrimination of negative and neutral facial expressions (FAN Test). Consistent with earlier findings, patients demonstrated a negative bias in the evaluation of neutral facial expressions. When processing time was unlimited (ER Test), BPD patients performed as well as healthy subjects in the recognition of specific emotions. In addition, an association between performance in the fast discrimination task (FAN Test) and post-traumatic stress disorder (PTSD) co-morbidity was indicated. CONCLUSIONS Our data suggest a selective deficit of BPD patients in rapid and direct discrimination of negative and neutral emotional expressions that may underlie difficulties in social interactions.

Differential brain activation during facial emotion discrimination in first-episode schizophrenia

BACKGROUND Aberrant brain activation during facial emotion discrimination has been described in chronic schizophrenia, while little is known about early stages of the illness. The aim of the current study was to investigate valence-specific brain activation of emotion discrimination in first-episode schizophrenia. These patients provide the advantage of lacking the effects of long-term medication and chronic illness course and can hence further enhance the understanding of underlying psychopathological mechanisms. METHODS Using event-related fMRI, we investigated 18 first-episode schizophrenia patients and 18 matched healthy subjects during an explicit emotion discrimination task presenting happy, sad and neutral monochromatic facial expressions. A repeated measure analysis of variance (ANOVA) with the factors Group (patients, healthy subjects), Gender and Emotion (happy, sad, neutral) was performed on behavioural and functional data. RESULTS Behavioural performance did not differ between groups. Valence-independent hypoactivations in patients were observed for the anterior cingulate and orbitofrontal cortex while hyperactivations emerged in the posterior cingulate and the precuneus. Emotion-specific group differences were revealed in inferior parietal and orbitofrontal brain areas and the hippocampus. CONCLUSIONS First-episode schizophrenia already affects areas involved in processing of both, emotions and primary facial information. Our study underlines the role of dysfunctional neural networks as the basis of disturbed social interactions in early schizophrenia.

Cerebral dysfunctions of emotion-cognition interactions in adolescent-onset schizophrenia.

OBJECTIVE Schizophrenia is among the most severe of psychiatric disorders, leading to impairments of affective and cognitive abilities. These dysfunctions affect each other mutually. Adolescent-onset schizophrenia (AOS) constitutes a particularly severe form of the disorder. In this study, possible dysfunctions of the neural correlates underlying the interaction of negative emotion and working memory in AOS were investigated. METHOD During functional magnetic resonance imaging, 12 patients with AOS and 12 non-AOS adolescents performed a verbal n-back task. Intermittently, negative and neutral emotions were induced by olfactory stimulation. Group differences in working memory, emotion, and their interaction were evaluated. RESULTS In patients with AOS, lower performance sensitivity was observed, along with dorsolateral prefrontal, anterior cingulate, and inferior parietal hypoactivation during working memory demands. For negative versus neutral emotion induction, patients with AOS mainly showed increased brain activation compared with control subjects in widespread brain regions including the left orbitofrontal cortex and the medial frontal gyrus. Finally, during the interaction of emotion and cognition, altered patterns of activation in patients with AOS were found in the thalamocortical network, including the angular and the middle cingulate gyri extending to the precuneus. These activation differences were further decomposed by parameter estimates. CONCLUSIONS Our results provide new insights into the neural correlates underlying the mutual influence of affective and cognitive symptoms in AOS. During the n-back task, areas typically associated with working memory performance were found hypoactivated in patients relative to the control subjects, including the dorsolateral prefrontal and parietal cortex and the anterior cingulate. However, patients with AOS mainly demonstrated increased activation in key areas of emotion processing, such as the left orbitofrontal cortex and medial frontal areas, during negative emotion induction. A dysfunctional thalamocortical network during the interaction mainly included regions involved in the integration of converging information--either on the subcortical (thalamus) or on a higher-order cortical level (comprising the angular gyrus). These findings point to dysfunctional emotion-cognition interactions in AOS, which may explain its poor prognosis.

Psychiatric symptoms in Parkinson’s disease

Parkinson’s disease (PD) is a neurodegenerative disorder which is often reduced to a mere dysfunction of motor performance. Non-motor symptoms, however, are frequent impairments in PD and result in a major impact on the patients and their caregivers. The major neuropsychiatric comorbidities depression, anxiety, and psychotic symptoms are briefly discussed. Additionally, a brief outlook on deep brain stimulation and its effect on psychiatric symptoms is provided. Several studies did show that neuropsychiatric symptoms are underdiagnosed and consecutively treated inadequately. All in all more attention should be directed to the detection and treatment of psychiatric symptoms in PD patients in routine clinical settings.

The interaction of working memory and emotion in persons clinically at risk for psychosis: An fMRI pilot study

Subtle emotional and cognitive dysfunctions may already be apparent in individuals at risk for psychosis. However, there is a paucity of research on the neural correlates of the interaction of both domains. It remains unclear whether those correlates are already dysfunctional before a transition to psychosis. We used functional magnetic resonance imaging to examine the interaction of working memory and emotion in 12 persons clinically at high risk for psychosis (CHR) and 12 healthy subjects individually matched for age, gender and parental education. Participants performed an n-back task while negative or neutral emotion was induced by olfactory stimulation. Although healthy and psychosis-prone subjects did not differ in their working memory performance or the evaluation of the induced emotion, decreased activations were found in CHR subjects in the superior parietal lobe and the precuneus during working memory and in the insula during emotion induction. Looking at the interaction, CHR subjects, showed decreased activation in the right superior temporal gyrus, which correlated negatively with psychopathological scores. Decreased activation was also found in the thalamus. However, an increase of activation emerged in several cerebellar regions. Dysfunctions in areas associated with controlling whether incoming information is linked to emotional content and in the integration of multimodal information might lead to compensatory activations of cerebellar regions known to be involved in olfactory and working memory processes. Our study underlines that cerebral dysfunctions related to cognitive and emotional processes, as well as their interaction, can emerge in persons with CHR, even in absence of behavioral differences.

Emotion–cognition interactions in schizophrenia

Abstract Objectives. Negative emotion exerts a considerable influence on cognitive processes. This may have clinical implications in mental illnesses, such as schizophrenia, where negative emotions often prevail. Experimentally this influence can be studied by using olfactory emotion induction. Methods. Fourteen schizophrenia patients and 14 healthy volunteers were investigated with functional magnetic resonance imaging with respect to the neural correlates of emotion–cognition interactions. Emotion was induced by odorants during an n-back working memory task. Results. Similar detrimental effects of negative stimulation on working memory performance were observed in patients and control subjects. Among the neural correlates modulating this interaction a decreased activation emerged in patients in the anterior cingulate and the medial superior frontal cortex and increased activation in the medial orbitofrontal and middle frontal area. Conclusions. During emotion–cognition interaction hypoactivations were found in regions crucial for the monitoring/control of ongoing processes but also for emotion regulation. Decreased activations may reflect failure to adapt to higher task requirements. In contrast, increased activations could be indicative of a greater emotional response and irritation induced by the odour. These patterns may represent the neural correlates of an inefficient control of emotional influences on cognitive processes in patients with schizophrenia.

Brain imaging: on the way toward a therapeutic discipline

Abstract Brain imaging has proven its importance as an essential tool of neuroscientific research, especially in psychiatry. Several of these methods at hand promise to enhance our understanding of function and dysfunction of neural processes and their disturbances in mental disorders in the near future. But the convincing success of imaging tools in research has not yet answered the demand to lead to new therapies or to new and useful tools in the diagnosis and treatment of single subjects. This article tries to point out how new methodological developments are promising to lead to a further step in this way. This therapeutic option is based on technical developments like high-field magnetic resonance imaging (MRI) or the further development of neurofeedback. This concept might make brain imaging such as realtime fMRI a therapeutic option at least in specialized institutions in the foreseeable future, especially since MR-scanners are already widely available nowadays.

Empathy in individuals clinically at risk for psychosis: brain and behaviour

BACKGROUND Empathy is a basic human ability, and patients with schizophrenia show dysfunctional empathic abilities on the behavioural and neural level. AIMS These dysfunctions may precede the onset of illness; thus, it seems mandatory to examine the empathic abilities in individuals at clinical high risk for psychosis. METHOD Using functional magnetic resonance imaging, we measured 15 individuals at clinical high risk of psychosis (CHR group) and compared their empathy performance with 15 healthy volunteers and 15 patients with schizophrenia. RESULTS Behavioural data analysis indicated no significant deficit in the CHR group. Functional data analysis revealed hyperactivation in a frontotemporoparietal network including the amygdala in the CHR group compared with the other two groups. CONCLUSIONS Despite normal behavioural performance, the CHR group activated the neural empathy network differently and specifically showed hyperactivation in regions critical for emotion processing. This could suggest a compensatory mechanism reflecting emotional hypersensitivity or dysfunctional emotion regulation. Further investigations should clarify the role of these neural alterations for development and exacerbation of psychosis.

Incidental Memory Encoding Assessed with Signal Detection Theory and Functional Magnetic Resonance Imaging (fMRI)

In functional magnetic resonance imaging (fMRI) studies that apply a “subsequent memory” approach, successful encoding is indicated by increased fMRI activity during the encoding phase for hits vs. misses, in areas underlying memory encoding such as the hippocampal formation. Signal-detection theory (SDT) can be used to analyze memory-related fMRI activity as a function of the participant’s memory trace strength (d′). The goal of the present study was to use SDT to examine the relationship between fMRI activity during incidental encoding and participants’ recognition performance. To implement a new approach, post-experimental group assignment into High- or Low Performers (HP or LP) was based on 29 healthy participants’ recognition performance, assessed with SDT. The analyses focused on the interaction between the factors group (HP vs. LP) and recognition performance (hits vs. misses). A whole-brain analysis revealed increased activation for HP vs. LP during incidental encoding for remembered vs. forgotten items (hits > misses) in the insula/temporo-parietal junction (TPJ) and the fusiform gyrus (FFG). Parameter estimates in these regions exhibited a significant positive correlation with d′. As these brain regions are highly relevant for salience detection (insula), stimulus-driven attention (TPJ), and content-specific processing of mnemonic stimuli (FFG), we suggest that HPs’ elevated memory performance was associated with enhanced attentional and content-specific sensory processing during the encoding phase. We provide first correlative evidence that encoding-related activity in content-specific sensory areas and content-independent attention and salience detection areas influences memory performance in a task with incidental encoding of facial stimuli. Based on our findings, we discuss whether the aforementioned group differences in brain activity during incidental encoding might constitute the basis of general differences in memory performance between HP and LP.