Facial Recognition has long been thought to be an innate human and primate ability. It has been believed that from birth humans and primate babies prefer gazing at faces because they innately recognize faces. A new study from Harvard Medical School casts this belief in a different light. Researchers found that the absence of exposure to faces in the early days of development causes an absence of neuron network development in the brain area "responsible for recognizing faces."

Facial recognition disorders and early neuro-development

Two neuro-development disorders of the brain that affect a person's ability to recognize or to be attracted to faces are prosopagnosia and autism.

In prosopagnosia, failures in neuron development "machinery" produce an inability to recognize as familiar — or as known — faces repeatedly encountered on a daily basis. This facial blindness, as it is sometimes called, can be present from birth or caused by traumatic brain injury to the temporal lobe.

In autism, failures in the development of neuron clusters dedicated to preference attraction for faces create a contrary aversion to faces. In this developmental condition, present from birth, a person avoids looking at faces.

Facial recognition areas and functional MRI

Harvard researchers, led by neurobiologists Margaret Livingstone, Michael Arcaro and Peter Schade, used functional MRI (fMRI) to examine brain images to measure the "presence of facial recognition patches," which are specialized neuron clusters in specific brain areas.

Patches related to attraction toward and recognition of faces develop during the first 200 days (approximately six months) of life. The fMRI images showed that deprivation of exposure to faces during this Early Development resulted in the total absence of facial recognition patches.

In contrast, the development of other neuron cluster patches, for example, in the "hand [recognition] domain in their brains," were "disproportionately large."

Conclusion of study linking seeing faces with recognizing faces

The neurobiology research team proposes that their study links seeing faces with the development of the brain domain associated with recognizing faces.

They suggest that the environmental factor of exposure to faces "influences viewing behavior" and that it is viewing behavior that determines, or "drives," neuron cluster development. It is this "neuronal activity" that "sculpts" — or "installs" — facial recognition brain "domain formation."

The study "Seeing faces is necessary for face-domain formation" was published in Nature Neuroscience. Authors of the study were Michael J. Arcaro, Peter F. Schade, Justin L. Vincent, Carlos R. Ponce and Margaret S. Livingstone, Harvard Medical School Takeda Professor of Neurobiology. Justin Vincent and Carlos Ponce, also from Harvard Medical School, were co-investigators in the research.