Frontal Lobes

The frontal lobe is an area of the brain that can be seen in both humans and other mammals. It is positioned at the front of the cerebral hemispheres and is thought to be the most complex lobe of the brain. This is because it is responsible for a number of higher brain functions, including mediating abstract thought, as well a planning and organising behaviour and emotions. It is also involved in memory, creativity, intelligence and language among other functions.
Over the last 150 years there have been a large number of case studies of patients with damage to the frontal lobes. The most well known is an individual called Phineas Gage who suffered a severe accident, in which an iron rod was blown through his head during a construction accident. This caused severe damage to the frontal lobes and severely altered aspects of his personality. Later case studies showed that damage to the frontal cortex was associated with impaired cognitive and intellectual functioning. Although observable effects from brain damaged individuals have been a useful tool into mapping the frontal lobes, there are a number of tests that have been designed to measure frontal lobe function.
The most commonly used test to measure frontal lobe function is the Controlled Oral Word Association test which was formulated to measure verbal fluency and involves asking the patient to name as many words as possible beginning with the same letter. Those with frontal lobe damage often perform much poorly than controls. The Wisconsin card sorting test is another well known test used to analyse frontal lobe functioning. This involves the subject sorting cards in to piles, using different rules for example by shape colour or number, without warning the experimenter changes the sorting principle. It is commonly found that those with frontal lobe damage take much longer to adjust to the new principle ( this is called perseveraton), compared to normal controls.
The symptoms caused by brain injury to the frontal lobes can be quite vast but most commonly it reduces a persona ability to plan and organise, effecting both planning ahead and voluntary motor behaviour. An individuals perception of smell and taste can also be altered when the frontal lobes are damaged. t is also found that damage to the frontal lobes causes individuals to become lethargic and speak very little, often doing poorly on verbal tests.