The Uncanny Valley

Cover: AI generated Bunraku puppet faces. Bunraku puppets, a traditional form of Japanese puppetry, offer an intriguing perspective on the concept of the Uncanny Valley. These meticulously crafted puppets are remarkably lifelike, with intricate movements controlled by skilled puppeteers who remain visible on stage. While they fall short of complete human resemblance, their high degree of realism can sometimes evoke feelings of eerie familiarity and strangeness in the audience. This blurring of lines between the artificial and human-like qualities of Bunraku puppets raises questions about the Uncanny Valley’s relevance in cross-cultural artistic expressions and the complex interplay between perception and emotion in puppetry.

“The expression of this [Trigonocephalus] snake’s face was hideous and fierce; the pupil consisted of a vertical slit in a mottled and coppery iris; the jaws were broad at the base, and the nose terminated in a triangular projection. I do not think I ever saw anything more ugly, excepting, perhaps, some of the vampire bats. I imagine this repulsive aspect originates from the features being placed in positions, with respect to each other, somewhat proportional to the human face; and thus we obtain a scale of hideousness.” — Charles Darwin, The Voyage of the Beagle —

“Since I was a child, I have never liked looking at wax figures. They looked somewhat creepy to me. At that time, electronic prosthetic hands were being developed, and they triggered in me the same kind of sensation. These experiences had made me start thinking about robots in general, which led me to write that essay. The uncanny valley was my intuition. It was one of my ideas.”
— Masahiro Mori in an interview with IEEE Spectrum —

Maurício Pinheiro

Introduction

The concept of the “Uncanny Valley” (Japanese: 不気味の谷, Hepburn: bukimi no tani) is a fascinating subject that has captured the attention and challenges of researchers, engineers, and robotics enthusiasts since pioneering robotics professor Masahiro Mori introduced it in 1970. This complex psychological phenomenon plays a crucial role at the intersection of robotics, artificial intelligence (AI), and our own interaction with machines. In this AI-Talks Wiki article, we will expand our understanding of the Uncanny Valley, bringing new examples and information to deepen our analysis.

Understanding the Uncanny Valley

The “Uncanny Valley” describes people’s emotional response as robots become more similar to humans. When a robot has a clearly mechanical and distinctive appearance, people tend to respond positively, often feeling curiosity and empathy. However, as the robot approaches perfection in human likeness, the emotional response can turn into discomfort or even revulsion.

The Uncanny Valley graph is a visual representation of the relationship between the degree of an object’s resemblance to a human being and the emotional response to such an object. The x-axis represents the human likeness from low to high, while the y-axis represents the observer’s emotional response from negative to positive.

As an object becomes more like a human, the emotional response becomes increasingly positive and empathetic, until it reaches a point where the object is almost, but not quite, human. At this point, there is a sharp dip in the emotional response, plunging into the negative territory of repulsiveness – this is the “Uncanny Valley”.

For example, consider a moving robot that doesn’t resemble a human (like an industrial robot). People tend to have a neutral or slightly positive response to it. As the robot starts to look more human-like (like humanoid robots), our response becomes more positive. But when it’s very close to being human but not quite perfect (like a prosthetic hand), our response dips into the uncanny valley. We feel unease or even revulsion because something seems off. However, if resemblance is perfect (like Bunraku puppets), our response becomes positive again.

The same concept applies to still objects. For instance, people might feel comfortable looking at a stuffed animal, slightly more comfortable looking at a photo of a humanoid robot, but feel uneasy looking at a photo of an object that appears almost perfectly human but not quite (like a corpse or zombies).

This phenomenon isn’t limited to visuals – it can also apply to behaviors and sounds. For instance, people might feel comfortable hearing synthesized speech that sounds mechanical, slightly more comfortable hearing synthesized speech that sounds somewhat human, but feel uneasy hearing synthesized speech that sounds almost perfectly human but not quite.

As a robot becomes more similar to a human, the emotional response tends to become more positive and empathetic until it reaches a critical point where the emotional response quickly turns into strong repulsion. This point is known as the Uncanny Valley. However, as the robot’s appearance continues to become less distinguishable from a human, the emotional response becomes positive again and approaches levels of human-to-human empathy.

To better understand this phenomenon, it is important to explore some theories that explain it:

• Defensive Reaction Theory: This theory suggests that the revulsion toward almost-human robots is a defense response. People may associate highly similar robots with potential threats, triggering a negative reaction.
• Empathetic Reaction Theory: Another theory posits that discomfort arises from an empathetic response. When robots resemble humans too closely, they remind us of our own mortality, generating discomfort.
• Familiarity Reaction Theory: This theory argues that discomfort originates from familiarity. People may feel uncomfortable with robots that are too similar to humans simply because they are not accustomed to interacting with beings so similar to us.

Each of these theories offers a valuable perspective on the Uncanny Valley and contributes to a more comprehensive understanding of this complex phenomenon.

The Influence of Artificial Intelligence

Artificial Intelligence plays a crucial role in intensifying the Uncanny Valley. As AI algorithms advance, robots not only appear more human but also behave in a more humanized manner. For example, AI-based voice assistants like Siri and Alexa are capable of engaging in more natural conversations and responding to a variety of nuanced commands, enhancing the feeling of interaction with an almost-human entity.

However, the pursuit of perfection in simulating human behavior brings new challenges. Another example of AI that interacts with humans in a realistic manner is OpenAI’s GPT. This AI large language model can generate human-like text based on the prompts it’s given, making it capable of tasks such as drafting emails, writing articles, and even engaging in conversation. Some people have found GPT’s output so convincing that they’ve had difficulty distinguishing between text generated by the AI and text written by a human. This raises ethical questions about consent and transparency in human-machine interaction, which can be unsettling for many.

Examples

To illustrate the Uncanny Valley in action, we can examine specific cases of robots or AI products:

• Honda’s Asimo: Asimo is a humanoid robot developed by Honda. It is capable of walking, running, and even dancing. You may find Asimo cute, as it closely resembles what we collectively perceive as a typical humanoid robot.
• Telenoid: Telenoid is a spooky robotic communication device designed by Japanese roboticist Hiroshi Ishiguro. Its bald head, lifeless face, and lack of limbs make it appear more alien than human.
• Geminoid HI: Geminoid HI is an android replica of Hiroshi Ishiguro himself, even featuring hair harvested from his own scalp for his robotic twin. Ishiguro conceived Geminoid HI as a tool for delving deeper into the human experience. However, it undeniably possesses an uncanny and somewhat eerie appearance, particularly when placed side by side with its creator.
• Sophia: Engineered by David Hanson of Hanson Robotics, Sophia emerges as one of the most celebrated humanoid robots. Her distinctive bald and transparent head leaves no doubt in our perception that she is unmistakably a robot, reminiscent of AVA from the 2014 movie ‘Ex Machina.’ Sophia showcases a wide spectrum of emotional expressions and boasts advanced natural language processing capabilities.
• BINA48: Bina48, on the other hand, is a remarkably lifelike robot meticulously crafted to emulate the appearance and behavior of an actual person. Nevertheless, numerous individuals have expressed experiencing discomfort or an eerie sensation during interactions with Bina48, primarily owing to its nearly flawless resemblance.

Overcoming the Uncanny Valley

Researchers and developers are committed to finding ways to overcome the Uncanny Valley. Some strategies include:

• Stylization and Caricaturization: By intentionally stylizing or caricaturing robots, they can maintain a distinctive visual identity that avoids the feeling of discomfort.
• Quality Improvement: Continuous improvement in the quality of robots and AI allows them to cross the Uncanny Valley and achieve a level of human likeness that does not provoke a negative response.
• Customization: Customizing robots to fit individual user preferences can reduce the discomfort caused by similarity to humans.
• Transparency: Designing robots to be transparent about their artificial nature can help users understand that they are not human and should not be treated as such.

Conclusion

The Uncanny Valley is a complex and intriguing phenomenon that presents significant challenges for the field of robotics and AI. As we continue to advance in these fields, it is essential to address this challenge to promote a more natural and comfortable interaction between humans and machines. With a deeper understanding of the Uncanny Valley, new strategies to overcome it, and concrete examples illustrating its complexities, we can approach this phenomenon in a more informed and effective manner, ensuring that technology benefits our society ethically and harmoniously.

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References

1. Mori, M. (2012). Translated by MacDorman, K. F.; Kageki, Norri. “The uncanny valley”. IEEE Robotics and Automation. New York City: Institute of Electrical and Electronics Engineers. 19 (2): 98–100. doi:10.1109/MRA.2012.2192811.
2. Kageki, Norri (12 June 2012). “An Uncanny Mind: Masahiro Mori on the Uncanny Valley and Beyond”. IEEE Spectrum. New York City: Institute of Electrical and Electronics Engineers. Retrieved 1 April 2015.
3. https://en.wikipedia.org/wiki/Uncanny_valley

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