Uncanny Valley

What is Uncanny Valley?

Uncanny valley refers to a phenomenon in human perception when encountering human-like objects, such as robots and images, that aren’t perfectly lifelike. As an object becomes more human-like, reactions become positive and empathetic until a certain point. Beyond this, slight imperfections cause discomfort and revulsion.

This explains why robots like Pixar’s Wall-E and Eve are seen as cute, while extremely human-like robots, such as Showa Hanako, a dental training android, and the CB2 child robot, are disturbing. These robots fall into the uncanny valley due to their human-like faces, off proportions, rubbery skin texture, or blank stares. CGI characters in movies or video games can also evoke an eerie feeling if highly realistic but not perfect.

The phenomenon also applies to AI-generated voices that sound almost human. Slight inconsistencies in tone, rhythm, or pronunciation can evoke an unsettling feeling similar to that experienced with robots or digital characters.

The uncanny valley effect occurs across different mediums and technologies, including avatars in virtual reality (VR) environments, dolls crafted to look like real babies and realistic wax figures with slight imperfections such as unnatural skin texture or lifeless eyes.

History of Uncanny Valley

The uncanny valley concept was first identified by Masahiro Mori, a robotics professor, in 1970, who called it “Bukimi no Tani Gensho.” The term “uncanny valley” gained wider recognition and usage after its inclusion in the English-speaking world through various discussions and writings on robotics and computer graphics, including the book “Robots: Fact, Fiction, and Prediction” written by Jasia Reichardt and published in 1978.

The concept of the uncanny valley is also linked to Ernst Jentsch’s 1906 essay “On the Psychology of the Uncanny,” which was further elaborated upon by Sigmund Freud in his 1919 essay “The Uncanny.”

How Uncanny Valley Works

The uncanny valley definition refers to the dip in comfort levels (from an eerie feeling to revulsion) people experience when a human-like robot or character appears almost human but has subtle imperfections that make it appear strange or unsettling.

The concept is often illustrated with a graph, formed when plotting people’s reactions to different objects that increasingly resemble humans. As the human likeness of the object increases, people’s affinity to it increases until a point where the likeness becomes off-putting, disturbing, and weird. This drop in affinity forms the uncanny “valley,” in the graph, as there is an immediate decline in comfort levels followed by a rise on the other side, forming the shape of a “V” or a valley.

Causes of Uncanny Valley Effect

The uncanny valley effect is influenced by several factors that cause discomfort when encountering human-like robots. One primary cause is cognitive dissonance, where the mind struggles to reconcile the almost human appearance with the knowledge that the object is not truly human.

Other examples include:

• Absence of human traits, like expressions or natural breathing patterns.
• Inconsistent emotional cues, such as a happy expression paired with a monotone voice.
• Inconsistencies in tone, rhythm, or pronunciation in AI-generated voices.
• Subtle imperfections in facial expressions, movements, or gestures.
• Unnatural eye movements and lack of eye contact.

Uncanny Valley Research

When Masahiro Mori first wrote his influential essay pointing out the existence of the uncanny valley, it served more as advice to robot designers rather than a formal scientific statement. Over time, however, the concept has been the subject of research involving a series of experiments aimed at understanding the underlying mechanisms of this phenomenon.

Researchers have identified specific brain regions involved in creating the sense of the uncanny valley. These studies have traced the effect back to brain circuits important for processing and evaluating social cues, such as facial expressions. This research has helped to explain why certain human-like objects elicit feelings of discomfort and unease?.

Uncanny Valley Examples

How to Avoid the Uncanny Valley

Avoiding the uncanny valley effect involves careful consideration of various factors when creating human-like robots, avatars, or digital characters.

Strategies include:

• Avoid overly smooth or plastic-like appearances.
• Ensure audio and visual components are well-synchronized.
• Focus on accurate and subtle facial expressions.
• Maintain a consistent style.
• Use advanced motion capture to achieve realistic animations.
• Utilize cartoonish features that are clearly not human.

The Bottom Line

The uncanny valley meaning is illustrated with a graph showing people’s reactions to objects resembling humans. Comfort levels dip from positive to eerie or revulsion when imperfections are noticed. This is caused by factors like absent human expressions, lack of emotional cues, unnatural eye movements, or inconsistent AI voice pronunciation.

To avoid this phenomenon, designers should synchronize audio and visual components, use cartoonish features, and focus on subtle facial expressions to create more appealing and less unsettling human-like characters and robots.

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