Evaluating False Memory, Deception, and Truth-Telling using fNIRS

False memories happen when someone mis-remembers a past event that occurred. The study of false memories is commonly done using the DRM paradigm which can form false memories through semantic list learning. The current study is evaluating false memory, deception, and truth-telling using the DRM paradigm while measuring cortical activation with fNIRS. Results indicated no interactions between specific condition responses and brain regions in the prefrontal cortex. A main effect of condition was found indicating that correct responses have the lowest level of activation. Additionally, there were no significant differences found between deception and false memory responses. Further research needs to be conducted to help further analyze possible differences between these conditions as well as in more subcortical regions of the prefrontal cortex. FALSE MEMORY, DECEPTION, AND TRUTH-TELLING USING FNIRS 1 Evaluating False Memory, Deception, and Truth-Telling using fNIRS As brain imaging has become more advanced and accessible in research various topics of interests have integrated this form of measurement into different research areas. Psychology and neuroimaging have become quite interlinked resulting in the field of cognitive neuroscience (Sarter, Berntson, & Cacioppo, 1992). The study of false memory is still fairly new in psychology, it is the hope that integrating neuroimaging into studies of false memory that a better understanding of how false remembering works can be obtained. False Memory False memory gained interest in the field of psychology in the late 20th century when children who were in therapy began to recall abuse they previously had not been aware of (Loftus, 1993). While some allegations were true, many instances were cases of false memory where the children were recalling events that had never occurred. This created a need to understand why these false memories were happening and led to a large increase in the research of false memory. One of the earliest known studies about false memory was Bartlett’s 1932 study using the story known as “The War of the Ghosts”. Bartlett claimed to have found that the story became more and more misconstrued as the participants had to repeatedly retell the story. While these results have not been able to be replicated with this specific story, his research did help to distinguish between reproductive and reconstructive memory. Reproductive memory is defined as accurate production of material from memory (Roediger & McDermott, 1995). Reconstructive memory on the other hand is more likely to have errors as people fill in missing information as information is recalled (Roediger & McDermott, 1995). FALSE MEMORY, DECEPTION, AND TRUTH-TELLING USING FNIRS 2 These two concepts of memory have led to many different theories that explain false memory including the spreading activation theory (Anderson, 1983; Roediger III, Balota, & Watson, 2001)of memory fuzzy-trace theory (FTT). Anderson (1983) created the framework for Activation Monitoring theory of factual memory. In this theory information is placed into cognitive units. These units are affected by practicing effects as well as delays in recall. When an individual attempts to retrieve information from memory the cognitive units, which form a large network with other units, are activated to retrieve the needed information. According to this theory, the retrieval occurs through spreading across this network with higher levels of network activation indicating better recall (Anderson, 1983). Transitivity development was what sparked the thinking behind FTT. Reyna and Brainerd (1990) used FTT as an alternative theory to both the information-processing theory and the Piagetian concept of retrieval. This theory works on a fuzzy-to-verbatim continuum of memory where individuals remember information using multiple representations of the information during encoding. Some of these representations can be verbatim, clear and specific memory traces, (like remembering the exact numbers given in a sequence) but are typically more difficult to retrieve while others are remembered more in a gist (that is, fuzzy memory trace) format (like remembering the general idea of a speech that was given rather than a word-for-word recount of what was said) (Reyna & Brainerd, 1990). It is this gist aspect of FTT that is used to explain the phenomenon of false memory. Having a global idea of a construct can cause false memories that are associated with the previously encoded information. The DRM Paradigm While there has been extensive research into false memory in recent years, the DeeseRoediger-McDermott (DRM) paradigm is the most frequently used research set up. An example FALSE MEMORY, DECEPTION, AND TRUTH-TELLING USING FNIRS 3 of a DRM list is: hot, snow, warm, winter, ice, wet, frigid, chilly, heat, weather, freeze, air, shiver, Artic, frost with the critical lure word being cold. The phrase “critical lure” refers to the word that is supposed to come to mind as a false memory, as it is not on the original list but is associated with the words in the original list. In a meta-analysis study, researchers evaluated all false memory studies from 1994 to 2004 (N = 198) and found that DRM paradigms made up 41% of all false memory research (Pezdek & Lam, 2007). The DRM paradigm stems from research by Deese (1959) which was largely ignored for several decades (as cited in Roediger & McDermott, 1995). Deese wanted to test memory using free recall of word lists to see if he could elicit false memories from the participants. While his research for the most part was exploratory, he found interesting results showing that certain word lists were more inclined to produce false memories occur than others; the example above with the critical lure cold is an instance of one of these lists. This is where Roediger and McDermott’s (1995) hallmark study comes into play. They first replicated Deese’s original findings, illustrating that false memories in free recall occurred more than 50% of the time across participants with a fairly high confidence level. Once they established that Deese’s findings could be replicated, they then created a set of fifteen-word lists each containing a total of fifteen words along with a single critical lure word. Using these lists the researchers were again able to show a high level of false recall of the critical items. Since this study many researchers have replicated Roediger and McDermott’s findings. However other researchers soon began to look into the saliency of these word lists and began to study identifiability of the critical lures (Neuschatz, Benoit, & Payne, 2003). Identifiability refers to how easily a person can detect the critical lure. A list with high identifiability would be one that takes little effort to figure out what the intended lure word is, FALSE MEMORY, DECEPTION, AND TRUTH-TELLING USING FNIRS 4 while a list with low identifiability would not typically be assumed by the participants. An example of a high identifiability list is: door, glass, pane, shade, ledge, sill, house, open, curtain, frame, view, breeze, sash, screen, shutter with the critical lure being the word window. An example of a low identifiability list is queen, England, crown, prince, George, dictator, palace, throne, chess, rule, subjects, monarch, royal, leader, reign with the critical lure being the word king. Both of these example lists were tested for their identifiability in a single study, researchers found the high identifiability list elicited false memory 65% of the time while the low identifiability list had only a 10% rate of false memory (Stadler, Roediger, & McDermott, 1999). The study of identifiability with DRM lists has addressed two key research areas. In the first area, researchers evaluate the differences in false recognition across different levels of identifiability. Neuschatz, et al. (2003) evaluated false memories in a two by three design where participants were either warned or not warned about critical lures. There were further groups based on identifiability of the critical lure with there being a low condition, a high condition, and a condition where the participants were explicitly presented with the critical lure. The researchers found indications in the results that there was a reduction in false memories if the participants were in the high identifiability condition and were warned about the lure. However, participants who were in the low identifiability condition did not have a difference in false memories that was statistically significant between the no warning and warning condition. This showed that there was an interaction between level of identifiability and false memory rates. In the second area investigators evaluate how warnings about the critical lure affects false recognition across different levels of identifiability. Gallo, Roberts, and Seamon (1997) warned participants to be aware of any possible false alarms or were explicitly warned about actual false memory lure. Those who were explicitly warned about false memory did have a reduction in FALSE MEMORY, DECEPTION, AND TRUTH-TELLING USING FNIRS 5 false recognition, but it did not eliminate the effect indicating that awareness about the possibility of false memory does not completely inhibit creating a false memory. It is also important to note that there is a key difference in the effect of a warning depending on when the warning was given. This concept was explored by McCabe and Smith (2002) in a two-part study evaluating critical lure warnings in younger and older adults. In the first experiment, they found that both older and younger adults were able to reduce false memories when given the warning prior to studying the word list. This effect was not seen if the warnings were given after the lists were learned, but only before recall. A reason for this difference revolved around participants being able to try and guess what the critical lure items w