In particular, the cholinergic system which is widely distributed in brain and differentially more affected in DLB than AD may have a role; pharmacological evidence has demonstrated that anticholinergic drugs can induce a symptom profile of altered arousal (Perry et al., 1999) that is similar to FC seen in DLB and, by contrast, cholinesterase inhibitors (CHEI) can significantly improve FC and attentional function in DLB (McKeith et al., 2000; Wesnes et al., 2002). Here, BCHE is linked to Lewy body dementia.