Frauke Musial

Interpretive bias in social phobia : An ERP study with morphed emotional schematic faces

Individuals with social phobia fear negative evaluation, which is most directly signalled by an angry expression of the interlocutors face. This study investigated the processing of 3 series of schematic emotional faces, which were morphed in 7 steps from a neutral face to an angry, happy, or sad face by systematically varying features of the mouth, eyes, and eyebrows. Individuals with social phobia or spider phobia rated angry faces as more arousing than controls. Social phobics did not identify angry faces faster and showed no greater latent trait to identify a face as angry than controls. ERP data showed a modulation of the face-specific N170 by facial emotion, although this did not discriminate social phobics from controls. Instead, phobic subjects exhibited generally increased visual P1 amplitudes, suggesting a state of hypervigilance for incoming stimuli. Results are discussed in the context of psychophysiological abnormalities in the anxiety disorder spectrum.

Event-related potentials to schematic faces in social phobia

Social phobia has been associated with an attentional bias for angry faces. This study aimed at further characterising this attentional bias by investigating reaction times, heart rates, and ERPs while social phobics, spider phobics, and controls identified either the colour or the emotional quality of angry, happy, or neutral schematic faces. The emotional expression of angry faces did not interfere with the processing of their colour in social phobics, and heart rate, N170 amplitude and parietal late positive potentials (LPPs) of these subjects were also no different from those of non-phobic subjects. However, social phobics showed generally larger P1 amplitudes than non-phobic controls with spider phobic subjects in between. No general threat advantage for angry faces was found. All groups identified neutral schematic faces faster and showed larger late positive amplitudes to neutral than to emotional faces. Furthermore, in all groups the N170 was modulated by the emotional quality of faces. This effect was most pronounced in the emotion identification task.

Event-related potentials when identifying or color-naming threatening schematic stimuli in spider phobic and non-phobic individuals

BackgroundPrevious studies revealed increased parietal late positive potentials (LPPs) in response to spider pictures in spider phobic individuals. This study searched for basic features of fear-relevant stimuli by investigating whether schematic spider images are sufficient to evoke differential behavioral as well as differential early and late ERP responses in spider phobic, social phobic (as a clinical control group), and non-phobic control participants.MethodsBehavioral and electrophysiological correlates of the processing of schematic spider and flower images were investigated while participants performed a color (emotional Stroop) and an object identification task. Stimuli were schematic pictures of spiders and flowers matched with respect to constituting visual elements.ResultsConsistent with previous studies using photographic spider pictures, spider phobic persons showed enhanced LPPs when identifying schematic spiders compared to schematic flowers. In addition, spider phobic individuals showed generally faster responses than the control groups. This effect was interpreted as evidence for an increased general behavioral hypervigilance in this anxiety disorder group. Furthermore, both phobic groups showed enhanced P100 amplitudes compared to controls, which was interpreted as evidence for an increased (cortical) hypervigilance for incoming stimuli in phobic patients in general. Finally, all groups showed faster identification of and larger N170 amplitudes in response to schematic spider than flower pictures. This may reflect either a general advantage for fear-relevant compared to neutral stimuli, or might be due to a higher level of expertise in processing schematic spiders as compared to the more artificially looking flower stimuli.ConclusionResults suggest that schematic spiders are sufficient to prompt differential responses in spider-fearful and spider-non-fearful persons in late ERP components. Early ERP components, on the other hand, seem to be modified by anxiety status per se, which is consistent with recent theories on general hypervigilance in the anxiety disorder spectrum.

A Robust Measurement of Correlation in Dependent Time Series

A special problem in behavioral sciences are time series where the data points of one series are dependent on the just prior values of the other series. The data structure may additionally exhibit an interdependence between the variables that changes over time. Pfanzagls T provides a robust test of trend independence between such data sets. At the same time the applicability of Pearsons r can be extended by using the statistical considerations for T. For this purpose, the time series are transformed into binary series, consisting either of the values 1 or 0. These series may show distinct trend patterns of consecutive data points with the value 1 or with the value 0. Data points belonging to the same trend pattern are regarded as cohering values for any further mathematical operation applied. Based on the trend identifcation the T-value is derived, providing information on the coherent development of trend patterns in the two series. Additionally Pearsons r together with a modified sampling theory offers a standard measure of linear association between the time series. The procedures are described and a computer program is provided, combining Pfanzagls T and Pearsons r with a bootstrap procedure for the statistical evaluation of the correlation coefficients.

Psychophysiologie des Eingeweideschmerzes

ZusammenfassungIn der vorliegenden Übersichtsarbeit werden die einflussreichsten Ansätze zur Psychophysiologie des Eingeweideschmerzes dargestellt und im Zusammenhang mit den wichtigsten Untersuchungsmethoden diskutiert. Im einzelnen wird ein Überblick über die wesentlichsten Befunde zur Motilitätshypothese, zur viszeralen Hypersensibilitätshypothese, sowie über Untersuchungen zur zentralnervösen Reizverarbeitung bei Patienten mit funktionellen Darmerkrankungen gegeben. Insgesamt ergibt sich ein, auch aus psychophysiologischer Sicht, komplexes Störungsbild, an dessen Entstehung gestörte Stressverarbeitungsmechanismen ebenso wahrscheinlich beteiligt sein können wie peripher-physiologische Pathomechanismen oder zentralnervöse Prozesse der Aufmerksamkeitslenkung.AbstractThis paper reviews the most important research strategies in the context of the psychophysiology of visceral pain.These are disturbed gastrointestinal motility, visceral hypersensitivity and central nervous system mechanisms such as response bias, attentional bias and affective evaluation.The most prominent research methods and results are reviewed and methodological problems are discussed.From a psychophysiological perspective, visceral pain remains a complex and heterogeneous syndrome in which stress and coping may be etiologically as important as pathophysiological mechanisms of peripheral origin and central nervous system mechanisms like attentional bias.

A case of spider phobia in a congenitally blind person

Vision is the key sensory system in humans, leading to the implicit assumption that the acquisition of spider phobia is predominantly mediated through the visual pathway. We report on a congenitally blind person with spider phobia, showing that the acquisition of spider phobia does not necessarily depend on visual cues.