The science behind ‘face blindness’
Much of human engagement relies upon the ability to recognize familiar faces. And yet this seemingly simple, widespread human capacity, which builds and strengthens social bonds, is not a given for everyone.
People with “face blindness”— known as prosopagnosia (from the Greek words for “face” and “without knowledge”) — find it difficult, and sometimes impossible, to recognize best friends, family members, and even themselves. A 2016 review in Eye and Brain noted that although it’s often linked to brain damage resulting from trauma, face blindness can also be passed down in families and found in children.
British actor Stephen Fry describes how despite being deep in conversation with a new colleague, an hour later, he is often unable to recognize who they are. Describing his condition in an interview with the BBC, Fry says it has made social events difficult for him, as he regularly fails to identify co-workers, high-profile celebrities, and even close friends.
In even more extreme cases, the condition can be socially crippling. In her book, You Don’t Look Like Anyone I Know,Heather Sellers describes how, as a child, she became temporarily lost in a grocery store. When reunited with her mother, the staff were confused about why a child should fail to recognize their parent. Unsurprisingly, later in life, similar experiences caused Sellers considerable anxiety and embarrassment. “A few times, I have been in a crowded elevator with mirrors all around, and a woman will move, and I will get out of the way and then realize that woman is me,” she says.
The brain is the most complicated organ within the human body. Even the latest advances in medicine provide a limited understanding of its inner workings. However, malfunctions and failures in the processes involved in problem-solving, perception, and sensation help neuroscientists and cognitive scientists gain crucial, deep insights into the complicated mechanisms involved in human perception.
British actor Stephen Fry describes how despite being deep in conversation with a new colleague, an hour later he is often unable to recognize who they are.
Research into people with visual perception damage suggests that processing and identification of facial images take place at multiple levels. In a 2010 paper, professor of psychology Thomas Busigny reported that a stroke patient who suffered an injury on the right side of his brain was able to identify all the elements of a face, but could not form them into a recognizable whole.
The brain, therefore, appears to process individual facial features — the shape of the mouth, eye color, and distance between eyes — to produce a holistic representation before matching it against stored memories. Such processing is immediate — occurring without conscious effort — and, usually, effective. But for patients with face blindness, either a component of the brain linked to a late stage in face processing is not being triggered, or is not being supplied with the required information.
Galia Avidan, a psychologist at Ben-Gurion University of the Negev, Israel, also believes “normal” face processing involves multiple regions of the brain, with those near the front forming a connective hub, like a busy airport. Such a high level of connectivity is absent at the front of the brain in people with prosopagnosia but higher at the rear. The degree of difference from a typical brain predicts the level of face blindness.
Prosopagnosia may be more common than once thought. In a 2006 study, Thomas Grüter, at the Institute for Human Genetics in Münster, a prosopagnosic himself, identified that 2.47% of 689 local secondary school pupils and medical students who were asked to complete a questionnaire reported face blindness symptoms.
Also, sufferers — along with families and friends — may be unaware of their condition. Even persistent failure to recognize faces can remain hidden. In some cases, identification is managed covertly using other salient identifiers: voice, body shape, hairstyle, clothing, and behavior. The brain is, therefore, able to compensate by strengthening supporting perceptual processes. Indeed, research shows that visual perception training has been found to help children and adults diagnosed with prosopagnosia. It teaches them to focus on specific features of the face — noting memorable characteristics such as position and shape of the eyes, brow area, nose, and mouth — and has been shown to improve recognition significantly.
In the future, medical intervention may offer more permanent relief. Zaira Cattaneo, a neuroscientist at the University of Milano-Bicocca in Italy, has successfully used transcranial magnetic stimulation to block the functioning of the prefrontal cortex in healthy brains to mirror the issues of prosopagnosics. It may one day be possible to use this noninvasive procedure, using magnetic fields, to stimulate nerve cells and restore “normal” functioning to areas of the brain currently switched off.
This article, along with others like it, originally appeared on Medium