Friday, December 30, 2005

The Psychology of Deafness

November 15, 2005

When talking about the “psychology of deafness”, perhaps the first questions that must be asked are: “Is the state of being deaf pathology, or is it a culture?” Does this distinction matter? In either case, does the description, “psychology of deafness”, apply?

The definition pathology that best applies: “a departure or deviation from a normal condition.” The “normal condition” of humans includes having a sense of hearing; any deviation from this norm, such as deafness or “substantial hearing loss” falls under this definition. If we want to, we can conclude that deafness is pathological.

On the other hand, the Cambridge Dictionary Online gives us one definition of “culture” as “the way of life of a particular people, esp. as shown in their ordinary behavior and habits.” Do deaf people, collectively, exhibit behaviors and habits that set them apart from hearing people?

When answering this question, it seems helpful to refer to people who cannot hear as either deaf (lower case “d”) or Deaf (upper case “d”). People who consider themselves “Deaf” see themselves as part of the deaf community (or culture) and regard their state as a way of life. Much like an ethnic identity, their culture is not something that they need to have “fixed”.
Deaf people use sign language as their primary means of communication and frequently as their “native language.

People who are “deaf” do not consider themselves culturally “Deaf”, though they may socialize with Deaf people. The “deaf” (in English speaking countries) use English or a form of signed English as their primary language and view themselves as part of the hearing world. The deaf see their deafness is primarily pathological (a deviation from the norm), rather than cultural.

To the Deaf and the deaf, it matters. The deaf see their state of being as an interference with normal communication and learning; by extension, their deafness interferes with life in general. The Deaf see themselves as a group of people with a common language, and for whom vision serves as their primary means of interacting with the world. There is nothing “wrong” with them, they don’t need “fixing”; hearing people are visitors to the Deaf world, not the other way around.

For some deaf people, this distinction feels awkward and difficult; they feel excluded from both the hearing and Deaf cultures. The hearing culture finds it difficult to understand the deaf; few hearing people understand “sign” and a deaf person with verbal skills may be difficult to understand. Deaf people who read lips may find it hard to keep up with conversations with hearing people.

The Deaf care deeply about their culture and protect it from “outsiders”. We can easily understand this attitude – if we look at deafness as a disability, certain prejudices develop. As with all disabilities, there is something wrong. When people are treated as if there is something wrong with them, they react in kind. When Deaf people are treated as “disabled”, they respond.
I have learned from deaf people that I know that people Deaf from birth often see people that have lost their hearing as a sort of “second class citizen” of the Deaf Culture and people that can hear are even lower on the “social scale”.

A woman that works with me told me that she had dated a Deaf man. They would have his friends over and many of them would not even look at her, much less interact with her. She belonged to the “hearing culture”, not the “Deaf Culture” and they were not going to let her in. She eventually quit dating this man because he (understandably) would not give up his culture and his culture refused to include her.

K.M., on a Deaf Culture web forum, wrote: I am a hearing person who has been interested in the Deaf culture for many years. I learned some ASL years ago, and practiced it off and on, but didn't have much contact with the Deaf. One day in Walmart I passed a man and his wife who were signing to each other and I made the sign for "Excuse me" since the row was narrow. He stopped and asked me if I was Deaf. I said no, but I knew some sign, but he just waved me off and made a sign I've been told means "lousy", and walked away. I was crushed! I hadn't meant to offend, but clearly the fact that I had the audacity to use his language to speak to him was something I had no right to do in his mind.

A dear friend has a father and a stepmother who are both profoundly deaf. His dad began losing his hearing early in life and his stepmother lost her hearing totally as the result of an illness. They relate how they have been included in social events for Deaf people, but then are excluded and snubbed when it becomes known that they both have verbal skills and neither one of them were born deaf.

Clearly, a “Deaf Culture” exists and guards itself carefully.

If we consider the definition of “psychology” as “the study of human behavior and mental process”, does the state of deafness mean observable differences in behavior and mental process?

In other words, do the behaviors of non-hearing people (Deaf or deaf) appear different from those of hearing? Clearly, the answer must be, “yes.” Deaf people use a visual language, versus the verbal language of the hearing. Hearing people rely on sound to alert them to activity or conversations around them, deaf people rely on sight and touch. Deaf people find it extremely rude to break eye contact during a conversation, hearing people not so much. Hearing people might whistle or call out to gain attention, deaf people tap, wave, touch or even switch a light on and off. These different behaviors are easily observed.

Some research indicates that these different behaviors don’t necessarily indicate different mental processes.

The human brain uses different parts of the brain to process sight and sound. The prevailing view has been that speech and sound are critical to the organization of language in the brain. But two studies conducted by Laura Ann Petitto, a psychology professor from McGill University, challenges this view, suggesting instead that the specialization concerns patterns rather than sound.

In 1991 Petitto published a paper in Science explaining that profoundly deaf infants, when exposed to sign language from birth, begin to “babble”, using their hands, at the same age (seven and ten months) hearing babies begin to use vocal language, a “syllabic babbling stage.” The deaf infants began using single “real” words at about eleven to fourteen months – the same age that hearing children begin using single words.

In fact, the deaf infants using signed language matched the hearing infants using speech milestone for linguistic milestone. Petitto said, “The question this raised was: How is it possible? If language acquisition is so dependent on speech, how could the profoundly deaf children be matching the hearing children milestone for milestone? The only way it could be explained was if there was some common mechanism at work for both spoken and signed language."

This led to the second study, by Petitto and Robert Zatorre, a neuropsychologist from the Montreal Neurological Institute. Consisting of 22 individuals, 10 of the people were hearing and had no experience with signed language, the other 11 were born deaf and used only signed language. Positron Emission Tomography ("PET" or brain-imaging) was used to study the blood flow in the brains of these people.

The research team made two remarkable discoveries. The deaf people processed the highly specific parts of language (words and parts of words) at the same specific brains sites as the hearing people processed words. Even more remarkably, the processes took place in brain tissue that had been regarded for over 100 years as used only for processing of sound.

This discovery led the research team to offer a new look at the “system” of language processing. Rather than being “programmed” to understand only speech and sound as language, our “human computer” may recognize patterns - highly specific patterns that are common to the language of sound and to sign languages.

The “planum temporale” area of the brain, until this study, has been believed to be a type of sound processing tissue called “unimodal”, meaning that it performs only one function. The planum termporale is much larger in the left side of the brain than in the right side in both right and left handed people. Interestingly, 94% of chimpanzees studied at Mount Sinai School of Medicine in New York share this characteristic. When a person hears meaningless sounds in spoken language (such as la, ba, ta), the brain processes the sounds in the planum termporale. Petitto’s study discovered that the brain activates planum termporale in deaf people when they see meaningless hand movements that are part of sign language. These findings reinforce the finding that the brain processes both spoken and signed languages in much the same way.

There are (expected) differences in language processing between the brains of deaf people and hearing people as well. Petitto’s study showed that deaf and hearing people have increased blood flow to language portions of their brains, the deaf people also showed increased blood flow to primary visual areas. Since they use a visual language, not verbal, the brain must recruit different areas of the brain for language processing that hearing people do not use.

We can establish that hearing people and Deaf/deaf people alike can choose to see deafness as either pathological or cultural. For hearing people, this choice has an impact on how they relate to the deaf and Deaf. For the Deaf and deaf, they can choose to see themselves either as part of the “Deaf Culture”, or they can choose to see themselves pathologically “outside the norm” (having something wrong with them). This choice can have a great impact on how they view themselves, their abilities, and how they interact with others.

We can also establish that some in the Deaf Culture choose to exclude those who are different than they are (either not born deaf or being hearing). We see this same tendency in many cultures; White Culture, Black Culture, religious cultures of many varieties. The fact that some people in the Deaf Culture mistreat those who do not fit in may only serve to tell us how they act like people in other cultures, not how different they are.

The “Psychology of Deafness” also shows how similar deaf people are to hearing people. The way we process language is important to our humanity, and the finding that the way these two groups of people (deaf and hearing) are so similar in this brain process is more significant to our alikeness than our differences.

My conclusion is that (as with most cultures) the more we learn about others, the more we see similarities, rather than differences.*1+0&dict=A


Kevin Knox said...

Came to finish a re-read of your other paper, but found this and got distracted.


How cool is all that. I have never given a moment's thought to your original question, but how fascinating. Thanks for posting it.

Anonymous said...

Thanks - this was triggered by a dear friend whose dad and step-mom are both profoundly deaf.