In daily life, recognizing faces is an almost automatic process for humans. Despite changes in location, clothing, hairstyle, or facial expression, we can effortlessly identify friends, family members, and acquaintances. This ability plays a fundamental role in establishing social interactions. However, in some individuals, this seemingly natural skill can be severely impaired. They may fail to recognize close relatives, spouses, and sometimes even themselves. This condition is associated with a neurological disorder known as prosopagnosia.
Although prosopagnosia is sometimes perceived simply as “poor face memory,” it is actually a disruption of the brain mechanisms responsible for face recognition. Therefore, the problem cannot be explained by general memory deficits or visual impairments. Patients understand that a face is a face but cannot determine to whom it belongs. This feature distinguishes prosopagnosia from other recognition disorders and highlights its significance for social life.
Prosopagnosia is considered a subtype of visual agnosia, a disorder in which the ability to recognize stimuli is impaired due to brain damage or functional disruption. Visual agnosia can affect different sensory modalities. In prosopagnosia, the main problem is the inability to recognize previously seen faces and to encode new faces into memory. This disorder can be categorized into two main forms: acquired and developmental. Acquired prosopagnosia arises from brain damage, caused by trauma, stroke, tumors, encephalitis, or degenerative brain diseases, which disrupt the face recognition system. One of the earliest documented cases of acquired prosopagnosia was reported by Bodamer in 1947 in patients injured during wartime.
In contrast, developmental prosopagnosia occurs without brain injury and is characterized by an underdeveloped ability to recognize faces from childhood. This form is relatively more prevalent. Some studies suggest that approximately 2.5% of the population may be affected. Familial patterns observed across multiple generations also indicate a possible genetic predisposition.
Primarily, prosopagnosia affects face recognition, but in some cases it may also interfere with the recognition of emotional expressions, familiar scenes, or certain objects. Nevertheless, patients perceive the structure of faces and understand that they are human faces. They can identify facial features but cannot associate a specific face with a particular individual.
As a result, individuals with prosopagnosia rely on alternative cues to recognize people, such as voice tone, hairstyle, clothing, gait, or body shape. However, when these cues change, recognition errors occur. For example, a patient may fail to recognize a friend whose hairstyle has changed or walk past a relative on the street as if they were a stranger.
These impairments significantly impact social interactions. Patients are often perceived as rude or indifferent because they fail to recognize others, which can lead to embarrassment, social anxiety, and reduced self-confidence. Consequently, many patients avoid meeting new people or participating in social environments. In children, this condition may create challenges in school settings and pose safety risks. Therefore, prosopagnosia is not only a neurological disorder but also a serious cognitive impairment with socio-psychological consequences.
In 2025, a study conducted by M. V. Peelen and colleagues analyzed the eye-tracking patterns and deep learning-based gaze strategies of individuals with prosopagnosia compared to healthy control groups during face recognition tasks. The study evaluated both acquired and developmental prosopagnosia groups and analyzed gaze patterns using deep learning models.
Results indicated that healthy individuals focused the majority of their gaze on the eye region, particularly the left eye. In prosopagnosia, however, gaze priority shifted away from the eyes toward the nose and mouth regions. This group difference appeared early and became clearly observable after the fourth fixation, indicating a disruption in the initial stages of face processing.
Deep learning models accurately distinguished acquired prosopagnosia from healthy controls and confirmed that gaze patterns were more stereotyped and shifted away from the eyes in this group. In developmental prosopagnosia, gaze distribution was more diffuse and partially resembled that of healthy individuals, which may be explained by the absence of structural brain lesions in the hereditary form.
Prosopagnosia is not merely an individual recognition problem; it is a disorder that directly affects social interactions. Proper diagnostic approaches and social support can enhance patients’ adaptation and coping strategies. Therefore, prosopagnosia should be considered in a comprehensive manner, addressing both clinical and social dimensions.
References
Corrow SL, Dalrymple KA, Barton JJS. Prosopagnosia: current perspectives. Eye and Brain. 2016.
American Academy of
Ophthalmology. Prosopagnosia. EyeWiki. 2025.
Farah MJ, et al. Prosopagnosia – overview. ScienceDirect Topics. Elsevier. 2017.
Kazemian A, Oruc I, Barton JJS. Scanning faces: a deep learning approach to studying eye movements in prosopagnosia. Frontiers in Neurology. 2025;16.
