The impact of perfectionism and anxiety traits on action monitoring in major depressive disorder

Perfectionism and anxiety features are involved in the clinical presentation and neurobiology of major depressive disorder (MDD). In MDD, cognitive control mechanisms such as action monitoring can adequately be investigated applying electrophysiological registrations of the error-related negativity (ERN) and error positivity (Pe). It is also known that traits of perfectionism and anxiety influence ERN amplitudes in healthy subjects. The current study explores the impact of perfectionism and anxiety traits on action monitoring in MDD. A total of 39 MDD patients performed a flankers task during an event-related potential (ERP) session and completed the multidimensional perfectionism scale (MPS) with its concern over mistakes (CM) and doubt about actions (DA) subscales and the trait form of the State Trait Anxiety Inventory. Multiple regression analyses with stepwise backward elimination revealed MPS-DA to be a significant predictor (R2:0.22) for the ERN outcomes, and overall MPS (R2:0.13) and MPS-CM scores (R2:0.18) to have significant predictive value for the Pe amplitudes. Anxiety traits did not have a predictive capacity for the ERPs. MPS-DA clearly affected the ERN, and overall MPS and MPS-CM influenced the Pe, whereas no predictive capacity was found for anxiety traits. The manifest impact of perfectionism on patients’ error-related ERPs may contribute to our understanding of the action-monitoring process and the functional significance of the Pe in MDD. The divergent findings for perfectionism and anxiety features also indicate that the wide range of various affective personality styles might exert a different effect on action monitoring in MDD, awaiting further investigation

Controlling the stereochemistry and regularity of butanethiol self-assembled monolayers on Au(111)

© 2014 American Chemical Society. The rich stereochemistry of the self-assembled monolayers (SAMs) of four butanethiols on Au(111) is described, the SAMs containing up to 12 individual C, S, or Au chiral centers per surface unit cell. This is facilitated by synthesis of enantiomerically pure 2-butanethiol (the smallest unsubstituted chiral alkanethiol), followed by in situ scanning tunneling microscopy (STM) imaging combined with density functional theory molecular dynamics STM image simulations. Even though butanethiol SAMs manifest strong headgroup interactions, steric interactions are shown to dominate SAM structure and chirality. Indeed, steric interactions are shown to dictate the nature of the headgroup itself, whether it takes on the adatom-bound motif RS•Au(0)S•R or involves direct binding of RS• to face-centered-cubic or hexagonal-close-packed sites. Binding as RS• produces large, organizationally chiral domains even when R is achiral, while adatom binding leads to rectangular plane groups that suppress long-range expression of chirality. Binding as RS• also inhibits the pitting intrinsically associated with adatom binding, desirably producing more regularly structured SAMs

A cognitive neuropsychiatric analysis of psychomotor symptoms in major depression and schizophrenia

Contains fulltext : 90469.pdf (publisher's version ) (Closed access)A cognitive neuropsychiatric analysis will be proposed by presenting recent research on -1-motor control, and -2-action monitoring in two psychiatric disorders i.e. major depression and schizophrenia. Motor control is best studied from the broader cognitive neuropsychological perspective of action control. Even very simple actions implicate quite diverse brain activities reflecting the cognitive processes of planning, selection, visuomotor integration, timing, force adjustment, and action monitoring. The extent to which deficits in these cognitive processes cause slowed or stereotypic actions can be experimentally studied in clinical settings by means of graphic tasks, as will be illustrated. A central process in motor/action control is error monitoring. The last decade research on this higher cognitive control process has been booming, also because the detection of errors is accompanied by a clear peak in the EEG, known as the error-related negativity (ERN). Deficient error monitoring has been observed in several psychiatric disorders. ERN studies in major depression and schizophrenia will be discussed. Psychiatric disorders can best be understood by considering three perspectives, i.e. psychopathology, cognitive neuropsychology and neuroscience. The findings support the view that cognitive neuropsychiatry should involve the combined study of psychiatric symptoms, cognitive dimensions and neurological structures

Study of fiber waviness in composite structures supported by simulation

n/