Temporal lobe injuries result in a wide variety of cognitive and emotional difficulties. In particular, sensory input and memory retention problems are common in individuals with these injuries. More rarely, social skills and personality may also be adversely affected.
Although many of the functions of the temporal portion of the brain remain a mystery, evidence points to a strong correlation between temporal lobe injuries and difficulties with auditory and visual processing. In specific, patients with extensive damage to this area of the brain have trouble paying attention to conversation. Furthermore, even when concentrating on speech, these patients often fail to understand common words and phrases. This condition, called Wernicke’s aphasia, seems to be more common in patients with damage to the left temporal lobe.
Visual recognition also seems to be affected by temporal lobe injuries. Patients suffering from brain damage in these areas are prone to forget the names of objects and, in more extreme cases, lose the ability to recognize familiar faces. Often, these individuals have difficulties categorizing things into common groups as well. For example, a person with a temporal lobe injury may be able to identify an apple but not be able to associate it with other fruits.
Both long- and short-term memory also seem to be negatively impacted in patients with temporal lobe injuries. Some professionals believe this impact is closely related to processing problems. In short, the theory is that memories are never formed because the data being processed by the brain is corrupt. Closely related is the theory that a small area, called the hippocampus, within the temporal lobe is responsible for the transference of short-term to long-term memory. If this area is damaged, it is believed that the individual may not be able to form new memories from the time of the injury forward.
People with temporal lobe injuries may also experience changes in behavior. Commonly, these individuals experience increased verbal and, more rarely, physical aggressiveness. In general, even those patients who do not become verbally abusive may still experience increased talkativeness with decreased empathy to how their comments may affect those within earshot. In addition, patients with temporal lobe damage may be unable to process nonliteral dialogue and, thus, may become confused or hurt by lighthearted jesting.
In addition, temporal lobe injuries may lead to severe emotional disruptions. Frequently, these disruptions manifest as sexual dysfunctions, including abnormally high or low sex drives. In rarer cases, however, a patient may form a fixation on a certain object, person, or idea. Paranoia and the formation of compulsive or ritualistic behaviors have also been observed in these patients.