BCHE and Lewy body dementia: BOLD activity was significantly lower in V1 and trending lower in V2/V3 in those in the DLB group who were on cholinesterase inhibitors (V1: mean 0.45 (s.d. = 0.24); V2/V3: mean 0.62 (s.d. = 0.10)) compared with those in the DLB group not taking these agents (V1: mean 0.82 (s.d. = 0.28), P= 0.02; V2/V3: mean 0.88 (s.d. = 0.33), P = 0.10) although phosphene thresholds were similar, as was cerebral perfusion in V1 and V2/V3 between the DLB group on and off cholinesterase inhibitors (phosphene threshold: mean 76.7% (s.d.= 20.2%) v. 78.2% (s.d.= 21.1%), P= 0.90.