[W6] - CH16 Flashcards
What is Semantic memory and when to assess it?
Semantic memory is encyclopaedic information retrieved from long-term memory stores.
4- to 6-year-olds with learning and memory difficulties may initially appear to have average/slightly below average scores on measures of semantic memory. Early measures of semantic memory are largely dependent upon information that most children learn through watching television. However, when learning and memory problems persist into middle childhood and adolescence, semantic memory scores often drop SIGNIFICANTLY because the student is not able to acquire new information to add to their encyclopaedic knowledge base.
Children who are not yet fully acculturated into our society may also achieve low scores on measures of semantic memory, NOT due to poor semantic memory, but due to lack of acculturation.
If there are concerns about a student’s long-term memory, it is good practice to assess their semantic memory.
The Broad, then Second-Order, then Third-Order classifications of Acquired Knowledge: Semantic Memory within the Integrated SNP/CHC Model
Broad:
Acculturation Knowledge.
Second-Order:
Semantic Memory
Third Order:
- Verbal Comprehension
- Visual Comprehension
- Domain-specific knowledge
Neuroanatomy Associated with Semantic Memory
Semantic memory is known to be severely impaired by damage to the medial temporal lobe.
The Lateralization of Language
Language skills are lateralized in the left side of the brain in 90% of the population.
While the left hemisphere plays a major role in the production and understanding of language, the right hemisphere plays a role in organizing narrative and is involved in the expression and recognition of emotion in tone of voice.
[right hemisphere might take over language functions in cases of early left hemisphere dysfunction]
Aphasia and Global Aphasia
Aphasia: A deficit in the ability to produce or understand language, not due to defects in speech or hearing organs, but due to brain impairment.
Global Aphasia: The complete loss of all linguistic functions including fluency, comprehension, repetition, reading, and writing.
Agrammatism and Anomia
Agrammatism refers to a child’s difficulty or inability to produce a grammatical or comprehensible sentence.
Anomia refers to difficulty finding the right word.
Anomia is characteristic of many forms of aphasia, but it is particularly apparent in expressive or Broca’s aphasia.
Expressive Aphasias
Broca’s/Expressive Aphasia:
- Involves: Inferior prefrontal cortex of the left hemisphere (Broca’s area) — Head of the caudate nucleus in the basal ganglia — Subcortical white matter below Broca’s area and surrounding cortical areas,
- Characterized by: Slow, laborious, and non-fluent speech — much stronger speech comprehension than speech production.
Apraxia of Speech:
- Involves: Left precentral gyrus of the insula.
- Characterized by:
Impairment in the ability to program movements of the lips, tongue, and throat to produce speech.
Receptive Aphasias
Wernicke’s Aphasia:
- Involves: Left temporal lobe just posterior to the primary auditory cortex in an area known as the planum temporale (Wernicke’s area)
- Characterized by: Poor speech comprehension and fluent/free flowing but meaningless speech.
Conduction aphasia: - Involves: Damage to the arcuate fasciculus pathway connecting frontal and posterior language areas.
- Characterized by: Intact comprehension and spontaneous speech but would have difficulty repeating words that they had just heard.
Transcortical sensory aphasia:
- Damage to Wernicke’s area alone; isolating it from the posterior language areas.
- Can repeat what others say, but cannot comprehend the meaning of what they hear/produce meaningful speech on their own (similar to Wernicke’s except that repetition is preserved)
The Right Hemisphere, Language and Prosody
Oral language usually has a cadence or rhythm to it. Our speech also contains intonations and changes in pitch and volume, and hints of our emotional states.
The rhythmic, emotional, and melodic aspects of speech are referred to as prosody of speech. Prosody is the use of changes in intonation and emphasis to convey meaning in speech besides that specified by the words themselves; and appears to be a right-hemispheric function.
Orthographic vs. Phonological Representations
Orthographic representation: A visual-based storage of a word.
Phonological representation: A sound-based storage of a word.
Severe Auditory Language Disorders and ADHD
It is also important to evaluate students suspected of having ADHD with a thorough language evaluation (to rule out an auditory or receptive language disorder). Indeed, students with auditory processing difficulties might seem like they are not paying attention and often get misdiagnosed with ADHD (usually ADHD-Inattentive type).
Research has found relationships between language deficits and a wide variety of neurodevelopmental disorders including autism, non-specific developmental delays, externalizing disorders, internalizing disorders, deaf and hard of hearing, reading disabilities (dyslexia), written language disabilities, some math disabilities, processing speed and attentional deficits, some chronically ill disorders, some types of brain tumours, some types of seizure disorders, and some types of traumatic brain injury (TBIs).
Identifying Language Ability Concerns with the Neuropsychological Processing Concerns Checklist for Children and Youth (NPCC-3)
Oral Expression Difficulties:
- Slow laboured speech.
- Limited amount of speech.
- Distorts sounds (e.g., by slurring or stuttering)
- Difficulty finding the right word to say.
Receptive Language Difficulties:
- Trouble understanding what others are saying.
- Does not do well with verbal directions.
- Loses track of what they were told to do.
- Does not follow conversations well.
The Broad, then Second-Order, then Third-Order classifications of Acquired Knowledge: Language Abilities within the Integrated SNP/CHC Model
Broad:
Language Abilities
Second-Order (2)
- Oral Expression
- Receptive Language (listening comprehension)
Third-Order:
- Oral Expression- [Overall Language Abilities; Vocabulary Knowledge and Oral Expression; Qualitative behaviours]
- Receptive Language (i.e., listening comprehension) -[Receptive language with verbal response;
Receptive language with nonverbal motor response; Qualitative behaviours]
Common tests of oral expression
- Oromotor Sequences test on the NEPSY-II
- NEPSY-II’s Repetition of Nonsense Words test.
- Twenty Questions test on the D-KEFS - [A high number of spatial questions could indicate an oral language deficit such as developmental or acquired aphasia]
