Investigation of neural correlates of faces and emotional expressions using magnetoencephalography

The recognition of faces and of facial expressions in an important evolutionary skill, and an integral part of social communication. It has been argued that the processing of faces is distinct from the processing of non-face stimuli and functional neuroimaging investigations have even found evidence of a distinction between the perception of faces and of emotional expressions. Structural and temporal correlates of face perception and facial affect have only been separately identified. Investigation neural dynamics of face perception per se as well as facial affect would allow the mapping of these in space, time and frequency specific domains. Participants were asked to perform face categorisation and emotional discrimination tasks and Magnetoencephalography (MEG) was used to measure the neurophysiology of face and facial emotion processing. SAM analysis techniques enable the investigation of spectral changes within specific time-windows and frequency bands, thus allowing the identification of stimulus specific regions of cortical power changes. Furthermore, MEG’s excellent temporal resolution allows for the detection of subtle changes associated with the processing of face and non-face stimuli and different emotional expressions. The data presented reveal that face perception is associated with spectral power changes within a distributed cortical network comprising occipito-temporal as well as parietal and frontal areas. For the perception of facial affect, spectral power changes were also observed within frontal and limbic areas including the parahippocampal gyrus and the amygdala. Analyses of temporal correlates also reveal a distinction between the processing of faces and facial affect. Face perception per se occurred at earlier latencies whereas the discrimination of facial expression occurred within a longer time-window. In addition, the processing of faces and facial affect was differentially associated with changes in cortical oscillatory power for alpha, beta and gamma frequencies. The perception of faces and facial affect is associated with distinct changes in cortical oscillatory activity that can be mapped to specific neural structures, specific time-windows and latencies as well as specific frequency bands. Therefore, the work presented in this thesis provides further insight into the sequential processing of faces and facial affect

An Investigation of first-year students’ and lecturers’ expectations of university education

Transition from school to university can cause concern for many students. One issue is the gap between students' prior expectations and the realities of university life, which can cause significant distress, poor academic performance and increased drop-out rates if not managed effectively. Research has shown several similarities in the expectations of staff and students in regards to which factors determine academic success, but there is also evidence of dissonance. For example, staff consider independent study and critical evaluation as key factors, whereas students view feedback on drafts of work and support from staff as being most important. The aim of the current study was to determine what expectations students hold when starting university education, and what expectations university lecturers have of students entering university. Lecturers (n = 20) and first year students (n = 77) completed a series of questionnaires concerning their expectations of learning in HE (staff and students) and their approach to teaching (staff). Results revealed that students have largely realistic expectations of university. For example, the majority expected to be in charge of their own study. Some unrealistic expectations were also evident, e.g., most expected that teaching would be the same at university as it had been at school. The expectation that lecturers would provide detailed notes varied as a function of student age. Lecturers reported modifying their expectations of students and adapting their teaching approach according to year of study. Information-transmission/teacher-focused style was more common when teaching 1st year students; a more concept-changing/student-focused approach tended to be used when teaching 2nd year students (and above). Lecturer's expectations of student engagement did not differ according to year. Less experienced lecturers reported more negative expectations of student engagement than did experienced lecturers. In line with previous work, we observed overlap in expectations of staff and students, but some clear differences to

Knospung-steuernde Gene in Hydra vulgaris: Ein evolutionsgeschichtlich alter FGFR kontrolliert die Knopsenablösung

Mittels eine Genexpressions-Screening wurde eine Fibroblasten-Wachstums-Faktor-Rezeptor(FGFR)-ähnliche Tyrosinkinase (Kringelchen)in Hydra vulgaris identifiziert.Das Hochdynamisch regulierte Expressionsmuster während der Knospung deutet darauf hin, dass Kringelchen eine wichtige Rolle bei der Vegetativen Fortpflanzung in Hydra spielt. Durch Behandlung mit SU5402, einen spezifischen Inhibitor für FGFR, und ducht Elektroporation von Antisense-Oligonukleotiden konnten verzweigte Polypen erzeugt werden. Das Ablösen der Knospe wurde verhindert. Das führte zu der Hypothese, dass Kringelchen essentiell ist für die korrekte Knospenablösung. Die Analyse von kringelchen-Expressionsmustern während der Regeneration von Kopf-und Fußstrukturen und der Entwicklung von Hydra aus Einzelzellaggregaten deuteten eine Beteiligung An der Achsenbildung hin. Die Identifikation eines FGF-ähnlichen Proteins bei Hydra legt die Vermutung nahe, dass Kringlechen an FGF-Liganden binden kann

Naming emotions in motion:Alexithymic traits impact the perception of implied motion in facial displays of affect

Something akin to motion perception occurs when actual motion is not present but implied. However, it is not known if the experience of implied motion occurs during the perception of static faces nor if the effect would vary for different facial expressions. To examine this, participants were presented with pairs of faces where successive expressions depicted either increasing emotional intensity or its diminution. Participants indicated if the second face in the pair was the same as, or different from, the first face shown. To measure general facial emotion recognition ability, the Ekman 60 faces test was administered. As individual differences in depression, anxiety, and alexithymia have been shown to influence face processing, we measured these factors using the Hospital Anxiety and Depression scale (HADS) and the Toronto Alexithymia scale (TAS-20). As expected, participants were more likely to endorse the second face as being a match to the first when its expression implied forward motion compared to backward motion. This effect was larger for happiness and fear and positively related to accuracy on the Ekman 60 faces task. The effect was not related to depression or anxiety but it was negatively related to scores on the difficulty identifying feelings subscale of the TAS-20, suggesting that individuals who have problems identifying their own and others' feelings experienced a reduction in implied motion. Observers process implied motion from some facial expressions of emotion but the experience is modified by the ability to recognize one's own feelings and those of others

Editorial: Case reports in neuroimaging and stimulation: [case report]

The brain, a remarkable and intricate system, plays a fundamental role in shaping our behavior, encompassing cognitive and emotional processes (1–3). Understanding its structural and functional organization has been greatly enhanced through the utilization of neuroimaging and brain stimulation techniques. These powerful tools not only provide insights into the complex workings of the brain but also hold promise as potential therapeutic interventions for mental disorders (4)

Thalamocortical connectivity in major depressive disorder

Background: Major Depressive Disorder (MDD) is highly prevalent and potentially devastating, with widespread aberrations in brain activity. Thalamocortical networks are a potential candidate marker for psychopathology in MDD, but have not yet been thoroughly investigated. Here we examined functional connectivity between major cortical areas and thalamus. Method: Resting-state fMRI from 54 MDD patients and 40 healthy controls were collected. The cortex was segmented into six regions of interest (ROIs) consisting of frontal, temporal, parietal, and occipital lobes and pre-central and post-central gyri. BOLD signal time courses were extracted from each ROI and correlated with voxels in thalamus, while removing signals from every other ROI. Results: Our main findings showed that MDD patients had predominantly increased connectivity between medial thalamus and temporal areas, and between medial thalamus and somatosensory areas. Furthermore, a positive correlation was found between thalamo-temporal connectivity and severity of symptoms. Limitations: Most of the patients in this study were not medication naïve and therefore we cannot rule out possible long-term effects of antidepressant use on the findings. Conclusion: The abnormal connectivity between thalamus and temporal, and thalamus and somatosensory regions may represent impaired cortico-thalamo-cortical modulation underlying emotional, and sensory disturbances in MDD. In the context of similar abnormalities in thalamocortical systems across major psychiatric disorders, thalamocortical dysconnectivity could be a reliable transdiagnostic marker

Hepatotoxic pyrrolizidine alkaloids induce DNA damage response in rat liver in a 28-day feeding study

Pyrrolizidine alkaloids (PA) are secondary plant metabolites that occur as food and feed contaminants. Acute and subacute PA poisoning can lead to severe liver damage in humans and animals, comprising liver pain, hepatomegaly and the development of ascites due to occlusion of the hepatic sinusoids (veno-occlusive disease). Chronic exposure to low levels of PA can induce liver cirrhosis and liver cancer. However, it is not well understood which transcriptional changes are induced by PA and whether all hepatotoxic PA, regardless of their structure, induce similar responses. Therefore, a 28-day subacute rat feeding study was performed with six structurally different PA heliotrine, echimidine, lasiocarpine, senecionine, senkirkine, and platyphylline, administered at not acutely toxic doses from 0.1 to 3.3 mg/kg body weight. This dose range is relevant for humans, since consumption of contaminated tea may result in doses of ~ 8 µg/kg in adults and cases of PA ingestion by contaminated food was reported for infants with doses up to 3 mg/kg body weight. ALT and AST were not increased in all treatment groups. Whole-genome microarray analyses revealed pronounced effects on gene expression in the high-dose treatment groups resulting in a set of 36 commonly regulated genes. However, platyphylline, the only 1,2-saturated and, therefore, presumably non-hepatotoxic PA, did not induce significant expression changes. Biological functions identified to be affected by high-dose treatments (3.3 mg/kg body weight) comprise cell-cycle regulation associated with DNA damage response. These functions were found to be affected by all analyzed 1,2-unsaturated PA.publishedVersio

Right orbitofrontal corticolimbic and left corticocortical white matter connectivity differentiate bipolar and unipolar depression

Objectives - The absence of pathophysiologically relevant diagnostic markers of bipolar disorder (BD) leads to its frequent misdiagnosis as unipolar depression (UD). We aimed to determine whether whole brain white matter connectivity differentiated BD from UD depression. Methods - We employed a three-way analysis of covariance, covarying for age, to examine whole brain fractional anisotropy (FA), and corresponding longitudinal and radial diffusivity, in currently depressed adults: 15 with BD-type I (mean age 36.3 years, SD 12.0 years), 16 with recurrent UD (mean age 32.3 years, SD 10.0 years), and 24 healthy control adults (HC) (mean age 29.5 years, SD 9.43 years). Depressed groups did not differ in depression severity, age of illness onset, and illness duration. Results - There was a main effect of group in left superior and inferior longitudinal fasciculi (SLF and ILF) (all F = 9.8; p = .05, corrected). Whole brain post hoc analyses (all t = 4.2; p = .05, corrected) revealed decreased FA in left SLF in BD, versus UD adults in inferior temporal cortex and, versus HC, in primary sensory cortex (associated with increased radial and decreased longitudinal diffusivity, respectively); and decreased FA in left ILF in UD adults versus HC. A main effect of group in right uncinate fasciculus (in orbitofrontal cortex) just failed to meet significance in all participants but was present in women. Post hoc analyses revealed decreased right uncinate fasciculus FA in all and in women, BD versus HC. Conclusions - White matter FA in left occipitotemporal and primary sensory regions supporting visuospatial and sensory processing differentiates BD from UD depression. Abnormally reduced FA in right fronto-temporal regions supporting mood regulation, might underlie predisposition to depression in BD. These measures might help differentiate pathophysiologic processes of BD versus UD depression

Elevated left and reduced right orbitomedial prefrontal fractional anisotropy in adults with bipolar disorder revealed by tract-based spatial statistics

Context - Diffusion tensor imaging (DTI) studies in adults with bipolar disorder (BD) indicate altered white matter (WM) in the orbitomedial prefrontal cortex (OMPFC), potentially underlying abnormal prefrontal corticolimbic connectivity and mood dysregulation in BD. Objective - To use tract-based spatial statistics (TBSS) to examine WM skeleton (ie, the most compact whole-brain WM) in subjects with BD vs healthy control subjects. Design - Cross-sectional, case-control, whole-brain DTI using TBSS. Setting - University research institute. Participants - Fifty-six individuals, 31 having a DSM-IV diagnosis of BD type I (mean age, 35.9 years [age range, 24-52 years]) and 25 controls (mean age, 29.5 years [age range, 19-52 years]). Main Outcome Measures - Fractional anisotropy (FA) longitudinal and radial diffusivities in subjects with BD vs controls (covarying for age) and their relationships with clinical and demographic variables. Results - Subjects with BD vs controls had significantly greater FA (t > 3.0, P = .05 corrected) in the left uncinate fasciculus (reduced radial diffusivity distally and increased longitudinal diffusivity centrally), left optic radiation (increased longitudinal diffusivity), and right anterothalamic radiation (no significant diffusivity change). Subjects with BD vs controls had significantly reduced FA (t > 3.0, P = .05 corrected) in the right uncinate fasciculus (greater radial diffusivity). Among subjects with BD, significant negative correlations (P < .01) were found between age and FA in bilateral uncinate fasciculi and in the right anterothalamic radiation, as well as between medication load and FA in the left optic radiation. Decreased FA (P < .01) was observed in the left optic radiation and in the right anterothalamic radiation among subjects with BD taking vs those not taking mood stabilizers, as well as in the left optic radiation among depressed vs remitted subjects with BD. Subjects having BD with vs without lifetime alcohol or other drug abuse had significantly decreased FA in the left uncinate fasciculus. Conclusions - To our knowledge, this is the first study to use TBSS to examine WM in subjects with BD. Subjects with BD vs controls showed greater WM FA in the left OMPFC that diminished with age and with alcohol or other drug abuse, as well as reduced WM FA in the right OMPFC. Mood stabilizers and depressed episode reduced WM FA in left-sided sensory visual processing regions among subjects with BD. Abnormal right vs left asymmetry in FA in OMPFC WM among subjects with BD, likely reflecting increased proportions of left-sided longitudinally aligned and right-sided obliquely aligned myelinated fibers, may represent a biologic mechanism for mood dysregulation in BD

Impaired sustained attention and executive dysfunction:bipolar disorder versus depression-specific markers of affective disorders

Objective - To identify neurocognitive measures that could be used as objective markers of bipolar disorder. Methods - We examined executive function, sustained attention and short-term memory as neurocognitive domains in 18 participants with bipolar disorder in euthymic state (Beuth), 14 in depressed state (Bdep), 20 with unipolar depression (Udep) and 28 healthy control participants (HC). We conducted four-group comparisons followed by relevant post hoc analyses. Results - Udep and Bdep, but not Beuth showed impaired executive function (p = 0.045 and p = 0.046, respectively). Both Bdep and Beuth, but not Udep, showed impaired sustained attention (p = 0.001 and p = 0.045, respectively). The four groups did not differ significantly on short-term memory. Impaired sustained attention and executive dysfunction were not associated with depression severity, duration of illness and age of illness onset. Only a small number of abnormal neurocognitive measures were associated with medication in Bdep and Beuth. Conclusion - Impaired sustained attention appears specific to bipolar disorder and present in both Beuth and Bdep; it may represent an objective marker of bipolar disorder. Executive dysfunction by contrast, appears to be present in Udep and Bdep and likely represents a marker of depression