Predicting attitudinal and behavioral responses to COVID-19 pandemic using machine learning.

At the beginning of 2020, COVID-19 became a global problem. Despite all the efforts to emphasize the relevance of preventive measures, not everyone adhered to them. Thus, learning more about the characteristics determining attitudinal and behavioral responses to the pandemic is crucial to improving future interventions. In this study, we applied machine learning on the multinational data collected by the International Collaboration on the Social and Moral Psychology of COVID-19 (N = 51,404) to test the predictive efficacy of constructs from social, moral, cognitive, and personality psychology, as well as socio-demographic factors, in the attitudinal and behavioral responses to the pandemic. The results point to several valuable insights. Internalized moral identity provided the most consistent predictive contribution-individuals perceiving moral traits as central to their self-concept reported higher adherence to preventive measures. Similar results were found for morality as cooperation, symbolized moral identity, self-control, open-mindedness, and collective narcissism, while the inverse relationship was evident for the endorsement of conspiracy theories. However, we also found a non-neglible variability in the explained variance and predictive contributions with respect to macro-level factors such as the pandemic stage or cultural region. Overall, the results underscore the importance of morality-related and contextual factors in understanding adherence to public health recommendations during the pandemic.

How culturally unique are pandemic effects? Evaluating cultural similarities and differences in effects of age, biological sex, and political beliefs on COVID impacts.

Despite being bio-epidemiological phenomena, the causes and effects of pandemics are culturally influenced in ways that go beyond national boundaries. However, they are often studied in isolated pockets, and this fact makes it difficult to parse the unique influence of specific cultural psychologies. To help fill in this gap, the present study applies existing cultural theories via linear mixed modeling to test the influence of unique cultural factors in a multi-national sample (that moves beyond Western nations) on the effects of age, biological sex, and political beliefs on pandemic outcomes that include adverse financial impacts, adverse resource impacts, adverse psychological impacts, and the health impacts of COVID. Our study spanned 19 nations (participant N = 14,133) and involved translations into 9 languages. Linear mixed models revealed similarities across cultures, with both young persons and women reporting worse outcomes from COVID across the multi-national sample. However, these effects were generally qualified by culture-specific variance, and overall more evidence emerged for effects unique to each culture than effects similar across cultures. Follow-up analyses suggested this cultural variability was consistent with models of pre-existing inequalities and socioecological stressors exacerbating the effects of the pandemic. Collectively, this evidence highlights the importance of developing culturally flexible models for understanding the cross-cultural nature of pandemic psychology beyond typical WEIRD approaches.

Increasing self-other similarity modulates ethnic bias in sensorimotor resonance to others' pain.

The tendency to simulate the pain of others within our own sensorimotor systems is a vital component of empathy. However, this sensorimotor resonance is modulated by a multitude of social factors including similarity in bodily appearance, e.g. skin colour. The current study investigated whether increasing self-other similarity via virtual transfer to another colour body reduced ingroup bias in sensorimotor resonance. A sample of 58 white participants was momentarily transferred to either a black or a white body using virtual reality technology. We then employed electroencephalography to examine event-related desynchronization (ERD) in the sensorimotor beta (13-23 Hz) oscillations while they viewed black, white and violet photorealistic virtual agents being touched with a noxious or soft object. While the noxious treatment of a violet agent did not increase beta ERD, amplified beta ERD in response to black agent's noxious vs soft treatment was found in perceivers transferred to a black body. Transfer to the white body dismissed the effect. Further exploratory analysis implied that the pain-related beta ERD occurred only when the agent and the participant were of the same colour. The results suggest that even short-lasting changes in bodily resemblance can modulate sensorimotor resonance to others' perceived pain.

Dynamic emotional expressions do not modulate responses to gestures.

The tendency to imitate the actions of others appears to be a fundamental aspect of human social interaction. Emotional expressions are a particularly salient form of social stimuli (Vuilleumier & Schwartz, 2001) but their relationship to imitative behaviour is currently unclear. In this paper we report the results of five studies which investigated the effect of a target's dynamic emotional stimuli on participants' tendency to respond compatibly to the target's actions. Experiment one examined the effect of dynamic emotional expressions on the automatic imitation of opening and closing hand movements. Experiment two used the same basic paradigm but added gaze direction as an additional factor. Experiment three investigated the effect of dynamic emotional expressions on compatibility responses to handshakes. Experiment four investigated whether dynamic emotional expressions modulated response to valenced social gestures. Finally, experiment five compared the effects of dynamic and static emotional expressions on participants' automatic imitation of finger lifting. Across all five studies we reliably elicited a compatibility effect however, none of the studies found a significant modulating effect of emotional expression. This null effect was also supported by a random effects meta-analysis and a series of Bayesian t-tests. Nevertheless, these results must be caveated by the fact that our studies had limited power to detect effect sizes below d = 0.4. We conclude by situating our findings within the literature, suggesting that the effect of emotional expressions on automatic imitation is, at best, minimal.

The Detached Self: Investigating the Effect of Depersonalisation on Self-Bias in the Visual Remapping of Touch.

There is a growing consensus that our most fundamental sense of self is structured by the ongoing integration of sensory and motor information related to our own body. Depersonalisation (DP) is an intriguing form of altered subjective experience in which people report feelings of unreality and detachment from their sense of self. The current study used the visual remapping of touch (VRT) paradigm to explore self-bias in visual-tactile integration in non-clinical participants reporting high and low levels of depersonalisation experiences. We found that the high-DP group showed an increased overall VRT effect but a no-self-face bias, instead showing a greater VRT effect when observing the face of another person. In addition, across all participants, self-bias was negatively predicted by the occurrence of anomalous body experiences. These results indicate disrupted integration of tactile and visual representations of the bodily self in those experiencing high levels of DP and provide greater understanding of how disruptions in multisensory perception of the self may underlie the phenomenology of depersonalisation.

The neural basis of shared preference learning.

During our daily lives, we often learn about the similarity of the traits and preferences of others to our own and use that information during our social interactions. However, it is unclear how the brain represents similarity between the self and others. One possible mechanism is to track similarity to oneself regardless of the identity of the other (Similarity account); an alternative is to track each other person in terms of consistency of their choice similarity with respect to the choices they have made before (consistency account). Our study combined functional Magnetic Resonance Imaging (fMRI) and computational modelling of reinforcement learning (RL) to investigate the neural processes that underlie learning about preference similarity. Participants chose which of two pieces of artwork they preferred and saw the choices of one agent who usually shared their preference and another agent who usually did not. We modelled neural activation with RL models based on the similarity and consistency accounts. Our results showed that activity in brain areas linked to reward and social cognition followed the consistency account. Our findings suggest that impressions of other people can be calculated in a person-specific manner, which assumes that each individual behaves consistently with their past choices.

The way others move can influence what we choose.

Whether pointing at a menu item or rifling through a clothes rack, when we choose we often move. We investigated whether people's tendency to copy the movements of others could influence their choices. Participants saw pairs of pictures in private and indicated which one they preferred. They then entered a virtual art gallery and saw the same picture pairs in the presence of a virtual character. Having observed the virtual character point to indicate her preference with either a high or low movement trajectory, participants indicated their preference. There was either an anatomical (same movement, same choice) or spatial correspondence (same movement, different choice) between the participant's pictures and those of the virtual character. We found that participants copied the movement made by the virtual character rather than her action goal (i.e., her choice of picture). This resulted in a shift towards the virtual character's preferences in the anatomical condition but away from her preferences in the spatial condition. This effect was driven by the observation of the virtual character's high pointing movements. In a further experiment, we did not find any significant differences in imitation behaviour in autism, although autistic participants were less consistent in their choices. Our findings demonstrate that we are not only influenced by other's choices but also the types of movements others make to indicate those choices.

The functions of imitative behaviour in humans.

This article focuses on the question of the function of imitation and whether current accounts of imitative function are consistent with our knowledge about imitation's origins. We first review theories of imitative origin concluding that empirical evidence suggests that imitation arises from domain-general learning mechanisms. Next, we lay out a selective account of function that allows normative functions to be ascribed to learned behaviours. We then describe and review four accounts of the function of imitation before evaluating the relationship between the claim that imitation arises out of domain-general learning mechanisms and theories of the function of imitation.

Contingency and contiguity of imitative behaviour affect social affiliation.

Actions of others automatically prime similar responses in an agent's behavioural repertoire. As a consequence, perceived or anticipated imitation facilitates own action control and, at the same time, imitation boosts social affiliation and rapport with others. It has previously been suggested that basic mechanisms of associative learning can account for behavioural effects of imitation, whereas a possible role of associative learning for affiliative processes is poorly understood at present. Therefore, this study examined whether contingency and contiguity, the principles of associative learning, affect also the social effects of imitation. Two experiments yielded evidence in favour of this hypothesis by showing more social affiliation in conditions with high contingency (as compared to low contingency) and in conditions of high contiguity (compared to low contiguity).

Reputation in an economic game modulates premotor cortex activity during action observation.

Our interactions with other people - and our processing of their actions - are shaped by their reputation. Research has identified an Action Observation Network (AON) which is engaged when observing other people's actions. Yet, little is known about how the processing of others' actions is influenced by another's reputation. Is the response of the AON modulated by the reputation of the actor? We developed a variant of the ultimatum game in which participants watched either the visible or occluded actions of two 'proposers'. These actions were tied to decisions of how to split a pot of money although the proposers' decisions on each trial were not known to participants when observing the actions. One proposer made fair offers on the majority of trials, establishing a positive reputation, whereas the other made predominantly, unfair offers resulting in a negative reputation. We found significant activations in two regions of the left dorsal premotor cortex (dPMC). The first of these showed a main effect of reputation with greater activation for the negative reputation proposer than the positive reputation proposer. Furthermore individual differences in trust ratings of the two proposers covaried with activation in the right primary motor cortex (M1). The second showed an interaction between visibility and reputation driven by a greater effect of reputation when participants were observing an occluded action. Our findings show that the processing of others' actions in the AON is modulated by an actor's reputation, and suggest a predictive role for the PMC during action observation.

Status and Power Do Not Modulate Automatic Imitation of Intransitive Hand Movements.

The tendency to mimic the behaviour of others is affected by a variety of social factors, and it has been argued that such "mirroring" is often unconsciously deployed as a means of increasing affiliation during interpersonal interactions. However, the relationship between automatic motor imitation and status/power is currently unclear. This paper reports five experiments that investigated whether social status (Experiments 1, 2, and 3) or power (Experiments 4 and 5) had a moderating effect on automatic imitation (AI) in finger-movement tasks, using a series of different manipulations. Experiments 1 and 2 manipulated the social status of the observed person using an associative learning task. Experiment 3 manipulated social status via perceived competence at a simple computer game. Experiment 4 manipulated participants' power (relative to the actors) in a card-choosing task. Finally, Experiment 5 primed participants using a writing task, to induce the sense of being powerful or powerless. No significant interactions were found between congruency and social status/power in any of the studies. Additionally, Bayesian hypothesis testing indicated that the null hypothesis should be favoured over the experimental hypothesis in all five studies. These findings are discussed in terms of their implications for AI tasks, social effects on mimicry, and the hypothesis of mimicry as a strategic mechanism to promote affiliation.

Neural basis of understanding communicative actions: Changes associated with knowing the actor's intention and the meanings of the actions.

People can communicate by using hand actions, e.g., signs. Understanding communicative actions requires that the observer knows that the actor has an intention to communicate and the meanings of the actions. Here, we investigated how this prior knowledge affects processing of observed actions. We used functional MRI to determine changes in action processing when non-signers were told that the observed actions are communicative (i.e., signs) and learned the meanings of half of the actions. Processing of hand actions activated the left and right inferior frontal gyrus (IFG, BA 44 and 45) when the communicative intention of the actor was known, even when the meanings of the actions remained unknown. These regions were not active when the observers did not know about the communicative nature of the hand actions. These findings suggest that the left and right IFG play a role in understanding the intention of the actor, but do not process visuospatial features of the communicative actions. Knowing the meanings of the hand actions further enhanced activity in the anterior part of the IFG (BA 45), the inferior parietal lobule and posterior inferior and middle temporal gyri in the left hemisphere. These left-hemisphere language regions could provide a link between meanings and observed actions. In sum, the findings provide evidence for the segregation of the networks involved in the neural processing of visuospatial features of communicative hand actions and those involved in understanding the actor's intention and the meanings of the actions.

Attending to the bodily self.

Humphreys and Sui provide a powerful theoretical framework to explain processing biases toward self-related information. However, the framework is primarily applied to information relevant to a conceptual self-representation. Here, we show a similar processing bias for information related to the bodily self, grounded in sensorimotor representations. Furthermore, we can use bodily illusions to explore the ways in which embodied self-associations can affect our perceptual and attentional processing. It is possible to extend the current framework to take into account these effects, and we argue that this will yield considerable benefits for our understanding of self-relevance.

Change my body, change my mind: the effects of illusory ownership of an outgroup hand on implicit attitudes toward that outgroup.

The effect of multisensory-induced changes on body-ownership and self-awareness using bodily illusions has been well established. More recently, experimental manipulation of bodily illusions have been combined with social cognition tasks to investigate whether changes in body-ownership can in turn change the way we perceive others. For example, experiencing ownership over a dark-skin rubber hand reduces implicit bias against dark-skin groups. Several studies have also shown that processing of skin color and facial features play an important role in judgements of racial typicality and racial categorization independently and in an additive manner. The present study aimed at examining whether using multisensory stimulation to induce feelings of body-ownership over a dark-skin rubber hand would lead to an increase in positive attitudes toward black faces. We here show, that the induced ownership of a body-part of a different skin color affected the participants' implicit attitudes when processing facial features, in addition to the processing of skin color shown previously. Furthermore, when the levels of pre-existing attitudes toward black people were taken into account, the effect of the rubber hand illusion on the post-stimulation implicit attitudes was only significant for those participants who had a negative initial attitude toward black people, with no significant effects found for those who had positive initial attitudes toward black people. Taken together, our findings corroborate the hypothesis that the representation of the self and its relation to others, as given to us by body-related multisensory processing, is critical in maintaining but also in changing social attitudes.

More of myself: manipulating interoceptive awareness by heightened attention to bodily and narrative aspects of the self.

Psychology distinguishes between a bodily and a narrative self. Within neuroscience, models of the bodily self are based on exteroceptive sensorimotor processes or on the integration of interoceptive sensations. Recent research has revealed interactions between interoceptive and exteroceptive processing of self-related information, for example that mirror self-observation can improve interoceptive awareness. Using heartbeat perception, we measured the effect on interoceptive awareness of two experimental manipulations, designed to heighten attention to bodily and narrative aspects of the self. Participants gazed at a photograph of their own face or at self-relevant words. In both experimental conditions interoceptive awareness was significantly increased, compared to baseline. Results show that attention to narrative aspects of self, previously regarded as relying on higher-order processes, has an effect similar to self-face stimuli in improving interoceptive awareness. Our findings extend the previously observed interaction between the bodily self and interoception to more abstract amodal representations of the self.

Beyond the colour of my skin: how skin colour affects the sense of body-ownership.

Multisensory stimulation has been shown to alter the sense of body-ownership. Given that perceived similarity between one's own body and those of others is crucial for social cognition, we investigated whether multisensory stimulation can lead participants to experience ownership over a hand of different skin colour. Results from two studies using introspective, behavioural and physiological methods show that, following synchronous visuotactile (VT) stimulation, participants can experience body-ownership over hands that seem to belong to a different racial group. Interestingly, a baseline measure of implicit racial bias did not predict whether participants would experience the RHI, but the overall strength of experienced body-ownership seemed to predict the participants' post-illusion implicit racial bias with those who experienced a stronger RHI showing a lower bias. These findings suggest that multisensory experiences can override strict ingroup/outgroup distinctions based on skin colour and point to a key role for sensory processing in social cognition.

Lateralization of motor excitability during observation of bimanual signs.

Viewing another person's hand actions enhances excitability in an observer's left and right primary motor (M1) cortex. We aimed to determine whether viewing communicative hand actions alters this bilateral sensorimotor resonance. Using single-pulse transcranial magnetic stimulation (TMS), we measured excitability in the left and right M1 while right-handed non-signing participants observed bimanual communicative hand actions, i.e., meaningful signs in British Sign Language. TMS-induced motor evoked potentials were recorded from hand muscles during sign observation before and after teaching the participants to associate meanings with half of the signs. Before this teaching, when participants did not know that the presented hand actions were signs, excitability of left and right M1 was modulated equally. After learning the meanings of half the signs, excitability of the left, but not right, M1 was significantly enhanced. This left-lateralized enhancement of M1 excitability occurred during observation of signs with known and unknown meanings. The findings suggest that awareness of the communicative nature of another person's hand actions strengthens sensorimotor resonance in the left M1 cortex and alters hemispheric balance during action observation.