You will be presented with the abstract, introduction, and discussion section from a biomedical research article. Your task is to create a summary that a layperson can understand, capturing the essence of the research article. Keep essential scientific terms, but ensure that the language remains clear and the concepts are explained in an uncomplicated manner.

Title: Perception of social interaction compresses subjective duration in an oxytocin-dependent manner}
Article:
Abstract:
Communication through body gestures permeates our daily life. Efficient perception of the message therein reflects one’s social cognitive competency. Here we report that such competency is manifested temporally as shortened subjective duration of social interactions: motion sequences showing agents acting communicatively are perceived to be significantly shorter in duration as compared with those acting noncommunicatively. The strength of this effect is negatively correlated with one’s autistic-like tendency. Critically, intranasal oxytocin administration restores the temporal compression effect in socially less proficient individuals, whereas the administration of atosiban, a competitive antagonist of oxytocin, diminishes the effect in socially proficient individuals. These findings indicate that perceived time, rather than being a faithful representation of physical time, is highly idiosyncratic and ingrained with one’s personality trait. Moreover, they suggest that oxytocin is involved in mediating time perception of social interaction, further supporting the role of oxytocin in human social cognition.
Introduction:
As a joke, Albert Einstein once gave this picture to explain his theory of relativity: “Put your hand on a hot stove for a minute, and it seems like an hour. Sit with a pretty girl for an hour, and it seems like a minute. That's relativity. ” This seemingly intuitive picture has no bearing on the structure of space-time, yet nicely illustrates the now established finding that mental time deviates, sometimes significantly, from physical time( Eagleman, 2008). To date, the deviation between our experienced time and the physical time has mostly been attributed to sensory properties of the external stimuli( Eagleman, 2008) and their context( Shi et al., 2013). It has been proposed that subjective time is ‘warped’ by the neural energy involved in representing sensory inputs( Eagleman and Pariyadath, 2009; Zhou et al., 2018). For instance, intense and/or moving stimuli are generally experienced as longer in duration( Fraisse, 1984) as they evoke stronger perceptual responses in cortical neurons( Mayo and Sommer, 2013). Little is known as to what role, if any, we the experiencers play in the time we experience. Considering our gregarious nature and the ubiquity of social interactions in daily life, we set out to probe this issue by examining time perception of social interactions and the inter-individual differences therein. An important medium of social interaction is body gestures, from which most humans efficiently extract others’ attitudes and intentions even when the gestures are portrayed by only a handful of point lights attached to the head and major joints( Johansson, 1973). Such efficacy is considered evolutionarily endowed –– Human newborns and infants exhibit a predisposition to attend to the motions of biological entities( i. e. biological motion)( Fox and McDaniel, 1982; Simion et al., 2008); and the perception of biological motion engages a specific network of distributed neural areas, particularly the superior temporal sulcus( STS)( Grossman et al., 2005; Grossman and Blake, 2002; Vaina et al., 2001) that plays an important role in social perception in both monkeys and humans( Allison et al., 2000). Meanwhile, inter-individual variation is noteworthy. People with autism characterized by impaired social interaction and communication show both a deficit of biological motion perception( Blake et al., 2003; Klin et al., 2009) and abnormalities in the STS( Zilbovicius et al., 2006). Social proficiency varies widely even among neurotypical individuals, and is manifested behaviorally as a stable personality trait( Digman, 1990). This inter-individual variance has been associated with plasma concentrations of oxytocin, a well-documented prosocial neuropeptide, as well as polymorphisms of its receptor gene OXTR( Andari et al., 2014; Donaldson and Young, 2008; Modahl et al., 1998; Parker et al., 2014; Skuse et al., 2014; Tost et al., 2010). Likely through interactions with endogenous oxytocin, intranasally administered oxytocin( Dal Monte et al., 2014; Freeman et al., 2016; Lee and Weerts, 2016; Striepens et al., 2013) is found to alter the processing of social stimuli including biological motion in manners that depend on one’s social proficiency( Bartz et al., 2011; Kéri and Benedek, 2009) as well as blood oxytocin concentration( Parker et al., 2017). There has been limited research on the perceptual processing of social interaction between biological entities, particularly as depicted in biological motion displays. Nonetheless, social interaction is far beyond the movements of individuals. In its simplest form, it involves two agents acting in a meaningful manner: one agent executes a gesture, the other recognizes it and acts accordingly. Temporally adjacent actions generally tend to be inferred as a causal sequence and hence communicative( Lagnado and Sloman, 2006). But ultimately that social ‘meaning’ is derived from the observer’s interpretations of the agents’ actions and the relationship in between, and is, to a certain degree, subjective in nature. The present study aimed to address the effect of perceived social interaction on subjective time and its relationship with one’s intrinsic social proficiency. In a series of experiments, we carefully manipulated point-light displays of acting agents to dissociate the perception of social interaction and that of biological motion. We assessed temporal perception of such displays in individuals varying in social proficiency, and critically examined the role of oxytocin in this process. Given the aforementioned relationships among social proficiency, oxytocin and neural processing of social stimuli, our hypothesis was that both social proficiency, which reflects endogenous oxytocin level, and exogenous manipulations of oxytocin level would influence the neural efficacy in processing social interactions, and thereby modulate the subjective time of perceived social interactions.
Discussion:
As one of many social species, humans seek out companionship and social interactions. The current study demonstrates that such a motive is weaved in our mental representation of time: Motion sequences depicting agents engaging in social interactions tend to be perceived as shorter in duration than those showing agents acting noncommunicatively. This temporal compression effect is independent of the basic visual features or the non-biological properties of the agents( Experiment 1), or the spatial-temporal correlations in between( Experiments 2 and 3), and cannot be explained by the inference of causality or the contingency between two entities’ movements( Supplementary Experiment). Rather, it relies on the observer’s intrinsic autistic-like tendency, such that socially less proficient individuals are less susceptible to the effect than socially proficient ones( Experiment 4). The mechanism underlying this phenomenon critically involves oxytocin. In socially less proficient individuals that overall have lower levels of endogenous oxytocin( Andari et al., 2014; Modahl et al., 1998; Parker et al., 2014), oxytocin administration promotes the social interaction induced temporal compression effect( Experiment 5). By contrast, in socially proficient individuals with overall higher levels of endogenous oxytocin, the very effect is diminished following the application of an oxytocin antagonist named atosiban( Experiment 6). Whereas distortion of time perception has been widely associated with properties of the stimuli( Eagleman, 2008) and the context( Shi et al., 2013), these findings provide, to our best knowledge, the first empirical evidence that links the subjective time of an event with a personality trait, namely social proficiency. In doing so, they open up a new avenue to probe automatic processing of complex social interplays at the individual level. Social perception involves multifaceted information processing that culminates in the accurate recognition of others’ dispositions and intensions. It inherently entails the integration of information, including the integration between origin and effect( causal integration), the integration of clues( e. g. motion cues) to form impressions, extract intentions, and arrive at judgments( cognitive algebra), etc( Anderson, 1981; Blythe et al., 1999; Heider, 1944; Smith, 1984). Autism spectrum disorders have been associated with deficits in sensory integration( Brandwein et al., 2013; Gepner and Mestre, 2002), though not with unisensory temporal function per se( Stevenson et al., 2014). It is plausible that such deficits cascade into the domain of social interactions and partially cause the aforementioned effects. Multiple brain regions are engaged in social perception, and coordinately enable efficient assessment and interpretation of social signals. They include not only the STS that supports the understanding of actions( Allison et al., 2000), but also higher cortical areas like the temporal-parietal junction( TPJ) that represents mental states( Carter and Huettel, 2013) and the dorsal medial prefrontal cortex( dmPFC) that is implicated in the uniquely human representation of triadic interactions between two minds and an object( Saxe, 2006). The observed temporal compression effect, being independent of the perception of biological motion, likely arises from these higher stages of social processing( Cusack et al., 2015; von der Lühe et al., 2016). Subjective time has been proposed to be a signature of the amount of energy expended in representing a stimulus( Eagleman and Pariyadath, 2009). It is plausible that communicative motion sequences are processed with increased efficiency in TPJ and dmPFC relative to motion sequences without a recognizable communicative intention, thus leading to lowered metabolic cost( Gutnisky and Dragoi, 2008; Laughlin, 2001) and shortened subjective duration, particularly in socially proficient individuals. Of note here is that this temporal compression effect can hardly be accounted for by the operation of a dedicated neural module specialized for representing the temporal relationships between events( Ivry and Schlerf, 2008), since it is specific to the perception of social interactions. Oxytocin partially drives social motivation( Dölen et al., 2013) and has increasingly been identified as an important modulator of social behaviors( Carter, 2014; Donaldson and Young, 2008) ranging from social recognition( Oettl et al., 2016) to consolation( Burkett et al., 2016) and ethnocentrism( De Dreu et al., 2011). It has also been linked to repetitive behaviors –– a core feature of autism( Hollander et al., 2003; Insel et al., 1999). Results from human brain imaging studies indicate that the application of oxytocin modulates responses in the STS, TPJ and the prefrontal cortex, among others, in various social cognitive tasks( Zink and Meyer-Lindenberg, 2012). Such alterations of neural activities presumably facilitate social processing in socially less proficient individuals, where exogenous oxytocin has been shown to exert a more definitive prosocial effect( Bartz et al., 2010; Bartz et al., 2011), thereby giving rise to their shortened subjective duration of social interactions following oxytocin administration. In socially proficient individuals, the influence of exogenous oxytocin is more complicated, even hard to predict and interpret( Bartz, 2016; Bartz et al., 2010; Bartz et al., 2011; Olff et al., 2013). Nevertheless, we were able to show that antagonizing the effect of endogenous oxytocin with atosiban in this group of observers reduced the temporal compression effect as compared to a placebo control. The comparison between oxytocin and atosiban spoke directly to the role of oxytocin in mediating time perception of social interactions. This finding also adds to and extends the extant pharmacological research on time perception, which has primarily focused on dopamine, serotonin and acetylcholine( Allman and Meck, 2012; Meck, 1998). We conclude that the perceived duration of social interactions is a product of complex neuroendocrine and neural processes, the exact mechanism awaiting further investigation, and is ingrained with one’s social traits. Subjective time is not only nonuniform, like Einstein alluded to in his analogy, but also idiosyncratic.
Einstein once joked: “Put your hand on a hot stove for a minute , and it seems like an hour . Sit with a pretty girl for an hour , and it seems like a minute . That’s relativity . ” While it may not have helped explain the space-time continuum , his joke neatly captures how time can appear to pass at different rates . This perception depends in part on the sensory properties of the stimuli we are experiencing . Intense stimuli , such as bright and fast-moving objects , trigger stronger responses in the brain than less intense stimuli , and so we perceive them as longer lasting . But what role do we , as the experiencers , play in how we perceive time ? To find out , Liu , Yuan , Chen et al . showed volunteers pairs of movie clips , each featuring two human figures outlined by dots . In one clip , the two figures interacted socially , for example by passing an object between them . In the other , the two figures moved independently of each other . The volunteers had to decide which clip lasted longer . The volunteers generally judged clips containing social interactions to be shorter than those without such interactions , even when this was not the case . Moreover , volunteers with better social skills tended to underestimate the length of the social interaction clips to a greater extent . Previous studies have shown that people who are more social tend to have higher levels of a hormone called oxytocin in their blood . Oxytocin is sometimes referred to as the ‘love hormone’ because it promotes social behavior and bonding . Applying an oxytocin nasal spray to the volunteers who were less socially proficient caused them to perceive the social interaction clips as shorter than before . By contrast , socially proficient volunteers who used a nasal spray that blocks the effects of oxytocin perceived these clips as longer than they had done previously ( although they still judged the clips to be shorter than videos that did not show people interacting ) . The perception of time thus varies between people and may depend at least in part on personality . These results open up a new avenue for studying and manipulating how we process social situations . This could eventually benefit people who struggle with social interactions , such as those with autism spectrum disorders .