How does AOS typically affect diadochokinetic rates (AMR and SMR) compared to fluent patterns?

• A. AMR and SMR are both impaired with SMR more demanding.
• B. AMR is normal while SMR is severely impaired.
• C. There is no impairment in diadochokinetic tasks.
• D. AMR is more impaired than SMR due to shorter sequences.

Answer: (A)

In AOS, the motor planning and programming for speech are disrupted, so rapid articulatory movements show deficits on diadochokinetic tasks. AMR measures quick repetition of a single syllable, so rates slow and can become irregular because the planning for repeating the same gesture quickly is affected. SMR requires a rapid sequence of different articulators (like pat-a-ka), which places higher demands on coordinating multiple movements in quick succession. That extra sequencing load makes SMR more vulnerable, so it tends to be more impaired than AMR. Overall, both AMR and SMR are affected, with SMR typically the more challenging one due to the greater planning and sequencing demands. Other options suggesting no impairment or that only one type is affected don’t fit the pattern seen in AOS, where the planning deficit shows up across diadochokinetic tasks, especially in the more complex SMR.