SenseCam reminiscence and action recall in memory-unimpaired people.

Case studies of memory-impaired individuals consistently show that reminiscing with SenseCam images enhances event recall. This exploratory study examined whether a similar benefit would occur for the consolidation of memories in memory-unimpaired people. We tested delayed recall for atypical actions observed on a lengthy walk. Participants used SenseCam, a diary, or no external memory aid while walking, followed by reminiscence with SenseCam images, diary entries, or no aid, either alone (self-reminiscence) or with the experimenter (social reminiscence). One week later, when tested without SenseCam images or diary entries, prior social reminiscence produced greater recall than self-reminiscence, but there were no differences between memory aid conditions for action free recall or action order recall. When methodological variables were controlled, there was no recall advantage for SenseCam reminiscence with memory-unimpaired participants. The case studies and present study differ in multiple ways, making direct comparisons problematic. SenseCam is a valuable aid to the memory impaired, but its mnemonic value for non-clinical populations remains to be determined.

Can survival processing enhance story memory? Testing the generalizability of the adaptive memory framework.

Research from the adaptive memory framework shows that thinking about words in terms of their survival value in an incidental learning task enhances their free recall relative to other semantic encoding strategies and intentional learning (Nairne, Pandeirada, & Thompson, 2008). We found similar results. When participants used incidental survival encoding for a list of words (e.g., "Will this object enhance my survival if I were stranded in the grasslands of a foreign land?"), they produced better free recall on a surprise test than did participants who intentionally tried to remember those words (Experiment 1). We also found this survival processing advantage when the words were presented within the context of a survival or neutral story (Experiment 2). However, this advantage did not extent to memory for a story's factual content, regardless of whether the participants were tested by cued recall (Experiment 3) or free recall (Experiments 4-5). Listening to a story for understanding under intentional or incidental learning conditions was just as good as survival processing for remembering story content. The functionalist approach to thinking about memory as an evolutionary adaptation designed to solve reproductive fitness problems provides a different theoretical framework for research, but it is not yet clear if survival processing has general applicability or is effective only for processing discrete stimuli in terms of fitness-relevant scenarios from our past.

Memorising Milton's Paradise lost: a study of a septuagenarian exceptional memoriser.

At age 58, JB began memorising Milton's epic poem Paradise Lost. Nine years and thousands of study hours later, he completed this process in 2001 and recalled from memory all 12 books of this 10,565-line poem over a 3-day period. Now 74, JB continues to recite this work. We tested his memory accuracy by cueing his recall with two lines from the beginning or middle of each book and asking JB to recall the next 10 lines. JB is an exceptional memoriser of Milton, both in our laboratory tests in which he did not know the specific tests or procedures in advance, and in our analysis of a videotaped, prepared performance. Consistent with deliberate practice theory, JB achieved this remarkable ability by deeply analysing the poem's structure and meaning over lengthy repetitions. Our findings suggest that exceptional memorisers such as JB are made, not born, and that cognitive expertise can be demonstrated even in later adulthood.

Did we see someone shake hands with a fire hydrant?: collaborative recall affects false recollections from a campus walk.

An experimenter presented familiar and bizarre action statements (e.g., "Rest on the fire hydrant" vs. "Shake hands with the fire hydrant") to a participant and confederate during a campus walk. They watched the experimenter perform half the actions and imagined the experimenter performing the other half. One day later, they took a second walk where actions were only imagined. Some actions from the first walk were repeated, and new actions were added. Two weeks later, the participant and confederate collaboratively recalled whether specific actions were presented in the first walk and, if so, whether they were imagined or performed. For different actions, the confederate was accurate, was inaccurate, or provided no information. When later tested individually, participants demonstrated imagination inflation by falsely remembering familiar and bizarre actions as performed on the first walk that were merely imagined on the second. These memory errors were greatly reduced if the confederate was accurate during collaborative recall.

Does feigning amnesia impair subsequent recall?

Defendants who are accused of serious crimes sometimes feign amnesia to evade criminal responsibility. Previous research has suggested that feigning amnesia might impair subsequent recall. In two experiments, participants read and heard a story about a central character, described as "you," who was responsible for the death of either a puppy (Experiment 1) or a friend (Experiment 2). On free and cued recall tests immediately after the story, participants who had feigned amnesia recalled less than did participants who had recalled accurately. One week later, when all participants recalled accurately, participants who had previously feigned amnesia still performed worse than did participants who had recalled accurately both times. However, the participants who had formerly feigned amnesia did not perform worse than did a control group who had received only the delayed recall tests. Our results suggest that a "feigned amnesia effect" may reflect nothing more than differential practice at recall. Feigning amnesia for a crime need not impair memory for that crime when a person later seeks to remember accurately.

Evidence that nonconscious processes are sufficient to produce false memories.

Are nonconscious processes sufficient to cause false memories of a nonstudied event? To investigate this issue, we controlled and measured conscious processing in the DRM task, in which studying associates (e.g., bed, rest, awake...) causes false memories of nonstudied associates (e.g., sleep). During the study phase, subjects studied visually masked associates at extremely rapid rates, followed by immediate recall. After this initial phase, nonstudied test words were rapidly presented for perceptual identification, followed by recognition memory judgments. On the perceptual identification task, we found significant priming of nonstudied associates, relative to control words. We also found significant false recognition of these nonstudied associates, even when subjects did not recall this word at study or identify it at test, indicating that nonconscious processes can cause false recognition. These recognition effects were found immediately after studying each list of associates, but not on a delayed test that occurred after the presentation of several intervening lists. Nonconscious processes are sufficient to cause this memory illusion on immediate tests, but may be insufficient for more vivid and lasting false memories.

Can false memories spontaneously recover?

Can false memories that were suppressed at one time spontaneously recover at a later time? Fuzzy trace theory and activation-monitoring theory predict that false memories in the Deese, Roediger, and McDermott (DRM) procedure become substantially reduced as list learning progresses because participants employ a memory-editing process. It follows that if the editing process is rendered less effective, false memories should spontaneously recover. We found that after DRM lists were well learned and false recognition to critical words was substantially reduced by multiple study-test trials, those false memories spontaneously recovered when participants were either rushed or delayed on a retest. We attributed the reduction in false recognition over trials to a memory-editing process that suppresses false recognition as participants gradually learn which words were in the lists and which words, though similar, were not. Rushing or delaying the participants on a retest made it more difficult for them to edit their memory, and false memories spontaneously returned.

Do you remember proposing marriage to the Pepsi machine? False recollections from a campus walk.

During a campus walk, participants were given familiar or bizarre action statements (e.g., "Check the Pepsi machine for change" vs. "Propose marriage to the Pepsi machine") with instructions either to perform the actions or imagine performing the actions (Group 1) or to watch the experimenter perform the actions or imagine the experimenter performing the actions (Group 2). One day later, some actions were repeated, along with new actions, on a second walk. Two weeks later, the participants took a recognition test for actions presented during the first walk, and they specified whether a recognized action was imagined or performed. Imagining themselves or the experimenter performing familiar or bizarre actions just once led to false recollections of performance for both types of actions. This study extends previous research on imagination inflation by demonstrating that these false performance recollections can occur in a natural, real-life setting following just one imagining.

When do false memories cross language boundaries in English-Spanish bilinguals?

To determine whether false memories cross language boundaries, we presented English-Spanish bilinguals with conceptually related word lists for five study-test trials. Some lists were heard in English, some in Spanish, and they were then followed by a recognition memory test composed of studied words, conceptually related nonstudied critical words, and unrelated words presented in the same language used at study or in a different language. Even though participants were instructed to recognize only previously heard words, they falsely recognized both same-language and different-language critical words. With practice, participants increased their accurate recognition of list words and decreased their false recognition of critical words when the study-test language was the same, and they decreased their false recognition of list words and critical words when the language differed. False memories can cross language boundaries when participants rely on conceptual representations from the word lists, but these errors decrease over trials as participants increasingly rely on language-specific lexical representations.

Are nonconscious processes sufficient to produce false memories?

Seamon, Luo, and Gallo (1998) reported evidence that nonconscious processes could produce false recognition in a converging-associates task, whereby subjects falsely remember a nonstudied lure (e.g., sleep) after studying a list of related words (bed, rest, awake...). Zeelenberg, Plomp, and Raaijmakers (2003) failed to observe this false recognition effect when list word recognition was at chance. We critically evaluate the evidence for nonsconscious processing and report the results of a new experiment designed to overcome previous methodological limitations. Consistent with Seamon et al., we found that conscious activation of a related lure during study was not necessary for its subsequent recognition; consistent with Zeelenberg et al., we found no evidence for recognition of related lures under conditions where there was no memory for studied words. It is currently unknown whether conscious recollection of the studied items is necessary for false recognition or if nonconscious activation of the lure is sufficient.

"If I didn't write it, why would I remember it?" Effects of encoding, attention, and practice on accurate and false memory.

In two experiments involving recall and recognition, we manipulated encoding strategies, attention, and practice in the Deese, Roediger, and McDermott false memory procedure. During the study of auditory word lists, participants listened to the words, wrote the words, wrote the second letter of the words, or counted backward by threes and wrote numbers in time with the words. The results from both experiments showed that, relative to the full-attention hear word condition, the divided-attention write number condition impaired accurate memory, but not false memory. In contrast, the focused-attention write word and write second letter conditions were comparable to the hear word condition in producing accurate memory, yet they were better at reducing false memory. But even after multiple study-test trials, people still falsely recalled or recognized words that they had never written during study. These results are consistent with predictions generated from fuzzy trace theory and the activation/monitoring framework.

Accurate and false recall in the Deese/Roediger and McDermott procedure: a methodological note on sex of participant.

Research suggests that individuals may differ in their susceptibility to false memory in the Deese/Roediger and McDermott procedure. Prior studies of differences have focused on the effects of age, personality, personal past history of abuse, and neurological status on false memory susceptibility. This study examined whether sex might also differentially influence false memory. After listening to a series of word lists designed to elicit false recall of nonstudied associates, 50 male and 50 female college students free recalled the lists. Analysis showed no sex difference in accurate recall, false recall, or unrelated intrusions. A robust false memory effect was observed, but sex did not differentiate performance.

Thinking of critical words during study is unnecessary for false memory in the Deese, Roediger, and McDermott procedure.

Do participants in the Deese, Roediger, and McDermott (DRM) procedure demonstrate false memory because they think of nonpresented critical words during study and confuse them with words that were actually presented? In two experiments, 160 participants studied eight visually presented DRM lists at a rate of 2 s or 5 s per word. Half of the participants rehearsed silently: the other half rehearsed overtly. Following study, the participants' memory for the lists was tested by recall or recognition. Typical false memory results were obtained for both memory measures. More important, two new results were observed. First, a large majority of the overt-rehearsal participants spontaneously rehearsed approximately half of the critical words during study. Second, critical-word rehearsal at study enhanced subsequent false recall, but it had no effect on false recognition or remember judgments for falsely recognized critical words. Thinking of critical words during study was unnecessary for producing false memory.

False memories are hard to inhibit: differential effects of directed forgetting on accurate and false recall in the DRM procedure.

Directed forgetting research shows that people can inhibit the retrieval of words that they were previously instructed to forget. The present research applied the directed forgetting procedure to the Deese/Roediger and McDermott (DRM) recall task to determine if directed forgetting instructions have similar or different effects on accurate and false memory. After studying lists of semantically related words, some participants were told to forget those lists, whereas other participants were not. All participants were then shown additional lists to remember. Following study, all participants were asked to free recall as many of the studied words as possible, including those they were previously instructed to forget. Directed forgetting instructions inhibited the accurate recall of studied words, but not the false recall of nonstudied critical words, whether measured by a within-participant or between-participants design. Contrary to an implicit activation hypothesis, false memories survived instructions to forget. These findings were reviewed in terms of fuzzy trace theory and the activation/monitoring approach to false memory.

Misremembering pictured objects: people of all ages demonstrate the boundary extension illusion.

In the boundary extension illusion, subjects recollect more of a photographed scene than was originally shown. In this study, first- and fifth-grade children, young adult college students, and older adults studied 4 one-object or 4 two-object picture stimuli for 15 s each. Immediately after each visual scene was shown, the subjects drew it from memory inside a rectangle that was the same size as the previous picture. This study demonstrated that all age groups, from young children to older adults, were susceptible to the boundary extension illusion. This finding is discussed in terms of Intraub's perceptual schema hypothesis and Johnson's source-monitoring hypothesis.

Are false memories more difficult to forget than accurate memories? The effect of retention interval on recall and recognition.

What is the effect of retention interval on accurate and false recollection in the Deese, Roediger, and McDermott (DRM) procedure? Previous research has suggested that false recall is more persistent than accurate recall but the recognition results have been inconsistent. In two parametric studies, we tested recall and recognition for the same DRM lists, over retention intervals that ranged from no delay to a 2-month delay. We found that accurate and false memory were diminished by increases in retention interval, false memory persistence was present for recall and recognition, greater persistence for false memory than for accurate memory was more readily observed for recall than recognition, and the high-threshold (Pr), signal detection (d'), and nonparametric (A') recognition measures differed in their sensitivity for detecting change. The effect of retention interval on accurate and false memory is consistent with expectations from fuzzy trace theory. In the DRM procedure, truth is not more memorable than fiction.