Prefrontal Cortex :: Neurology Brain Medical Essays

Prefrontal Cortex The prefrontal cortex is the most anterior portion of the frontal lobe. It responds mostly to stimuli signaling the need for movement, however it is also responsible for many other specialized functions. It receives information from all sensory systems and can integrate a large amount of information (Kalat 2004). Studies have shown that the prefrontal cortex is responsible for working memory. Working memory is defined as "the information that is currently available in memory for working on a problem" (Anderson 2005). The prefrontal cortex (PFC) also controls behaviors that depend on context (Kalat 2004). For example, if my cell phone rings when I am at the mall or grocery store I would answer it. If it rings while I am at the movies or in class I wouldn't answer it. People with frontal lobe damage often exhibit inappropriate behaviors due to the inability to recognize context. Other studies indicate that the PFC is also responsible for regulating emotions and decision-making. A study was conducted in which participants were presented with three dilemmas. One dilemma was called the Trolley Dilemma: a trolley is headed toward five people standing on the track. You can switch the trolley to another track killing only one person instead of five. Subjects were asked to decide between right and wrong. Brain scans of the participants show that contemplating the dilemmas activates the prefrontal cortex and other areas that respond to emotion (Kalat 2004). Sustaining a lesion to the prefrontal cortex produces a wide variety of side effects. The effects range from minor to severe. You can get a lesion by head trauma or stroke (CJ Long 2005). Possible deficits associated with minor lesions of the prefrontal cortex: - Inability to respond quickly to verbal instructions - Speech dysfluency - Disturbances in understanding complex pictures or words - Difficulties with problem-solving - Deficits in complex tasks requiring inhibition of habitual behavior patterns With more extensive lesions the person experiences greater behavior deficits. These deficits include: perseveration, which is the inability to make behavioral shifts in attention, movement and attitude, decreased creativity, poor recall of verbal and nonverbal material, difficulty writing, and deficits in comprehension of logical-grammatical constructions (CJ Long 2005). Other effects of extensive lesions: - easily distracted - disturbances in memory - defects in time sense - decreased anxiety - less critical of oneself - difficulty with unfamiliar analogies - impulsivity