Influence of ageing and educational level on the prevalence of body-part-as-objects in normal subjects.

When pantomiming gestures to verbal command, the overall production of body-part-as-object (BPO) errors is differentially affected by age and educational level in normal subjects. The higher overall frequency of BPO with age may be related to difficulties in the inhibition of the automatic activation of tool emblems (i.e., the BPO) instead of the appropriate hand posture to hold the tool. However, all subjects are equally able to correct errors in BPO on subsequent trials, which suggests the integrity of these gestural representations. In a clinical perspective, BPO data have therefore to be considered carefully when one wants to include this error type as an indicator of limb apraxia.