This paper presents a controlled examination of assumptions made by the U.S. legal system regarding the ability of people to lie about currently viewed events; the paper discusses the motivation, methodology, and findings, which have implications for the legal and justice systems.
This paper reports on a study that used subjects’ electroencephalogram (EEG) and behavior to test an assumption that underlies both the Federal Rules of Evidence (FRE) as well as most cognitive models of lie generation. The assumption involves the Present Sense Impression (PSI), which suggests that people are unable to lie about something they are currently viewing. This article describes the use of two behavioral paradigms and EEG recordings to assess the validity of the legal assumption that drives the FRE, and the assumption of most lie-generation theories, that lying requires the generation and maintenance of multiple representations of a to-be-lied-about stimulus. The EEG measurement results suggested that for simple stimuli, individuals hold less information in visual working memory when lying compared to truth-telling, possibly by dropping the truthful representation from visual working memory. With more complex stimuli, however, findings indicated that individuals did not appear to switch cognitive strategies suggesting that either this switch isn’t possible or requires additional time in more complex settings. Research results suggest that the generation and maintenance of multiple representations of a to-be-lied-about stimulus is not an absolute prerequisite to lie generation, but probably occurs in all but the simplest of settings. Similarly, research results suggest that the assumptions of the PSI are accurate in simple situations and for very short delays, but that the rule should be limited to situations involving only true contemporaneity.