Facial Recognition in Infants

There’s little debate on the importance of facial recognition in infancy. On October 10^th, Dr. Greg Reynolds discussed his study on the neural correlates of individuation and categorization in infancy. In his study, groups of infants were exposed to various faces of the same and/or different monkeys viewed at different positions. The goal of the experiment was to look at the infant’s ability to individuate and categorize the faces of other species. The findings showed that infants could categorize monkey faces by species, however, were never able to familiarize monkey faces on an individual level (Reynolds, 2019). Dr. Reynolds made use of 9-month old infants able to categorize at the subordinate level.

Rebecca Saxe discussed her team’s theories regarding early facial recognition in infants. In 2017, fMRI studies in 4-6-month-old infants hinted that specific regions of the brain become tuned to activated to human faces over time (Saxe 2018). These face specific cortical regions would initially activate at the sight of anything, but with repeated activation, starts to only activate in response to human faces. One theory is that repeatedly putting a face in front of an infant repeatedly allows it to become more sensitive to different aspects of facial features. The more a baby closely views various faces, the more it notices the smaller differences between faces. This theory is missing the explanation of why babies seek out faces rather than passively learning what general features make up a face.

Another theory proposed was that babies have an innate face template or idea of what to look for in faces. This theory doesn’t have much evidence as stated by Saxe; however, it does explain human infant’s attraction have faces. This is like how animals instinctually know to follow their mothers after birth. Additionally, it’s been studied that human infants have both inherent expected experiences and unexpected experiences. For example, vision is an inherently expected experience to the human infant. The body expects there to be visual stimulus after birth and if an infant is deprived of that during its critical period of development, there will be a loss of visual ability. Though there may not be much evidence for this theory, it is not one to ignore.

The third theory is that the medial prefrontal cortex (mPFC) is responsible for linking social interactions to development of face-selective cortical areas. When baby looks at a face, response is social, and could be key to subsequent development of organized face recognition areas in brain. The mPFC is linked to social cognition and behaviors and is known to activate when exposed to dynamic faces and social dynamics in infants. Research currently being done with functional near infrared spectrography (fNIRS) to measure blood flow in the brain to see mPFC responses to social cues and face response areas of the brain.

Basically, facial recognition in human infants is a significant part of human development which holds potential information to better educational and developmental systems implemented globally. Both Dr. Reynolds and Rebecca Saxe both look at facial recognition with human infants to see how the categorization and organization of memory and facial recognition can be mapped in infants. There’s an attentional and/or motivational aspect to these studies, as human infant’s motivators of attention are also studied. Dr. Reynold’s study showed infants not being able to individuate non-human faces, while Rebecca Saxe discussed the attentional motivators of infants and their natural draw to human faces. Infancy is a critical time for development in human children and studying their neural development holds significant potential for the future of society.

Works Cited:

Dixon, K. C., Reynolds, G. D., Romano, A. C., Roth, K. C., Stumpe, A. L., Guy, M. W., & Mosteller, S. M. (2019). Neural correlates of individuation and categorization of other-species faces in infancy. Neuropsychologia, 126, 27–35. doi: 10.1016/j.neuropsychologia.2017.09.037

Trafton, A. (2019, February 12). A social side to face recognition by infants. Retrieved October 18, 2019, from https://mcgovern.mit.edu/2018/08/20/a-social-side-to-face-recognition-by-infants/.

Reynolds, G. D., & Roth, K. C. (2018). The Development of Attentional Biases for Faces in Infancy: A Developmental Systems Perspective. Frontiers in Psychology, 9. doi: 10.3389/fpsyg.2018.00222