ادراک اختلالات فکری و روانی و دره غیر طبیعی در شخصیت های مجازی

Virtual characters with a realistic, human-like appearance are increasingly being used in video games and animation. However, increased realism does not necessarily imply increased acceptance and factors such as aberrant facial expression may evoke the Uncanny Valley phenomenon. In humans, personality traits such as anger, callousness, coldness, dominance, being unconcerned, and untrustworthiness are associated with psychopathy; a visual facial marker of this condition being a lack of visible response in the eye region to emotive situations. As such, the present study investigated if inadequate upper facial animation in human-like virtual characters evoked the uncanny due to a perception of psychopathic traits within a character. The results revealed that virtual characters that showed a lack of a startle response to a scream sound were regarded as most uncanny and perceptions of personality traits associated with psychopathy were a strong predictor of reported uncanniness but, that other negative personality traits not associated with psychopathy were not. The study presents possible psychological drivers of uncanniness to inform designers why a lack of detail in a character’s upper face when portraying a startle response may evoke perception of specific negative personality traits in a character, to help control the uncanny in character design.

Recent empirical investigation into the Uncanny Valley in synthetic agents has helped elucidate factors which may exaggerate the uncanny. Tinwell, Grimshaw, and Williams (2011a) revealed that some facial expressions of emotion are more prone to perception of uncanniness than others. Specifically, viewers are especially sensitive to uncanniness in realistic, human-like, male characters presenting the emotions fear and surprise when the uncanny is exaggerated by eliminating movement (and therefore emotional expressivity) in the character’s upper face including the eyelids, eyebrows and forehead ( Tinwell, Grimshaw, Williams, & Abdel Nabi, 2011b). While the study by Tinwell et al., 2011a and Tinwell et al., 2011b successfully investigated how aspects of a character’s appearance may be manipulated to reduce the uncanny for empathetic characters (or to enhance the uncanny for antipathetic characters intended to be frightening), the possible psychological processes driving the uncanny response were not empirically examined. The present study sought to replicate Tinwell et al.’s findings for male characters and tested whether it generalized to female characters too. It then moved onto investigate some of the psychological processes that may drive the uncanny response by exploring if inadequate upper facial animation (i.e., lack of upper facial emotional expressivity) leads to the perception of a particular type of negative personality traits in virtual characters, psychopathy, and whether it is this which elicits an uncanny response in viewers. The findings from this study may be used to inform character designers in video games and animation and elucidate how, and importantly why, a lack of detail in the upper face region in particular contexts may evoke perception of specific negative personality traits in a character. Furthermore, it may help towards building a conceptual framework of the uncanny in virtual characters to help us better understand which factors contribute to the uncanny, and how it may be controlled in character design. 1.1. The Uncanny Valley The concept of the uncanny was first proposed in psychological writings of the early twentieth century as a way to explain why some objects may appear strange or eerie to a viewer. For example, the psychologist Jentsch (1906) suggested that life-like wax-work dolls and automata are often regarded as frightening because the viewer cannot distinguish if the object is real or unreal and that this indecision constitutes “uncanniness”. In 1919, Freud offered an alternative perspective by theorizing that the uncanny occurred when objects or situations evoke a sinister revelation of that which is normally concealed from human experience and should, for psychological health and ego stability purposes, remain out of conscious awareness. Given that Jentsch’s examples of uncanny objects included automata, it is understandable that in more recent times human experience of uncanniness in response to robots has been investigated. In a seminal study, the roboticist Marashiro Mori (2012) explored human reaction to human-like robots and drafted a graph to demonstrate the relationship between experience of the uncanny and increasing human-likeness in a robot’s appearance (see Fig. 1). Mori originally used the Japanese neologism Shinwa-kan as a measure of perceived uncanniness that has since been translated in English as one’s “affinity” towards to a given object (see MacDorman & Kageki, 2012; also, Bartneck et al., 2009 and Ho and MacDorman, 2010). Full-size image (21 K) Fig. 1. Mori’s plot of perceived familiarity against human-likeness depicting the Uncanny Valley (taken from a translation by MacDorman and Kageki of Mori’s “The Uncanny Valley”). Figure options As Fig. 1 shows, unlike robots with a traditionally mechanical appearance, the level of affinity towards human-like robots drops sharply at a point where the robot appears close to, but not quite, authentically human-like. The incongruence between a robot’s behavior and their human-like, physical appearance caused a negative affective response in the viewer, thus creating a valley shaped dip in the otherwise linear relationship between perceived affinity and human-likeness (see Fig. 1). Furthermore, the effect of object movement would amplify the uncanny effect for the viewer. Rather than just one particular factor such as facial expression (Tinwell et al., 2011a and Tinwell et al., 2011b), it has been suggested that multiple factors may contribute to uncanniness, especially so with animated characters (Hanson, 2006 and Pollick, 2010). For example, a perception of jerky or unnatural movement (MacDorman, Coram, Ho, & Patel, 2010) may exaggerate the uncanny as might perception of a lack of synchronization of lip movement with speech (Tinwell, Grimshaw, & Williams, 2010). This line of investigation follows the work of previous authors who have put forward a range of explanations as to why we experience the uncanny including whether it may be an instinctive reaction to a perception of potential danger. 1.2. Explanations of the Uncanny Valley In an attempt to understand and explain the Uncanny Valley, in his original paper Mori (2012) reflected on issues related to its function: Why were we equipped with this eerie sensation? Is it essential for human beings? I have not yet considered these questions deeply, but I have no doubt it is an integral part of our instinct for self-preservation. (Note: The sense of eeriness is probably a form of instinct that protects us from proximal, rather than distal, sources of danger. Proximal sources of danger include corpses, members of different species, and other entities we can closely approach. Distal sources of danger include windstorms and floods.) (Mori, 2012, p. 3). Mori (2012) postulated that experience of the uncanny in almost, fully human-like characters may serve as a reminder of one’s own death and the resulting feelings of dread, a supposition prompted by the fact that corpses and human-like robots possess a physical human appearance but show no behavioral fidelity. Building on Mori’s (2012) explanation that the Uncanny Valley may be in response to a proximate threat of danger, Kang (2009) later theorized that the uncanny was caused when a man-made object, such as a robot, is regarded as a threat to the viewer; something that intends to, or has the potential to cause harm. If the human is unquestionably of higher stature and in control, then there is little or no threat. In this way, characters such as “Pinocchio” or “Shrek” may be regarded as cute and comical. However, we may judge ourselves as having less (or no) control over other man-made objects such as powerful androids or highly human-like virtual characters which may be more dominant and, thus, a greater threat. Lewkowicz and Ghazanfar (2012) suggested that perception of the uncanny is not innate but a developmental phenomenon that relies on early perceptual experience of typical human facial expression; hence, the psychological substrates of uncanniness may be related to the adequate development of the skills required for adaptive interpersonal and social functioning. 1.3. Uncanny facial expression of emotion in virtual characters More recently, due to advances in digital technology for simulating realism, viewers have reported similar uncanny experiences in response to realistic, human-like virtual characters featured in animations and video games (see e.g. Brenton et al., 2005, Doerr, 2007, Geller, 2008, Green et al., 2008, Ho and MacDorman, 2010, Hoggins, 2010, MacDorman et al., 2009, Rose, 2011, Tinwell et al., 2011a and Tinwell et al., 2011b). Video game designers (working in genres such as action games and role-playing games) perceive an increased aesthetic realism as highly desirable as this may allow viewers to better appreciate the emotional state of characters, leading to a heightened state of engagement with that character and immersion in the game (Doerr, 2007 and Hoggins, 2010; Ravaja, Turpeinen, Saari, Puttonen, & Keltikangas-Järvinen, 2008). However, criticism has been leveled at this approach based on the inability of such characters to reliably, clearly communicate their emotional state to the viewer (Crigger, 2010; Doerr, 2007 and Rose, 2011), possibly due to the technological challenges of achieving this. For scenes involving full motion video (FMV) in video games, such as pre-recorded trailers and cut scenes, motion capture techniques are combined with post-production editing in 3D software to create a character’s facial expression. This process allows for the recording of high fidelity facial expression of emotion from a human that is then modeled to a 3D character. Designers may then use a key-framing technique to edit individual frames of existing motion capture data to attempt to make the character’s facial expression as realistic and accurate as possible and appropriate to the given context of the game. However, this process cannot be used for footage generated in real-time and, instead, automated and/or procedural generation techniques are used to generate a character’s facial expression. These automated techniques may not be as accurate as those used in pre-recorded FMV, nor do they always convey an appropriate facial expression for the character given the context and character’s state in-game. Even though advances in technology are increasingly allowing for greater detail in motion capture data and automated animation techniques when generating facial expression of emotion (both in pre-recorded and real-time footage), there is general agreement that, largely, such performances fall short of being perceived as authentically real and fail to cause suspension of disbelief in the viewer (Brenton et al., 2005, Doerr, 2007, Geller, 2008, Ho and MacDorman, 2010, Hoggins, 2010 and MacDorman et al., 2010; Pollick, 2010; Rose, 2011, Tinwell et al., 2010 and Wang et al., 2012). One such example can be found in the cinematic, drama-type game Heavy Rain ( Quantic Dream, 2010). The designers anticipated that increased realism in the appearance and performance of characters would evoke heightened emotional contagion in the player, increasing their participation with the story ( Doerr, 2007). However, the inadequately detailed, (essentially aberrant) facial expression of the main character, Ethan Mars, who was intended to be regarded as empathetic, was reported as awkward and bizarre with a glazed-over look. This left some players uninspired and disengaged with the game as they failed to make a “meaningful connection” ( Chick, 2011, p. 1) with this character due to his strange facial expression and inanimate eyes (see also, Hoggins, 2010 and Lui, 2011). Similarly, female empathetic video game characters, such as Naomi from the game King Kong (Ubisoft Entertainment, 2005); Sydney Bristow from the game Alias ( Acclaim Entertainment, 2004) have failed to achieve the desired positive viewer response, instead being described as “monsters” with “dead eyes” comparable to the zombie characters that they are fighting ( Thompson, 2004 and Thompson, 2005). Of particular importance to the present study, previous research has revealed that those with psychopathic traits generally demonstrate a lack of a startle reflex that includes a widening of the eyes and raising of the eyebrows and forehead in response to frightening or shocking/surprising stimuli (Benning et al., 2005, Herpertz et al., 2001, Justus and Finn, 2007 and Patrick et al., 1993). Those not diagnosed with psychopathy would typically show a startle reflex in such circumstances ( Benning et al., 2005, Herpertz et al., 2001 and Justus and Finn, 2007). Given that Tinwell et al., 2011a and Tinwell et al., 2011b identified that perception of uncanniness was particularly strong in a character when communicating the emotions fear and surprise with a lack of movement in the eyelids, eyebrows and forehead, we suggest that the lack of upper facial movement during facial expression of these emotions may be perceived by the viewer as a physiognomic marker of a lack of startle response and possible psychopathic behavior. Furthermore, we suggest that it is this appraisal and judgment that contributes to the associated uncanny experience. We put forward the notion that it is perception of psychopathic traits in such characters that is a possible psychological contributor to experience of the uncanny. To test the above idea, participants rated videos of: (1) humans (labeled human); (2) fully animated characters, (labeled virtual full) and; (3) characters with a lack of upper facial movement (labeled virtual lack); for perceived uncanniness, and personality traits associated with psychopathy. We manipulated of a lack of movement in the upper face region including the eye lids, eye brows and forehead, for characters in the experimental virtual lack condition based on the following criteria: firstly, the previous study by Tinwell et al., 2011a and Tinwell et al., 2011b had identified that perception of the uncanny was strongest in male virtual characters presenting the emotions fear and surprise when movement had been disabled in the upper face region (including the eye lids, eye brows and forehead). Moreover, previous empirical evidence (see e.g. Benning et al., 2005; Herpertz et al., 2001, Justus and Finn, 2007 and Patrick et al., 1993) has revealed that in humans, a lack of movement in the upper face in response to a frightening or surprising stimulus can be a visual marker of an individual with psychopathic traits (a formal diagnosis of which is Anti-Social Personality Disorder (ASPD) Hare, Hart, & Harpur, 1991). While the author’s acknowledge that other aspects of a character’s behavior and appearance may contribute to perception of the uncanny (for example, if the character is perceived to have jerky, automated movement ( MacDorman et al., 2010), or if they may have a lack of synchronization between their lip movement with speech ( Tinwell et al., 2010)) this particular facial manipulation for virtual lack characters facilitated a fundamental investigative aim of the present study; that is, it might trigger perception of possible anti-social, perhaps psychopathic traits, in virtual characters with a human-like appearance. In order to determine if it is perception of, specifically, psychopathic personality traits that contribute to the uncanny experience, the present study also examined whether other negative affective personality traits, such as depression or anxiety, conditions not associated with psychopathy, are also predictive of perceived uncanniness. Startled facial expressions were presented by both male and female characters to test generalizability across character gender for all character types (human, virtual full, and virtual lack). In order to promote viewer expectation of a startled response in characters, the sound of a female human scream preceded each character presentation 1. Based on the previously presented reasoning and findings, the following hypotheses were formulated: H1. Character type: The human group will be rated as least uncanny; the fully animated virtual characters rated second highest for uncanniness; and those characters with a lack of upper facial animation rated as most uncanny. This pattern will be the same across both character genders. H2. Personality Type: Detection of personality traits associated with psychopathy (evidenced by a character’s psychopathy rating), will be a stronger predictor of its uncanniness rating than ratings of negative non-psychopathic personality traits across all groups.

This study has shown that viewer perception of psychopathic personality traits is associated with perception of the uncanny in human-like virtual characters and this effect is maximal in the presence of aberrant facial expression of emotion by a character. The present study presents a possible explanation based on empirical evidence as to why viewers fail to connect or establish a rapport with characters of an increased human-like appearance that the designers of video games have otherwise intended to be perceived as empathetic. We propose that in such circumstances, instead of greater affinity with the human-like character, lack of upper facial expression is perceived as incongruous with their actions and this not only fails to communicate their emotional state, but paradoxically, may be interpreted as evidence of an attempt to hide (or even mask) more negative, unpleasant personality traits in that character. The character appears to possess personality traits commonly associated with psychopathy, with all the negative personal and social implications that this carries, and this, possibly along with other factors such as jerky movement ( MacDorman et al., 2010) or lip-sync error ( Tinwell et al., 2010), may contribute to experience of the uncanny. Of course, this tactic may be used strategically in games design. Viewer perception that a character may demonstrate a blatant disregard towards others, with a lack of empathy or remorse and an inability to forge a meaningful attachment with others (Glenn et al., 2011) may be beneficial for criminals featured in crime-thriller video games. Such personality traits may make it more believable that a character is defined as having an antagonist role in the story and heighten the dislike for the character so that the player becomes more engaged with the game. However, such characteristics might inadvertently elicit or exaggerate the Uncanny Valley effect in empathetic characters, to the disadvantage of both the player and designer. Human-like characters in video games (and animation) are frequently reported in trade press as having a “dead-eyed” look (see e.g. Thompson, 2004 and Thompson, 2005) and this factor contributes as to why the characters are criticized for being uncanny. While the current study does not, of course, assess other aspects that may contribute to a dead-eyed appearance in characters such as light reflectivity in the eyes, pixel dilation, or gaze behavior, the findings presented in this paper may provide a possible psychological explanation as to why we find this “dead-eyed” look so disturbing. An evident lack of a startle-response in characters to what would normally be considered shocking scenes or sounds in-game may exaggerate a perception of this dead-eyed look in a character. Therefore, it may be suggested that video game designers (and 3D animators) ensure that they are aware of the facial muscles involved (especially in the eye region and upper face) of a startled-response in humans. For example, to clearly portray a raising of the brows and a widening of the eye aperture to increase visual input so that such movements can be adequately translated to characters both in real-time and pre-recorded footage in an appropriate context. This may at least, in part, help to prevent or reduce perception of the uncanny in human-like virtual characters. Evidence indicates that perception of the uncanny is developmentally determined, and not evolutionary in origin, and relies heavily on perception of human faces from infancy (Lewkowicz & Ghazanfar, 2012). The findings from the current study indicate a relationship between perception of uncanniness and attribution of psychopathic characteristics. Collectively, this leads us to reflect on whether perception of psychopathy in others, like detection of uncanniness, is also, solely, the product of psychosocial experience; whether developing a ‘nose’ for the uncanny is a necessary precursor for such, or, whether we come armed with instinctive aversion/avoidance responses to characters who violate expectations and whom we may perceive as a potential threat. Mori (2012) stated that exploration as to the cause of the uncanny in robots is necessary so that we may better understand the essence of being human. The present study has attempted to contribute to this by highlighting possible psychological substrates of the uncanny in ‘not quite human’ virtual characters. The study has identified particular personality traits that we may not tolerate in characters designed to replicate human beings. In this way, we are closer to achieving not only a better understanding of human interaction with synthetic agents, but a better understanding of what makes us human.