Was naming pictures harder than reading or repeating words for two people with speech sound difficulties?

Details

In two case studies, researchers investigated speech sound production errors in a woman (NC) with dementia of the Alzheimer type and a man (HO) with a cerebrovascular etiology. Five tasks examined phonological retrieval in picture naming, reading and repetition; preservation of phonological contrast when producing one-syllable minimal pairs; articulatory execution in vowel production and diadochokinesis; and non-speech orofacial movements.

Both speakers made speech sound production errors in all single-word production tasks, but had greater difficulty retrieving spoken word forms in naming than in reading or repetition. Both preserved phonological contrast in one-syllable minimal pairs. HO was impaired in vowel production and diadochokinesis, while NC showed a lesser degree of impairment in diadochokinesis. In the orofacial praxis tasks, HO showed impaired laryngeal control, while NC was unimpaired.

The results suggest that both speakers had difficulty with the phasing, scaling and execution of articulatory gestures. The researchers concluded that a model with separate levels for phonemic retrieval and articulatory planning was not required to explain this pattern of performance.