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In eukaryotic cells, sphingoid long chain bases (LCBs) such as sphingosine or phytosphingosine (PHS) behave as second messengers involved in various processes including programmed cell death (PCD). In plants, induction of PCD by LCBs has now been described, but the signalling pathway is still enigmatic. Using Arabidopsis, we identify new key steps in this pathway. We demonstrate that PHS induces activation of the calcium-dependent kinase CPK3, which phosphorylates its binding partners, the 14-3-3 proteins. This phosphorylation leads to the disruption of the complex and to CPK3 degradation. Using cpk3 knockout lines, we demonstrate that CPK3 is a positive regulator of LCB-mediated PCD. These findings establish 14-3-3-regulated CPK3 as a key component of the LCB pathway leading to PCD in plants. [ABSTRACT FROM AUTHOR]

Social performance is associated with producing good relationships in social communication. In recent years, there has been a growing emphasis on the importance of collaborative problem- solving in social communication. Aiming to enhance collaborative problem-solving, we investigated the characteristics of behavioral signals that impact social performance. In this paper, we analyzed the eye movements and facial expressions of pairs of participants working on a collaborative problem-solving task online. Our eye movement analysis showed that the lower the percentage of looking at the conversation partner is and the higher the percentage of looking outside is, the lower is the social performance. Our facial expression analysis showed that the lower the intensity of expression is in inner brow raiser, the cheek raiser, and the lip corner puller, the lower is the social performance., Competing Interests: Declaration of competing interest None declared., (Copyright © 2025. Published by Elsevier B.V.)

Background: Social communication is a crucial factor influencing human social life. Quantifying the degree of difficulty faced in social communication is necessary for understanding developmental and neurological disorders and for creating systems used in automatic symptom screening and assistive methods such as social skills training (SST). SST by a human trainer is a well-established method. Previous SST used a modified roleplay test to evaluate human social communication skills. However, there are no widely accepted evaluation criteria or social behavioral markers to quantify social performance during SST., Objective: This paper has 2 objectives. First, we propose applying the Social Performance Rating Scale (SPRS) to SST data to measure social communication skills. We constructed a Japanese version of the SPRS already developed in English and French. Second, we attempt to quantify action units during SST for people with autism spectrum disorder (ASD) or schizophrenia., Methods: We used videos of interactions between trainers, adults with ASD (n=16) or schizophrenia (n=15), and control participants (n=19) during SST sessions. Two raters applied the proposed scale to annotate the collected data. We investigated the differences between roleplay tasks and participant groups (ASD, schizophrenia, and control). Furthermore, the intensity of action units on the OpenFace toolkit was measured in terms of mean and SD during SST roleplaying., Results: We found significantly greater gaze scores in adults with ASD than in adults with schizophrenia. Differences were also found between the ratings of different tasks in the adults with schizophrenia and the control participants. Action units numbered AU06 and AU12 were significantly deactivated in people with schizophrenia compared with the control group. Moreover, AU02 was significantly activated in people with ASD compared with the other groups., Conclusions: The results suggest that the SPRS can be a useful tool for assessing social communication skills in different cultures and different pathologies when used with the modified roleplay test. Furthermore, facial expressions could provide effective social and behavioral markers to characterize psychometric properties. Possible future directions include using the SPRS for assessing social behavior during interaction with a digital agent., (© Hiroki Tanaka, Kana Miyamoto, Jennifer Hamet Bagnou, Elise Prigent, Céline Clavel, Jean-Claude Martin, Satoshi Nakamura. Originally published in JMIR Formative Research (https://formative.jmir.org).)

Research on the sense of agency has shown that being the author of an action changes the way we estimate the timing and the intensity of the action-effect. Yet, there is a dearth of attempts to assess the influence of agency on perception per se. The present study used the Representational Momentum paradigm to measure participants' visual anticipation of movement while manipulating their agency. In line with previous literature emphasizing the impact of social factors on visual anticipation and on the sense of agency, we additionally investigated the modulating power of social affordances on the relationship between agency and visual anticipation. We conducted two experiments where participants viewed a virtual agent directing a handshake gesture toward a second virtual agent. In a first experiment, we addressed the role of agency on visual anticipation by comparing a condition in which participants triggered the virtual agent's gesture with a condition where the computer triggered the gesture. Results showed greater forward movement anticipation when participants triggered the gesture. The second experiment investigated how altering social interaction parameters (interindividual distance and body posture) modulated the relationship between agency and visual anticipation. The outcome contrasted with the first experiment, with participants anticipating a backward movement of the hand when the computer triggered the gesture and displaying a null anticipation when participants triggered the gesture. Those two experiments highlighted how active involvement and environmental affordance interact to shape perception and allowed us to propose an updated model of agency processing., Competing Interests: Declaration of Competing Interest The authors declare no competing interests., (Copyright © 2022 Elsevier B.V. All rights reserved.)

Context: Behavioral observation scales are important for understanding and assessing social skills. In the context of collaborative problem-solving (CPS) skills, considered essential in the 21st century, there are no validated scales in French that can be adapted to different CPS tasks. The aim of this study is to adapt and validate, by annotating a new video corpus of dyadic interactions that we have collected, two observational scales allowing us to qualitatively assess CPS skills: the Social Performance Rating Scale (SPRS) and the Social Skills of Collaboration Scale (SSC)., Method: The construct validity of these two scales was assessed by exploratory factor analysis and inter-item correlations. We also checked inter-judge agreement using inter-class correlation coefficients. Internal consistency was determined using Cronbach's alpha and convergent and divergent validity by assessing correlations between the two scales and measures of depression and alexithymia. Finally, the discriminative properties of the two scales were analyzed by comparing the scores obtained by a group of anxious individuals and a non-anxious control group., Results: The results show that our two scales have excellent inter-item correlations. Internal consistency is excellent (alpha SPRS =0.90; SSC = 0.93). Inter-rater agreement ranged from moderate to high. Finally, convergent validity was significant with the alexithymia scale, as was divergent validity with the depression scale. Anxious individuals had lower scores on both scales than non-anxious individuals., Conclusion: Both scales show good psychometric properties for assessing social skills relevant to different collaborative tasks. They also identify individuals with difficulties in social interaction. Thus, they could allow monitoring the effectiveness of training social skills useful in CPS., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Hamet Bagnou, Prigent, Martin and Clavel.)

Sign Language (SL) is a continuous and complex stream of multiple body movement features. That raises the challenging issue of providing efficient computational models for the description and analysis of these movements. In the present paper, we used Principal Component Analysis (PCA) to decompose SL motion into elementary movements called principal movements (PMs). PCA was applied to the upper-body motion capture data of six different signers freely producing discourses in French Sign Language. Common PMs were extracted from the whole dataset containing all signers, while individual PMs were extracted separately from the data of individual signers. This study provides three main findings: (1) although the data were not synchronized in time across signers and discourses, the first eight common PMs contained 94.6% of the variance of the movements; (2) the number of PMs that represented 94.6% of the variance was nearly the same for individual as for common PMs; (3) the PM subspaces were highly similar across signers. These results suggest that upper-body motion in unconstrained continuous SL discourses can be described through the dynamic combination of a reduced number of elementary movements. This opens up promising perspectives toward providing efficient automatic SL processing tools based on heavy mocap datasets, in particular for automatic recognition and generation., Competing Interests: The authors have declared that no competing interests exist.

Sign language (SL) motion contains information about the identity of a signer, as does voice for a speaker or gait for a walker. However, how such information is encoded in the movements of a person remains unclear. In the present study, a machine learning model was trained to extract the motion features allowing for the automatic identification of signers. A motion capture (mocap) system recorded six signers during the spontaneous production of French Sign Language (LSF) discourses. A principal component analysis (PCA) was applied to time-averaged statistics of the mocap data. A linear classifier then managed to identify the signers from a reduced set of principal components (PCs). The performance of the model was not affected when information about the size and shape of the signers were normalized. Posture normalization decreased the performance of the model, which nevertheless remained over five times superior to chance level. These findings demonstrate that the identity of a signer can be characterized by specific statistics of kinematic features, beyond information related to size, shape, and posture. This is a first step toward determining the motion descriptors necessary to account for the human ability to identify signers., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2021 Bigand, Prigent, Berret and Braffort.)

When we observe a dynamic emotional facial expression, we usually automatically anticipate how that expression will develop. Our objective was to study a neurocognitive biomarker of this anticipatory process for facial pain expressions, operationalized as a mismatch effect. For this purpose, we studied the behavioral and neuroelectric (Event-Related Potential, ERP) correlates, of a match or mismatch, between the intensity of an expression of pain anticipated by the participant, and the intensity of a static test expression of pain displayed with the use of a representational momentum paradigm. Here, the paradigm consisted in displaying a dynamic facial pain expression which suddenly disappeared, and participants had to memorize the final intensity of the dynamic expression. We compared ERPs in response to congruent (intensity the same as the one memorized) and incongruent (intensity different from the one memorized) static expression intensities displayed after the dynamic expression. This paradigm allowed us to determine the amplitude and direction of this intensity anticipation by measuring the observer's memory bias. Results behaviorally showed that the anticipation was backward (negative memory bias) for high intensity expressions of pain (participants expected a return to a neutral state) and more forward (memory bias less negative, or even positive) for less intense expressions (participants expected increased intensity). Detecting mismatch (incongruent intensity) led to faster responses than detecting match (congruent intensity). The neuroelectric correlates of this mismatch effect in response to the testing of expression intensity ranged from P100 to LPP (Late Positive Potential). Path analysis and source localization suggested that the medial frontal gyrus was instrumental in mediating the mismatch effect through top-down influence on both the occipital and temporal regions. Moreover, having the facility to detect incongruent expressions, by anticipating emotional state, could be useful for prosocial behavior and the detection of trustworthiness., Competing Interests: The authors have declared that no competing interests exist.

To estimate the time-to-contact (TTC) of a moving object, numerous studies have focused on the type of information or gaze strategy used by the observer. However, it remains to be determined whether and how attention could affect TTC estimation. In particular, how does TTC estimation operate when less attention is available? To answer this question, we conducted two experiments in which the participants had to perform an absolute (Experiment 1) or relative (Experiment 2) prediction-motion task, either alone (i.e., in single-task condition) or along with a secondary, visual working-memory task (i.e., in dual-task condition). In both experiments, we found that TTC estimation was superior in dual-task condition relative to single-task condition. This finding suggests that the reduction of available attention actually improves TTC estimation. We discuss possible explanations as well as theoretical implications for this seemingly counter-intuitive finding. Further research is needed to investigate if (in)attention facilitates or only shifts TTC estimation.

Humans have developed a specific capacity to rapidly perceive and anticipate other people's facial expressions so as to get an immediate impression of their emotional state of mind. We carried out two experiments to examine the perceptual and memory dynamics of facial expressions of pain. In the first experiment, we investigated how people estimate other people's levels of pain based on the perception of various dynamic facial expressions; these differ both in terms of the amount and intensity of activated action units. A second experiment used a representational momentum (RM) paradigm to study the emotional anticipation (memory bias) elicited by the same facial expressions of pain studied in Experiment 1. Our results highlighted the relationship between the level of perceived pain (in Experiment 1) and the direction and magnitude of memory bias (in Experiment 2): When perceived pain increases, the memory bias tends to be reduced (if positive) and ultimately becomes negative. Dynamic facial expressions of pain may reenact an "immediate perceptual history" in the perceiver before leading to an emotional anticipation of the agent's upcoming state. Thus, a subtle facial expression of pain (i.e., a low contraction around the eyes) that leads to a significant positive anticipation can be considered an adaptive process-one through which we can swiftly and involuntarily detect other people's pain.

In recent decades, many studies have shown that schizophrenia is associated with severe social cognitive impairments affecting key components, such as the recognition of emotions, theory of mind, attributional style, and metacognition. Most studies investigated each construct separately, precluding analysis of the interactive and immersive nature of real-life situation. Specialized batteries of tests are under investigation to assess social cognition, which is thought now as a link between neurocognitive disorders and impaired functioning. However, this link accounts for a limited part of the variance of real-life functioning. To fill this gap, advances in virtual reality and affective computing have made it possible to carry out experimental investigations of naturalistic social cognition, in controlled conditions, with good reproducibility. This approach is illustrated with the description of a new paradigm based on an original virtual card game in which subjects interpret emotional displays from a female virtual agent, and decipher her helping intentions. Independent variables concerning emotional expression in terms of valence and intensity were manipulated. We show how several useful dependant variables, ranging from classic experimental psychology data to metacognition or subjective experiences records, may be extracted from a single experiment. Methodological issues about the immersion into a simulated intersubjective situation are considered. The example of this new flexible experimental setting, with regards to the many constructs recognized in social neurosciences, constitutes a rationale for focusing on this potential intermediate link between standardized tests and real-life functioning, and also for using it as an innovative media for cognitive remediation.

To predict where a thrown ball will land, an observer may use visual information about its trajectory. However, in addition, the thrower's body language (i.e., body movement and facial expression) may contain useful information that could be used by the observer to understand intention and emotional state. Here, we investigated how observers estimated a ball's landing point thrown by a virtual agent with different amounts of information from body language. In addition, occlusion time was varied to examine how it potentiates the use of body-language information. Results showed that body movement and facial expression carry information about thrower's effort. However, once the ball has left the thrower's hand, advance information on facial expression does contribute to judgments only if consistent with the amplitude of the throw. Moreover, as the occlusion time increases, a stronger influence of the body movement is observed for estimating the landing point. The overriding effect of ball's trajectory availability over body language is discussed.