Episodic memory reconsolidation: Updating or source confusion?

Reactivation of apparently stable, long-term memory can render it fragile, and dependent on a re-stabilisation process referred to as “reconsolidation”. Recently we provided the first demonstration of reconsolidation effects in human episodic memory (Hupbach, Gomez, Hardt, & Nadel, 2007 Hupbach, A., Gomez, R., Hardt, O. and Nadel, L. 2007. Reconsolidation of episodic memories: A subtle reminder triggers integration of new information. Learning & Memory, 14: 47–53. [Crossref], [PubMed], [Web of Science ®] , [Google Scholar]; Hupbach, Hardt, Gomez, & Nadel, 2008 Hupbach, A., Hardt, O., Gomez, R. and Nadel, L. 2008. The dynamics of memory context-dependent updating. Learning & Memory, 15: 574–579.  [Google Scholar]). Memory for a set of objects was modified by the presentation of a new set, if and only if participants were reminded of the first learning episode before learning the new set. The present study asks whether this effect can be interpreted as a source discrimination problem; i.e., participants have difficulties remembering which objects were presented during which session, and do not actually incorporate new objects into the reactivated memory. The present study used a recognition test and asked participants directly about the source of their memories. Participants in the no-reminder group showed very few source errors. Participants in the reminder group misattributed the source of objects from the second set as being from the first set but not vice versa, thus demonstrating updating of the original memory. This finding is informative with respect to the misinformation paradigm, and reconsolidation is discussed as a possible mechanism underlying our results and the misinformation effect.     

Fact learning: How information accuracy,delay, and repeated testing change retention and retrieval experience

Previous classroom studies have shown that the phenomenology of studied facts changes over time. However, pedagogical needs preclude both the study of errors and the separation of the effects that delay and repeated testing have on retention and retrieval experience. We addressed these issues together in an experiment where participants read stories containing correct and misleading information and provided Remember, Just Know, and Familiar judgements on immediate and delayed general knowledge tests. After 2 days, information learned from the stories shifted from Remembered to Just Known, but repeated testing attenuated this shift. Interestingly, similar patterns of retrieval and phenomenology were observed for correct and misleading information with one important difference—the shift over time to Just Knowing was significantly greater for correct than for misleading information. Together, these findings show the roles of information accuracy, delay, and testing in determining both retention and the subjective experience of retrieval.     

The effects of source trustworthiness and inference type on human belief revision

We investigated whether people revise their beliefs as a function of inference type or source trustworthiness. By doing so we aimed to find out if belief revision is better explained by mental model theory (Johnson-Laird & Byrne, 2002 Johnson-Laird, P. N. and Byrne, R. M. J. 2002. Conditionals: A theory of meaning, pragmatics, and inference. Psychological Review, 109: 211–228. [Crossref], [Web of Science ®] , [Google Scholar]) or by a conditional probability view (Evans, Handley, & Over, 2003 Over, D. E. and Evans, J. St. B. T. 2003. The probability of conditionals: The psychological evidence. Mind & Language, 18: 340–358. [Crossref], [Web of Science ®] , [Google Scholar]; Oaksford & Chater, 2001 Oaksford, M. and Chater, N. 2001. The probabilistic approach to human reasoning. Trends in Cognitive Science, 5: 349–357. [Crossref], [PubMed], [Web of Science ®] , [Google Scholar]). We used modified modes ponens (MP) and modus tollens (MT) problems in which the first two premises were uttered by persons with varying degrees of trustworthiness. A third statement was presented as a fact and established inconsistency in the set of propositions. The participants' task was to indicate which of the first two premises they believed more after receiving the fact. We found that the belief in the conditional premise dropped significantly when this premise was stated by a low- rather than a high-trustworthy source. Moreover we found that the conditional premise was believed more in MT than in MP problems. Both findings are best explained by the conditional probability hypothesis (e.g., Evans et al., 2003 Evans, J. St. B. T., Handley, S. J. and Over, D. E. 2003. Conditionals and conditional probability. Journal of Experimental Psychology: Learning, Memory, and Cognition, 29, : 321–335. [Crossref] , [Google Scholar]).     

Positive emotion can protect against source memory impairment

Despite widespread belief that memory is enhanced by emotion, evidence also suggests that emotion can impair memory. Here we test predictions inspired by object-based binding theory, which states that memory enhancement or impairment depends on the nature of the information to be retrieved. We investigated emotional memory in the context of source retrieval, using images of scenes that were negative, neutral or positive in valence. At study each scene was paired with a colour and during retrieval participants reported the source colour for recognised scenes. Critically, we isolated effects of valence by equating stimulus arousal across conditions. In Experiment 1 colour borders surrounded scenes at study: memory impairment was found for both negative and positive scenes. Experiment 2 used colours superimposed over scenes at study: valence affected source retrieval, with memory impairment for negative scenes only. These findings challenge current theories of emotional memory by showing that emotion can impair memory for both intrinsic and extrinsic source information, even when arousal is equated between emotional and neutral stimuli, and by dissociating the effects of positive and negative emotion on episodic memory retrieval.     

The role of specificity in the lexical encoding of participants

In addition to information about phonology, morphology and syntax, lexical entries contain semantic information about participants (e.g., Agent). However, the traditional criteria for determining how much participant information is lexically encoded have proved unreliable. We have proposed two semantic criteria (obligatoriness and selectivity) that jointly identify the participants that are lexically encoded in verbs. We tested whether one of these criteria, semantic selectivity, makes psychologically real distinctions between participant information that is lexically encoded and participant information that is not. We examined how readers integrated syntactically optional WH-constituents in filler-gap sentences when the participant information conveyed by the WH-filler was specific to a restricted class of verbs (i.e., source locations) and when it was not (i.e., event locations). Our results provide support for the role of specificity in the lexical encoding of participant information of syntactically optional constituents.     

Developments in source monitoring: the role of thinking of others

Adults' source judgments are more accurate when they focus on speakers' emotions than when adults focus on their own emotions. Focusing on speakers may lead to better source memory because it encourages processing of the perceptual characteristics of the source and binding of that information to the content of what is being said. The purpose of the current work was to evaluate whether young children's source memory similarly benefits from this outward encoding focus and whether this effect changes developmentally. In Experiment 1, when 4- and 5-year-olds heard an audiotape of two dissimilar speakers, only the 5-year-olds showed better source memory when asked to adopt an other-focus. In Experiment 2, when 4- and 5-year-olds watched a videotape of two similar speakers, the same pattern was found. However, in Experiment 3, when 4-year-olds watched a videotape of two dissimilar speakers (a more optimal encoding condition in which 5-year-olds showed ceiling performance), 4-year-olds benefited from taking an other-focus during encoding. Overall, the data suggest that the benefit for source memory of focusing on another person develops over the preschool years.     

论文物的使用价值及其源泉

文物不同于现实物品,也不同于一般物品,文物是在时间的推移和空间的变迁中逐渐形成的。文物具有四种使用价值,即自然使用价值、审美使用价值、增值使用价值和信息使用价值,除自然使用价值之外,其余三种使用价值的发展变化都直接与时空条件有关,而与人的劳动、自然力的作用关系并不明确。因此,时空条件是文物使用价值的重要源泉。     

Fantasy proneness, mental imagery and reality monitoring

Individual differences in fantasy proneness and vividness of mental imagery have been suggested to be related to source memory confusions. To test this hypothesis, two groups scoring either high or low on a measure of fantasy proneness (selected from a group of 231 subjects) were compared on measures of self report vividness of mental imagery, objective imagery ability and reality monitoring performance. The two groups differed significantly on ratings of imagery vividness (p<0.01), but not on the imagery performance tasks, nor on reality monitoring performance. Our results indicate that, although fantasy proneness is associated with experiences of vivid mental imagery, it does not necessarily lead to reality monitoring errors.