Giving words new life: generalization of word retraining outcomes in semantic dementia

Anomia is a common and debilitating symptom for many dementia sufferers, but is particularly marked in patients with the semantic variant of primary progressive aphasia, semantic dementia (SD). Recent studies have demonstrated that through cognitive training these patients can re-learn the names of objects, but it remains unclear whether this translates to improved use of these relearned words in contexts other than picture naming.

Five SD patients completed a 2-month, online word training program and were assessed pre- and post-intervention on picture naming and spoken word-picture-matching plus two novel ecological tasks: video description and responses to verbal requests.

All participants showed clear gains in naming the trained pictures (p < 0.001). Importantly, improvements were also observed for four out of the five patients on the video description task. Milder patients also demonstrated improved comprehension of verbal instructions. Severe SD patients showed improvements on matching trained words to pictures. As expected, improvements were not found for untrained items.

There was clear evidence of generalization especially in patients with milder semantic impairments. Future studies should investigate the utility of this training in other forms of dementia.