Facial expressions are usually linked to emotional states of a person, and are among the most salient cues for automatic emotion recognition. They are an indispensable social communication tool, and therefore, they can also be fabricated to face complex situations in social interaction. Despite efforts to either deliberately or unconsciously conceal an emotion, micro-expressions are usually leaked. Because of their revealing nature, potential applications can arise from automatically detecting them, both at a personal and inter-personal levels. Therefore, we explored micro-expression detection using a wearable device that detects distal facial EMG signals unobtrusively, as an alternative to Computer Vision-based detection. EMG recognition is advantageous over commonly used video recognition techniques because of its robustness against occlusion and light changes, good temporal resolution, and independence of movement. We evaluated the performance of the wearable device on micro-smile recognition. The results show the potential of EMG to detect such fast and subtle spontaneous expressions. Finally, we evaluated the device as a tool to provide affective annotations of Advertisement Videos, and social interaction in a face-to-face context while watching these stimuli.

According to cognitive-dissonance theory, performing counterattitudinal behavior produces a state of dissonance that people are motivated to resolve, usually by changing their attitude to be in line with their behavior. One of the most popular experimental paradigms used to produce such attitude change is the induced-compliance paradigm. Despite its popularity, the replication crisis in social psychology and other fields, as well as methodological limitations associated with the paradigm, raise concerns about the robustness of classic studies in this literature. We therefore conducted a multilab constructive replication of the induced-compliance paradigm based on Croyle and Cooper (Experiment 1). In a total of 39 labs from 19 countries and 14 languages, participants ( N = 4,898) were assigned to one of three conditions: writing a counterattitudinal essay under high choice, writing a counterattitudinal essay under low choice, or writing a neutral essay under high choice. The primary analyses failed to support the core hypothesis: No significant difference in attitude was observed after writing a counterattitudinal essay under high choice compared with low choice. However, we did observe a significant difference in attitude after writing a counterattitudinal essay compared with writing a neutral essay. Secondary analyses revealed the pattern of results to be robust to data exclusions, lab variability, and attitude assessment. Additional exploratory analyses were conducted to test predictions from cognitive-dissonance theory. Overall, the results call into question whether the induced-compliance paradigm provides robust evidence for cognitive dissonance.

Virtual co-embodiment enables two users to share a single avatar in Virtual Reality (VR). During such experiences, the illusion of shared motion control can break during joint-action activities, highlighting the need for position-aware feedback mechanisms. Drawing on the perceptual crossing paradigm, we explore how haptics can enable non-verbal coordination between co-embodied participants. In a within-subjects study (20 participant pairs), we examined the effects of vibrotactile haptic feedback (None, Present) and avatar control distribution (25-75%, 50-50%, 75-25%) across two VR reaching tasks (Targeted, Free-choice) on participants’ Sense of Agency (SoA), co-presence, body ownership, and motion synchrony. We found (a) lower SoA in the free-choice with haptics than without, (b) higher SoA during the shared targeted task, (c) co-presence and body ownership were significantly higher in the free-choice task, (d) players’ hand motions synchronized more in the targeted task. We provide cautionary considerations when including haptic feedback mechanisms for avatar co-embodiment experiences.

Facial expressions are behavioural cues that represent an affective state. Because of this, they are an unobtrusive alternative to affective self-report. The perceptual identification of facial expressions can be performed automatically with technological assistance. Once the facial expressions have been identified, the interpretation is usually left to a field expert. However, facial expressions do not always represent the felt affect; they can also be a communication tool. Therefore, facial expression measurements are prone to the same biases as self-report. Hence, the automatic measurement of human affect should also make inferences on the nature of the facial expressions instead of describing facial movements only. We present two experiments designed to assess whether such automated inferential judgment could be advantageous. In particular, we investigated the differences between posed and spontaneous smiles. The aim of the first experiment was to elicit both types of expressions. In contrast to other studies, the temporal dynamics of the elicited posed expression were not constrained by the eliciting instruction. Electromyography (EMG) was used to automatically discriminate between them. Spontaneous smiles were found to differ from posed smiles in magnitude, onset time, and onset and offset speed independently of the producer’s ethnicity. Agreement between the expression type and EMG-based automatic detection reached 94% accuracy. Finally, measurements of the agreement between human video coders showed that although agreement on perceptual labels is fairly good, the agreement worsens with inferential labels. A second experiment confirmed that a layperson’s accuracy as regards distinguishing posed from spontaneous smiles is poor. Therefore, the automatic identification of inferential labels would be beneficial in terms of affective assessments and further research on this topic.

Recently, we saw a trend toward using physiological signals in interactive systems. These signals, offering deep insights into users’ internal states and health, herald a new era for HCI. However, as this is an interdisciplinary approach, many challenges arise for HCI researchers, such as merging diverse disciplines, from understanding physiological functions to design expertise. Also, isolated research endeavors limit the scope and reach of findings. This workshop aims to bridge these gaps, fostering cross-disciplinary discussions on usability, open science, and ethics tied to physiological data in HCI. In this workshop, we will discuss best practices for embedding physiological signals in interactive systems. Through collective efforts, we seek to craft a guiding document for best practices in physiological HCI research, ensuring that it remains grounded in shared principles and methodologies as the field advances.

The Human-computer Interaction (HCI) community has the opportunity to foster the integration of research practices across the Global South and North to begin overcoming colonial relationships. In this paper, we focus on the case of Latin America (LATAM), where initiatives to increase the representation of HCI practitioners lack a consolidated understanding of the practices they employ, the factors that influence them, and the challenges that practitioners face. To address this knowledge gap, we employ a mixed-methods approach, comprising a survey (66 respondents) and in-depth interviews (19 interviewees). Our analyses characterize a set of research perspectives on how HCI is practiced in/about LATAM; a set of driving forces and tensions with a heavy reliance on diasporic dynamics; and a set of professional demands and associated structural limitations. We also offer a roadmap towards building connections across HCI communities, in an attempt to rebuild HCI as a pluriverse.