Who Said What? The Effects of Cognitive Load on Source Monitoring and Memory for Multiple witnesses' Accounts

Investigative interviewers are often required to accurately remember information that has been provided by different people. This can be at the scene of an event or during follow-up investigations in interview rooms. Interviewers must accurately monitor the source of information to differentiate between witnesses' accounts and to assess what information is novel and what has been corroborated by others or by physical evidence. The current research examined the effects of cognitive load on memory and source monitoring accuracy for information provided by multiple witnesses. Participants, under conditions of high cognitive load (HCL) where load was induced via interviewer-relevant tasks (e.g., formulating questions) or no cognitive load (NCL), watched five mock-witnesses' accounts of the same crime. Each witness provided several details of the crime that were unique to their individual account. When asked about account details, and which witness had provided each detail, mock-interviewers' memory accuracy was lower in the HCL condition than the NCL condition. There was no difference between cognitive load conditions for source monitoring accuracy, which was poor regardless of condition.