An analysis of signal detection and threshold models of source memory

The authors analyzed source memory performance with an unequal-variance signal detection theory model and compared the findings with extant threshold (multinomial and dual-process) models. In 3 experiments, receiver operating characteristic (ROC) analyses of source discrimination revealed curvi-linear functions, supporting the relative superiority of a continuous signal detection model when compared with a threshold model. This result has implications for both multinomial and dual-process models, bom of which assume linear ROCs in their description of source memory performance. Source memory refers to memory for the context in which information was acquired (Johnson, Hashtroudi, & Lindsay, 1993). For example, memory for the person with whom one is conversing or the place where one is conversing can be interpreted as source memory. In psychological experiments, source memory is typi-cally assessed by asking participants to determine the origin of previously presented information, such as whether the information was presented verbally or visually, presented by a male or a female voice, or presented in one spatial location or another. As these examples imply, source memory depends on memory for autobio-graphical or episodic information. Various cognitive and neuro-psychological findings have suggested that, to some degree, mem-ory for source can be dissociated from item memory (see Dodso