Shared attention experiments examine the potential differences in function or behavior when stimuli are experienced alone or in the presence of others, and when simultaneous attention of the participants to the same stimulus or set is involved. Previous work has found enhanced reactions to emotional stimuli in social situations, yet these changes might represent enhanced communicative or motivational purposes. This study examines whether viewing emotional stimuli in the presence of another person influences attention to or memory for the stimulus. Participants passively viewed emotionally-valenced stimuli while completing another task (counting flowers). Each participant performed this task both alone and in a shared attention condition (simultaneously with another person in the same room) while EEG signals were measured. Recognition of the emotional pictures was later measured. A significant shared attention behavioral effect was found in the attention task but not in the recognition task. Compared to event-related potential responses for neutral pictures, we found higher P3b response for task relevant stimuli (flowers), and higher Late Positive Potential (LPP) responses for emotional stimuli. However, no main effect was found for shared attention between presence conditions. To conclude, shared attention may therefore have a more limited effect on cognitive processes than previously suggested. Humans are social animals that often prefer acting together, rather than alone 1,2. Potential differences in function or behavior when experienced alone or in the presence of others are referred to as co-presence effects that can be either generated from the mere presence of another or from a shared experience that occurs in the physical or psychological presence of another person 3-5. When simultaneous attention of the participants to the same stimulus or set is involved, shared experience overlaps with the term shared attention 4,6. Indeed, both shared experience and shared attention have been found to affect cognitive function and behavior, such as attention to a target stimuli 3,7 , social learning 8 , memory 9,10 , motivation 11 , judgment 12 and inhibitory control 13. Specifically, shared attention has been found to amplify these processes (etc. memories, emotions, and behavioral learning) 4,6. For example, higher manifestation of social learning was found in the shared attention condition compared to an unshared condition 8. Several 5,14,15 studies have examined the effect of shared attention in emotional contexts, but yielded mixed results. For example, Shteynberg and colleagues examined online shared attention effects on reactions to emotional stimuli. In a series of studies, they presented either short clips or pictures to participants and found enhancement of the subjective feelings (self-reported) for emotional stimuli in the online presence of another person. Specifically, scary advertisements led to higher "scariness" scores in the shared attention condition compared to the same stimuli viewed alone. Similar...

Non-invasive brain stimulation has been suggested as a potential treatment for improving symptomology and cognitive deficits in Attention-Deficit/Hyperactivity Disorder (ADHD), the most common childhood neurodevelopmental disorder. Here, we examined whether a novel form of stimulation, high-frequency transcranial random noise stimulation (tRNS), applied with cognitive training (CT), may impact symptoms and neural oscillations in children with ADHD. We conducted a randomized, double-blind sham-controlled trial in 23 unmedicated children with ADHD, who received either tRNS over the right inferior frontal gyrus (rIFG) and left dorsolateral prefrontal cortex (lDLPFC) or sham stimulation for 2 weeks, combined with CT. tRNS + CT yielded significant clinical improvements (reduced ADHD rating-scale scores) following treatment, compared to the control intervention. These improvements were maintained at a 3-week follow-up. Moreover, resting state (RS)-EEG periodic beta bandwidth of the extracted peaks was reduced in the experimental compared to control group immediately following treatment, with further reduction at follow-up. A marginally lower aperiodic exponent which reflects a higher excitation/inhibition was seen in the experimental compared to control group. The experimental group further exhibited longer sleep onset latencies and more wake-up times following treatment compared to the control group. No significant group differences were seen in executive functions, nor in reported adverse events. We conclude that tRNS + CT has a lasting clinical effect on ADHD symptoms and on beta activity. These results provide a promising direction towards a novel intervention in paediatric ADHD that induces sustained effects.

Social cognition allows humans to understand and predict other people’s behavior by inferring or sharing their emotions, intentions and beliefs. Few studies have investigated the impact of one’s own emotional state on understanding others. Here, we tested the effect of being in an angry state on empathy and theory of mind (ToM). In a between-groups design we manipulated anger status with different paradigms in three studies (autobiographical recall (N = 45), negative feedback (N = 49), frustration (N = 46)) and checked how this manipulation affected empathic accuracy and performance in the EmpaToM. All paradigms were successful in inducing mild anger. We did not find the expected effect of anger on empathy or ToM performance but observed small behavioral changes. Together, our results validate the use of three different anger induction paradigms and speak for rather weak behavioral effects of mild state anger on empathy and ToM.