Publications by authors named "Karsten Rauss"

Performing a motor response to a sensory stimulus creates a memory trace whose behavioral correlates are classically investigated in terms of repetition priming effects. Such stimulus-response learning entails two types of associations that are partly independent: (1) an association between the stimulus and the motor response and (2) an association between the stimulus and the classification task in which it is encountered. Here, we tested whether sleep supports long-lasting stimulus-response learning on a task requiring participants (1) for establishing stimulus-classification associations to classify presented objects along two different dimensions ("size" and "mechanical") and (2) as motor response (action) to respond with either the left or right index finger.

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The C1 event-related potential (ERP) captures the earliest stage of feedforward processing in the primary visual cortex (V1). An ongoing debate is whether top-down selective attention can modulate the C1. One side of the debate pointed out that null findings appear to outnumber positive findings; thus, selective attention does not seem to influence the C1.

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Attention helps us to select what is relevant from the enormous amounts of information taken up by our senses. However, it remains unclear just how early in sensory processing attentional selection can occur. Here, we investigated this question in healthy volunteers by assessing the effect of attentional load on the earliest component (C1) of the visual evoked potential (VEP).

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While norm-violating behavior in antisocial individuals has been widely studied, little is known about how these people react to unfair behavior directed towards them. Previous research yields inconclusive results with some evidence for rational and strategic behavior in antisocial individuals. Electrophysiological correlates as well as socio-contextual factors such as group affiliation that may inform decision making on fairness considerations have not been investigated in previous studies.

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Study Objectives: The brain appears to use internal models to successfully interact with its environment via active predictions of future events. Both internal models and the predictions derived from them are based on previous experience. However, it remains unclear how previously encoded information is maintained to support this function, especially in the visual domain.

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Visual perceptual learning refers to long-lasting performance improvements on a visual skill - an ability supported by plastic changes in early visual brain areas. Visual perceptual learning has been shown to be induced by training and to benefit from consolidation during sleep, presumably via the reactivation of learning-associated neuronal firing patterns. However, previous studies have almost exclusively relied on a single paradigm, the texture discrimination task, on which performance improvements may rely on higher-order rather than lower-level perceptual skills.

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Early visual processing is surprisingly flexible even in the adult brain. This flexibility involves both long-term structural plasticity and online adaptations conveyed by top-down feedback. Although this view is supported by rich evidence from both human behavioral studies and invasive electrophysiology in nonhuman models, it has proven difficult to close the gap between species.

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Sleep supports the consolidation of recently encoded declarative and procedural memories. An important component of this effect is the repeated reactivation of neuronal ensemble activity elicited during memory encoding. For perceptual learning, however, sleep benefits have only been reported for specific tasks and it is not clear whether sleep targets low-level perceptual, higher-order temporal or attentional aspects of performance.

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Predictive-coding theories assume that perception and action are based on internal models derived from previous experience. Such internal models require selection and consolidation to be stored over time. Sleep is known to support memory consolidation.

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The cognitive mechanisms of increased distractibility in attention-deficit/hyperactivity disorder (ADHD) are poorly understood. The current study investigated the influence of two major modulating factors (emotional saliency, task difficulty) on behavioral and electrophysiological parameters underlying distractibility in ADHD. In addition, the attentional focus (indirect and direct processing of distractors) was examined.

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Antisocial personality disorder is characterized by a stable, lifelong pattern of disregard for and violation of others' rights. Disruptions in the representation of fairness norms may represent a key mechanism in the development and maintenance of this disorder. Here, we investigated fairness norm considerations and reactions to their violations.

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Baumgartner and colleagues (this issue) report a replication of an ERP study by Kelly, Gomez-Ramirez, and Foxe (2008). Unlike the original authors, they failed to observe a significant modulation of the C1 by visuo-spatial attention. They conclude that initial afferent processing in V1 is impermeable to visuo-spatial attention.

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Reports of modulations of early visual processing suggest that retinotopic visual cortex may actively predict upcoming stimuli. We tested this idea by showing healthy human participants images of human faces at fixation, with different emotional expressions predicting stimuli in either the upper or the lower visual field. On infrequent test trials, emotional faces were followed by combined stimulation of upper and lower visual fields, thus violating previously established associations.

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Sleep benefits the consolidation of individual episodic memories. In the long run, however, it may be more efficient to retain the abstract gist of single, related memories, which can be generalized to similar instances in the future. While episodic memory is enhanced after one night of sleep, effective gist abstraction is thought to require multiple nights.

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Everyone knows what bottom-up is, and how it is different from top-down. At least one is tempted to think so, given that both terms are ubiquitously used, but only rarely defined in the psychology and neuroscience literature. In this review, we highlight the problems and limitations of our current understanding of bottom-up and top-down processes, and we propose a reformulation of this distinction in terms of predictive coding.

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The cognitive appraisal of an event is crucial for the elicitation and differentiation of emotions, and causal attributions are an integral part of this process. In an interdisciplinary project comparing Tonga and Germany, we examined how cultural differences in attribution tendencies affect emotion assessment and elicitation. Data on appraising causality and responsibility and on emotional responses were collected through questionnaires based on experimentally designed vignettes, and were related to culture-specific values, norms, and the prevailing self-concept.

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Previous studies have shown that healthy participants learn to control local brain activity with operant training by using real-time functional magnetic resonance imaging (rt-fMRI). Very little data exist, however, on the dynamics of interaction between critical brain regions during rt-fMRI-based training. Here, we examined self-regulation of stimulus-elicited insula activation and performed a psychophysiological interaction (PPI) analysis of real-time self-regulation data.

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A growing number of studies suggest that early visual processing is not only affected by low-level perceptual attributes but also by higher order cognitive factors such as attention or emotion. Using high-density electroencephalography, we recently demonstrated that attentional load of a task at fixation reduces the response of primary visual cortex to irrelevant peripheral stimuli, as indexed by the C1 component. In the latter study, peripheral stimuli were always presented during intervals without task-relevant stimuli.

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An increasing number of human electroencephalography (EEG) studies examining the earliest component of the visual evoked potential, the so-called C1, have cast doubts on the previously prevalent notion that this component is impermeable to top-down effects. This article reviews the original studies that (i) described the C1, (ii) linked it to primary visual cortex (V1) activity, and (iii) suggested that its electrophysiological characteristics are exclusively determined by low-level stimulus attributes, particularly the spatial position of the stimulus within the visual field. We then describe conflicting evidence from animal studies and human neuroimaging experiments and provide an overview of recent EEG and magnetoencephalography (MEG) work showing that initial V1 activity in humans may be strongly modulated by higher-level cognitive factors.

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Recent theories of selective attention assume that the more attention is required by a task, the earlier are irrelevant stimuli filtered during perceptual processing. Previous functional MRI studies have demonstrated that primary visual cortex (V1) activation by peripheral distractors is reduced by higher task difficulty at fixation, but it remains unknown whether such changes affect initial processing in V1 or subsequent feedback. Here we manipulated attentional load at fixation while recording peripheral visual responses with high-density EEG in 28 healthy volunteers, which allowed us to track the exact time course of attention-related effects on V1.

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Psychophysical and neuroimaging studies suggest that perceptual learning may affect activity in primary visual cortex (V1). Yet, it remains unclear whether such changes involve intrinsic V1 plasticity or feedback from later processing stages. Here we recorded high-density electro-encephalography in 24 volunteers, 24-h after training on a visual texture discrimination task in the upper or lower visual-field.

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