Abstract
BACKGROUND
Facial expressions are critical for conveying emotions and facilitating social interaction. Yet, little is known about how accurately sighted individuals recognize emotions facially expressed by people with visual impairments in online communication settings.
OBJECTIVE
This study aimed to investigate sighted individuals’ ability to understand facial expressions of six basic emotions in people with visual impairments during Zoom calls. It also aimed to examine whether education on facial expressions specific to people with visual impairments would improve emotion recognition accuracy.
METHODS
Sighted participants viewed video clips of individuals with visual impairments displaying facial expressions. They then identified the emotions displayed. Next, they received an educational session on facial expressions specific to people with visual impairments, addressing unique characteristics and potential misinterpretations. After education, participants viewed another set of video clips and again identified the emotions displayed.
RESULTS
Before education, participants frequently misidentified emotions. After education, their accuracy in recognizing emotions improved significantly.
CONCLUSIONS
This study provides evidence that education on facial expressions of people with visual impairments can significantly enhance sighted individuals’ ability to accurately recognize emotions in online settings. This improved accuracy has the potential to foster more inclusive and effective online interactions between people with and without visual disabilities.
1. Introduction
Facial expression plays a critical role in communication while conveying a rich, non-verbal information, specifically emotional states which significantly contribute to promoting social interaction [1]. The human face has a complex network of muscles on each side, working together to enable chewing, speech, and a wide range of facial expressions [2]. Despite various channels available to humans for expressing emotions, such as non-verbal vocalizations, language, prosody, and chemosensory signals, humans tend to heavily rely on facial expressions [3]. While humans have the capacity to perceive a limitless number of emotions [4], Ekman [5] suggests six basic emotions (happiness, sadness, anger, fear, surprise, and disgust) that are deemed innate and expressed through universal facial expressions. Ekman’s view has been widely embraced by numerous scholars [6, 7, 8, 9, 10].
The Facial Action Coding System (FACS) is a widely adopted method for analyzing facial muscle movements involved in expressing facial expressions [11, 12]. These movements are segmented into individual components, termed Action Units (AUs). Each AU corresponds to distinct facial actions; for instance, AU 6 denotes Cheek Raiser, AU 27 represents Mouth Stretch, AU 45 signifies Blink, and AU 64 indicates Eyes Down [13]. For example, Scherer et al. [14] observed individuals expressing various emotions and noted specific combinations of AUs: AU 5
In addition to expressing emotions effectively, accurately perceiving and understanding the emotions of others is a crucial aspect of emotional intelligence that contributes to social interaction [16, 17, 18, 19]. Even infants possess the ability to perceive facial emotions [20], typically beginning to recognize emotional expressions after six months of age [21]. Ichikawa et al. [22] discovered that infants aged 6 to 7 months were capable of recognizing subtle facial expressions of anger. It has been well documented that an individual’s capacity to recognize emotions through facial expressions can be significantly improved through education [23, 24]. For instance, Patel et al. [25] conducted a study involving social cognition training aimed at enhancing the recognition of facial emotions. Their findings revealed an increase in the accuracy of recognizing facial expressions depicting anger and neutrality. Moreover, they observed a decrease in reaction time, measured as the duration between stimulus presentation and the subsequent mouse-click response for recognizing neutral, fearful, and sad facial expressions. Furthermore, Ekman et al. [26] proposed the potential establishment of a universal expression and perception of emotion through culture-constant learning. This learning encompasses acquiring knowledge about facial expressions that are commonly shared across various cultures. It could be facilitated through diverse means, such as watching movies and television shows, reading books, and engaging with individuals from different cultural backgrounds.
Learning about facial expressions can be challenging for individuals with visual impairments, as they have limited ability to observe how others use facial muscles to convey emotions. This difference in visual experience might lead to differences in facial expressions between individuals with and without visual impairments, depending on their visual acuity levels. Valente et al. [3] argued that prior visual experience might not significantly impact spontaneous facial expressions but could influence voluntary expressions. Spontaneous facial expressions occur involuntarily in response to an emotional state, while voluntary expressions are intentionally produced to convey specific emotions [27]. Several studies [28, 29, 30, 31] support this notion, reporting no significant differences in spontaneous facial expressions between individuals with and without visual impairments. Galati et al. [32] proposed that significant distinctions exist in voluntary facial expressions, based on varying visual acuity levels. This findings suggest that individuals with and without visual impairments may present different voluntary facial expressions. This raises the critical need for further research to investigate the extent to which sighted individuals recognize voluntary facial expressions among people with visual impairments, particularly within cyberspace contexts.
In today’s interconnected world, people extensively leverage diverse information and communication tools for remote communication. Remarkably, individuals with visual impairments have been using various assistive technologies (e.g., screen readers and voice user interfaces) [33] to leverage mainstream technologies including video conferencing applications [34, 35]. These video conferencing applications enable individuals, both with and without visual impairments, to communicate while expressing emotional states through facial expressions. Several studies have delved into understanding of facial expressions shared via cyberspace, which would be beneficial to various stakeholders. For instance, in computer-mediated psychotherapy, understanding emotional interactions between healthcare providers and consumers is pivotal for delivering high quality services [36]. Furthermore, online-collected facial expressions have shown promise in detecting Parkinson’s disease [37] and assessing online users’ personalities [38]. Real-time analysis of facial expressions has been instrumental in promoting communication between online users [39] and designing online recommender systems for e-commerce [40]. User satisfaction in virtual museums has been measured through facial expressions [41]. Moreover, facial expressions play a critical role in assessing online students’ attentiveness and engagement in virtual teaching and learning environments [42, 43, 44].
However, understanding facial expressions of individuals with visual impairments in online settings remains a relatively unexplored area that requires further exploration, particularly when compared to their sighted peers. Various systems have been developed to help people with visual impairments interpret facial expressions of sighted individuals in face-to-face interactions [45, 46]. For instance, engineers developed innovative solutions such as wearable vibrotactile devices and smartphone applications, enabling individuals with visual impairments to understand facial expressions when interacting with others in person. Similarly, systems have also been created to assist sighted individuals in interpreting facial expressions of general populations during face-to-face interactions [47]. Recent studies [15, 48] have contributed to a deeper understanding of how individuals with visual impairments express facial emotions in online interaction. However, despite these efforts, a significant gap remains in understanding the degree to which sighted individuals can accurately discern the emotions expressed through facial expressions of people with visual impairments in online communication settings.
To bridge this knowledge gap, this study investigated the accuracy of sighted individuals’ ability to identify emotions by having them watch videos featuring basic emotions expressed facially by people with visual impairments via Zoom. We further investigated whether their perception could be improved through education focusing on facial expressions specific to people with visual impairments.
2. Methods
2.1. Participants
This study recruited a convenience sample of 43 participants (mean age: 28.86
2.2. Materials
Facial expression videos were randomly chosen from a prior study (citation omitted for anonymized peer review). The videos depicted voluntary facial expressions of six basic emotions (happiness, sadness, anger, fear, surprise, and disgust) displayed by people with visual impairments during online interaction via Zoom. Each video sequence started with a neutral expression, transitioned to a peak emotional expression, and concluded with a return to a neutral expression.
Emotions perceived by sighted participants when viewing facial expression videos of anger displayed by people with visual impairments
Emotions perceived by sighted participants when viewing facial expression videos of disgust displayed by people with visual impairments
2.3. Procedures
Phase I (pre-education). Participants were presented with a set of 30 facial expression videos (five videos for each of the six basic emotions) via Zoom. The order of video was randomized. Participants were instructed to watch each video carefully and identify the emotion being displayed. Their responses were recorded for later analysis.
Education. Following the pre-education phase, participants received a 30-minute education delivered remotely through Zoom. The education aimed to familiarize participants with the findings of the earlier study (citation omitted for anonymized peer review), highlighting the Facial Action Coding System (FACS) and FACS-based models that account for the nuances of facial expressions displayed by people with visual impairments in online settings.
Phase II (post-education). After the education session, participants completed another set of 30 facial expression videos (different from the videos used in the pre-education phase). The videos were again presented in a randomized order. Participants completed the same emotion recognition task as in Phase I.
2.4. Data analysis
Emotion recognition performance was assessed for both phases. Chi-square testing was conducted to determine if there was a significant difference in the perceived emotions before and after education. Statistical analyses were carried out using the IBM SPSS Statistics for Macintosh, version 24 [50].
3. Results
In summary, the study revealed significant differences in participants’ ability to perceive emotions displayed by individuals with visual impairments in online settings. Prior to education (baseline), participants exhibited inaccurate interpretations for all facial expressions, except for happiness. Post-education, their accuracy significantly improved for all emotions displayed, except for fear. This suggests that participants might have encountered challenges in selectively attending to and interpreting subtle facial cues in individuals with visual impairments. Detailed results are available below.
3.1. Anger
Chi-square testing revealed a significant difference in perceived emotions before and after education when participants viewed facial expression videos depicting anger (see Table 1). Before education, there was no specific emotion that was significantly perceived as all the six basic emotions were equally likely to be perceived,
3.2. Disgust
Chi-square testing revealed a significant difference in perceived emotions before and after education by participants when they were presented with facial expression videos depicting disgust (see Table 2). Before education, the most frequently perceived emotion was sadness followed by disgust,
3.3. Fear
Emotions perceived by sighted participants when viewing facial expression videos of fear displayed by people with visual impairments
Chi-square testing revealed a significant difference in perceived emotions before and after education when participants viewed facial expression videos depicting fear (see Table 3). Before education, the most frequently perceived emotion was surprise,
3.4. Happiness
Emotions perceived by sighted participants when viewing facial expression videos of happiness displayed by people with visual impairments
Chi-square testing revealed a significant difference in perceived emotions before and after education when participants viewed facial expression videos depicting happiness (see Table 4). Before education, happiness was the most perceived emotion,
3.5. Sadness
Emotions perceived by sighted participants when viewing facial expression videos of sadness displayed by people with visual impairments
Chi-square testing revealed a significant difference in perceived emotions before and after education when participants viewed facial expression videos depicting sadness (see Table 5). Before education, the most frequently perceived emotion was disgust, followed by sadness,
3.6. Surprise
Emotions perceived by sighted participants when viewing facial expression videos of surprise displayed by people with visual impairments
Chi-square testing revealed a significant difference in perceived emotions before and after education when participants viewed facial expression videos depicting surprise (see Table 6). Before education, the predominantly perceived emotion was happiness, followed by surprise,
4. Discussion
The predominant emotions perceived by participants between before and after education
This study contributes to advancing the understanding of sighted individuals’ capacity to accurately recognize facially expressed emotions in people with visual impairments in online settings. As presented in Table 7 (a summary of Tables 1 to 6), participants exhibited incongruent perception for all facially expressed emotions except happiness, suggesting difficulty in recognizing emotions accurately. However, after education they demonstrated congruent perception for all facially expressed emotions except fear, indicating a significant improvement in recognizing emotions accurately. The following sections offer a detailed discussion of these findings, providing further insights and interpretations.
4.1. Anger
Angry facial expressions presented a unique challenge for participants before education. Participants perceived a range of emotions, including anger, disgust, fear, happiness, sadness, and surprise. However, no specific emotion stood out significantly among these varied emotions. This suggests that sighted individuals are likely to experience challenges interpreting angry facial expressions exhibited by people with visual impairments, potentially confusing them with other emotions such as disgust, fear, happiness, sadness, or surprise. The presentation of angry expressions among individuals with visual impairments primarily involved Action Units (AU) 4
Following education, a significant shift occurred in the perception of emotions. Anger emerged as the prominently perceived emotion, while happiness – which previously held that position – became the least perceived emotion. This substantial change underscores the effectiveness of education in reshaping participants’ interpretations of facial expressions among individuals with visual impairments in online communication settings.
4.2. Disgust
Before education, participants primarily perceived sadness followed by disgust when presented with facial expressions of disgust displayed by individuals with visual impairments. The primary facial expression used to convey both sadness and disgust was a neutral face (AU), potentially contributing to confusion between these emotions. Before education, participants also associated happiness with the facial expressions of disgust, despite the fundamental distinction between these emotions – one positive and the other negative. Wegrzyn et al. [56] found that sighted individuals tended to focus on lower facial muscles (e.g., the mouth) when perceiving such emotion as happiness and disgust. It can therefore be argued that participants in this study might have focused more on the lower part of the face. This selective attention might have led to perceiving similarities between the lower facial expressions of disgust and happiness, causing confusion between the two emotions. A more comprehensive attention encompassing both upper and lower facial areas might have helped participants to avoid such confusion. After education, the perception of happiness significantly diminished in response to the facial expression of disgust, indicating the effectiveness of education in improving the accurate identification of disgust.
4.3. Fear
Despite having received education, sighted participants tended to consistently misinterpret the facial expressions of fear as surprise. Jack et al. [57] proposed a reclassification of human emotions into four categories – (i) anger/disgust, (ii) fear/surprise, (iii) happiness, and (iv) sadness – instead of Ekman’s six categories [5]. According to Jack et al., fear and surprise are not distinctively expressed via facial muscles, resulting in potential confusion between the two emotions. Neta et al. [58]similarly reported that fear expressions were often misinterpreted as surprise due to shared facial muscle movements, particularly widened eyes, in the upper face. This study suggests that education should emphasize the importance of examining the lower parts of the face. This emphasis would enable sighted individuals to develop comprehensive analysis skills, leading to accurate interpretation of facial expressions of fear displayed by people with visual impairments.
4.4. Happiness
The predominantly perceived emotion was happiness both before and after education. Happiness was the only positive emotion among the six basic emotions, making it consequently easier for participants to identify happiness when viewing facial expressions. Hess et al. [59] found that the accuracy of recognizing facially expressed emotions is positively related with the intensity of the facial expression (i.e., the degree of facial muscle activity). Hess et al. also found that happy facial expressions even with a relatively low level of physical intensity are likely to be recognized with high accuracy. Leppänen and Hietanen [60] argued that a greater degree of facial muscle movements is typically observed in happy expressions compared to negative ones, which would make happy facial expressions more visually distinctive than other emotions. Adolphs [61] also noted that happiness could be easily recognized via even a single facial cue,
4.5. Sadness
Before education, disgust was the predominantly perceived emotion but it shifted to sadness after education, highlighting the effectiveness of education. Prior to education, participants primarily perceived disgust and anger, followed by sadness. It is well documented [57, 63] that anger and disgust are often confused due to similarities in their facial expressions. The sad facial expression in this study was mainly conveyed through neutral face (AU 0). AU 0 was also prominently engaged in the facial expressions of disgust and anger. Such similarities in facial expressions might have resulted in confusion among the three emotions: disgust, anger, and sadness. However, after education, participants were less likely to perceive anger and disgust, which is evidence of the educational effect.
4.6. Limitations
A few limitations might have influenced the findings. Participants viewed a series of 60 video clips, which could have induced fatigue potentially impacting their ability to accurately perceive emotions (cognitive fatigue [64]). However participants spent only a few seconds per video clip and were provided a break time after the initial set of 30 video clips, mitigating the expected impact of fatigue. The videos featured background images (e.g., household goods), which might have influenced participants’ emotions [65].
5. Conclusion
This study investigated the ability of sighted individuals to recognize facial expressions of emotions in people with visual impairments in online settings. Initially, participants frequently missed, misinterpreted and/or misclassified critical facial cues in the videos featuring facial expressions of individuals with visual impairments. However, after education, participants showed significantly improved performance in recognizing these facially expressed emotions. These findings suggest that proper education can effectively enhance the ability of sighted individuals to accurately interpret facial expressions conveyed by people with visual impairments in cyberspace.
Footnotes
Acknowledgments
This material is based upon work supported by the National Science Foundation under Grant No. 1831969.
Conflict of interest
The author has no conflicts of interest to report.
Ethical considerations
Ethical approval for this study was obtained from the Institutional Review Board. Informed consent was obtained for all study participants.
