Memory最新文献

Age-related losses in executive control are widely assumed to contribute to prospective memory (PM) lapses in late adulthood, but to date, this assumption has gained only inconsistent support from lab-based studies. The present study tested whether age indirectly affects PM via (1) individual differences in specific executive control operations (a parallel mediated model), or (2) a serially mediated model, with processing speed as the first mediator. Older adults (n = 166) completed four measures of PM that had higher ecological validity than standard lab-based paradigms, as well as measures of executive function and other cognitive abilities. The results showed that, although age was a significant predictor of reduced performance on three of the PM measures, particularly time-based tasks, these negative age associations were only slightly diminished when executive functions were controlled for. Performance on the PM task with the greatest ecological validity (MEMO) was independent of age and measures of executive function but positively related to both learning and retention. Processing speed was a poor predictor of PM performance on all measures (accounting for between 0% and 4% of variance). Taken together, these results highlight the need for circumspection in generalising the role of executive control in age-related prospective memory performance.

Music-evoked autobiographical memories (MEAMs) are typically elicited by music that listeners have heard before. While studies that have directly manipulated music familiarity show that familiar music evokes more MEAMs than music listeners have not heard before, music that is unfamiliar to the listener can also sporadically cue autobiographical memory. Here we examined whether music that sounds familiar even without previous exposure can produce spontaneous MEAMs. Cognitively healthy older adults (N = 75, ages 65-80 years) listened to music clips that were chosen by researchers to be either familiar or unfamiliar (i.e., varying by prior exposure). Participants then disclosed whether the clip elicited a MEAM and later provided self-reported familiarity ratings for each. Self-reported familiarity was positively associated with the occurrence of MEAMs in response to familiar, but not the unfamiliar, music. The likelihood of reporting MEAMs for music released during youth (i.e., the "reminiscence bump") relative to young adulthood (20-25 years) included both music released during participants' adolescence (14-18 years) and middle childhood (5-9 years) once self-reported familiarity was accounted for. These developmental effects could not be accounted for by music-evoked affect. Overall, our results suggest that the phenomenon of MEAMs hinges upon both perceptions of familiarity and prior exposure.

False memories during testimony are an enormous challenge for criminal trials. Exposure to post-event misinformation can lead to inadvertent creation of false memories, known as the misinformation effect. We investigated anodal transcranial direct current stimulation (tDCS) on the left inferior parietal lobe (IPL) during recall testing to enhance accurate recall while addressing the misinformation effect. Participants (N = 60) watched a television series depicting a fictional terrorist attack, then received an audio recording with misinformation, consistent information, and control information. During cued recall testing, participants received anodal or sham tDCS. Results revealed a robust misinformation effect in both groups, with participants falsely recalling on average 26.6% of the misinformed items. Bayesian statistics indicated substantial evidence in favour of the null hypothesis that there was no difference between groups in the misinformation effect. Regarding correct recall however, the anodal group exhibited significantly improved recall for items from the original video. Together, these results demonstrate that anodal tDCS of the left IPL enhances correct recall of the episodes from the original event without affecting false recall of misinformation. The findings support the IPL's role in recollection and source attribution of episodic memories.

Prior work has shown Americans have higher levels of memory specificity than East Asians. Neuroimaging studies have not investigated mechanisms that account for cultural differences at retrieval. In this study, we use fMRI to assess whether mnemonic discrimination, distinguishing novel from previously encountered stimuli, accounts for cultural differences in memory. Fifty-five American and 55 Taiwanese young adults completed an object recognition paradigm testing discrimination of old targets, similar lures and novel foils. Mnemonic discrimination was tested by comparing discrimination of similar lures from studied targets, and results showed the relationship between activity in right fusiform gyrus and behavioural discrimination between target and lure objects differed across cultural groups. Parametric modulation analyses of activity during lure correct rejections also indicated that groups differed in left superior parietal cortex response to variations in lure similarity. Additional analyses of old vs. new activity indicated that Americans and Taiwanese differ in the neural activity supporting general object recognition in the hippocampus, left inferior frontal gyrus and middle frontal gyrus. Results are juxtaposed against comparisons of the regions activated in common across the two cultures. Overall, Americans and Taiwanese differ in the extent to which they recruit visual processing and attention modulating brain regions.

True and false memories recruit a number of shared brain regions; however, they are not completely overlapping. Extensive sex differences have been identified in the brain during true memories and, recently, we identified sex differences in the brain during false memories. In the current fMRI study, we sought to determine whether sex differences existed in the location and extent of overlap between true and false memories. True and false memories activated a number of shared brain regions. Compared to females, males produced a greater number of overlapping brain regions (8 versus 2 activations for males and females, respectively) including the prefrontal cortex, parietal cortex, and early/late visual processing cortices (including V1) in males and prefrontal and parietal cortices in females. Males had significantly higher similarity between true and false memory activation maps, revealed by our novel multi-voxel pattern correlation analysis. Moreover, higher similarity between true and false memory activation maps was associated with higher false memory rates. The current results suggest that true and false memories are more similar in males than females. The significant brain-behavior relationship also suggests that males may be more susceptible to false memory errors due to their highly similar true memory-false memory cortical representations.

ABSTRACTSchemas allow us to make assumptions about the world based upon previous experiences and aid in memory organisation and retrieval. However, a reliance on schemas may also result in increased false memories to schematically related lures. Prior neuroimaging work has linked schematic processing in memory tasks to activity in prefrontal, visual, and temporal regions. Yet, it is unclear what type of processing in these regions underlies memory errors. The current study examined where schematic lures exhibit greater neural similarity to schematic targets, leading to this memory error, as compared to neural overlap with non-schematic lures, which, like schematic lures, are novel items at retrieval. Results showed that patterns of neural activity in ventromedial prefrontal cortex, medial frontal gyrus, middle temporal gyrus, hippocampus, and occipital cortices exhibited greater neural pattern similarity for schematic targets and schematic lures than between schematic lures and non-schematic lures. As such, results suggest that schematic membership, and not object history, may be more critical to the neural processes underlying memory retrieval in the context of a strong schema.

After learning semantically related words, some people are more likely than others to incorrectly recall unstudied but semantically related lures (i.e., Deese-Roediger-McDermott [DRM] false recall). Previous studies have suggested that neural activity in subcortical regions (e.g., the caudate) is involved in false memory, and that there may be sex differences in the neural basis of false memory. However, sex-specific associations between subcortical volumes and false memory are not well understood. This study investigated whether sex modulates the associations between subcortical volumes and DRM false recall in 400 healthy college students. Volumes of subcortical regions including the caudate, accumbens, amygdala, hippocampus, pallidum, putamen and thalamus were obtained from structural magnetic resonance images and measured using FreeSurfer. The results showed that males had lower true and false recall but larger subcortical volumes than females. Interestingly, higher false recall was associated with a larger caudate in males, but not in females. This association was significant after controlling for age and intracranial volume. This study provides new evidence on the neural basis of false recall. It suggests that the caudate plays a role in false recall in young men, and that future studies of the neural correlates of false memory should consider sex differences.

Memory is notoriously fallible and susceptible to misinformation. Yet little is known about the underlying cognitive and neural mechanisms that render individuals vulnerable to this type of false memory. The current experiments take an individual differences approach to examine whether susceptibility to misinformation reflects stable underlying factors related to memory retrieval. In Study 1, we report for the first time the existence of substantial individual variability in susceptibility to misinformation in the context of repeated memory retrieval, when the misinformation effect is most pronounced. This variability was not related to an individual's tendency to adopt an episodic retrieval style during remembering (trait mnemonics). In Study 2, we next examined whether susceptibility to misinformation is related to intrinsic functional connectivity in medial temporal lobe (MTL) networks known to coordinate memory reactivation during event retrieval. Stronger resting-state functional connectivity between the MTL and cortical areas associated with visual memory reactivation (occipital cortex) was associated with better protection from misinformation. Together, these results reveal that while memory distortion is a universal property of our reconstructive memory system, susceptibility to misinformation varies at the individual level and may depend on one's ability to reactivate visual details during memory retrieval.

During ongoing narratives, event boundaries trigger processes relevant for subsequent memory. Previous work has shown that novel, unrelated input presented at an event boundary can retroactively interfere with short-term retention of the preceding event. This interference was attributed to a perturbation of offset-related processes taking place within seconds after encoding and supporting the binding of elements into a coherent event memory. However, the temporal specificity of this memory interference and whether its impact extends to longer retention delays has not been addressed. Here, participants viewed either individual or pairs of short narrative movie clips. Susceptibility to interference at event boundaries was probed by presenting the second clip either immediately after the first, or with a 2s encoding delay. In free and cued recall, after 20 min and 24 h, only memory for movie clips that were immediately followed by a second clip was reduced compared to clips shown in isolation. Intact offset-related processes (as indexed by successful recall of the first movie) did not negatively affect encoding of the subsequent clip. Together, these results indicate that the 2s time-window immediately after an event is relevant for successful consolidation and long-term retention of memory.