A systematic review and multivariate meta-analysis of the physical and mental health benefits of touch interventions.

Receiving touch is of critical importance, as many studies have shown that touch promotes mental and physical well-being. We conducted a pre-registered (PROSPERO: CRD42022304281) systematic review and multilevel meta-analysis encompassing 137 studies in the meta-analysis and 75 additional studies in the systematic review (n = 12,966 individuals, search via Google Scholar, PubMed and Web of Science until 1 October 2022) to identify critical factors moderating touch intervention efficacy. Included studies always featured a touch versus no touch control intervention with diverse health outcomes as dependent variables. Risk of bias was assessed via small study, randomization, sequencing, performance and attrition bias. Touch interventions were especially effective in regulating cortisol levels (Hedges' g = 0.78, 95% confidence interval (CI) 0.24 to 1.31) and increasing weight (0.65, 95% CI 0.37 to 0.94) in newborns as well as in reducing pain (0.69, 95% CI 0.48 to 0.89), feelings of depression (0.59, 95% CI 0.40 to 0.78) and state (0.64, 95% CI 0.44 to 0.84) or trait anxiety (0.59, 95% CI 0.40 to 0.77) for adults. Comparing touch interventions involving objects or robots resulted in similar physical (0.56, 95% CI 0.24 to 0.88 versus 0.51, 95% CI 0.38 to 0.64) but lower mental health benefits (0.34, 95% CI 0.19 to 0.49 versus 0.58, 95% CI 0.43 to 0.73). Adult clinical cohorts profited more strongly in mental health domains compared with healthy individuals (0.63, 95% CI 0.46 to 0.80 versus 0.37, 95% CI 0.20 to 0.55). We found no difference in health benefits in adults when comparing touch applied by a familiar person or a health care professional (0.51, 95% CI 0.29 to 0.73 versus 0.50, 95% CI 0.38 to 0.61), but parental touch was more beneficial in newborns (0.69, 95% CI 0.50 to 0.88 versus 0.39, 95% CI 0.18 to 0.61). Small but significant small study bias and the impossibility to blind experimental conditions need to be considered. Leveraging factors that influence touch intervention efficacy will help maximize the benefits of future interventions and focus research in this field.

Open-label placebo treatment does not enhance cognitive abilities in healthy volunteers.

The use of so-called 'smart drugs' such as modafinil to improve cognitive performance has recently attracted considerable attention. However, their side effects have limited user enthusiasm. Open-label placebo (OLP) treatment, i.e., inert treatments that are openly disclosed to individuals as having no active pharmacological ingredient, has been shown to improve various medical symptoms and conditions, including those related to cognitive performance. OLP treatment could therefore be an exciting alternative to pharmacological cognitive enhancers. Here, we used a randomized-controlled design to investigate the effect of a 21-day OLP treatment on several sub-domains of cognitive performance in N = 78 healthy volunteers. Subjective and objective measures of cognitive performance as well as different measures of well-being were obtained before and after the treatment period. Using a combination of classic Frequentist and Bayesian analysis approaches showed no additional benefit from OLP treatment in any of the subjective or objective measures of cognitive performance. Our study thus highlights possible limitations of OLP treatment in boosting cognitive performance in healthy volunteers. These findings are discussed in the light of expectancy-value considerations that may determine OLP efficacy.

A pill as a quick solution: association between painkiller intake, empathy, and prosocial behavior.

Previous research has demonstrated a link between the administration of analgesic drugs and the reduction of empathy levels in humans. This apparent blunting effect of pain medication has been explained through shared neural mechanisms for the first-hand and the empathic experience of pain (simulation theory). Considering that analgesics are among the most consumed drugs in the world and the ability to empathize with others is fundamental to human social interactions, the aim of the present study was to investigate whether the typical day-to-day analgesic consumption rate in Austria and Germany is associated with a reduction in empathy and prosocial behavior. We therefore collected self-reports of analgesic consumption behavior as well as empathy for pain and prosocial behavior measures in an online survey (n = 940). Analyses revealed no significant association between the analgesic intake frequency and measures of empathy or prosocial behavior. However, liberal intake of analgesics (i.e. mind-set of "a pill is a quick solution") was linked to lower empathic concern and helping behavior, which may hint towards a negative effect in people who take pain medication for non-pain related issues or episodes of low pain. Nevertheless, further research is needed to investigate the effects of analgesic drugs in high frequency users.

To respond or not to respond: exploring empathy-related psychological and structural brain differences between placebo analgesia responders and non-responders.

Introduction: Placebo responsiveness is highly variable across individuals. In the domain of pain, it may range from pronounced hypoalgesia to no response at all. Which factors predict such variation awaits clarification, as the available literature is characterized by mixed and inconclusive results. Particularly interesting in this case are social factors such as empathy or prosocial behavior, as prior work has stressed the connection between feeling pain yourself and empathizing with pain observed in others. Methods: In a mixed confirmatory and exploratory approach, this study investigated potential psychological and structural brain differences between placebo responders and non-responders in the domain of pain. We aggregated data of four behavioral and neuroimaging studies that had been designed to investigate the effects of placebo analgesia on empathy. Results: Analyses comparing groups of placebo responders and non-responders showed significant group differences in trait characteristics, with responders reporting increased helping behavior and lower psychopathic traits compared to non-responders. Uncorrected results further showed higher pain-related empathic concern in responders vs. non-responders. These results were accompaniedby tentative group differences in brain structure: placebo analgesia non-responders exhibited increased gray matter volume in left inferior temporal and parietal supramarginal cortical areas, and an increased cortical surface area in bilateral middle temporal cortex. Discussion: Together, our findings suggest that modifiability of one's pain perception by means of placebo effects is linked to personality traits characterizing social emotions and behavior. They also hint that these psychological as well as brain structural characteristics might be beneficial for the identification of placebo responders. At the same time, they stress the importance of considering contextual factors such as the study setting or paradigm when investigating the association between individual characteristics and placebo responding.

Teaching open and reproducible scholarship: a critical review of the evidence base for current pedagogical methods and their outcomes.

In recent years, the scientific community has called for improvements in the credibility, robustness and reproducibility of research, characterized by increased interest and promotion of open and transparent research practices. While progress has been positive, there is a lack of consideration about how this approach can be embedded into undergraduate and postgraduate research training. Specifically, a critical overview of the literature which investigates how integrating open and reproducible science may influence student outcomes is needed. In this paper, we provide the first critical review of literature surrounding the integration of open and reproducible scholarship into teaching and learning and its associated outcomes in students. Our review highlighted how embedding open and reproducible scholarship appears to be associated with (i) students' scientific literacies (i.e. students' understanding of open research, consumption of science and the development of transferable skills); (ii) student engagement (i.e. motivation and engagement with learning, collaboration and engagement in open research) and (iii) students' attitudes towards science (i.e. trust in science and confidence in research findings). However, our review also identified a need for more robust and rigorous methods within pedagogical research, including more interventional and experimental evaluations of teaching practice. We discuss implications for teaching and learning scholarship.

Placebo Analgesia Reduces Costly Prosocial Helping to Lower Another Person's Pain.

Painkiller administration lowers pain empathy, but whether this also reduces prosocial behavior is unknown. In this preregistered study, we investigated whether inducing analgesia through a placebo painkiller reduced effortful helping. When given the opportunity to reduce the pain of another person, individuals experiencing placebo analgesia (n = 45 adults from Austria; 21 male, 24 female) made fewer prosocial choices at the lowest helping level and exerted less physical effort when helping, compared with controls whose pain sensitivity was unaltered (n = 45; 21 male, 24 female). Self-reported empathic unpleasantness positively correlated with prosocial choices across the whole sample. While not replicating group differences in empathy, a mediation analysis revealed that the level of unpleasantness to other people's pain fully mediated the effect of placebo analgesia on prosocial choices. Given the importance of prosociality for social cohesion, these findings have broad potential implications both for individuals under the influence of painkillers and for society at large.

Emotional Ego- and Altercentric Biases in High-Functioning Autism Spectrum Disorder: Behavioral and Neurophysiological Evidence.

Self-other distinction is a crucial aspect of social cognition, as it allows us to differentiate our own mental and emotional states from those of others. Research suggests that this ability might be impaired in individuals on the autism spectrum, but convincing evidence of self-other distinction difficulties in the emotional domain is lacking. Here we aimed at evaluating emotional self-other distinction abilities in autistic and non-autistic adults, in two behavioral pilot studies and one fMRI study. By using a newly developed virtual ball-tossing game that induced simultaneous positive and negative emotional states in each participant and another person, we were able to measure emotional egocentric and altercentric biases (namely the tendency to ascribe self-/other-related emotions to others/ourselves, respectively). Despite no behavioral differences, individuals on the autism spectrum showed decreased activation (1) in the right temporoparietal junction (rTPJ) during active overcoming of the emotional egocentric bias vs. passive game viewing, and (2) in the right supramarginal gyrus (rSMG) during ego- vs. altercentric biases, compared to neurotypical participants. These results suggest a different recruitment of these two regions in autistic individuals when dealing with conflicting emotional states of oneself and another person. Furthermore, they highlight the importance of considering different control conditions when interpreting the involvement of rTPJ and rSMG during self-other distinction processes.

Placebo Analgesia Does Not Reduce Empathy for Naturalistic Depictions of Others' Pain in a Somatosensory Specific Way.

The shared representations account postulates that sharing another's pain recruits underlying brain functions also engaged during first-hand pain. Critically, direct causal evidence for this was mainly shown for affective pain processing, while the contribution of somatosensory processes to empathy remains controversial. This controversy may be explained, however, by experimental paradigms that did not direct attention towards a specific body part, or that did not employ naturalistic depictions of others' pain. In this preregistered functional magnetic resonance imaging study, we aimed to test whether causal manipulation of first-hand pain affects empathy for naturalistic depictions of pain in a somatosensory-matched manner. Forty-five participants underwent a placebo analgesia induction in their right hand and observed pictures of other people's right and left hands in pain. We found neither behavioral nor neural evidence for somatosensory-specific modulation of pain empathy. However, exploratory analyses revealed a general effect of the placebo on empathy, and higher brain activity in bilateral anterior insula when viewing others' right hands in pain (i.e., corresponding to one's own placebo hand). These results refine our knowledge regarding the neural mechanisms of pain empathy, and imply that the sharing of somatosensory representations seems to play less of a causal role than the one of affective representations.

Neural Correlates of Interpersonal Space Permeability and Flexibility in Autism Spectrum Disorder.

Previous research indicates that the size of interpersonal space at which the other is perceived as intrusive (permeability) and the ability to adapt interpersonal distance based on contextual factors (flexibility) are altered in Autism Spectrum Disorder (ASD). However, the neurophysiological basis of these alterations remains poorly understood. To fill this gap, we used fMRI and assessed interpersonal space preferences of individuals with ASD before and after engaging in cooperative and non-cooperative social interactions. Compared to matched controls, ASDs showed lower comfort in response to an approaching confederate, indicating preference for larger interpersonal space in autism (altered permeability). This preference was accompanied by reduced activity in bilateral dorsal intraparietal sulcus (dIPS) and left fusiform face area (FFA), regions previously shown to be involved in interpersonal space regulation. Furthermore, we observed differences in effective connectivity among dIPS, FFA, and amygdala in ASDs compared to controls, depending on the level of experienced comfort. No differences between groups were observed in interpersonal space regulation after an experienced social interaction (flexibility). Taken together, the present findings suggest that a dysregulation of the activity and connectivity of brain areas involved in interpersonal space processing may contribute to avoidance of physical proximity and social impairments in ASD.

Another's pain in my brain: No evidence that placebo analgesia affects the sensory-discriminative component in empathy for pain.

The shared representations account of empathy suggests that sharing other people's emotions relies on neural processes similar to those engaged when directly experiencing such emotions. Recent research corroborated this by showing that placebo analgesia induced for first-hand pain resulted in reduced pain empathy and decreased activation in shared neural networks. However, those studies did not report any placebo-related variation of somatosensory engagement during pain empathy. The experimental paradigms used in these studies did not direct attention towards a specific body part in pain, which may explain the absence of effects for somatosensation. The main objective of this preregistered study was to implement a paradigm overcoming this limitation, and to investigate whether placebo analgesia may also modulate the sensory-discriminative component of empathy for pain. We induced a localized, first-hand placebo analgesia effect in the right hand of 45 participants by means of a placebo gel and conditioning techniques, and compared this to the left hand as a control condition. Participants underwent a pain task in the MRI scanner, receiving painful or non-painful electrical stimulation on their left or right hand, or witnessing another person receiving such stimulation. In contrast to a robust localized placebo analgesia effect for self-experienced pain, the empathy condition showed no differences between the two hands, neither for behavioral nor neural responses. We thus report no evidence for somatosensory sharing in empathy, while replicating previous studies showing overlapping brain activity in the affective-motivational component for first-hand and empathy for pain. Hence, in a more rigorous test aiming to overcome limitations of previous work, we again find no causal evidence for the engagement of somatosensory sharing in empathy. Our study refines the understanding of the neural underpinnings of empathy for pain, and the use of placebo analgesia in investigating such models.