Biological Markers for Attentional Bias in Social Anxiety and its Modification

Diese Dissertationsschrift beschäftigt sich mit biologischen Korrelaten von Aufmerksamkeits-verzerrungen und eruiert deren Modifikation in einem längsschnittlich angelegten Experiment. Hierfür wurden über 100 sozial-ängstliche Teilnehmer mit Hilfe einer Screening-Prozedur gewonnen und hinsichtlich der Ausprägung einer ereigniskorrelierten Lateralisation namens „N2pc“ untersucht. Während der ersten Labormessung indizierte die N2pc bei der Bearbeitung eines Dot Probe Paradigmas einen mittelgroßen, statistisch hochbedeutsamen Attentional Bias hin zu wütenden Gesichtern im Vergleich zu neutralen. Das hierfür klassischerweise verwendete Maß von Reaktionszeitunterschieden hingegen konnte diese Verzerrung der Aufmerksamkeit nicht abbilden. Ferner zeigten weder die elektrophysiologische noch die behaviorale Messgröße einen Zusammenhang mit Fragebögen sozialer Angst, was teilweise auf ein Fehlen interner Konsistenz zurückgeführt werden kann. Im weiteren Verlauf absolvierten die überwiegend weiblichen Teilnehmer an acht unterschiedlichen Terminen über zwei bis vier Wochen fast 7000 Durchgänge eines Aufmerksamkeitsverzerrungsmodifikationstrainings oder einer aktiven Kontrollprozedur. Daraufhin zeigte sich eine Auslöschung der ereigniskorrelierten Lateralisation, allerdings in einem späteren Zeitfenster als erwartet. Dieses Verschwinden des Attentional Bias blieb bis elf Wochen nach Ende der Trainingsprozedur stabil. Außerdem trat dieselbe Modifikation ebenfalls für die Kontrollgruppe auf. Die selbstberichtete Schwere der Symptomausprägung veränderte sich zwar nicht, allerdings konnte eine Reduktion des Persönlichkeitsmerkmals Neurotizismus verzeichnet werden, welches konzeptuell mit dem Begriff der Ängstlichkeit eng verwoben ist. Durch explorative Folgeanalysen konnte eine stärkere Modulation der rechten Großhirnhälfte, also durch Reize im linken visuellen Halbfeld aufgedeckt werden. Eine Neuberechnung des Attentional Bias separat für jede Hemisphäre scheint daher auch für künftige Untersuchungen angebracht. Ferner wurde als Träger der Modifikation über die Zeit eine Veränderung der Hyperpolarisation nach der N2-Komponente identifiziert. Ob durch eine Anpassung der Prozedur eine Modulation einer früheren ereigniskorrelierten Komponente erzielt werden kann, bleibt zum aktuellen Zeitpunkt unbeantwortet.This dissertation is concerned with biological correlates of attentional biases and investigates their modification within a longitudinal experiment. For this purpose, more than 100 socially anxious participants were recruited with the aid of on online screening procedure. These individuals were examined with respect to the occurrence of an event-related lateralization called “N2pc”. During the first experimental session, the N2pc indexed a highly significant attentional bias of medium size toward angry compared to neutral faces within a Dot Probe paradigm. In contrast, reaction time differences, which are typically utilized for this purpose, could not represent this distortion of attention. Moreover, neither electrophysiological nor behavioral measures were related to questionnaires of social anxiety which in part can be attributed to a lack of internal consistency. In the further process, the predominantly female participants completed close to 7000 trials of an attentional bias modification training or of an active control procedure on eight different days within a period of two to four weeks. Thereupon, the event-related lateralization was extinguished, albeit during a later time window than expected. This disappearance of an attentional bias remained stable until eleven weeks after completion of the training procedure. This very modification also occurred within the control procedure. While extent of self-reported symptoms did not change, a reduction of the personality trait neuroticism could be observed which is closely tied to the concept of anxiety. By means of explorative follow-up analyses, an exaggerated modulation of the right cerebral hemisphere, i.e. by stimuli in the left visual hemifield could be unveiled. A recalculation of the attentional bias score separately for each hemisphere seemed appropriate also for future investigations. Furthermore, a shift in hyperpolarization after the N2 component has been identified as the carrier of this modification. Whether adjusting the procedure will allow for earlier modulations of event-related components remains unanswered for now

Attentional bias modification in social anxiety: Effects on the N2pc component

Several meta-analyses to date have confirmed the efficacy of attentional bias modification (ABM) in shifting reaction times away from threatening stimuli, reducing anxiety symptoms, and buffering against stressor vulnerability. The reliability of reaction time differences, however, has been found to show unacceptable psychometric properties. In this study, we tested the impact of an extensive Dot-Probe ABM procedure, consisting of close to 7000 trials, concurrently with behavioral and electrophysiological measures within a large sample of over 100 highly socially anxious participants. Results indicated that the N2pc component demonstrates superior internal consistency and more statistical power in detecting attentional biases and their modification than reaction time (RT) differences. RTs were neither indicative of an attentional bias before ABM nor of a modification over time. In contrast, the N2pc indexed both an initial attentional preference for threatening stimuli and an alteration of this relationship after training. Outcomes were not specific for attentional training away from threat but also occurred in the no-contingency control procedure, casting doubt on the theoretic underpinnings of ABM. Electrophysiological measures are an important complement to the ABM literature and should be further utilized to assess attentional biases with excellent reliability

Enhancing precision in human neuroscience

Human neuroscience has always been pushing the boundary of what is measurable. During the last decade, concerns about statistical power and replicability – in science in general, but also specifically in human neuroscience – have fueled an extensive debate. One important insight from this discourse is the need for larger samples, which naturally increases statistical power. An alternative is to increase the precision of measurements, which is the focus of this review. This option is often overlooked, even though statistical power benefits from increasing precision as much as from increasing sample size. Nonetheless, precision has always been at the heart of good scientific practice in human neuroscience, with researchers relying on lab traditions or rules of thumb to ensure sufficient precision for their studies. In this review, we encourage a more systematic approach to precision. We start by introducing measurement precision and its importance for well-powered studies in human neuroscience. Then, determinants for precision in a range of neuroscientific methods (MRI, M/EEG, EDA, Eye-Tracking, and Endocrinology) are elaborated. We end by discussing how a more systematic evaluation of precision and the application of respective insights can lead to an increase in reproducibility in human neuroscience

It's costly punishment, not altruistic: Low midfrontal theta and state anger predict punishment

Punishment in economic games has been interpreted as “altruistic.” However, it was shown that punishment is related to trait anger instead of trait altruism in a third‐party dictator game if compensation is also available. Here, we investigated the influence of state anger on punishment and compensation in the third‐party dictator game. Therefore, we used movie sequences for emotional priming, including the target states anger, happy, and neutral. We measured the Feedback‐Related Negativity (FRN) and midfrontal theta band activation, to investigate an electro‐cortical correlate of the processing of fair and unfair offers. Also, we assessed single‐trial FRN and midfrontal theta band activation as a predictor for punishment and compensation. We found that punishment was linked to state anger. Midfrontal theta band activation, which has previously been linked to altruistic acts and cognitive control, predicted less punishment. Additionally, trait anger led to enhanced FRN for unfair offers. This led to the interpretation that the FRN depicts the evaluation of fairness, while midfrontal theta band activation captures an aspect of cognitive control and altruistic motivation. We conclude that we need to redefine “altruistic punishment” into “costly punishment,” as no direct link of altruism and punishment is given. Additionally, midfrontal theta band activation complements the FRN and offers additional insights into complex responses and decision processes, especially as a single trial predictor.

Low midfrontal theta and state anger predict punishment

Punishment in economic games has been interpreted as “altruistic.” However, it was shown that punishment is related to trait anger instead of trait altruism in a third‐party dictator game if compensation is also available. Here, we investigated the influence of state anger on punishment and compensation in the third‐party dictator game. Therefore, we used movie sequences for emotional priming, including the target states anger, happy, and neutral. We measured the Feedback‐Related Negativity (FRN) and midfrontal theta band activation, to investigate an electro‐cortical correlate of the processing of fair and unfair offers. Also, we assessed single‐trial FRN and midfrontal theta band activation as a predictor for punishment and compensation. We found that punishment was linked to state anger. Midfrontal theta band activation, which has previously been linked to altruistic acts and cognitive control, predicted less punishment. Additionally, trait anger led to enhanced FRN for unfair offers. This led to the interpretation that the FRN depicts the evaluation of fairness, while midfrontal theta band activation captures an aspect of cognitive control and altruistic motivation. We conclude that we need to redefine “altruistic punishment” into “costly punishment,” as no direct link of altruism and punishment is given. Additionally, midfrontal theta band activation complements the FRN and offers additional insights into complex responses and decision processes, especially as a single trial predictor