Verb comprehension and naming in frontotemporal degeneration: The role of the static depiction of actions

We report the case study of a patient JB with the frontal variant of frontotemporal dementia (fv-FTD), who was disproportionately impaired in naming and comprehending verbs in comparison with nouns. We examined to what extent the patient's verb disproportionate deficit was dependent on the type of stimuli used to assess verb processing, that is, static depictions of actions, videotaped actions, or verbal stimuli. We found that the verb disproportionate deficit JB presented when her naming or comprehension was assessed from static depictions of actions (i.e., photographs) disappeared when naming or comprehension was assessed from videotaped actions or verbal stimuli. These results indicated that JB did not present disproportionate difficulties with verb processing per se (i.e., with retrieving the lexical and semantic features of verbs). Instead, the seemingly disproportionate verb deficit found in JB – and possibly also in other previously reported patients with executive resource limitation – was likely due to the picture stimuli used to probe verb versus noun naming and comprehension not being equal in executive resource demands. The finding of this study thus underscores the need of considering carefully the specific effects of task and type of stimuli in the patients' performance with action pictures before making theoretical claims about the noun versus verb or object versus action lexical and semantic representation in the brain.