Learning to see faces

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A note for Lesson no. 3, "Little Brains Wire Themselves to Their World," in Seven and a Half Lessons About the Brain by Lisa Feldman Barrett.
Some context from page 48‌‌‌‌ is:

When you cradle a newborn girl in your arms, you expose your face to her at just the right distance to teach her brain to process and recognize faces.

Face perception is not innate. Newborn infants do have a preference for face-like images and objects at birth (see references), and this preference may be due to learning in utero. Human faces are full of visual contrast (between light and dark) and can be detected by a developing fetus during the third trimester.[1] So this permits a hypothesis that the preference for human faces at birth could be due to prior visual experience with faces that is wired into the brain in utero.

Light would have to hit the retina of a mammal's eye, in utero, for the retina to develop normally.[2] This implies that, at a certain stage, in utero, a fetus's retina is detecting changes in light and dark.[3] Light that conveys perceptual information (such as three dots in the orientation of two eyes and a mouth) were projected through the uterine wall and perceived by third trimester human fetuses. Using ultrasound recording, it was discovered that a third trimester fetus turns is more likely to turn its head towards three dots oriented like a face compared to three dots in other configurations.

For the first few months of life, infants primarily see faces, creating a "curriculum" for learning to perceive faces and recognize individual people.[4]

This type of learning, which is sometimes mistaken for "innate" capabilities, is pervasive in the animal kingdom. For example, may so-called "instincts" are actually the result of learning that shapes an existing response (such as learning to peck for food).[5]


  1. Reid, Vincent M., Kirsty Dunn, Robert J. Young, Johnson Amu, Tim Donovan, and Nadja Reissland. 2017. “The Human Fetus Preferentially Engages with Face-like Visual Stimuli.” Current Biology 27 (12): 1825–1828.
  2. Sujata Rao, Christina Chun, Jieqing Fan, J. Matthew Kofron, Michael B. Yang, Rashmi S. Hegde, Napoleone Ferrara, David R. Copenhagen, and Richard A. Lang. 2013. "A Direct and Melanopsin-Dependent Fetal Light Response Regulates Mouse Eye Development." Nature 494 (7436): 243–246.
  3. Del Giudice, Marco. 2011. "Alone in the Dark? Modeling The Conditions For Visual Experience In Human Fetuses." Developmental Psychobiology 53 (2): 214–219.
  4. Smith, Linda B., Swapnaa Jayaraman, Elizabeth Clerkin, and Chen Yu. 2018. “The Developing Infant Creates A Curriculum For Statistical Learning.” Trends in Cognitive Sciences 22 (4): 325–336.
  5. Hailman, Jack P. 1969. "How an Instinct is Learned." Scientific American 221 (6): 98–108.