There are two samples on this page.

Sample 1 describes Phineas Gage, a man who suffered a severe brain injury.

Sample 2 describes Kanzi, a bonobo who lives in a language-rich environment for the purpose of demonstrating whether primates can acquire a human language.

Sample 1

Much of what psychologists know about the human brain has come from case studies of individuals who had brain surgery or brain damage in accidents. Phineas Gage is one such case study. He was a young railroad worker in 1848 who had an accident at work. He was forcing gun powder into a rock with a long iron rod when the gun powder exploded. The iron rod shot through his cheek and out the top of his head, resulting in substantial damage to his frontal lobe. Incredibly, he did not appear to be very hurt. His memory and mental abilities were intact, and he could speak and work. However, his personality totally changed. Before the accident, he had been nice to be around, but afterward he became ill-tempered and dishonest. He lost his job and ended up working as an exhibit at fairs.

Phineas Gage’s injury served as a case study for the effects of frontal lobe damage. He did not lose a specific mental ability, such as the ability to speak or follow directions. However, his personality and moral sense were altered. Psychologists now know that parts of the cortex (called the association areas) are involved in general mental processes, and damage to those areas can greatly change a person.

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Sample 2

Animals are also used in case studies. One area of psychology that uses primate case studies is the field of language acquisition. Researchers debate whether language is something unique to humans, or if it appears in lower animals also. If a psychologist could show that a non-human animal uses language like humans, it would demonstrate that language is not a unique feature of humans.

Dr. Sue Savage-Rumbaugh at the Language Research Center (LRC) at Georgia State University is working with a collection of chimpanzees and bonobos on the question of whether non-human primates can acquire language. One such bonobo is Kanzi.

Kanzi was born in 1980 and was raised in an English language environment. His mother was a research subject in language training studies. He spent all of his time with her during her training. When Kanzi was two years old, his mother was sent to a different primate center to breed. It was at this point that the researchers at the LRC discovered that Kanzi could understand their language. It seemed that he had acquired language much the same way a human child does—by being exposed to it throughout infancy and early childhood.

Kanzi could use a picture board to point to the correct symbol when the experimenters said the name of an item. New symbols were added to his picture board, but he was not trained in their meaning. Instead, researchers used the new words in conversation. Kanzi can point to the symbol or the real object when he hears the word. In addition, he can “tell” his human companions what he wants to do by pointing to the symbols on his picture board.

Dr. Savage-Rumbaugh interprets Kanzi’s behavior as evidence that non-human primates can understand and acquire human language. She believes this demonstrates that language is not a unique capability of humans. Other psychologists disagree with her findings and believe that Kanzi has been trained, much like a circus animal. They do not believe that he creates or understands new word combinations, which is the crucial aspect of human language acquisition.

You can read more about Kanzi and the animals at the LRC at the animal biographies web site (part of the LRC site).

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