Dissociable neural oscillatory mechanisms underlying unconscious priming of externally and intentionally initiated inhibition

Neural correlates of empathy in donation decisions: Insights from EEG and machine learning

Empathy is central to individual and societal well-being. Numerous studies have examined how trait of empathy affects prosocial behavior. However, little studies explored the psychological and neural mechanisms by which different dimensions of trait empathy influence prosocial behavior. Addressing this knowledge gap is important to understand empathy-driven prosocial behavior. We employed an EEG experiment combined with interpretable machine learning methods to probe these questions. We found that empathic concern (EC) played the most pivotal role in donation decision. Behaviorally, EC negatively moderates the effect of perceived closeness and deservedness of charity projects on the willingness to donate. The machine learning results indicate that EC significantly predicts late positive potential (LPP) and beta-band activity during donation information processing. Further regression analysis results indicate that EC, rather than other dimensions of trait empathy, can positively predict LPP amplitude and negatively predict beta-band activity. These results indicated that participants with higher EC scores may experience heightened emotional arousal and the vicarious experience of others' emotions while processing donation information. Our work adds weight to understanding the relationship between trait empathy and prosocial behavior and provides electrophysiological evidence.

How effort-based self-interest motivation shapes altruistic donation behavior and brain responses

Prosocial behaviors are central to individual and societal well-being. Although the relationship between effort and prosocial behavior is increasingly studied, the impact of effort-based self-interested motivation on prosocial behavior has received less attention. In the current study, we carried out two experiments to examine the effect of motivation to obtain a reward for oneself on donation behavior and brain response. We observed that individuals who accumulated more money in the effort-expenditure rewards task (EEfRT) donated a lower proportion of their earnings. The sigmoid model fitted participants' choices in the EEfRT task, and the effort-reward bias and sigma parameters negatively correlated with the amount of money donated in the donation task. Additionally, the effort-reward bias and sigma parameters negatively predicted N2 amplitude during processing of charitable donation-related information. We propose that individuals who exhibit a lower level of effort-based self-interest motivation may allocate more cognitive control or attentional resources when processing information related to charitable donations. Our work adds weight to understanding the relationship between effort-based self-interest motivation and prosocial behavior and provides electrophysiological evidence.

Does response inhibition occur unconsciously? A systematic review and Bayesian meta-analysis

Consciousness is traditionally considered necessary for response inhibition. Recently, researchers have attempted to explore unconscious response inhibition using the masked go/no-go task. However, their findings were controversial and might have been confounded by the methodology employed. Therefore, we used a three-level Bayesian meta-analysis to provide the first systematic overview of the field of unconscious response inhibition. Finally, 34 studies in 16 articles with a total sample size of 521 were included. In summary, we found only inconclusive evidence of a reaction time slowing effect after excluding studies with conscious no-go experience (mean difference = 8.47 ms, BF10 = 2.71). In addition, the overall effect size of the difference in sensitivity to masked stimuli between the masked go/no-go task and the objective awareness task was small and uncertain (mean difference = 0.09, BF10 = 2.39). Taken together, these findings indicate a lack of solid evidence for the occurrence of unconscious response inhibition. Our findings do not oppose the possibility of unconscious response inhibition, but rather emphasize the need for more rigorous research methodologies in this field.

Transcranial Focused Ultrasound to V5 Enhances Human Visual Motion Brain-Computer Interface by Modulating Feature-Based Attention

Paralysis affects roughly 1 in 50 Americans. While there is no cure for the condition, brain-computer interfaces (BCI) can allow users to control a device with their mind, bypassing the paralyzed region. Non-invasive BCIs still have high error rates, which is hypothesized to be reduced with concurrent targeted neuromodulation. This study examines whether transcranial focused ultrasound (tFUS) modulation can improve BCI outcomes, and what the underlying mechanism of action might be through high-density electroencephalography (EEG)-based source imaging (ESI) analyses. V5-targeted tFUS significantly reduced the error for the BCI speller task. ESI analyses showed significantly increased theta activity in the tFUS condition at both V5 and downstream the dorsal visual processing pathway. Correlation analysis indicates that the dorsal processing pathway connection was preserved during tFUS stimulation, whereas extraneous connections were severed. These results suggest that V5-targeted tFUS' mechanism of action is to raise the brain's feature-based attention to visual motion.

A study of intentional inhibition of food stimuli among female restricted eaters

Restrictive eating is the propensity to restrict food consumption to control body weight. Most previous studies have focused on reactive inhibition induced by external cessation signals. Individuals usually engage in intentional inhibition, an internal form of inhibitory control that arises spontaneously in the absence of an explicit external inhibitory signal. However, there has been no clear research on intentional inhibition in restricted eaters. Therefore, the Go/No-Go/Choose experimental paradigm was used in this study to investigate the performance of intentional inhibition among restrained and unrestrained eaters under general stimuli, food stimuli, and food context conditions. The findings showed that only when food stimuli were present did the intentional inhibition of restricted and non-restricted eaters differ. In contrast to non-restricted eaters, restricted eaters significantly inhibit high-calorie foods in favor of low-calorie ones. There was no difference in intentional inhibition responses between the two groups in the non-food-related or food-context conditions, indicating that the intentional inhibition process was specific to restricted/non-restricted eaters.