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HOME > No.14, Sep 2018 > Do We Subconsciously Judge Face-likeness?

Do We Subconsciously Judge Face-likeness?

Keys to uncovering the face-likeness recognition mechanism using brain waves By Yuji Nihei
Assistant Professor Kojiro Matuo (1st from right, 2nd raw) with his laboratory members

Yuji Nihiei, a Ph.D student, and a member of the research team of the Visual Perception and Cognition Laboratory at the Toyohashi University of Technology has suggested that face-likeness is judged by early visual processing at around 100ms after viewing an object. The present study focused on the relation between face-likeness recognition and brain activity to suggest for the first time that face-likeness recognition is influenced by early visual processing.
The results of the present study were published in Frontiers in Human Neuroscience.

Face-likeness recognition is the act of recognizing a non-face object as a human face. This phenomenon is called "pareidolia," and refers to "perceiving an inherently meaningless object such as a pattern, landscape or object as another object with meaning." Many spirit photographs rely on this phenomenon. While pareidolia has been argued to occur in relatively low-level visual processing, at what level of visual processing pareidolia actually occurs was never previously discerned.

Therefore, the research team of the Visual Perception and Cognition Laboratory at the Toyohashi University of Technology decided to study the relation between behavior when a face-like object is viewed and brain activity to reveal the level of visual processing at which face-likeness is recognized.

Fig.1 Brain's reaction when a face-like object is viewed

PhD student and lead author of the study Yuji Nihei explains that, "Visual processing of the human face is divided into three different stages. The first stage is early visual processing of roughly identifying the object. Then, if the object is a face, distinguishing the parts of the face (eyes, nose, mouth) from one another and processing the outline and parts of the face. Lastly, expression and individual differences are distinguished. We studied the relation between activity at these three stages of processing and the results of actual recognition and determined that face-likeness recognition occurs in the first stage of visual processing. This processing occurs at a speed of approximately 100ms after viewing an object, and so we believe that face-likeness processing occurs before we are aware of the object."

Associate Professor Minami Testuto, who leads the research team, says that, "While seeing face-likeness in various objects could be considered incorrect in terms of object recognition, we believe this is not just a mistake and actually makes us reconsider an important cognitive function. We would like to continue our study of face-likeness recognition from an objective approach."

The results of this study are believed to serve as a key to uncovering the mechanism of how humans recognize and distinguish between two types of information - "face-likeness" and objects. The results of the present study also suggest that "face-likeness" recognition occurs in early visual processing and that face-like objects are processed in the same manner as a human face in later stages. Due to this, we believe that face-likeness can be caused by an effect that gathers attention to the face, or some other like stimulus.

The present study was conducted with the assistance of Grants-in-Aid for Scientific Research numbers A(26240043) and C(25330169) from the Japan Society for the Promotion of Science. The lead writer Yuji Nihei also received a grant as part of the Program for Leading Graduate Schools (R03) run by the Japan Society for the Promotion of Science.


Nihei, Y., Minami, T., Nakauchi, S., Brain Activity Related to the Judgment of Face-Likeness: Correlation between EEG and Face-Like Evaluation, Frontiers in Human Neuroscience,


By 二瓶 裕司

豊橋技術科学大学情報・知能工学系視覚認知情報学研究室の研究チームは、顔らしさの判断が物体を見てから約100msという早期の視覚処理で行われることを示唆しました。本研究では、顔らしさの認知と脳活動の関連に着目し、世界で初めて顔らしさ認知が早期の視覚処理の影響を受けていることを示しました。本研究成果はオープンアクセス誌frontiers in Human Neuroscienceに掲載されました。







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Researcher Profile

Takeshi Kawano
Name Yuji Nihei
Affiliation Department of Computer Science and Engineering
Title PhD student
Fields of Research Vision Science, Cognitive Neuroscience