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THE NATURE OF HUMAN LANGUAGE - Coggle Diagram
THE NATURE OF HUMAN LANGUAGE
The human brain
the most complex organ of the body
the brain is composed of cerebral hemispheres, one on the right and one on the left, joined by the corpus callosum
contralateral brain function
the localization of human brain
localization therory
proposed by Franz
Joseph Gal
phrenology
the practice of determining personality traits, intellectual capacities,
and other matters by examining the “bumps” on the skull.
the idea that different human cognitive abilities and behaviours are localized in specific part of the brain
aphasia
the neurological term for any
language disorder that results from brain damage caused by disease or trauma
Paul Broca
language is localized to the left hemisphere of the brain, and more specifically to the front part
of the left hemisphere
Broca’s area
Carl Wernicke
another variety of aphasia that occurred in patients with lesions in areas of the left hemisphere temporal lobe
Wernicke’s area
The Linguistic Characterization of Aphasic Syndromes
Most aphasics do not show total language loss. Rather, different aspects of language are selectively impaired, and the kind of impairment is generally related
to the location of the brain damage
Patients with injuries to Broca’s area may have Broca’s aphasia
labored speech and certain
kinds of word-finding difficulties
Wernicke’s aphasia is often referred to as jargon aphasia
The linguistic deficits exhibited by people with Broca’s and Wernicke’s aphasia point to a
modular organization of language in the brain
Historical Descriptions of Aphasia
Greek Hippocratic
loss of speech often occurred simultaneously with paralysis of the right side
of the body
Psalm 137 states: “If I forget thee, Oh Jerusalem, may my right
hand lose its cunning and my tongue cleave to the roof of my mouth.”
phrase that shows the connection of the lost of speech and the paralysis pf the right side
Pliny the Elder r (c.e. 23–79) refers to an Athenian
"with the stroke of a stone fell presently to forget his letters only, and could read no more; otherwise his memory served him well enough"
The language difficulties were not attributed to either general intellectual deficits or loss
of memory, but to a specific impairment of language.
Carl Linnaeus
“as if it were a foreign language, having his own names for
all words.”
a man suffering from jargon
aphasia
Brain Imaging Technology
Noninvasive brain recording technologies such as computer tomography
(CT) scans and magnetic resonance imaging (MRI) can reveal lesions in the living brain shortly after the damage occurs
variety of scanning techniques permit us to measure metabolic activity in
particular areas of the brain
positron emission tomography (PET) scans, functional MRI (fMRI) scans, and single photon emission
CT (SPECT) scans provide images of the brain in action
Supplemented by magnetic
encephalography(MEG)measures magnetic fields in the living brain,
these techniques can show us how the healthy brain reacts to particular linguistic stimuli
Brain Plasticity and Lateralization in Early Life
Lateralization of language to the left hemisphere
process that begins very
early in life.
infant as young as one week old show a greater electrical response in the left hemisphere to language and in the right hemisphere to music
A study that had been conducted
during smiling
the babies had a greater opening of the
left side of the mouth (the side controlled by the right hemisphere)
more left hemisphere involvement even at this very
early stage of productive language development
during babbling
greater opening of the right side (controlled by the left
hemisphere). T
under certain circumstances, the right hemisphere can take over many of the language
functions that would normally reside in the left hemisphere.
children who have undergone a procedure
known as hemispherectomy
produced an impressive illustration of plasticity
This procedure is used to treat otherwise intractable cases of epilepsy
for adult
surgical removal of the left hemisphere inevitably results
in severe loss of language function
Split brain
People suffering from intractable epilepsy may be treated by severing communication between their two hemispheres
to make it easier to understand, it is a surgery to separate the connection between left and right brain
when the path is severed, there will be no communication between those two side of brain
split-brain patients also provide evidence for language lateralization and
for understanding contralateral brain function
with the corpus callosum intact, the two halves of the body have no secrets from each other. with it sectioned the two halves become two different conscious mental spheres, each with its own experience base and control system from behavioral operations
When the brain is surgically split, certain information from the left side of
the body is received only by the right side of the brain, and vice versa
In humans who have undergone split-brain operations, the two hemispheres
appear to be independent
facts
In humans who have undergone split-brain operations, the two hemispheres
appear to be independent
The left brain is superior for language, rhythmic perception, temporal-order judgments,
and arithmetic calculations.
Other Experimental Evidence of Brain Organization
Dichotic listening
experimental technique that uses auditory signals to
observe the behavior of the individual hemispheres of the human brain
it is a soundtest with two different sound signals that willl be heard simultaneouslty with an earphone
both hemispheres receive signals from both ears, but the contralateral stimuli prevail over the ipsilateral(same side) stimuli because they are processed mre robustly
the accuracy of which the subjects of this exxperiment reports what they hear is the evidence that the left hemisphere is superior for linguistic processing and the right hemisphere is superior for nonverbal information
The Autonomy of Language
specific language impairment (SLI)
linguistic ability is affected, and often only specific aspects of
grammar are impaired.
have problems with the use of function words
prepositions
auxiliary verbs
articles
have difficulties with inflectional suffixes on nouns and verbs such as markers of tense and agreement
Other Dissociations of Language and Cognition
savants
individuals that have the talents but lack the ability as a normal human such as taking care of themselves
examples
human calculator
can perform arithmetic computations at phenomenal speed
calendrical calculator
can tell without pause on
which day of the week any date in the last or next century falls
two such case of savants
Laura
a retarded young woman with a nonverbal IQ of 41 to 44
lacked almsot all numebr concept , includng basic counting principles, and could draw only at a preschool lever
had an auditory memory span limited to
three units
BUT
she used and understood passive sentences, and seh was able to inflect verbs for numbers and person to agree with the subject of the sentence
She formed past tenses in accord with adverbs that
referred to past time
Laura produced complex sentences with multiple phrases and
sentences with other sentences inside them
Cristopher
has a nonverbal IQ between 60 and 70
must live in an institution
because he is unable to take care of himself
The tasks of buttoning a shirt, cutting
his fingernails, or vacuuming the carpet are too difficult for him
BUT
when given written texts in some fifteen to twenty languages, he
translates them quickly, with few errors, into English
his
linguistic competence is as rich and as sophisticated as that of any native speaker
loves to study and
learn languages. Little else is of interest to him
Genetic Basis of Language
one cognitive domain can develop
normally along with abnormal development in other domains
example
Children with Turner syndrome have normal language and advanced reading
skills along with serious nonlinguistic cognitive deficits
williams syndrome reveal a unique behavioural profile i nwhich certain linguistic functions seem to be relatively preserved in the face of visual and spatial cognitive deficits and moderate retardation
Language and Brain Development
The Critical Period
children need exposure to language in order to develop normally
Children who do not receive linguistic
input during their formative years do not achieve nativelike grammatical competence
critical-age hypothesis
language is biologically based and that the ability ot learn a native language develops within a fixed period, form , birth to middle childhood
A Critical Period for Bird Song
Bird song lacks certain fundamental characteristics of human language
certain species of birds show a critical period for acquiring their "language" similar to the critical period of human language acquisition
it depends on the geographic area that
the bird inhabits
The message is the same, but the form or “pronunciation” is
different
On the other hand, some bird species show no critical period
The cuckoo
sings a fully developed song even if it never hears another cuckoo sing
The Development of Language in the Species
The biologist Stephen Jay Gould expresses
The Darwinist model would say that language, nlike other complex organic language is such an integrated "all on none"system. it is hard to imagine systems, evolved step by step, each step beign an adaptive solution . yet it evolving that way
Other linguists, however, support a more Darwinian natural selection development of what is sometimes called “the language instinct”