Actions anchored by concepts: defective action comprehension in semantic dementia

et al. 77 (12): 1313 -- Journal of Neurology, Neurosurgery, and Psychiatry

By Nishio, Y, Kazui, H, Hashimoto, M, Shimizu, K, Onouchi, K, Mochio, S, Suzuki, K, Mori, E

Objective:
To study the ability of patients with semantic dementia to understand
actions, in order to examine the contribution of semantic memory to
action comprehension.

Methods: The ability to comprehend symbolic and instrumental
actions was assessed in 6 patients with semantic dementia and 10
healthy controls. The patients were also given the imitation test of
meaningful and meaningless actions.

Results: In all patients with semantic dementia,
comprehension of both symbolic and instrumental actions was defective.
The comprehension of symbolic actions was more impaired than that of
instrumental actions. Their ability to imitate other’s actions was well
preserved.

Conclusion: This study showed that comprehension of action
was impaired in semantic dementia, suggesting that semantic memory has
an important role in