Unlike the simultaneous condition, the successive condition necessarily requires the use of conscious
memory imagery to perform the comparison and it shows a particularly strong relationship between response times, accuracy, and imagery vividness scores measured using the VVIQ (McKelvie, 1 995 a, Table 12, Task 46) while simultaneous comparison shows no such relationships (Gur & Hilgard, 1975; McKelvie, 1995 a, Table 12, Task 45).