Complex lying leads to more memory impairments in daily life

Previous studies have demonstrated that lying can undermine memory and that its memory-undermining effects could be modulated by the cognitive resources required to tell a lie. We extended the investigation of the memory-undermining effect by using a daily life setting in which participants were highly involved in a mock shopping task. Participants were randomly assigned to truth-telling, simple lying or complex lying conditions. After finishing the shopping task, participants were told that two people wanted to know about their shopping lists and would ask them some questions in an interview. In answering the interview questions, the truth-telling group was asked to respond honestly, the simple lying group was asked to give denial responses, and the complex lying group was required to respond deceptively. The item memory test, source memory test and destination memory test were given in an orderly manner 48 hours after the interview. We found that the complex lying group, rather than the simple lying group, forgot the lies they told in the interview and mistakenly believed they had lied about something that they had not lied about. Moreover, the complex lying group retained fewer memories about the person they responded to than the honest group. In addition, participants in the complex lying group had more nonbelieved memories than those in the truth-telling group in both item and source memory tests. We conclude that complex lying that requires more cognitive resources could result in more memory impairments in daily life.既往研究已证实，说谎行为会损害记忆，且该记忆损害效应可受说谎所需的认知资源（cognitive resources）调控。本研究采用参与者高度投入的模拟购物任务这一日常情境，拓展了关于说谎记忆损害效应的研究范围。参与者被随机分配至诚实讲述（truth-telling）、简单说谎（simple lying）与复杂说谎（complex lying）三种实验条件。完成模拟购物任务后，参与者被告知将有两名人员希望了解其购物清单，并会在后续访谈环节向其提出相关问题。在回答访谈问题时，诚实讲述组需如实作答，简单说谎组需做出否认式回应，复杂说谎组则需进行欺骗性回答。访谈结束48小时后，我们依次开展了项目记忆测试（item memory test）、来源记忆测试（source memory test）与目标记忆测试（destination memory test）。本研究结果显示，相较于简单说谎组，复杂说谎组遗忘了其在访谈中所述的谎言，且错误地认为自己曾就某些并未说谎的内容进行过说谎。此外，相较于诚实讲述组，复杂说谎组对其访谈对象的记忆留存量更少。进一步而言，在项目记忆与来源记忆测试中，复杂说谎组参与者所拥有的非确信记忆（nonbelieved memories）数量显著多于诚实讲述组。综上，本研究得出结论：需要更多认知资源的复杂说谎行为，可在日常生活中引发更为严重的记忆损伤。