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Alzheimer’s disease is named after the German psychiatrist, Alois Alzheimer, who first described it
in 1907. The characteristic signs of Alzheimer’s are abnormalities in and loss of neurons in the
areas of the brain known as the hippocampus and the cortex. As the disease advances,
abnormalities of the brain can be identified with imaging techniques, such as magnetic resonance
imaging (MRI), but a definite diagnosis cannot be made until the brain tissue is examined after
death.
A book on dementias (dementia is Latin for madness) published in 1945, claimed that to date only 150
cases of Alzheimer’s disease had been reported and that the disease was considered to be very rare.
At the time, Alzheimer’s was classified as pre-senile dementia because the onset was thought to
occur before the age of 65. For people over 65, virtually the same pattern of signs and symptoms was
diagnosed as senile dementia. The cause of Alzheimer’s was unknown, but senile dementia was
attributed to age. As a result of the similarity of most cases of senile dementia to Alzheimer’s, it
came to be known as senile dementia of the Alzheimer’s type. In recent years, the distinction based
on age of onset has gradually been dropped. Presently, dementia is medically defined as a loss of
mental competence with significant decline from the person’s former mental capability.
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Approximately 5% of people over 65 develop Alzheimer’s, with the incidence rising to about 20% in
those past the age of 80. It is a degenerative disorder, progressive in its destruction of functional
abilities, is irreversible, and terminal. At the present, there is no known cure, although some
medication has been approved for its treatment. Diminution and loss of short-term memory is
generally the first indication of Alzheimer’s. A set of questions designed to test the reality
orientation of the individual includes such questions as “Where do you live?” and “What day of
the week is it?” The individual’s responses are one aspect of making tentative diagnosis in the early
stages of the disorder. Arriving at a tentative diagnosis of Alzheimer’s also involves a process of
elimination. Organic brain disorders such as schizophrenia, tumors, and strokes must be ruled out
as potential causes of the symptoms being displayed by the patient before hazarding a tentative
diagnosis of Alzheimer’s.
Following the initial loss of memory, deterioration of cognitive functioning is noted and, as the
disease progresses, the individual gradually loses the ability to walk, to feed him- or herself, and to
control the bladder and bowels. In the terminal stage of the disease, the individual is reduced to a
vegetative state, unaware of the presence of friends and family, the surrounding environment, and
even his or her own identity. Death usually occurs four to five years after onset, but the range is two
to ten years.
The cause of Alzheimer’s disease is not known. The disease, or some form of it, may be genetically
transmitted. There are similarities between Alzheimer’s disease and Down syndrome. Down
syndrome is sometimes called Trisomy 21 to indicate the presence of three, rather than two,
chromosomes at the 21st position. A gene on the same chromosome has been tentatively linked to
Alzheimer’s. Other hypotheses about the causal agent for Alzheimer’s include a slow-acting virus
and toxic substances such as aluminum. Whatever the primary causal agent, its presence is
believed to result in biochemical changes in the brain. These changes have been posited to include
reduction in the availability of one or more of the following substances: acetylcholine, a
neurotransmitter; corticotropin-releasing factor, a hormone; and ribonucleic acid (RNA). Another
change noted in brain tissue is the appearance of fibers in the cytoplasm of neurons. Dr. Alois
Alzheimer called these fibers neurofibrillary tangles. He also observed that some neurons appeared
to have shriveled, with their dendrites deteriorating to the degree that the cell could no longer
function, causing the neurons to collapse. Alzheimer referred to sections of the brain where clusters
of the collapsed neurons were found as neuritic plaques.
In spite of scientific advances in knowledge about Alzheimer’s disease, for the patient and the
patient’s family, the disease remains irreversible, incurable, and virtually untreatable. Custodial
care by a family member at home or in an institution is generally required as the disorder
progresses, in order to prevent the patient from hurting him- or herself or wandering off and getting
lost. The nature of the disease is best described as regressive in that a once-competent adult loses
the ability to think rationally, language deteriorates, temper tantrums like those of early childhood
may occur, motor skills are lost, and finally, with loss of the ability to feed oneself and to control the
bladder and bowels, the regression to an infant-like state is complete.
Critical Periods: The Story of Genie
In 1970, a 13-year-old girl was discovered in Los Angeles. Her name was Genie, and the conditions
in which she was found were appalling. Genie had been treated like an animal since the age of 20
months. She was confined to a small, curtained room and spent most of her days strapped to a
potty-chair, unable to move except for her hands and feet. At night, Genie was confined in a cage-
like crib, and restrained in a straightjacket-type garment. She had no bowel or bladder control,
could not stand in an erect posture, was severely malnourished, and was unable to chew solid
food. Genie was also mute; she could not speak and could not understand language. The only
sounds she had ever heard were those made by her father on the occasions he beat her for crying or
making noises. Genie had been held prisoner by her father, a man who never spoke to her, and
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would not allow anyone else to do so.
Genie was removed from her father’s custody, and taken to Los Angeles Children’s Hospital, where
she was nursed back to physical health. She underwent psychological evaluation to determine her
mental status and level of cognitive functioning, including her ability to produce and comprehend
language. Following all necessary assessments, psychologists embarked on the task of teaching
Genie language. Because Genie was attempting to acquire language at age 13, her psychologists
were presented with a unique opportunity to study the critical period theory relative to learning
language, the notion that there is a time early in a child’s life when language learning must begin, if
language is to be learned at all. Genie was far past that proposed critical period. Further, she knew
no grammar and had virtually no language ability.
The researchers working with Genie approached the task of teaching her language in much the
same manner they would teach a younger child, by direct exposure to spoken language as a
function of engagement in daily activities. Initially, Genie would speak only one or two words at a
time, but she did progress, up to a point. Though she eventually progressed to the degree of
combining two and three words into phrases, she never progressed beyond the level of a 3- or 4year-
old child in her language abilities, and never made the progression from simple words into
grammatically correct sentences.
The fact that Genie actually did acquire some facility for language denied support for the
hypothesis that there is a critical period for language acquisition, and that this period falls
somewhere between age 2 and puberty. However, Genie’s failure to attain fluency and grammar did
point to the potential for an optimal period for language acquisition, a period that, if missed, would
result in failure ever to attain complete facility for language. Unfortunately, no more specific
information could be gained from Genie’s experiences, because her lack of facility for language
could be attributable to her severely malnourished state, the emotional and physical abuse suffered
at the hands of her father, and her social isolation, as much as to a potential optimal period for
language acquisition.
By age 24, Genie had received 11 years of special education and rehabilitation to include foster care,
yet her language capability remained short of that expected in a 5-year-old child. Did Genie miss
her critical period for language acquisition?