Coverbal Gestures in Alzheimer's Type Dementia

These results agree with previous findings that DAT “empty” speech corresponds to reduced production of gestures showing semantic features (Glosser et al., 1998). However, the comparison between DAT with primarily lexical-semantic or conceptual deficits indicates that the nature of the cognitive impairment underlying poor information content and lack of reference in DAT discourse constrains the production of conversational gestures by patients with this disease. These findings are at variance with the hypothesis of parallel dissolution of speech and gestures in language disorders after brain damage (Cicone et al., 1979; McNeill, 1992; Glosser et al., 1998).