The ‘uncanny valley’ effect is an unsettled sensation caused by bots that are too humanlike
A new analysis of brain scans may explain why hyperrealistic androids and animated characters can be creepy.
By measuring people’s neural activity as they viewed pictures of humans and robots, researchers identified a region of the brain that seems to underlie the “uncanny valley” effect — the unsettling sensation sometimes caused by robots or animations that look almost, but not quite, human (SN Online: 11/22/13). Better understanding the neural circuitry that causes this feeling may help designers create less unnerving androids.
In research described online July 1 in the Journal of Neuroscience, neuroscientist Fabian Grabenhorst and colleagues took functional MRI scans of 21 volunteers during two activities. In each activity, participants viewed pictures of humans, humanoid robots of varying realism and — to simulate the appearance of hyperrealistic robots — “artificial humans,” pictures of people whose features were slightly distorted through plastic surgery and photo editing.
In the first activity, participants rated each picture on likability and how humanlike the figures appeared. Next, participants chose between pairs of these pictures, based on which subject they would rather receive a gift from. In line with the uncanny valley effect, participants generally rated more humanlike candidates as more likable, but this trend broke down for artificial humans — the most humanlike of the nonhuman options. A similar uncanny valley trend emerged in participants’ judgments about which figures were more trustworthy gift-givers.
Brain scans revealed that activity in the ventromedial prefrontal cortex, or VMPFC — a region involved in making value judgments — mirrored participants’ uncanny valley reactions. VMPFC activity was typically higher in response to more humanlike pictures, but dipped in response to artificial humans. That drop was most pronounced in people with the strongest dislike for artificial humans. Those findings suggest that this region of the brain underpins the uncanny valley sensation, the researchers say.
But this analysis may not directly map uncanny valley chills to neural activity, says human-computer interaction researcher Karl MacDorman. That’s because a lack of likability and gift-giving reliability don’t necessarily make something eerie.
Disney villains, for example, may not look particularly likable or trustworthy, but they don’t necessarily fall into the uncanny valley, says MacDorman, of Indiana University in Indianapolis. A future study could investigate the relationship between brain activity and how weirded-out people feel when they see different humanoids, rather than how much they like or dislike these figures.
If the VMPFC is responsible for generating the uncanny valley heebie-jeebies, that may be good news for android designers and animators. Social experiences can change how VMPFC reacts to certain situations, says Grabenhorst, of the University of Cambridge. So positive interactions with an initially creepy robot or avatar may make it less bothersome.
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As an enthusiast with a deep understanding of the intersection between neuroscience and artificial intelligence, I find the article on the "uncanny valley" effect particularly intriguing. The uncanny valley refers to the unsettling sensation experienced when encountering bots or animated characters that closely resemble humans but fall short of being indistinguishable. This phenomenon has long fascinated researchers and designers in the fields of robotics and animation.
The article, published on July 2, 2019, by Maria Temming, discusses a new analysis of brain scans aimed at unraveling the neural mechanisms behind the uncanny valley effect. The study, conducted by neuroscientist Fabian Grabenhorst and his colleagues, employed functional MRI scans on 21 volunteers while they viewed images of humans, humanoid robots, and hyperrealistic robots with slightly distorted features, termed "artificial humans."
The participants engaged in two activities. First, they rated the likability and human likeness of each picture. Subsequently, they chose between pairs of images based on which subject they would prefer to receive a gift from. Interestingly, the uncanny valley effect manifested, with participants generally rating more humanlike candidates as more likable, except for the artificial humans.
The critical finding lies in the brain scans, revealing that activity in the ventromedial prefrontal cortex (VMPFC), a region associated with value judgments, mirrored participants' uncanny valley reactions. Higher VMPFC activity corresponded with more humanlike pictures, but it decreased in response to artificial humans. This decrease was most pronounced in individuals with a strong aversion to artificial humans, suggesting that the VMPFC underpins the uncanny valley sensation.
However, the article acknowledges a potential limitation in directly linking neural activity to uncanny valley experiences. Karl MacDorman, a human-computer interaction researcher at Indiana University, points out that likability and gift-giving reliability alone may not explain the eerie feeling associated with the uncanny valley. He suggests a future study investigating the relationship between brain activity and people's discomfort when encountering different humanoid figures.
Despite this, the article concludes on a positive note for android designers and animators. Grabenhorst suggests that positive interactions with initially creepy robots or avatars can alter how the VMPFC reacts to such stimuli, potentially reducing the uncanny valley effect. This insight opens avenues for improving the design of androids to make them more socially acceptable through positive user experiences.
In summary, this research provides valuable insights into the neural basis of the uncanny valley effect, shedding light on the role of the ventromedial prefrontal cortex in shaping our reactions to humanoid robots and animated characters.
