How do errors in apraxia of speech (AOS) compare to errors in aphasia?

• A. AOS errors are consistent; aphasia errors are inconsistent
• B. AOS errors are inconsistent; aphasia errors are consistent
• C. Both disorders have consistent errors
• D. Both disorders have inconsistent errors

Answer: (A)

In this contrast, the key idea is how stable errors are across attempts. Apraxia of speech is a motor planning and programming problem. Once a motor plan is set for producing a word, the resulting articulatory substitutions or distortions tend to follow a repeatable pattern across attempts and contexts. That means you’ll see similar error patterns when the person tries the same word again, reflecting the consistent motor sequence that’s being generated.

Aphasia, on the other hand, is a language and lexical retrieval issue. The errors arise from linguistic formulation and word selection, which can vary with context, word frequency, and cueing. Because the underlying language processes fluctuate from moment to moment, the errors are less predictable and can change from trial to trial.

So, the statement that AOS errors are consistent while aphasia errors are inconsistent aligns with how motor planning disturbances produce stable articulatory patterns, whereas language-based errors tend to vary more across attempts.