The fusiform face area and neural mechanisms of face recognition

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Recognizing Faces

There is a region in the brain, called the fusiform face area or FFA, which is vital in recognizing and distinguishing faces (Andrews et al., 2010). Brain scientists have been acquiring an understanding of the mechanisms, which distinguish faces. A baby's brain processes faces at four months as distinct objects. Faces tell a baby a lot of things, such as the person's identity, gender, race, emotion and truthfulness. The loss of that ability to recognize and distinguish faces is called proposophagnosia or face blindness. It often follows a stroke or brain injury. A person who suffers from this damage, even with normal vision, cannot recognize the faces he already knows very well, such as spouse and children. The damage is often on the fusiform gyrus, which is located in the underside of the brain and other areas (Andrews et al.).

Face Recognition, Identification and Classification

Basic-level categorization is the common entry-point recognition for faces but not enough to identify them (Tarr & Cheng, 2003). The entry point is at the individual level. It would be later understood that faces can be recognized only holistically as opposed to the parts of an object. An object is recognized and discriminated according to their parts. Recent evidence shows that the fusiform face area lights up when objects are viewed in the same way as faces. It was originally thought that the area lights up only when faces are recognized (Tarr & Cheng).

Long-Term Memory and Face Recognition

Encoding and the retrieval process are essential to face recognition (Tarr & Cheng, 2003). The encoding process inputs the face features in long-term memory and helps in storing images permanently as well as for ease of retrieval later. The encoding must be correct or it can be lost. The stored information becomes like a databank, which is later used in recognizing or distinguishing faces. Encoding consists of a view-centered description process and an expression-independent description process. The view-centered description process is later used to represent the person's primary facial features or information, such as contrast or light intensity. This is influenced by the representation of the face, which includes the size, orientation, and the intensity of light. The expression-independent description process, on the other hand, is the abstract representation of the person's facial features and then the whole face for facial recognition. The description derives from the common characteristics of the face as viewed from different angles. The expression-independent description process compares codes sent from this description with another stored in the face recognition unit. If they match, the face is recognized. This kind of encoding helps in the matching and in retrieving long-term memory and facial recognition. Encoded information must not be distorted and must be located for easy retrieval (Tarr & Cheng).

A study asked 10 healthy young adults, 8 men and 2 women, to perform face encoding, face recognition, face perception control and sensorimotor control (Haxby et al., 1996). These were measured in the regional cerebral blood flow with the PET equipment. The experiment found no overlap between the brain structure in these memory functions. Findings also showed that encoding activated the left prefrontal cortex while recognition activated the right prefrontal cortex. Overall findings revealed that the hippocampus and the adjacent cortex become involved in memory function at the time of the encoding of new memory. Face recognition was shown to involve anatomically dissociable operations rather than simply by recapitulation (Haxby et al.).

Error in Face Recognition

Neuropsychological investigations report that false self-recognition or mis-identification of faces can result from massive damage to the right hemisphere (Rapcsak et al., 1994). Extreme reliance on the feature-based, left-hemisphere approach to face processing and a damaged face recognition system's inability to critically evaluate output result in recognition errors and mis-identification. The findings of these investigations suggest that the feature-based left-hemisphere recognition system is prone to error. Its component facial features are often common to many different persons. This is so also because the reliable recognition and identification of faces is heavily dependent on the efficient processing of the configuration information of faces by the right hemisphere. Researchers propose that decision-making and monitoring functions of the face recognition system be more confined to the right frontal lobe (Rapcsak et al.).

Misidentification and False Self-Recognition

The face recognition process is subject to error, such as a person's inability to recognize his own face and mis-identification (Tarr & Cheng, 2003). A person who is unable to identify his own face is called a prosopagnosic. This means that the fusifrm face area in his brain is damaged (Tarr & Cheng).

In another occasion, he may not be able to correctly identify someone else's face because of an unconscious transference (Tarr & Cheng, 2003). Unconscious transference is a condition wherein the person cannot distinguish between the target person and the familiar face seen at another time. This happens to court witnesses of a trial who finds difficulty recalling having seen the target person committing the crime he is accused of or seeing him at another time or occasion (Tarr & Cheng).

Face recognition is basic to daily survival (Tarr & Cheng, 2003). It is also a complicated process capable of error. Memory is central to the very process. Without an accurate recall of facial features, the retrieval process is useless (Tarr & Cheng). #