Perceptual Expectations of Object Stimuli Modulate Repetition Suppression in a Delayed Repetition Design

Several fMRI and EEG/MEG studies show that repetition suppression (RS) effects are stronger when a stimulus repetition is expected compared to when a stimulus repetition is less expected. To date, the prevalent way to assess the influence of expectations on RS is via immediate stimulus repetition designs, that is, no intervening stimuli appear between the initial and repeated presentation of a stimulus. Since there is evidence that repetition lag may alter RS effects in a qualitative manner, the current study investigated how perceptual expectations modify RS effects on object stimuli when repetition lag is relatively long. Region of interest analyses in the left occipital cortex revealed a similar activation pattern as identified in previous studies on immediate lag: RS effects were strongest when repetitions were expected compared to decreased RS effects when repetitions were less expected. Therefore, the current study expands previous research in two ways: First, we replicate prior studies showing that perceptual expectation effects can be observed in object-sensitive occipital areas. Second, the finding that expectation effects can be found even for several-minute lags proposes that Bayesian inference processes are a relatively robust component in visual stimulus processing.P 30390-B27(VLID)286101

Impact of non‐CNS childhood cancer on resting‐state connectivity and its association with cognition

Introduction Non‐central nervous system cancer in childhood (non‐CNS CC) and its treatments pose a major threat to brain development, with implications for functional networks. Structural and functional alterations might underlie the cognitive late‐effects identified in survivors of non‐CNS CC. The present study evaluated resting‐state functional networks and their associations with cognition in a mixed sample of non‐CNS CC survivors (i.e., leukemia, lymphoma, and other non‐CNS solid tumors). Methods Forty‐three patients (off‐therapy for at least 1 year and aged 7–16 years) were compared with 43 healthy controls matched for age and sex. High‐resolution T1‐weighted structural magnetic resonance and resting‐state functional magnetic resonance imaging were acquired. Executive functions, attention, processing speed, and memory were assessed outside the scanner. Results Cognitive performance was within the normal range for both groups; however, patients after CNS‐directed therapy showed lower executive functions than controls. Seed‐based connectivity analyses revealed that patients exhibited stronger functional connectivity between fronto‐ and temporo‐parietal pathways and weaker connectivity between parietal‐cerebellar and temporal‐occipital pathways in the right hemisphere than controls. Functional hyperconnectivity was related to weaker memory performance in the patients' group. Conclusion These data suggest that even in the absence of brain tumors, non‐CNS CC and its treatment can lead to persistent cerebral alterations in resting‐state network connectivity

Erroneously Disgusted: fMRI Study Supports Disgust-Related Neural Reuse in Obsessive-Compulsive Disorder (OCD)

Objective: fMRI scans of patients with obsessive-compulsive disorder (OCD) consistently show a hyperactivity of the insular cortex, a region responsible for disgust-processing, when confronted with symptom-triggering stimuli. This asks for an investigation of the role of disgust and the insula in OCD patients.Methods: Seventeen inpatients with OCD and 17 healthy controls (HC) underwent fMRI scanning. Whole-brain contrasts were calculated for “Disgust vs. Neutral” for both groups, plus an analysis of variance (ANOVA) to assess the interaction between group and condition. Additionally, the emotional dimensions of valence and arousal, along with the ability to cope, were assessed by picture ratings.Results: The picture ratings confirmed the patients’ heightened sensitivity to disgust with higher values for arousal and inability to cope, but not for valence. fMRI scans revealed no hyperactivity of the insula in patients compared to controls for the condition “Disgust vs. Neutral,” indicating no basic hypersensitivity to disgusting stimuli. Increased activity in the precuneus in controls for this condition might correspond to the downregulation of arousal.Conclusions: The absent differences in neural activity of the insula in patients compared to controls for the disgust-condition, but heightened activity for symptom-provoking conditions, suggests that the illness is due to an erroneous recruitment of the insula cortex for OCD-stimuli. The finding is interpreted within the framework of the neural reuse hypothesis

Current Developmental Disorders Reports / The importance of the left occipitotemporal cortex in developmental dyslexia

Purpose of Review: Developmental dyslexia is characterized by an impaired acquisition of fluent and skilled reading ability. Numerous studies have explored the neural correlates of this neurodevelopmental disorder, with most classic accounts strongly focussing on left temporoparietal regions. We will review recent findings from structural and functional MRI studies that suggest a more important role of occipitotemporal cortex abnormalities in dyslexia. Recent Findings: Recent findings highlight the role of the occipitotemporal cortex which exhibits functional as well as structural abnormalities in dyslexic readers and in children at risk for dyslexia and suggest a more central role for the occipitotemporal cortex in the pathophysiology of dyslexia. Summary: We demonstrate the importance of the occipitotemporal cortex in for understanding impaired reading acquisition and point out how future research might enhance our understanding of functional and structural impairments in the reading network via large-scale data analysis approaches.(VLID)249243

Schizophrenia and Category-Selectivity in the Brain: Normal for Faces but Abnormal for Houses

Face processing is regularly found to be impaired in schizophrenia (SZ), thus suggesting that social malfunctioning might be caused by dysfunctional face processing. Most studies focused on emotional face processes, whereas non-emotional face processing received less attention. While current reports on abnormal face processing in SZ are mixed, examinations of non-emotional face processing compared to adequate control stimuli may clarify whether SZ is characterized by a face-processing deficit. Patients with SZ (n = 28) and healthy controls (n = 30) engaged in an fMRI scan where images of non-emotional faces and houses were presented. A simple inverted-picture detection task warranted the participants’ attention. Region of interest (ROI) analyses were conducted on face-sensitive regions including the fusiform face area, the occipital face area, and the superior temporal sulcus. Scene-sensitivity was assessed in the parahippocampal place area (PPA) and served as control condition. Patients did not show aberrant face-related neural processes in face-sensitive regions. This finding was also evident when analyses were done on individually defined ROIs or on in-house-localizer ROIs. Patients revealed a decreased specificity toward house stimuli as reflected in decreased neural response toward houses in the PPA. Again, this result was supported by supplementary analyses. Neural activation toward neutral faces was not found to be impaired in SZ, therefore speaking against an overall face-processing deficit. Aberrant activation in scene-sensitive PPA is also found in assessments of memory processes in SZ. It is up to future studies to show how impairments in PPA relate to functional outcome in SZ

Emotion recognition and social cognition in juvenile myoclonic epilepsy

Juvenile myoklonische Epilepsie (JME) ist die am häufigsten auftretende idiopathische generalisierte Epilepsie. Die Erkrankung beginnt typischerweise in der Pubertät und ist häufig mit sozialen Anpassungsstörungen und Verhaltensauffälligkeiten, frontalen Dysfunktionen gleichend, assoziiert. Aktuelle bildgebende Studien bei Patienten mit JME beschreiben eine Assoziation zwischen Beeinträchtigungen von Emotionen und Verhalten mit strukturellen und funktionellen Veränderungen im frontalen Kortex und Thalamus. Bei Patienten mit Beeinträchtigung der Emotionsverarbeitung bzw. -regulation (wie z.B. bei bipolarer Erkrankung) wurden außerdem Störungen zwischen dem Regelkreis des limbischen Systems und dem frontalen Kortex beschrieben. Bis dato gibt es bei Patienten mit JME keine bildgebenden und neuropsychologischen Untersuchungen hinsichtlich des limbischen Systems und der Emotionsverarbeitung. Ziel der Studie ist es daher, dies unter verschiedenen Aspekten mittels funktioneller und struktureller Methoden darzustellen und ein einheitliches, auf neurobiologischen Erkenntnissen basierendes Konzept zu etablieren. Die Ergebnisse dieser Studie können wesentlich zur Entwicklung von psychologischen und pharmakologischen Strategien bei Patienten mit JME beitragen und damit zu eineJuvenile myoclonic epilepsy (JME) is the most common idiopathic generalized epilepsy. Disease onset is typically in puberty and poor social adjustment and behavioral disturbances, which resemble frontal lobe dysfunction, are often observed. In recent advanced brain imaging studies on JME patients, emotional and behavioral problems have been associated to subtle structural and functional alterations mainly in frontal cortex and thalamus. There is emerging evidence that patients with abnormal emotion processing and regulation, such as those with bipolar disorder, show disrupted connectivity between limbic structures and frontal cortices. There are no neuroimaging or neuropsychological studies related to emotion processing in patients with JME with a focus on limbic structures. We aimed to address the problem of emotional disturbances and social adjustment in JME patients from multiple aspects through thorough functional and structural assessment, which would potentially enable elaboration of a unifying concept explaining neurobiological background of disturbances in emotional processing and social adjustment in JME patients. Results of this study may potentially enable the development of psychological and pharmacological interventional strategies for managing behavioral disturbances in patients with JME.(VLID)433756

Schizophrenia and category-selectivity in the brain : normal for faces but abnormal for houses.

Face processing is regularly found to be impaired in schizophrenia (SZ), thus suggesting that social malfunctioning might be caused by dysfunctional face processing. Most studies focused on emotional face processes, whereas non-emotional face processing received less attention. While current reports on abnormal face processing in SZ are mixed, examinations of non-emotional face processing compared to adequate control stimuli may clarify whether SZ is characterized by a face-processing deficit. Patients with SZ (n=28) and healthy controls (n=30) engaged in an fMRI scan where images of non-emotional faces and houses were presented. A simple inverted-picture detection task warranted the participants' attention. Region of interest (ROI) analyses were conducted on face-sensitive regions including the fusiform face area, the occipital face area, and the superior temporal sulcus. Scene-sensitivity was assessed in the parahippocampal place area (PPA) and served as control condition. Patients did not show aberrant face-related neural processes in face-sensitive regions. This finding was also evident when analyses were done on individually defined ROIs or on in-house-localizer ROIs. Patients revealed a decreased specificity toward house stimuli as reflected in decreased neural response toward houses in the PPA. Again, this result was supported by supplementary analyses. Neural activation toward neutral faces was not found to be impaired in SZ, therefore speaking against an overall face-processing deficit. Aberrant activation in scene-sensitive PPA is also found in assessments of memory processes in SZ. It is up to future studies to show how impairments in PPA relate to functional outcome in SZ.(VLID)250866

Erroneously Disgusted : fMRI Study Supports Disgust-Related Neural Reuse in Obsessive-Compulsive Disorder (OCD)

Objective: fMRI scans of patients with obsessive-compulsive disorder (OCD) consistently show a hyperactivity of the insular cortex, a region responsible for disgust-processing, when confronted with symptom-triggering stimuli. This asks for an investigation of the role of disgust and the insula in OCD patients. Methods: Seventeen inpatients with OCD and 17 healthy controls (HC) underwent fMRI scanning. Whole-brain contrasts were calculated for “Disgust vs. Neutral” for both groups, plus an analysis of variance (ANOVA) to assess the interaction between group and condition. Additionally, the emotional dimensions of valence and arousal, along with the ability to cope, were assessed by picture ratings. Results: The picture ratings confirmed the patients heightened sensitivity to disgust with higher values for arousal and inability to cope, but not for valence. fMRI scans revealed no hyperactivity of the insula in patients compared to controls for the condition “Disgust vs. Neutral,” indicating no basic hypersensitivity to disgusting stimuli. Increased activity in the precuneus in controls for this condition might correspond to the downregulation of arousal. Conclusions: The absent differences in neural activity of the insula in patients compared to controls for the disgust-condition, but heightened activity for symptom-provoking conditions, suggests that the illness is due to an erroneous recruitment of the insula cortex for OCD-stimuli. The finding is interpreted within the framework of the neural reuse hypothesis.(VLID)376886

Pathologically reduced neural flexibility recovers during psychotherapy of OCD patients

International audienceFlexibility is a key feature of psychological health, allowing the individual to dynamically adapt to changing environmental demands, which is impaired in many psychiatric disorders like obsessive-compulsive disorder (OCD). Adequately responding to varying demands requires the brain to switch between different patterns of neural activity, which are represented by different brain network configurations (functional connectivity patterns). Here, we operationalize neural flexibility as the dissimilarity between consecutive connectivity matrices of brain regions (jump length). In total, 132 fMRI scans were obtained from 17 patients that were scanned four to five times during inpatient psychotherapy, and from 17 controls that were scanned at comparable time intervals. Significant negative correlations were found between the jump lengths and the symptom severity scores of OCD, depression, anxiety, and stress, suggesting that high symptom severity corresponds to inflexible brain functioning. Further analyses revealed that impaired reconfiguration (pattern stability) of the brain seems to be more related to general psychiatric impairment rather than to specific symptoms, e.g., of OCD or depression. Importantly, the group × time interaction of a repeated measures ANOVA was significant, as well as the post-hoc paired t-tests of the patients (first vs. last scan). The results suggest that psychotherapy is able to significantly increase the neural flexibility of patients. We conclude that psychiatric symptoms like anxiety, stress, depression, and OCD are associated with an impaired adaptivity of the brain. In general, our results add to the growing evidence that dynamic functional connectivity captures meaningful properties of brain functioning