Andrew Williams

With technology allowing for increased realism in video games, realistic, human-like characters risk falling into the Uncanny Valley. The Uncanny Valley phenomenon implies that virtual characters approaching full human-likeness will evoke a negative reaction from the viewer, due to aspects of the character’s appearance and behavior differing from the human norm. This study investigates if “uncanniness” is increased for a character with a perceived lack of facial expression in the upper parts of the face. More important, our study also investigates if the magnitude of this increased uncanniness varies depending on which emotion is being communicated. Individual parameters for each facial muscle in a 3D model were controlled for the six emotions: anger, disgust, fear, happiness, sadness and surprise in addition to a neutral expression. The results indicate that even fully and expertly animated characters are rated as more uncanny than humans and that, in virtual characters, a lack of facial expression in the upper parts of the face during speech exaggerates the uncanny by inhibiting effective communication of the perceived emotion, significantly so for fear, sadness, disgust, and surprise but not for anger and happiness. Based on our results, we consider the implications for virtual character design.

This paper proposes that increasing technological sophistication in the creation of realism for human-like, virtual characters is matched by increasing technological discernment on the part of the viewer. One of the goals for achieving a realism that is believable for virtual characters is to overcome the Uncanny Valley where perceived strangeness or familiarity is rated against perceived human-likeness. Empirical evidence shows the uncanny can be applied to virtual characters, yet implies a more complex picture than the shape of a deep valley with a sharp gradient as depicted in Mori's original plot of the Uncanny Valley. Our results imply that: (1) perceived familiarity is dependent upon a wider range of variables other than appearance and behaviour; and (2) for realistic, human-like characters the Uncanny Valley is an impossible traverse, is not supported fully by empirical evidence and the concept is better replaced with the notion of an Uncanny Wall.

This study investigates the relationship between the perceived strangeness of a virtual character and the perception of human likeness for some attributes of motion and sound. Participants (N=100) were asked to rate thirteen video clips of twelve different virtual characters and one human. The results indicate that attributes of motion and sound do exaggerate the uncanny phenomenon and how frightening that character is perceived to be. Strong correlations were identified for the perceived strangeness of a character with how human-like a character's voice sounded, how human-like the facial expression appeared and how synchronized the character's sound was with lip movement; characters rated as the least synchronized were perceived to be the most frightening. Based on the results of this study, this article seeks to define an initial set of hypotheses for the fear-evoking aspects of character facial rendering and vocalization in survival horror games that can be used by game designers seeking to increase the fear factor in the genre, and that will form the basis of further experiments, which, it is hoped, will lead to a conceptual framework for the uncanny.