Psycolinguistics: Apraxia - Oleh Miftahul huda dan Nanang Mutasim Billah ~ Dunianya T.A.S.I.M

CHAPTER I

SPEECH AND LANGUAGE DISORDERS

A. Background of Study

Speech and language disorders are a grouping of disorders that involve problems in communication. Speech disorders refer to difficulties producing speech sounds or problems with voice quality. Language disorders refer to impairment in the ability to understand and/or use words in context, either verbally, nonverbally, or both. These disorders range in severity from sound substitutions to the inability to comprehend or use language.

B. Some Causes of Speech and Language Disorders

There are many causes of speech and language disorders; however, many times the cause of the speech and language disorder is unknown. Some of the known causes include:

• Hearing loss,

• Neurological disorders,

• Brain injury such as head trauma or stroke,

• Mental retardation,

• Drug abuse,

• Physical impairments such as cleft palate,

• Vocal abuse or misuse,

• Autism.

C. Some Types of Speech and Language Disorders

Some types of speech and language disorders include:

Apraxia of Speech—Difficulty sequencing and executing speech movements.
Nonverbal Learning Disorder—this is a neurological condition thought to result from damage to the right hemisphere of the brain. There are three categories of this disorder: motor, visual-spatial-organizational, and social. The social category pertains to speech and language disorders as one symptom of this type is difficulty comprehending nonverbal communication.
Hyperlexia—this condition includes the ability to read far above the normal reading level for a person’s age, significant difficulty understanding and using verbal language, and difficulty in reciprocal interactions.
Auditory Processing Disorder—this is a disorder that affects how sound is processed and interpreted.
Stuttering— This is a disorder that may cause a person to repeat syllables when saying a word. This can be accompanied by eye rolling, blinking, and head jerks. Stuttering is influenced by psychological factors but is not an emotional or nervous disorder.
Speech and Language Delay—a child is considered to have a speech and/or a language delay when he or she is following the normal path of speech and/or language development but at a slower rate. While it can be related to cognitive development, this is not always the case.
Perceptive-Expressive Language Disorder—this is an impairment in both receptive and expressive language development.
Pervasive Developmental Disorders—these disorders, such as autism, Rett’s Disorder, Childhood Disintegrative Disorder, and Asperger’s Syndrome can be the cause of speech and language disorders.
Pragmatic Language Disorder—Individuals with this disorder have difficulty using language to effectively communicate with others.
Phonological Disorder—Difficulty using expected speech sounds appropriate to one’s age and dialect is characteristic of this disorder.

CHAPTER II

DISCUSSION OF APRAXIA

A. Introduction

Apraxia is a disorder caused by damage to specific areas of the cerebrum, characterized by loss of the ability to execute or carry out learned purposeful movements, despite having the desire and the physical ability to perform the movements. It is a “disorder of motor planning” which may be acquired or developmental, but may not be caused by incoordination, sensory loss, or failure to comprehend simple commands (which can be tested by asking the person to recognize the correct movement from a series). Apraxia is one of the most important and least understood major behavioral neurology syndromes. It is one of the best localizing signs of the mental status examination and also predicts disability in patients with stroke or dementia (unlike aphasia). Patients with Apraxia cannot use tools; therefore, they are unlikely to perform activities of daily living well. Patients with aphasia, without coexisting Apraxia, can live independently, take the bus or subway, and lead a relatively normal life; a patient with significant limb Apraxia is likely to remain dependent.

B. General Types of Apraxia

There are several types of Apraxia including:

No	Types of Apraxia	Definition
1	Buccofacial apraxia	Impairment in performing mouth or face actions on verbal command or imitation (see also or ofacial apraxia).
2	Conceptual apraxia	Form of apraxia in which the concept of the action is lost; characterized by impaired ability to use tools and to understand meaningful gestures
3	Constructional apraxia	Inability to assemble component parts into a coherent whole
4	Ideational apraxia	Impairment in the sequential use of multiple objects. Traditionally, also used to refer to impairment in the concept of an action. The term conceptual apraxia (see above) was coined to distinguish between these two dissociable impairments.
5	Ideomotor apraxia	Impairment in the performance of skilled movements on verbal command or in imitation; most commonly characterized by spatial or temporal errors in movement execution.
6	Limb apraxia	Usually used to refer to ideomotor apraxia of the limbs; frequently includes impaired performance of actions that also depend on the hands and fingers.
7	Limb-kinetic apraxia	Slowness and stiffness of movements with a loss of fine and precise movements
8	Optical apraxia	Impairment in performing saccadic eye movements on command
9	Orofacial apraxia	Impairment in performing mouth or face actions on verbal command or imitation (see also buccofacial apraxia).
10	Speech apraxia	Selective impairment in ability to produce speech sounds
11	Tactile apraxia	Impairment of hand movements for the use of and interaction with an object, in the presence of preserved intransitive movements.
12	Unimodal apraxia	Any form of apraxia that is specific to actions demonstrated in a single modality, e.g. visual, but not auditory.

C. Apraxia and Developmental Apraxia of Speech

1. The main types and causes

There are two main types of speech Apraxia: acquired Apraxia of speech and developmental Apraxia of speech. Acquired Apraxia of speech can affect a person at any age, although it most typically occurs in adults. It is caused by damage to the parts of the brain that are involved in speaking, and involves the loss or impairment of existing speech abilities. The disorder may result from a stroke, head injury, tumor, or other illness affecting the brain. Acquired Apraxia of speech may occur together with muscle weakness affecting speech production (Dysarthria) or language difficulties caused by damage to the nervous system (aphasia).

Developmental Apraxia of speech (DAS) occurs in children and is present from birth. It appears to affect more boys than girls. This speech disorder goes by several other names, including developmental verbal Apraxia, developmental verbal dyspraxia, articulatory Apraxia, and childhood Apraxia of speech. DAS is different from what is known as a developmental delay of speech, in which a child follows the "typical" path of speech development but does so more slowly than normal.

The cause or causes of DAS are not yet known. Some scientists believe that DAS is a disorder related to a child's overall language development. Others believe it is a neurological disorder that affects the brain's ability to send the proper signals to move the muscles involved in speech. However, brain imaging and other studies have not found evidence of specific brain lesions or differences in brain structure in children with DAS. Children with DAS often have family members who have a history of communication disorders or learning disabilities. This observation and recent research findings suggest that genetic factors may play a role in the disorder.

2. The symptoms of Apraxia

People with either form of Apraxia of speech may have a number of different speech characteristics, or symptoms. One of the most notable symptoms is difficulty putting sounds and syllables together in the correct order to form words. Longer or more complex words are usually harder to say than shorter or simpler words. People with Apraxia of speech also tend to make inconsistent mistakes when speaking. For example, they may say a difficult word correctly but then have trouble repeating it, or they may be able to say a particular sound one day and have trouble with the same sound the next day. People with Apraxia of speech often appear to be groping for the right sound or word, and may try saying a word several times before they say it correctly. Another common characteristic of Apraxia of speech is the incorrect use of "prosody" -- that is, the varying rhythms, stresses, and inflections of speech that are used to help express meaning.

Children with developmental Apraxia of speech generally can understand language much better than they are able to use language to express themselves. Some children with the disorder may also have other problems. These can include other speech problems, such as Dysarthria; language problems such as poor vocabulary, incorrect grammar, and difficulty in clearly organizing spoken information; problems with reading, writing, spelling, or math; coordination or "motor-skill" problems; and chewing and swallowing difficulties.

The severity of both acquired and developmental Apraxia of speech varies from person to person. Apraxia can be so mild that a person has trouble with very few speech sounds or only has occasional problems pronouncing words with many syllables. In the most severe cases, a person may not be able to communicate effectively with speech, and may need the help of alternative or additional communication methods.

3. Apraxia Diagnosis

Professionals known as speech-language pathologists play a key role in diagnosing and treating Apraxia of speech. There is no single factor or test that can be used to diagnose Apraxia. In addition, speech-language experts do not agree about which specific symptoms are part of developmental Apraxia. The person making the diagnosis generally looks for the presence of some, or many, of a group of symptoms, including those described above. Ruling out other contributing factors, such as muscle weakness or language-comprehension problems, can also help with the diagnosis.

To diagnose developmental Apraxia of speech, parents and professionals may need to observe a child's speech over a period of time. In formal testing for both acquired and developmental Apraxia, the speech-language pathologist may ask the person to perform speech tasks such as repeating a particular word several times or repeating a list of words of increasing length (for example, love, loving, lovingly). For acquired Apraxia of speech, a speech-language pathologist may also examine a person's ability to converse, read, write, and perform non-speech movements. Brain-imaging tests such as magnetic resonance imaging (MRI) may also be used to help distinguish acquired Apraxia of speech from other communication disorders in people who have experienced brain damage.

4. The Apraxia Treatments

In some cases, people with acquired Apraxia of speech recover some or all of their speech abilities on their own. This is called spontaneous recovery. Children with developmental Apraxia of speech will not outgrow the problem on their own. Speech-language therapy is often helpful for these children and for people with acquired Apraxia who do not spontaneously recover all of their speech abilities.

Speech-language pathologists use different approaches to treat Apraxia of speech, and no single approach has been proven to be the most effective. Therapy is tailored to the individual and is designed to treat other speech or language problems that may occur together with Apraxia. Each person responds differently to therapy, and some people will make more progress than others. People with apraxia of speech usually need frequent and intensive one-on-one therapy. Support and encouragement from family members and friends are also important.

In severe cases, people with acquired or developmental apraxia of speech may need to use other ways to express themselves. These might include formal or informal sign language, a language notebook with pictures or written words that the person can show to other people, or an electronic communication device such as a portable computer that writes and produces speech.

CHAPTER III

RESEARCH FINDING

Deconstructing apraxia: understanding disorders of intentional movement after stroke by Lisa Koskia, Marco Iacobonia, and John C. Mazziotta

Impairments in praxic functioning are common after stroke, most frequently when the left hemisphere is affected. Several recent studies of apraxia after stroke have made advances in understanding the right hemisphere contribution to praxis, particularly for the performance of novel actions.

In this research, the researchers found the case of apraxia on the patient after stroke, which affected on the ability to perform an action in response to verbal command or in imitation. The researchers also specify their research on specific type of apraxia those are Limb apraxia and ideomotor apraxia. They identified stroke patient that impaired in left or right hemisphere.

Those are some features deserve further scrutiny. First, the model was developed from the study of ideomotor apraxia of the limb and, thus, emphasizes praxis of meaningful actions. Second, the separation of the input and output lexicons may prove untenable in light of the recent discovery of a so-called mirror system in the ventral premotor cortex and the posterior premotor cortex of the monkey brain.

Research Focus

1.b Ideomotor apraxia

Nowadays, the term ideomotor apraxia has been commonly used. In its strictest sense, ideomotor apraxia refers to the impaired reproduction of meaningful or learned actions, although the ability to perform or imitate meaningless actions is also decient in some cases. The use of the term ideational apraxia is less common now than when it was first conceived due to difficulties in establishing it as a valid and coherent entity distinct from the symptoms ascribed to ideomotor apraxia or deficits in executive functioning. Researchers soon saw a need to discriminate between sequencing errors, referred to in the traditional way as ideational apraxia, and impairments in action recognition, termed `conceptual apraxia'. Recent work comparing impairments in single-object and multiple-object use provides another illustration of the dificulties with the traditional concept of ideational apraxia. Tests of multiple-object use (e.g. lighting a candle) were originally designed to elicit sequencing, omission and perseverative errors viewed as characteristic of ideational apraxia, whereas single-object tests (e.g. using a key) were intended to elicit the spatiotemporal errors in tool use that characterized ideomotor apraxia.The Correlations and factor analyses of these two tasks within the same group of patients, however, indicate that both appear to involve similar underlying processes.

A wealth of case reports have demonstrated dissociations in the ability of individual patients to recognize versus use tools, imitate meaningful versus meaningless actions, perform transitive versus intransitive actions, and perform limb versus orofacial actions.observations are interpreted as reflecting modularity in the praxis system and a number of fairly complex models of apraxia have now been developed. Separate semantic and non-semantic pathways allow for dissociations in the ability to represent meaningful versus meaningless actions; separate input and output lexicons account for differences in the ability to conceptualize actions and the ability to perform them; and separate input pathways for verbal and visual stimuli explain the dissociation between the ability to perform an action on command versus in imitation.

2.b Lesion correlates of apraxia: Interhemispheric

Based on the research, it is found that roughly 30% of patients in the acute phase of stroke show evidence of apraxia, but the incidence is higher after damage to the left hemisphere (50%) than to the right hemisphere (510%). Several recent studies have focused on whether different patterns of apraxic impairment are associated with left hemisphere damage or right hemisphere damage. In a study of facial apraxia after stroke, patients with left hemisphere damage made more errors than patients with right hemisphere damage when imitating lower face actions, whereas both groups performed similarly for upper face actions. In a study of limb apraxia, patients with left hemisphere strokes were more likely than patients with right hemisphere strokes to be impaired at pantomiming the use of a tool in response to verbal command, whereas an equal proportion of left hemisphere and right hemisphere patients were impaired when imitating a pantomime demonstrated by experimenter. Although half of the patients with left hemisphere stroke also had aphasia, the correlation with apraxia was similar for the pantomime and imitation conditions. Patients with left hemisphere strokes were impaired at imitating all meaningless actions and at perceptual matching of meaningless hand-to-head actions. In contrast, patients with right hemisphere lesions were impaired at imitating meaningless postures of the fingers of the hand and at perceptual matching of all meaningless actions.

From this work, it may be concluded that the left hemisphere is important for representing actions in terms of knowledge about the structure of the human body, whereas the right hemisphere participates in the visuospatial analysis of gestures. This suggests that apraxia after right hemisphere strokes results from disruption of a pathway for translating visual input to motor output, which preferentially impairs the representation of novel actions.

3.b Lesion correlates of apraxia: Intrahemispheric

Patients with parietal lesions show the most severe impairments in the recognition and imitation of pantomimed actions and the deficit is particularly severe for left parietal lesions and actions directed toward their own bodies (e.g.brushing hair). In other words, if the lesion happened in the parietal, the patient can not do directed their body such as cutting their own knail. In contrast, patients with premotor or precentral lesions were not impaired on the recognition or performance of unimanual pantomimes, but those with damage to medial premotor regions were severely impaired at pantomiming bimanual actions that required different movements from each hand. The patient have different interpretation or different understanding about someone else action. Therefore, they difficult to imitate the action.

C. Other cases on Apraxia

1. A case study of Speech Apraxia from INSIDE Edition (a video on Youtube)

It happens in children with verbal Apraxia or (neurogical disorder) in which it makes them cannot speak because their mouths are getting out of the information from their brains.

Brandon 8th years old is unable to “speak intelligible complete sentences” The followings are the example of sentences produced by Brandon a Child Apraxic.

Ex; Stomach  tomach

I proud you diligent  I’m very listen

Till they fly  to the thing...

One nation  one needle

Underground  undergurl..

In the visible  in ivivisible

According to an expert of Children with speech disorders, that children who are with verbally Apraxic have been missed diagnosed mentally retarded or autistics. Why it happens because the path way from the motors central of the brain does not have a clear path to the muscle of the mouth.

REFERENCES

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22 Oktober 2010