Acquired Prosopagnosia

One of the processes thought to contribute to human face perception, the human visual system integrates facial features into a gestalt whole (referred to as holistic face processing). [1]. Research indicates that face components (e.g., the eyes, nose, and mouth) are recognized better as belonging to a certain face when they were shown within the context of the whole (upright) face than when they were shown alone. However in terms of race, the other-race effect (ORE) is a well-documented recognition advantage for same-race (SR) over other-race (OR) face and has been demonstrated in line up identification, photo line ups and eye witness testimonies [2]. FFA is less active in response to OR faces than SR

This double dissociation therefore suggests that recognition of faces and common objects is served by different mechanisms that are independent for each other. Although brain cells of face recognition have not been located, some functional models could help us interpret face recognition and prosopagnosia. One of the most influential models was proposed by Bruce and Young (1986). In this model face recognition involves several steps, and three steps more relate to prosopagnosia.

From the study conducted by Ferri et al., there was a slight statistical significance between amygdala activation to neutral and fearful faces in regards to anxiety levels. On the contrary, they did not find a significant difference. This could be due to the girls being unable to predict the

Observation of children who were born deaf and blind show that they make the same emotional expressions (3). There is no way that these children could have learned this behavior through sensory input. Similarly, a study involving sighted babies less than six months of age has shown that they react with fear to negative faces (7). These infants were too young to have learned which faces had negative connotations. This would have to be an innate response. Different cultures define when and

There are several different types of psychological and neurological phenomena that individuals live with every day. One of most interesting conditions that many individuals might not be aware of is prosopagnosia or face blindness. Prosopagnosia is the inability to recognize and distinguish faces. For example, individuals with this condition could have difficulty recognizing their child’s, spouse’s, parent’s, or friend’s face. Many individuals with prosopagnosia will rely on other features to distinguish between other people, such as hair style or color, voices, or posture. As discussed in Chapter 3, prosopagnosia is thought to affect the Fusiform Face Area.

The face recognition model developed by Bruce and Young has eight key parts and it suggests how we process familiar and unfamiliar faces, including facial expressions. The diagram below shows how these parts are interconnected. Structural encoding is where facial features and expressions are encoded. This information is translated at the same time, down two different pathways, to various units. One being expression analysis, where the emotional state of the person is shown by facial features. By using facial speech analysis we can process auditory information. This was shown by McGurk (1976) who created two video clips, one with lip movements indicating 'Ba' and other indicating 'Fa'. Both clips had the sound 'Ba' played over the clip.

This implies that bilateral and unilateral hippocampus does not contribute majorly to familiarity and recollection of unknown human’s faces.

The second type of configural processing is holistic processing. Holistic processing is when first-order information is given to categorize faces from other competing objects. People are slower and less accurate in perceiving the top half of a face with the bottom half of another face. This is called the composite face effect which affects holistic processing (Maurer et al., 2002). Holistic processing is when someone perceives a face as a whole and not as a set of separate, independently processed features. The process is generally accepted to be unique to faces and provides strong support for the notion that faces are processed differently relative to all other object categories. Furthermore, this process is demonstrated when internal features of upright faces are blurred together. This causes it to be difficult to analyze individual features (Hole, 1994). Holistic processing occurs between internal features and external contours which makes it hard to differentiate external contours and that the internal features of a face are the same. The last type of processing is detecting second-order

A recent study measured the magnitude of response in the STS and FA to both dynamic and static stimuli (Pitcher et al., 2011). Results were as expected, the response to movies of faces was not significantly different from the response to static images of faces from these same movies in the right FFA and right OFA. By contrast the face-selective region in the right posterior STS (pSTS) responded nearly three times as strongly to dynamic faces as to static faces. A face-selective region in the right anterior STS (aSTS), which is not mentioned in Haxby’s model, also responded to dynamic faces only. Dynamic stimuli was used to localise the face areas that reported more anterior face selective activations in the anterior superior temporal sulcus (aSTS-FA) and in the inferior frontal gyrus (IFG-FA). These two regions, similar to the pSTS-FA and in contrast to the ventral face areas, show an increased response to dynamic faces than static faces. Therefore providing further evidence for the functional relationship between the pSTS-FA, aSTS-FA and IFG-FA in the processing of dynamic facial expression.

This essay will talk about face recognition and several reasons why it has been studied separately. The ability to recognise faces is of huge significance of people’s daily life and differs in important ways from other forms of object recognition (Bruce and Young, 1986). Than this essay will talk about the processes involved in face recognition which comes from the diversity of research about familiar and unfamiliar faces-it includes behavioural studies, studies on brain-damaged patients, and neuroimaging studies. Finally, it will discuss how face recognition differs from the recognition of other object by involving more holistic or configuration processing and different areas of the brain (Eysenck & Keane, 2005).

Prosopagnosia is defined as the difficulty in recognizing an individuals face; it is broken down into 3 main types; Apperceptive prosopagnosia, associative prosopagnosia and developmental prosopagnosia. Perception is an important aspect when recognizing faces, without recognizing the stimulus (face) you would not be able to identify a person. Therefore the individuals who sufferer from this disorder is unable to accurately recognize a face whether that be the face of a familiar person such as a family member or close friend, the face of a famous person, or even their own face. This paper will look at prosopagnosia in greater detail, it will explain the 3 main types, as well as give insight as to why face recognition is important in our

The importance of the amygdala in social cognitions has been examined in both primate and human studies. Use of primates to study the social brain suggests that the amygdala contributes to social cognition. Kluver and Bucy made large bilateral lesions in monkey brains made across the amygdala, temporal neocortex, and surrounding structure. After the lesion, the animals engaged in hypersexual behaviors, unusual tameness, and a lack of knowledge about emotional stimuli. Lesions exclusively targeting the monkey’s amygdala resulted in similar, but more subtle impairments. This suggest that the amygdala may play a role in emotions elicited by social cues. Studies of the amygdala’s role in human social cognition suggest that the temporal lobes process socially relevant facial information from humans. Emotions from facial expressions, in particular fear are projected to the amygdala. Studies using FMRI to examine typical subjects and subjects with amygdala damage support this theory. Individuals with amygdala damage have difficulty recognizing facial expressions, specifically negative emotions such as fear.

Agnosia is defined as the inability to recognize objects through the processing of sensory information, which means there is no deficit in semantic memory or problems with naming objects. An individual suffering from agnosia still possesses all the relevant semantic information tied to a precept, but they cannot recognize the precept when it is presented to them and therefore trigger the recall of said information. There are many types of agnosia, but this essay will focus on visual object agnosia and prosopagnosia. The former is the inability to recognise objects: patients suffering from visual object agnosia do not have impaired vision, and in some cases can even copy the object they are seeing (patient H.J.A., Humphreys & Riddoch, 1987) or draw it from memory (patient D.F., Milner & Goodale, 1992), but are unable to recognize it when they see it. In the latter, prosopagnosia, patients cannot recognise faces of familiar individuals, and have to rely on other characteristics such as their voice or clothing to recognize them. Patients suffering from prosopagnosia can either acquire it through a lesion in relevant brain areas (acquired prosopagnosia) or for less understood reasons have it from birth, in which case it is termed developmental prosopagnosia. The study of patients with agnosia is integral to the field of visual recognition, as the specifics of their deficits can provide great insight into the ways our brain processes information; for example, the location of

Although some critiques can be made, the experiment overall was well structured and the scientists was able to gather good evidence. The authors agreed that the mechanism that is associated with the implicit recognition is different from the recognition awareness. The scientists had the participants take a forced-choice test for a second time after they had looked at the kaleidoscope images. By doing another experiment using the same technique, they are giving a variety of stimiulus that could reaffirm the correlation that they are trying to make.

Imagine a world wherein you meet someone again and again. Imagine a world wherein faces and objects are just blurred images that all look alike. Imagine having to learn other ways in order to remember them. Prosopagnosia does that to people. Prosopagnosia is a neurocognitive disorder characterized by severely impaired face recognition (Dalyrmple, Garrido & Duchaine, 2014). With this kind of disease, one can’t recognize their own family and close friends who have been with you for a long time. When looking at old pictures, one can’t even recognize themselves. Prosopagnosia is a condition to be dealt with and understood for one to be able to live with it.