Distractor inhibition: Evidence from lateralized readiness potentials

The present study investigated distractor inhibition on the level of stimulus representation. In a sequential distractor-to-distractor priming task participants had to respond to target letters flanked by distractor digits. Reaction time and stimulus-locked lateralized readiness potentials (S-LRPs) of probe responses were measured. Distractor-target onset asynchrony was varied. For RTs responses to probe targets were faster in the case of prime-distractor repetition compared to distractor changes indicating distractor inhibition. Benefits in RTs and the latency of S-LRP onsets for distractor repetition were also modulated by distractor-target onset asynchrony. For S-LRPs distractor inhibition was only present with a simultaneous onset of distractors and target. The results confirm previous results indicating inhibitory mechanisms of object-based selective attention on the level of distractor representations

The relationship between basal and acute HPA axis activity and aggressive behavior in adults

The hypothalamic–pituitary–adrenal (HPA) axis seems to play a major role in the development, elicitation, and enhancement of aggressive behavior in animals. Increasing evidence suggests that this is also true for humans. However, most human research on the role of the HPA axis in aggression has been focusing on highly aggressive children and adolescent clinical samples. Here, we report on a study of the role of basal and acute HPA axis activity in a sample of 20 healthy male and female adults. We used the Taylor Aggression Paradigm to induce and measure aggression. We assessed the cortisol awakening response as a trait measure of basal HPA axis activity. Salivary free cortisol measures for the cortisol awakening response were obtained on three consecutive weekdays immediately following awakening and 30, 45, and 60 min after. Half of the subjects were provoked with the Taylor Aggression Paradigm to behave aggressively; the other half was not provoked. Acute HPA axis activity was measured four times, once before and three times after the induction of aggression. Basal cortisol levels were significantly and negatively related to aggressive behavior in the provoked group and explained 67% of the behavioral variance. Cortisol levels following the induction of aggression were significantly higher in the provoked group when baseline levels were taken into account. The data implicate that the HPA axis is not only relevant to the expression of aggressive behavior in clinical groups, but also to a large extent in healthy ones

EUREC⁴A

The science guiding the EUREC⁴A campaign and its measurements is presented. EUREC⁴A comprised roughly 5 weeks of measurements in the downstream winter trades of the North Atlantic – eastward and southeastward of Barbados. Through its ability to characterize processes operating across a wide range of scales, EUREC⁴A marked a turning point in our ability to observationally study factors influencing clouds in the trades, how they will respond to warming, and their link to other components of the earth system, such as upper-ocean processes or the life cycle of particulate matter. This characterization was made possible by thousands (2500) of sondes distributed to measure circulations on meso- (200 km) and larger (500 km) scales, roughly 400 h of flight time by four heavily instrumented research aircraft; four global-class research vessels; an advanced ground-based cloud observatory; scores of autonomous observing platforms operating in the upper ocean (nearly 10 000 profiles), lower atmosphere (continuous profiling), and along the air–sea interface; a network of water stable isotopologue measurements; targeted tasking of satellite remote sensing; and modeling with a new generation of weather and climate models. In addition to providing an outline of the novel measurements and their composition into a unified and coordinated campaign, the six distinct scientific facets that EUREC⁴A explored – from North Brazil Current rings to turbulence-induced clustering of cloud droplets and its influence on warm-rain formation – are presented along with an overview of EUREC⁴A's outreach activities, environmental impact, and guidelines for scientific practice. Track data for all platforms are standardized and accessible at https://doi.org/10.25326/165 (Stevens, 2021), and a film documenting the campaign is provided as a video supplement

EUREC⁴A

The science guiding the EUREC⁴A campaign and its measurements is presented. EUREC⁴A comprised roughly 5 weeks of measurements in the downstream winter trades of the North Atlantic – eastward and southeastward of Barbados. Through its ability to characterize processes operating across a wide range of scales, EUREC⁴A marked a turning point in our ability to observationally study factors influencing clouds in the trades, how they will respond to warming, and their link to other components of the earth system, such as upper-ocean processes or the life cycle of particulate matter. This characterization was made possible by thousands (2500) of sondes distributed to measure circulations on meso- (200 km) and larger (500 km) scales, roughly 400 h of flight time by four heavily instrumented research aircraft; four global-class research vessels; an advanced ground-based cloud observatory; scores of autonomous observing platforms operating in the upper ocean (nearly 10 000 profiles), lower atmosphere (continuous profiling), and along the air–sea interface; a network of water stable isotopologue measurements; targeted tasking of satellite remote sensing; and modeling with a new generation of weather and climate models. In addition to providing an outline of the novel measurements and their composition into a unified and coordinated campaign, the six distinct scientific facets that EUREC⁴A explored – from North Brazil Current rings to turbulence-induced clustering of cloud droplets and its influence on warm-rain formation – are presented along with an overview of EUREC⁴A's outreach activities, environmental impact, and guidelines for scientific practice. Track data for all platforms are standardized and accessible at https://doi.org/10.25326/165 (Stevens, 2021), and a film documenting the campaign is provided as a video supplement

Impact of Stress and Provocation on the processing of emotional pictures

Research has shown that the stress hormone cortisol is important for the regulation of social motivational processes. Besides, aggression is a common behavior which is frequently involved in changes in higher level information processing patterns. However, the influence of the interaction between both on information processing has been hardly examined, even though there is some evidence that cortisol plays a crucial role in the attention to social threat and release of aggressive behavior. Thus, the aim of the present study was to access the effect of acute stress, the thereby caused cortisol release and provocation on affective picture processing. 71 healthy subjects were subjected to the socially evaluated cold pressor test or warm pressor test (control condition). Half of each group received high or low levels of provocation during the Taylor Aggression Paradigm. Afterwards, 144 emotional pictures with positive, negative or aggressive content were presented. Throughout the experiment EEG was recorded and acute levels of salivary cortisol were collected. Established effects within the event-related potentials depending on the presented emotion could be replicated. Moreover, preliminary results indicate that event-related earlier (N2, P2), as well as later components (P3, slow waves) are complexly influenced by endogenous cortisol and provocation, suggesting an effect on various stages of socially relevant information processing of stimuli

Akuter Stress führt zu einer veränderten Verarbeitung von provozierenden Stimuli im Taylor-Aggressions-Paradigma – eine EKP Studie

Befunde aus tier- und humanexperimentelle Studien zeigen, dass Stress ein wesentlicher Faktor in der Ausl ̈osung und Aufrechterhal- tung von aggressivem Verhalten ist. So beeinflusst Stress und Cor- tisol unter anderem die Verarbeitung von bedrohlichen Stimuli, wie z.B. w ̈utenden Gesichtern. Der Einfluss von Stress und Cortisol auf die Verarbeitung aggressionsausl ̈osender Stimuli w ̈ahrend eines ag- gressiven Encounters wurde bisher noch nicht erforscht. Um dies zu untersuchen, durchliefen in der vorliegenden Studie 71 gesunde Pro- banden (36 m, 35 w) zun ̈achst eine Stressprozedur (sozial evalua- tive Kaltwasser Stresstest) bzw. ein Warmwasser-Kontrollprozedur. Anschließend wurde die H ̈alfte jeder Gruppe im Taylor Aggressions- Paradigma provoziert. W ̈ahrend des Experiments wurde das EEG aufgezeichnet und mehrere Speichelproben zur Cortisolanalyse ge- nommen, auf deren Grundlage Probanden der Kaltwassergruppe in Cortisol-Responder und –Nonresponder unterteilt wurden. Die Aus- wertung von Ereigniskorrelierten Potentialen (EKPs) bez ̈uglich des provozierenden Stimulus ergab, dass provozierte Probanden eine po- sitivere frontozentrale P3 zeigten als nicht provozierte. W ̈ahrend stressinduzierter Cortisolanstieg diesen Effekt bei Frauen verst ̈arkte, zeigten provozierte m ̈annliche Cortisol-Responder reduzierte P3 Am- plituden. Diese Befunde zeigen eine neurophysiologische Assoziation zwischen Stress und Aggression bezüglich der Verarbeitung von ag- gressionsausl ̈osenden Signalen, was wesentlich für die Eskalation von aggressivem Verhalten sein könnte

Stress and Aggression – The influence of stress on processing of provoking stimuli during a retaliation paradigm- an ERP study

Many studies suggest a vicious circle between stress and aggression. But its physiological basis is not fully understood. Trait aggression and externalizing behavior are characterized by reduced P3 waves in Event Related Potentials (ERP). Stress affects the processing of aggression related stimuli. Moreover, the stress hormone cortisol enhances the attention to social threat and the propensity for aggression. The aim of the present study was to asses the effect of acute stress and the concomitant cortisol release on the processing of provoking stimuli during an aggressive encounter using the Taylor Aggression Paradigm (TAP). 71 healthy participants (36 men) were subjected to the socially evaluated cold pressor test as an experimental stressor or to a warm pressor test (control condition). Half of each group received high or low levels of provocation in the TAP. Throughout the experiment EEG was recorded, and salivary cortisol was collected. Stressed participants were divided into cortisol-responders and –non responders. Event-related potentials during provoking stimuli revealed that highly provoked participants had a more positive P3 amplitude (fronto-central) compared to hardly provoked participants, replicating previous findings. Increased cortisol combined with provocation led to a reduced P3 amplitude and reduced late positive potentials in cortisol-responders. The results suggest that an interaction between stressor-induced cortisol and provocation affects the processing of conflict signals and contributes to a vicious cycle between stress and aggression

visual block by hypnotic suggestion

Hypnotherapie nutzt Trance und Suggestion im therapeu- tischen Kontext erfolgreich und mit empirisch belegter Wirksamkeit, z.B. zur Therapie von Süchten, Belastungsstörungen und Schmerzen. Allerdings existieren kaum ex- perimentell gesicherte Erkenntnisse über die neurobiolo- gischen Mechanismen des Trancezustandes. Noch weniger ist bekannt, wie Suggestion die Informationsverarbeitung externer Reize so verändert, dass sie eine andere Quali- tät erhalten. Während erste Studien die neurobiologische Mechanismen von hypnotische Analgesie untersucht ha- ben, ist bisher kaum etwas über andere Sinnesmodalitäten bekannt. Die hier präsentierte Studie behandelt den Ein- fluss von hypnotisch suggerierter visueller Blockade auf die visuelle Wahrnehmung. Versuchspersonen wurden mittels Harvard Group Scale of Hypnotic Susceptibility und Stanford Hypnotic Susceptibility Scale auf ihre hyp- notische Suggestibilität getestet. 19 hochsuggestible Per- sonen (Jena) bzw. 12 Versuchspersonen (Trier: 4 niedrig-, 4 mittel-, 4 hochsuggestible) bearbeiteten zwei Mal einen visuellen 3 Stimulus Oddball, einmal mit und einmal ohne hypnotische Trance und hypnotischer Suggestion in aus- balancierter Reihenfolge. Für die hypnotische Suggestion wurden die Probanden zunächst in eine Entspannungs- trance gesprochen; anschließend wurde ihnen suggeriert, dass ein Brett ihre Sicht auf den Monitor blockiert. Die Ergebnisse zeigen, dass hochsuggestible Personen unter hypnotischer Trance mit suggerierter visueller Blockade weniger Zielreize zählten. Damit übereinstimmend, zei- gen die ereigniskorrelierten Potentiale der Hochsugges- tiblen eine deutliche Reduktion der parietalen P3 auf den Zielreiz. Somit beeinflusste die hypnotische Suggestion unter Trance nicht die sensorische Wahrnehmung der Reize, sondern veränderte spezifisch die Aufmerksamkeit und Bewertung des Zielreizes. Diese Replikationsstudien geben einen ersten Hinweis über die Wirkungsweise und neuronale Mechanismen der Hypnose und Suggestion und ihre Wechselwirkung mit Suggestibilität, einem sta- bilen Persönlichkeitskonstrukt

The Eletrophysiology of Prepulse Inhibition

The acoustic startle response is decreased by a prepulse occurring 30-500 ms earlier. This prepulse inhibition (PPI) is interpreted in terms of the Interruption and Protection hypotheses, in which startle responding interrupts prepulse processing, and PPI indicates the degree to which prepulse processing is protected from that interruption. We evaluated this hypotheses by measuring startle responding and evoked potentials (N1, P2) to both prepulse and startle stimuli under different attentional conditions (Attend Startle, Attend Prepulse, Ignore Both). 192 trials were presented in randomized order: Startle Alone (105dB noise), Prepulse Alone (70dB noise), and prepulse+startle stimuli with a stimulus onset asynchrony (SOA) of 120 (PPI120) or 500 ms (PPI500). 36 participants, randomly assigned to the three attention conditions, pressed a key to the startle or to the pre-pulse or did not respond. A 32-channel EEG and eyeblink EMG were measured. Independent of the attentional conditions, the EMG startle response was decreased by a pre-pulse at both SOAs, illustrating PPI. Prepulse N1/P2 amplitude was identical for the Prepulse Alone, PPI120, and PPI500 stimuli independent of the attentional conditions, demonstrating protection of primary sensory prepulse processing. N1/P2 potentials to the startle stimulus were affected by the SOAs and the attentional conditions, suggesting a change in startle processing by both variables. The results suggest a complete protection of prepulse processing. The reduced N1/P2 amplitudes to the startle stimulus at both SOAs suggest that the eliciting properties of the startle stimulus are decreased by the prepulse