Duration of face mask exposure matters: evidence from Swiss and Brazilian kindergartners' ability to recognise emotions.

Wearing facial masks became a common practice worldwide during the COVID-19 pandemic. This study investigated (1) whether facial masks that cover adult faces affect 4- to 6-year-old children's recognition of emotions in those faces and (2) whether the duration of children's exposure to masks is associated with emotion recognition. We tested children from Switzerland (N = 38) and Brazil (N = 41). Brazil represented longer mask exposure due to a stricter mandate during COVID-19. Children had to choose a face displaying a specific emotion (happy, angry, or sad) when the face wore either no cover, a facial mask, or sunglasses. The longer hours of mask exposure were associated with better emotion recognition. Controlling for the hours of exposure, children were less likely to recognise emotions in partially hideen faces. Moreover, Brazilian children were more accurate in recognising happy faces than Swiss children. Overall, facial masks may negatively impact children's emotion recognition. However, prolonged exposure appears to buffer the lack of facial cues from the nose and mouth. In conclusion, restricting facial cues due to masks may impair kindergarten children's emotion recognition in the short run. However, it may facilitate their broader reading of facial emotional cues in the long run.

The role of motor inhibition in implicit negation processing: two Go/No-Go behavioral studies.

Several studies demonstrated that explicit forms of negation processing (e.g., "I don't know") recruits motor inhibitory mechanisms. However, whether this is also true for implicit negation, in which the negative meaning is implicated but not explicitly lexicalized in the sentence (e.g., "I ignore"), has never been studied before. Two Go/No-Go studies, which differed only for the time-windows to respond to the Go stimulus, were carried out. In each, participants (N = 86 in experiment 1; N = 87 in experiment 2) respond to coloured circle while reading task-irrelevant affirmative, explicit negative and implicit negative sentences. We aimed to investigate whether: (i) the processing of implicit negations recruits inhibitory mechanisms; (ii) these inhibitory resources are differently modulated by implicit and explicit negations. Results show that implicit negative sentences recruit the inhibitory resources more strongly when compared to explicit ones, probably due to their inferential nature, likely requiring deeper processing of the negative meaning. Implicit and inferential meaning (i.e., pragmatic information) are grounded too in the same mechanisms that integrate action with perception. Such findings provide further evidence to the embodied account of language, showing that even abstract aspects, like implicit negation, are grounded in the sensory-motor system, by means of functional link between language and motor activity.

The effect of Surround sound on embodiment and sense of presence in cinematic experience: a behavioral and HD-EEG study.

Although many studies have investigated spectators' cinematic experience, only a few of them explored the neurophysiological correlates of the sense of presence evoked by the spatial characteristics of audio delivery devices. Nevertheless, nowadays both the industrial and the consumer markets have been saturated by some forms of spatial audio format that enrich the audio-visual cinematic experience, reducing the gap between the real and the digitally mediated world. The increase in the immersive capabilities corresponds to the instauration of both the sense of presence and the psychological sense of being in the virtual environment and also embodied simulation mechanisms. While it is well-known that these mechanisms can be activated in the real world, it is hypothesized that they may be elicited even in a virtual acoustic spatial environment and could be modulated by the acoustic spatialization cues reproduced by sound systems. Hence, the present study aims to investigate the neural basis of the sense of presence evoked by different forms of mediation by testing different acoustic space sound delivery (Presentation modes: Monophonic, Stereo, and Surround). To these aims, a behavioral investigation and a high-density electroencephalographic (HD-EEG) study have been developed. A large set of ecological and heterogeneous stimuli extracted from feature films were used. Furthermore, participants were selected following the generalized listener selection procedure. We found a significantly higher event-related desynchronization (ERD) in the Surround Presentation mode when compared to the Monophonic Presentation mode both in Alpha and Low-Beta centro-parietal clusters. We discuss this result as an index of embodied simulation mechanisms that could be considered as a possible neurophysiological correlation of the instauration of the sense of presence.

Is motor inhibition involved in the processing of sentential negation? An assessment via the Stop-Signal Task.

In the last decades, the embodied approach to cognition and language gained momentum in the scientific debate, leading to evidence in different aspects of language processing. However, while the bodily grounding of concrete concepts seems to be relatively not controversial, abstract aspects, like the negation logical operator, are still today one of the main challenges for this research paradigm. In this framework, the present study has a twofold aim: (1) to assess whether mechanisms for motor inhibition underpin the processing of sentential negation, thus, providing evidence for a bodily grounding of this logic operator, (2) to determine whether the Stop-Signal Task, which has been used to investigate motor inhibition, could represent a good tool to explore this issue. Twenty-three participants were recruited in this experiment. Ten hand-action-related sentences, both in affirmative and negative polarity, were presented on a screen. Participants were instructed to respond as quickly and accurately as possible to the direction of the Go Stimulus (an arrow) and to withhold their response when they heard a sound following the arrow. This paradigm allows estimating the Stop Signal Reaction Time (SSRT), a covert reaction time underlying the inhibitory process. Our results show that the SSRT measured after reading negative sentences are longer than after reading affirmative ones, highlighting the recruitment of inhibitory mechanisms while processing negative sentences. Furthermore, our methodological considerations suggest that the Stop-Signal Task is a good paradigm to assess motor inhibition's role in the processing of sentence negation.

Emotional body postures affect inhibitory control only when task-relevant.

A classical theoretical frame to interpret motor reactions to emotional stimuli is that such stimuli, particularly those threat-related, are processed preferentially, i.e., they are capable of capturing and grabbing attention automatically. Research has recently challenged this view, showing that the task relevance of emotional stimuli is crucial to having a reliable behavioral effect. Such evidence indicated that emotional facial expressions do not automatically influence motor responses in healthy young adults, but they do so only when intrinsically pertinent to the ongoing subject's goals. Given the theoretical relevance of these findings, it is essential to assess their generalizability to different, socially relevant emotional stimuli such as emotional body postures. To address this issue, we compared the performance of 36 right-handed participants in two different versions of a Go/No-go task. In the Emotional Discrimination task, participants were required to withhold their responses at the display of emotional body postures (fearful or happy) and to move at the presentation of neutral postures. Differently, in the control task, the same images were shown, but participants had to respond according to the color of the actor/actress' t-shirt, disregarding the emotional content. Results showed that participants made more commission errors (instances in which they moved even though the No-go signal was presented) for happy than fearful body postures in the Emotional Discrimination task. However, this difference disappeared in the control task. Such evidence indicates that, like facial emotion, emotional body expressions do not influence motor control automatically, but only when they are task-relevant.

The consequences of COVID-19 on social interactions: an online study on face covering.

The COVID-19 pandemic has dramatically changed the nature of our social interactions. In order to understand how protective equipment and distancing measures influence the ability to comprehend others' emotions and, thus, to effectively interact with others, we carried out an online study across the Italian population during the first pandemic peak. Participants were shown static facial expressions (Angry, Happy and Neutral) covered by a sanitary mask or by a scarf. They were asked to evaluate the expressed emotions as well as to assess the degree to which one would adopt physical and social distancing measures for each stimulus. Results demonstrate that, despite the covering of the lower-face, participants correctly recognized the facial expressions of emotions with a polarizing effect on emotional valence ratings found in females. Noticeably, while females' ratings for physical and social distancing were driven by the emotional content of the stimuli, males were influenced by the "covered" condition. The results also show the impact of the pandemic on anxiety and fear experienced by participants. Taken together, our results offer novel insights on the impact of the COVID-19 pandemic on social interactions, providing a deeper understanding of the way people react to different kinds of protective face covering.

Audience spontaneous entrainment during the collective enjoyment of live performances: physiological and behavioral measurements.

Cardiac synchrony is a crucial component of shared experiences, considered as an objective measure of emotional processes accompanying empathic interactions. No study has investigated whether cardiac synchrony among people engaged in collective situations links to the individual emotional evaluation of the shared experience. We investigated theatrical live performances as collective experiences evoking strong emotional engagement in the audience. Cross Recurrence Quantification Analysis was applied to obtain the cardiac synchrony of twelve spectators' quartets attending to two live acting performances. This physiological measure was then correlated with spectators' emotional intensity ratings. Results showed an expected increment in synchrony among people belonging to the same quartet during both performances attendance and rest periods. Furthermore, participants' cardiac synchrony was found to be correlated with audience's convergence in the explicit emotional evaluation of the performances they attended to. These findings demonstrate that the mere co-presence of other people sharing a common experience is enough for cardiac synchrony to occur spontaneously and that it increases in function of a shared and coherent explicit emotional experience.

Haptic Aesthetics and Bodily Properties of Ori Gersht's Digital Art: A Behavioral and Eye-Tracking Study.

Experimental aesthetics has shed light on the involvement of pre-motor areas in the perception of abstract art. However, the contribution of texture perception to aesthetic experience is still understudied. We hypothesized that digital screen-based art, despite its immateriality, might suggest potential sensorimotor stimulation. Original born-digital works of art were selected and manipulated by the artist himself. Five behavioral parameters: Beauty, Liking, Touch, Proximity, and Movement, were investigated under four experimental conditions: Resolution (high/low), and Magnitude (Entire image/detail). These were expected to modulate the quantity of material and textural information afforded by the image. While the Detail condition afforded less content-related information, our results show that it augmented the image's haptic appeal. High Resolution improved the haptic and aesthetic properties of the images. Furthermore, aesthetic ratings positively correlated with sensorimotor ratings. Our results demonstrate a strict relation between the aesthetic and sensorimotor/haptic qualities of the images, empirically establishing a relationship between beholders' bodily involvement and their aesthetic judgment of visual works of art. In addition, we found that beholders' oculomotor behavior is selectively modulated by the perceptual manipulations being performed. The eye-tracking results indicate that the observation of the Entire, original images is the only condition in which the latency of the first fixation is shorter when participants gaze to the left side of the images. These results thus demonstrate the existence of a left-side bias during the observation of digital works of art, in particular, while participants are observing their original version.

Sharing the filmic experience - The physiology of socio-emotional processes in the cinema.

As we identify with characters on screen, we simulate their emotions and thoughts. This is accompanied by physiological changes such as galvanic skin response (GSR), an indicator for emotional arousal, and respiratory sinus arrhythmia (RSA), referring to vagal activity. We investigated whether the presence of a cinema audience affects these psychophysiological processes. The study was conducted in a real cinema in Berlin. Participants came twice to watch previously rated emotional film scenes eliciting amusement, anger, tenderness or fear. Once they watched the scenes alone, once in a group. We tested whether the vagal modulation in response to the mere presence of others influences explicit (reported) and implicit markers (RSA, heart rate (HR) and GSR) of emotional processes in function of solitary or collective enjoyment of movie scenes. On the physiological level, we found a mediating effect of vagal flexibility to the mere presence of others. Individuals showing a high baseline difference (alone vs. social) prior to the presentation of film, maintained higher RSA in the alone compared to the social condition. The opposite pattern emerged for low baseline difference individuals. Emotional arousal as reflected in GSR was significantly more pronounced during scenes eliciting anger independent of the social condition. On the behavioural level, we found evidence for emotion-specific effects on reported empathy, emotional intensity and Theory of Mind. Furthermore, people who decrease their RSA in response to others' company are those who felt themselves more empathically engaged with the characters. Our data speaks in favour of a specific role of vagal regulation in response to the mere presence of others in terms of explicit empathic engagement with characters during shared filmic experience.

Embodying the camera: An EEG study on the effect of camera movements on film spectators´ sensorimotor cortex activation.

One key feature of film consists in its power to bodily engage the viewer. Previous research has suggested lens and camera movements to be among the most effective stylistic devices involved in such engagement. In an EEG experiment we assessed the role of such movements in modulating specific spectators´ neural and experiential responses, likely reflecting such engagement. We produced short video clips of an empty room with a still, a zooming and a moving camera (steadicam) that might simulate the movement of an observer in different ways. We found an event related desynchronization of the beta components of the rolandic mu rhythm that was stronger for the clips produced with steadicam than for those produced with a still or zooming camera. No equivalent modulation in the attention related occipital areas was found, thus confirming the sensorimotor nature of spectators´ neural responses to the film clips. The present study provides the first empirical evidence that filmic means such as camera movements alone can modulate spectators' bodily engagement with film.

How context influences the interpretation of facial expressions: a source localization high-density EEG study on the "Kuleshov effect".

Few studies have explored the specificities of contextual modulations of the processing of facial expressions at a neuronal level. This study fills this gap by employing an original paradigm, based on a version of the filmic "Kuleshov effect". High-density EEG was recorded while participants watched film sequences consisting of three shots: the close-up of a target person's neutral face (Face_1), the scene that the target person was looking at (happy, fearful, or neutral), and another close-up of the same target person's neutral face (Face_2). The participants' task was to rate both valence and arousal, and subsequently to categorize the target person's emotional state. The results indicate that despite a significant behavioural 'context' effect, the electrophysiological indexes still indicate that the face is evaluated as neutral. Specifically, Face_2 elicited a high amplitude N170 when preceded by neutral contexts, and a high amplitude Late Positive Potential (LPP) when preceded by emotional contexts, thus showing sensitivity to the evaluative congruence (N170) and incongruence (LPP) between context and Face_2. The LPP activity was mainly underpinned by brain regions involved in facial expressions and emotion recognition processing. Our results shed new light on temporal and neural correlates of context-sensitivity in the interpretation of facial expressions.

How Context Influences Our Perception of Emotional Faces: A Behavioral Study on the Kuleshov Effect.

Facial expressions are of major importance in understanding the mental and emotional states of others. So far, most studies on the perception and comprehension of emotions have used isolated facial expressions as stimuli; for example, photographs of actors displaying facial expressions corresponding to one of the so called 'basic emotions.' However, our real experience during social interactions is different: facial expressions of emotion are mostly perceived in a wider context, constituted by body language, the surrounding environment, and our beliefs and expectations. Already in the early twentieth century, the Russian filmmaker Lev Kuleshov argued that such context, established by intermediate shots of strong emotional content, could significantly change our interpretation of facial expressions in film. Prior experiments have shown behavioral effects pointing in this direction, but have only used static images as stimuli. Our study used a more ecological design with participants watching film sequences of neutral faces, crosscut with scenes of strong emotional content (evoking happiness or fear, plus neutral stimuli as a baseline condition). The task was to rate the emotion displayed by a target person's face in terms of valence, arousal, and category. Results clearly demonstrated the presence of a significant effect in terms of both valence and arousal in the fear condition only. Moreover, participants tended to categorize the target person's neutral facial expression choosing the emotion category congruent with the preceding context. Our results highlight the context-sensitivity of emotions and the importance of studying them under ecologically valid conditions.

"Embodied Body Language": an electrical neuroimaging study with emotional faces and bodies.

To date, most investigations in the field of affective neuroscience mainly focused on the processing of facial expressions, overlooking the exploration of emotional body language (EBL), its capability to express our emotions notwithstanding. Few electrophysiological studies investigated the time course and the neural correlates of EBL and the integration of face and body emotion-related information. The aim of the present study was to investigate both the time course and the neural correlates underlying the integration of affective information conveyed by faces and bodies. We analysed EEG activities evoked during an expression matching task, requiring the judgment of emotional congruence between sequentially presented pairs of stimuli belonging to the same category (face-face or body-body), and between stimuli belonging to different categories (face-body or body-face). We focused on N400 time window and results showed that incongruent stimuli elicited a modulation of the N400 in all comparisons except for body-face condition. This modulation was mainly detected in the Middle Temporal Gyrus and within regions related to the mirror mechanism. More specifically, while the perception of incongruent facial expressions activates somatosensory-related representations, incongruent emotional body postures also require the activation of motor and premotor representations, suggesting a strict link between emotion and action.

"Cuts in Action": A High-Density EEG Study Investigating the Neural Correlates of Different Editing Techniques in Film.

In spite of their striking differences with real-life perception, films are perceived and understood without effort. Cognitive film theory attributes this to the system of continuity editing, a system of editing guidelines outlining the effect of different cuts and edits on spectators. A major principle in this framework is the 180° rule, a rule recommendation that, to avoid spectators' attention to the editing, two edited shots of the same event or action should not be filmed from angles differing in a way that expectations of spatial continuity are strongly violated. In the present study, we used high-density EEG to explore the neural underpinnings of this rule. In particular, our analysis shows that cuts and edits in general elicit early ERP component indicating the registration of syntactic violations as known from language, music, and action processing. However, continuity edits and cuts-across the line differ from each other regarding later components likely to be indicating the differences in spatial remapping as well as in the degree of conscious awareness of one's own perception. Interestingly, a time-frequency analysis of the occipital alpha rhythm did not support the hypothesis that such differences in processing routes are mainly linked to visual attention. On the contrary, our study found specific modulations of the central mu rhythm ERD as an indicator of sensorimotor activity, suggesting that sensorimotor networks might play an important role. We think that these findings shed new light on current discussions about the role of attention and embodied perception in film perception and should be considered when explaining spectators' different experience of different kinds of cuts.

Correction: Proactive Control Strategies for Overt and Covert Go/NoGo Tasks: an Electrical Neuroimaging Study.

[This corrects the article DOI: 10.1371/journal.pone.0152188.].

Proactive Control Strategies for Overt and Covert Go/NoGo Tasks: An Electrical Neuroimaging Study.

Proactive and reactive inhibition are generally intended as mechanisms allowing the withholding or suppression of overt movements. Nonetheless, inhibition could also play a pivotal role during covert actions (i.e., potential motor acts not overtly performed, despite the activation of the motor system), such as Motor Imagery (MI). In a previous EEG study, we analyzed cerebral activities reactively triggered during two cued Go/NoGo tasks, requiring execution or withholding of overt or covert imagined actions, respectively. This study revealed activation of pre-supplementary motor area (pre-SMA) and right inferior frontal gyrus (rIFG), key nodes of the network underpinning reactive inhibition of overt responses in NoGo trials, also during MI enactment, enabling the covert nature of the imagined motor response. Taking into account possible proactive engagement of inhibitory mechanisms by cue signals, for an exhaustive interpretation of these previous findings in the present study we analyzed EEG activities elicited during the preparatory phase of our cued overt and covert Go/NoGo tasks. Our results demonstrate a substantial overlap of cerebral areas activated during proactive recruitment and subsequent reactive implementation of motor inhibition in both overt and covert actions; also, different involvement of pre-SMA and rIFG emerged, in accord with the intended type (covert or overt) of incoming motor responses. During preparation of the overt Go/NoGo task, the cue is encoded in a pragmatic mode, as it primes the possible overt motor response programs in motor and premotor cortex and, through preactivation of a pre-SMA-related decisional mechanism, it triggers a parallel preparation for successful response selection and/or inhibition during the response phase. Conversely, the preparatory strategy for the covert Go/NoGo task is centered on priming of an inhibitory mechanism in rIFG, tuned to the instructed covert modality of motor performance and instantiated during subsequent MI, which allows the imagined response to remain a potential motor act.

Motor Inhibition during Overt and Covert Actions: An Electrical Neuroimaging Study.

Given ample evidence for shared cortical structures involved in encoding actions, whether or not subsequently executed, a still unsolved problem is the identification of neural mechanisms of motor inhibition, preventing "covert actions" as motor imagery from being performed, in spite of the activation of the motor system. The principal aims of the present study were the evaluation of: 1) the presence in covert actions as motor imagery of putative motor inhibitory mechanisms; 2) their underlying cerebral sources; 3) their differences or similarities with respect to cerebral networks underpinning the inhibition of overt actions during a Go/NoGo task. For these purposes, we performed a high density EEG study evaluating the cerebral microstates and their related sources elicited during two types of Go/NoGo tasks, requiring the execution or withholding of an overt or a covert imagined action, respectively. Our results show for the first time the engagement during motor imagery of key nodes of a putative inhibitory network (including pre-supplementary motor area and right inferior frontal gyrus) partially overlapping with those activated for the inhibition of an overt action during the overt NoGo condition. At the same time, different patterns of temporal recruitment in these shared neural inhibitory substrates are shown, in accord with the intended overt or covert modality of action performance. The evidence that apparently divergent mechanisms such as controlled inhibition of overt actions and contingent automatic inhibition of covert actions do indeed share partially overlapping neural substrates, further challenges the rigid dichotomy between conscious, explicit, flexible and unconscious, implicit, inflexible forms of motor behavioral control.

Audio-visuomotor processing in the musician's brain: an ERP study on professional violinists and clarinetists.

The temporal dynamics of brain activation during visual and auditory perception of congruent vs. incongruent musical video clips was investigated in 12 musicians from the Milan Conservatory of music and 12 controls. 368 videos of a clarinetist and a violinist playing the same score with their instruments were presented. The sounds were similar in pitch, intensity, rhythm and duration. To produce an audiovisual discrepancy, in half of the trials, the visual information was incongruent with the soundtrack in pitch. ERPs were recorded from 128 sites. Only in musicians for their own instruments was a N400-like negative deflection elicited due to the incongruent audiovisual information. SwLORETA applied to the N400 response identified the areas mediating multimodal motor processing: the prefrontal cortex, the right superior and middle temporal gyrus, the premotor cortex, the inferior frontal and inferior parietal areas, the EBA, somatosensory cortex, cerebellum and SMA. The data indicate the existence of audiomotor mirror neurons responding to incongruent visual and auditory information, thus suggesting that they may encode multimodal representations of musical gestures and sounds. These systems may underlie the ability to learn how to play a musical instrument.

Comprehending body language and mimics: an ERP and neuroimaging study on Italian actors and viewers.

In this study, the neural mechanism subserving the ability to understand people's emotional and mental states by observing their body language (facial expression, body posture and mimics) was investigated in healthy volunteers. ERPs were recorded in 30 Italian University students while they evaluated 280 pictures of highly ecological displays of emotional body language that were acted out by 8 male and female Italian actors. Pictures were briefly flashed and preceded by short verbal descriptions (e.g., "What a bore!") that were incongruent half of the time (e.g., a picture of a very attentive and concentrated person shown after the previous example verbal description). ERP data and source reconstruction indicated that the first recognition of incongruent body language occurred 300 ms post-stimulus. swLORETA performed on the N400 identified the strongest generators of this effect in the right rectal gyrus (BA11) of the ventromedial orbitofrontal cortex, the bilateral uncus (limbic system) and the cingulate cortex, the cortical areas devoted to face and body processing (STS, FFA EBA) and the premotor cortex (BA6), which is involved in action understanding. These results indicate that face and body mimics undergo a prioritized processing that is mostly represented in the affective brain and is rapidly compared with verbal information. This process is likely able to regulate social interactions by providing on-line information about the sincerity and trustfulness of others.