KASPAR - a minimally expressive humanoid robot for human-robot interaction research

Original article can be found at: http://www.informaworld.com/smpp/title~content=t778164488~db=all Copyright Taylor and Francis / InformaThis paper provides a comprehensive introduction to the design of the minimally expressive robot KASPAR, which is particularly suitable for human-robot interaction studies. A low-cost design with off-the-shelf components has been used in a novel design inspired from a multi-disciplinary viewpoint, including comics design and Japanese Noh theatre. The design rationale of the robot and its technical features are described in detail. Three research studies will be presented that have been using KASPAR extensively. Firstly, we present its application in robot-assisted play and therapy for children with autism. Secondly, we illustrate its use in human-robot interaction studies investigating the role of interaction kinesics and gestures. Lastly, we describe a study in the field of developmental robotics into computational architectures based on interaction histories for robot ontogeny. The three areas differ in the way as to how the robot is being operated and its role in social interaction scenarios. Each will be introduced briefly and examples of the results will be presented. Reflections on the specific design features of KASPAR that were important in these studies and lessons learnt from these studies concerning the design of humanoid robots for social interaction will also be discussed. An assessment of the robot in terms of utility of the design for human-robot interaction experiments concludes the paper.Peer reviewe

Smiling is a Costly Signal of Cooperation Opportunities: Experimental Evidence from a Trust Game

We test the hypothesis that "genuine" or "convincing" smiling is a costly signal that has evolved to induce cooperation in situations requiring mutual trust. Potential trustees in a trust game made video clips for viewing by potential trusters before the latter decided whether to send them money. Ratings of the genuineness of smiles vary across clips; it is difficult to make convincing smiles to order. We argue that smiling convincingly is costly, because smiles from trustees playing for higher stakes are rated as significantly more convincing, so that rewards appear to induce effort. We show that it induces cooperation: smiles rated as more convincing strongly predict judgments about the trustworthiness of trustees, and willingness to send them money. Finally, we show that it is a honest signal: those smiling convincingly return more money on average to senders. Convincing smiles are to some extent a signal of the intrinsic character of trustees: less honest individuals find smiling convincingly more difficult. They are also informative about the greater amounts that trustees playing for higher stakes have available to share: it is harder to smile convincingly if you have less to offer.

Visual attention mechanisms in happiness vs. trustworthiness processing of facial expressions

A happy facial expression makes a person look (more) trustworthy. Do perceptions of happiness and trustworthiness rely on the same face regions and visual attention processes? In an eye-tracking study, eye movements and fixations were recorded while participants judged the un/happiness or the un/trustworthiness of dynamic facial expressions in which the eyes and/or the mouth unfolded from neutral to happy or vice versa. A smiling mouth and happy eyes enhanced perceived happiness and trustworthiness similarly, with a greater contribution of the smile relative to the eyes. This comparable judgement output for happiness and trustworthiness was reached through shared as well as distinct attentional mechanisms: (a) entry times and (b) initial fixation thresholds for each face region were equivalent for both judgements, thereby revealing the same attentional orienting in happiness and trustworthiness processing. However, (c) greater and (d) longer fixation density for the mouth region in the happiness task, and for the eye region in the trustworthiness task, demonstrated different selective attentional engagement. Relatedly, (e) mean fixation duration across face regions was longer in the trustworthiness task, thus showing increased attentional intensity or processing effort

Increasing ecological validity in studies of facial attractiveness : effects of motion and expression on attractiveness judgements

While our understanding of what makes a face attractive has been greatly furthered in recent decades, the stimuli used in much of the foregoing research (static images with neutral expressions) bear little resemblance to the faces with which we nonnally interact. In our social interactions, we frequently evaluate faces that move and are expressive, and thus, it is important to evaluate whether motion and expression influence ratings of attractiveness; this was the central aim of the experiments in this dissertation. Using static and dynamic stimuli with neutral or positive expression, the effects of motion and expression were also tested in combination with other factors known to be relevant to attractiveness judgements: personality attributions, sex-typicality and cultural influence. In general, the results from this set of experiments show that judgements of moving, expressive stimuli do differ, sometimes radically, from judgements made of more traditional types of stimuli. Motion and positive expression were both found to increase ratings of attractiveness reliably in most experiments, as well as across cultures, and in some instances, showed strong sex-specific effects. Intriguing sex differences were also found in personality trait ratings of the stimuli, particularly for male faces; while criteria for female faces remained relatively constant across all conditions, trait ratings associated with attractiveness for male faces were dependent on particular combinations of motion and expression. Finally, in line with previous research, cross-cultural experiments showed general agreement between Japanese and Caucasian raters, but also suggested slight, culture-specific differences in preferences for expression and motion. IV This set of experiments has integrated the factors of motion, expression, sextypicality, personality and cultural influence together in order to bring a greater degree of ecological validity into attractiveness studies. These findings offer major implications for researchers studying attractiveness, particularly that of males, and suggest that motion and expression are important dimensions that should be considered in future research while simultaneously placing a caution on the interpretation of findings made with static stimuli. Suggestions are also made for further research in light of the present finding

A Psychophysical Investigation of Recognition Strategy and Function Modeling for the Human Face-responsive Neural System

高知工科大学博士(工学) 平成21年9月30日授与 (甲第167号)高知工科大学, 博士論文.thesi

Three essays on likability factors, crowdfunding, and entrepreneurial performance

In this dissertation, I conduct three empirical studies exploring the relation between likability factors, crowdfunding characteristics and entrepreneurial performance. Together these studies integrate aspects of major entrepreneurial likability factors including liking of the entrepreneur (source attractiveness, credibility, personal traits) and liking of the message (verbal content and expression), and components of nonverbal and verbal cues. I apply computer-mediated communication (CMC) and persuasion theories, political and marketing literature to provide a more fine-grained understanding of likability on crowdfunding success. In the first essay, I study how the non-verbal cues of a crowdfunding video influence the crowdfunding success. By employing social presence theory, I argue, hypothesize and test that effective use of non-verbal cues in a pitch video increases funding success. In the second essay, I explore how verbal cues (readability and complexity) and non-verbal cues (smiling and professional attire) interact to influence crowdfunding outcome. Findings of this essay indicate that powerful persuasion results from both expression (verbal cues) and impression (non-verbal cues). The third essay examines the mediating effect of likability between nonverbal, verbal cues and crowdfunding success. According to the likability factors extracted from political and advertising campaign literature, I conclude five main dimensions of likability in crowdfunding context. The results show that message factors are more influential than source factors in affecting crowdfunding outcome. Findings of three essays show that entrepreneurs should be careful to deliver a message which is immediate, simple, informative, humorous, storytelling and less complimentary to their funders. The more their messages are liked, the more likely funders will back their projects, and then the more success their crowdfunding campaign will be

The Influence of Buccal corridors on perceived smile aesthetics – A dynamic smile visualisation study.

Objective: To assess the impact of varying sizes of buccal corridor as judged by orthodontists, dentists, and laypersons. Design: Cross-sectional study. Setting: Barts and the London School of Medicine and Dentistry, Queen Mary University of London, UK. Participants: Three groups of raters comprising 31 orthodontists, 28 dentists, and 29 laypersons. Methods: A three-dimensional video of a smiling white male and female displaying first molar to first molar were digitally manipulated with varying sizes of buccal corridors in increments of 5% from 0% to 25%. Second set of videos displayed 10 teeth that simulated removal of all first premolars were manipulated to have similar range of buccal corridors. Three rater groups assessed the attractiveness of videos using a visual analogue scale (VAS). Multiple regression analysis was undertaken, and videos were compared using the Tukey HSD method. Results: The interaction between video rating and buccal corridors (P<0.001) and video gender (P<0.001) were found to be statistically significant with 5% to 10% of buccal corridors considered to be most aesthetically pleasing for both male and female. There were no significant differences in both 10 and 12 teeth videos for both male (P=0.015) and female (P=0.346). Conclusion: Orthodontists, dentists, and laypersons prefer 0% to 10% of buccal corridors for both male and female. The number of teeth displayed has no impact on perceived smile aesthetics for varying sizes of buccal corridors. No differences were observed between orthodontists, dentists, and laypersons as well as raters’ gender with respect to perceived impact on smile aesthetics

Effect of Midline Deviation and Crown Width Disproportion on Perception of Smile Esthetics

Objectives: To evaluate the effect of maxillary midline deviation and crown width disproportion on the perception of smile attractiveness through full-face images among dentists and laypeople. Methods and materials: A full portrait image of a smiling 25-year-old female, exhibiting good dental alignment, midline position, and tooth size symmetry, was selected as a model for the present study. The original image was digitally modified using photo editing software (Photoshop CC, Version 25.12.0; Adobe) to simulate three different case scenarios of varying levels: Midline deviation (1-4 mm), single crown width disproportion, separately for central incisor, lateral incisor, and canine (1 and 2 mm), and crown width disproportions distributed to anterior teeth (1-4 mm). In total, 15 modified images were displayed randomly to 180 observers (90 laypeople and 90 dentists) including the original image that served as a control. Each observer scored the level of smile esthetics for each image using a visual analog scale ranging from point 0 (unattractive) to 100 (attractive). Bonferroni Test and Partial Eta Squared were utilized for the statistical data analyses (α < 0.05). Results: Attractiveness scores were significantly lower for the modified smiles with the single crown width disproportion than distributed crown width disproportion and midline deviation (p < 0.001 for each), of which two presented statistically similar attractiveness (p = 0.278). The highest attractiveness scores were obtained for the control image (90.35 ± 5.56A), midline deviation of 1 mm (88.89 ± 5.93AB), 2 mm (86.80 ± 6.70ABC), and distributed disproportion of crown width of 1 mm (87.75 ± 6.70AB). A single central incisor disproportion of 2 mm (45.51 ± 11.94I) was perceived significantly less attractive, followed by a midline deviation of 4 mm (57.51 ± 12.58H) and a distributed disproportion of crown width of 4 mm (59.11 ± 9.72H). Modified images were perceived as significantly more attractive by laypeople and male observers compared to dentists and female observers (p < 0.001 for each). Older observers between 35 and 50 years old scored significantly higher than younger observers (p = 0.001). Conclusions: Dentofacial midline discrepancy had less effect on smile attractiveness compared to crown width disproportions. Midline deviations up to 2 mm were not noticeable for both laypeople and dentists. The deviations of 3 mm were noticeable but still more attractive than the deviations of 4 mm, which were considered the least attractive. A single crown width disproportion was less perceived when moving from the central incisor toward the canine. Distributing the crown width disproportions among anterior teeth can be beneficial for smile attractiveness compared to non-distributed cases. Clinical significance: Generating symmetrical crown width proportions of the anterior teeth seems more important for smile esthetics than dentofacial midline harmony. Distribution of crown width disproportions among the anterior teeth can enhance smile esthetics

Photographic Assessment of Facial Components in Facial Esthetics as percieved by Orthodontists, Artists and Photographers: An In Vivo study

AIM OF THE STUDY: To establish the perception of facial aesthetics by different professionals namely orthodontists, artists and photographers and to investigate the most influential facial characteristics involved in rating overall attractiveness. MATERIALS AND METHODS: 22 subjects were selected based on inclusion criteria each of whom was evaluated by nine panelists consisting of three orthodontists, three artists and three photographers. Digital videography was used for dynamic recording of smile, which was accomplished with SLR digital camera, Canon 600D that was mounted on a tripod at a fixed distance of 1meter from the subject sitting in natural head position. The subject was asked to rehearse the phrase, “CHELSEA EATS CHEESECAKE ON THE CHESAPEAKE” in order relax and then asked to start smiling. A ten-second video was taken and the raw video was transferred to a video editing software (GOM player). The streaming video was converted into 300 frames. The frame that best represented the subjects natural/posed unstrained social smile was selected, which was 1 of the 15 consecutive frames in which the smile did not change. The selected posed smile frontal photograph of each subject was cropped using Adobe Photoshop 7.0. To create three types of images the first image being the face with the smile, the second image the face without the smile and the third image the smile only. The photos were placed in a photo album. A questionnaire containing 11 questions were given to each of the evaluators along with the 3 photographs of the subjects to establish the perception of facial aesthetics by different professionals namely orthodontists, artists and photographers and to investigate the most influential facial characteristics involved in rating overall attractiveness. RESULTS: The correlation was highest between the orthodontist and artists group followed by the photographer and artist group and finally the photographer and orthodontist group. Preferences for facial component differed between the three groups. The orthodontist group showed symmetry of face, cheekbone and shape of the lips to be strongly associated with overall attractiveness and exposure of gums to be least associated facial feature. Whereas the artists group considered the symmetry of face, shape of forehead, role of chin to be the most associated feature and the least associated feature was the smile. According to the photographers group cheekbone was the facial feature most strongly associated with overall attractiveness and least associated facial feature was the symmetry of face. CONCLUSION: The view about overall facial attractiveness significantly correlates for Orthodontists and Artists. The perception by the three professionals confirms that facial esthetics is not dependent on any isolated facial characteristic and overall facial attractiveness is more important than dental attractiveness

Automatic Detection and Intensity Estimation of Spontaneous Smiles

Both the occurrence and intensity of facial expression are critical to what the face reveals. While much progress has been made towards the automatic detection of expression occurrence, controversy exists about how best to estimate expression intensity. Broadly, one approach is to adapt classifiers trained on binary ground truth to estimate expression intensity. An alternative approach is to explicitly train classifiers for the estimation of expression intensity. We investigated this issue by comparing multiple methods for binary smile detection and smile intensity estimation using two large databases of spontaneous expressions. SIFT and Gabor were used for feature extraction; Laplacian Eigenmap and PCA were used for dimensionality reduction; and binary SVM margins, multiclass SVMs, and ε-SVR models were used for prediction. Both multiclass SVMs and ε-SVR classifiers explicitly trained on intensity ground truth outperformed binary SVM margins for smile intensity estimation. A surprising finding was that multiclass SVMs also outperformed binary SVM margins on binary smile detection. This suggests that training on intensity ground truth is worthwhile even for binary expression detection