Language Disorders

  • Childhood Onset
  • Adult Onset

Childhood Language Disorders

  1. Cognitive Disorder (Retardation)

Syntactic development looks normal if you match on mental age (MA), instead of chronological age.

Pragmatic development (conversational skills) are better than MA-matched controls, due to increased exposure to language.

  1. Emotional/Social Disorder (Autism)

Hard to measure linguistic competence, because children do not interact much socially.

Rewards often effect to elicit communication.

Signed communication often more successful than spoken communication.

Pragmatic deficits are severe.

  1. Perceptual Disorder (Deafness)

If parents are native signers, no deficit in acquisition of signed language. Deficits in read/writing English (any language in which writing system depends on phono-ortho mapping), and syntax of second language.

If child not exposed to signed language, deficits can be severe.

Hearing children raised bilingually in English/ASL households:

1st words are usually signed (appearing as early as 7 months!).

This may be because less fine motor control is required.

Related phenomenon: Popularity of “baby signs”—not ASL, just communicative gestures.

  1. Dysphasia (Developmental Language Disorders)

Language deficit despite normal IQ (often) and no obvious brain damage.

Causes can be environmental (Genie), perceptual (dyslexia), or organic.

Affects 8% of children.

Paula Tallal suggests that the problem for many of this children is an inability to process auditory information rapidly enough. Stop consonants are particularly difficult because their duration is so short. Thus “bat” is indistinguishable from “pat.” She has developed a video game in which the therapist can alter the amplitude and duration of speech sounds. The stop consonants are elongated until the child can successfully recognize them, and then gradually shortened. She reports 2 years worth of progress in one month of this training.

  1. Dyslexia (Reading/Writing Deficit)

About 85% of language impaired children also exhibit dyslexia.

IQ normal to high, but reading is slow and laborious. Speech and picture-naming can also be affected (e.g. difficulty pronouncing unfamiliar long words, calling a volcano a “tornado”).

Poor phonemic skills; likely a phonological coding disorder

Characterized by transpositions: was vs. saw

Affects 20% of school kids.

Phoneme: smallest meaningful segment of language. In English, the phonemes in a word usually correspond to the letters.

Reading requires translation of orthography into phonology. This is a skill that requires conscious awareness of the internal phonology of spoken words. For example, knowing that the word “cat” is made up of three distinct speech sounds:

C-A-T = “cat” It is this decoding process that seems to be impaired, blocking visual word recognition.

Diagnosis: Say the word “block” without the “buh”.

Therapy designed to increase phonological awareness is often effective.

Compensated Dyslexics perform well on tests of word accuracy, but RT is slow and they continue to find reading tiring.

6.Hemispherectomy (Dennis & Whitaker, 1976)

Infants with severe epilepsy sometimes have most of the offending hemisphere removed. D&W studied one patient without a RH and two without LH. Both had the surgery at under 5 months of age. At age 10, all 3 kids had normal IQ and grade level, all detected semantic anomalies, but kids without LH are less accurate in detecting syntactic anomalies.

Adult-Onset Disorders

Aphasias: Language disorders from brain damage, often caused by a stroke. Provides insights into lateralization and localization of language in the brain.

Some recovery of function is usually possible. Recovery is best in younger patients because they have greater brain plasticity.

Broca’s Aphasia/Agrammaticism

  • Frontal lesion, LH.
  • Sequential planning, syntax, greatly disturbed.
  • Slow, laborious speech & writing.
  • Function words missing.
  • Comprehension only mildly disturbed.

agrammaticism, expressive aphasia

Wernicke’s Aphasia/Jargon Aphasia

  • Temporal lobe lesion, LH
  • Fluent jargon.
  • Coherence & comprehension both greatly disturbed.
  • Trouble retrieving appropriate content words.
  • Function words present.
  • Syntactic accommodation for neologisms.

receptive aphasia

Agraphia/Alexia

  • Disorders of writing and reading, respectively