Definition and Components of Language and Speech
- Language: A communication system acquired through use, involving symbols sequenced to share attention and ideas.
- Speech: One mechanism for expressing language, but other methods like gestures, sign language, and iconic symbols can also be used.
Pre-linguistic Skills and Joint Attention
- Joint attention, the ability to share focus with another, is crucial for language acquisition.
Disorders Affecting Speech and Language Acquisition
- Defined by inclusionary (specific deficits) and exclusionary (absence of other explanations) criteria.
- Common conditions disrupt the typical progression of speech and language in children, measured relative to peers.
Diagnostic Criteria
- ICD-10 (WHO) and DSM-5 (APA) provide classifications:
- ICD-10 distinguishes receptive, expressive, and mixed disorders.
- DSM-5 groups these under "communication disorders" with subcategories:
- Language disorder
- Speech sound disorder
- Childhood-onset fluency disorder (stuttering)
- Social (pragmatic) communication disorder
- Unspecified communication disorder
Speech Disorders
- Speech sound disorder: Persistent difficulty with speech sound production affecting intelligibility.
- Dysfluency (e.g., stuttering):
- Repetition of sounds, syllables, or words; silent blocks; and associated physical movements.
- Often resolves between ages 3-5 but can become chronic with risk factors like family history.
Pragmatic Language Impairment
- Affects everyday language use without the social and behavioral features of ASD.
Severe and Rare Conditions
- Childhood Apraxia of Speech (CAS)/Verbal Dyspraxia: Impaired motor planning for speech, debated underlying mechanisms.
- Dysarthria: Weakness or involuntary movements affecting articulation, often in acquired disorders.
- Phonation Issues: Problems with voice projection and breath control, worsening intelligibility.
Neurological Paroxysmal Disorders
- DSM-5 includes speech and language disorders linked to epilepsy, affecting development and acquired abilities.
- Certain anticonvulsants may exacerbate speech issues.
Prevalence and Demographics