prosopagnosia — a neurological and psychiatric disorder
This is fascinating! Please read and leave a comment, we would love to get your reactions.
Today’s session was on prosopagnosia, a deficit in the ability to perceive and recognize faces. We covered how it’s different from other types of visual impairments and how it’s different from other cognitive impairments. We went over some evidence showing that prosopagnosia is often a result of bilateral posterior damage to the cortex, by the occipitotemporal junction. However, other evidence show little to no difference in brain activity in face processing regions between “normal” people and people who have developed prosopagnosia early in childhood—this has left us a bit stumped as to what neuroscience can tell us about the neural basis of prosopagnosia. We discussed how newer advances in neuroscience can help solve this question. We also discussed possible treatments of prosopagnosia, mostly focusing on compensatory mechanisms (e.g., by identifying people based on their voices, gait, hair).
See attached for some papers if you’re interested in learning more!
See you in December. Hope everyone has a great Thanksgiving break!
“If I didn’t already know this is a picture of me I wouldn’t recognise it. I remember once somebody showed me a picture that she carried around with her. It was cropped from a waist-up shot, and looked similar to this, so I didn’t recognise the original photo she’d cropped it from. I had to ask who it was.”
Andy Sutton struggles with prosopagnosia, a cognitive disorder of face perception which reduces an individual's ability to recognize familiar faces, including one's own face.
See the attached PDFs below if you’re interested in learning more!
See you in December. Hope everyone has a great Thanksgiving break!
Detailed Exploration of Face-related Processing in Congenital Prosopagnosia
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Abstract
◾️Specific regions of the human occipito-temporal cortex are consistently activated in functional imaging studies of face processing. To understand the contribution of these regions to face processing, we examined the pattern of fMRI activation in four congenital prosopagnosic (CP) individuals who are markedly impaired at face processing despite normal vision and intelligence, and with no evidence of brain damage. These individuals evinced a normal pattern of fMRI activation in the fusiform gyrus (FFA) and in other ventral occipito-temporal areas, in response to faces, build- ings, and other objects, shown both as line drawings in detection and discrimination tasks and under more natural- istic testing conditions when no task was required. CP individuals also showed normal adaptation levels in a block- design adaptation experiment and, like control subjects, exhibited evidence of global face representation in the FFA. The absence of a BOLD–behavioral correlation (profound behavioral deficit, normal face-related activation in the ventral occipito-temporal cortex) challenges existing accounts of face representation, and suggests that activation in these cortical regions per se is not sufficient to ensure intact face processing.
Face processing improvements in prosopagnosia: successes and failures over the last 50 years
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◾️Clinicians and researchers have widely believed that face processing cannot be improved in prosopagnosia. Though more than a dozen reported studies have attempted to enhance face processing in prosopagnosics over the last 50 years, evidence for effective treatment approaches has only begun to emerge. Here, we review the current literature on spontaneous recovery in acquired prosopagnosia (AP), as well as treatment attempts in acquired and developmental prosopagnosia (DP), differentiating between compensatory and remedial approaches. We find that for AP, rather than remedial methods, strategic compensatory training such as verbalizing distinctive facial features has shown to be the most effective approach (despite limited evidence of generalization). In children with DP, compensatory training has also shown some effectiveness. In adults with DP, two recent larger-scale studies, one using remedial training and another administering oxytocin, have demonstrated group-level improvements and evidence of generalization. These results suggest that DPs, perhaps because of their more intact face processing infrastructure, may benefit more from treatments targeting face processing than APs.