Using what we know: Consequences of intentionally retrieving gist versus item-specific information

Saccade-induced retrieval enhancement and the recovery of perceptual item-specific information

Saccade-induced retrieval enhancement (SIRE) effects refer to the finding that memory can be enhanced when a short period of saccadic eye movements takes place prior to retrieval. Previous published work testifies to this eye movement advantage, but no work has yet examined if SIRE effects can be found when retrieval demands are high as a result of testing non-studied memoranda that are identical in name/conceptual codes, similar in perceptual features, but differ in terms of perceptual-item-specific information. The results indicate SIRE effects can be found under such conditions and are independent of encoding orientation (intentional vs. incidental). More particularly, SIRE effects manifested themselves in terms of the retrieval of item-specific detail and recollection (vs. familiarity). In terms of the latter, recollection but not familiarity was enhanced by eye movements. These findings are considered in the context of extant theories of SIRE and related research.

Effects of survival processing and retention interval on true and false recognition in the DRM and category repetition paradigms

Two experiments examined the effects of survival processing and delay on true and related false recognition. Experiment 1 used the Deese-Roediger-McDermott paradigm and found survival processing to increase true and related false recognition. Extending the delay from 5-mins to 1-day reduced true, but not false memory. Measures of the characteristics of true and false memories showed survival processing increased "remember" and "know" responses for related false memory, "know" responses for true memory and gist processing. Experiment 2 made use of the category repetition procedure and found a broadly similar pattern of results for true memory. However, related false memory was decreased by survival processing. Except for one result, no interactions were found between encoding task and delay. Overall, survival processing produced similar or different effects on true/false memory depending on the nature of the list. The mechanisms that might underpin these are evaluated and considered in relation to future work.

The many routes of mental navigation: contrasting the effects of a detailed and gist retrieval approach on using and forming spatial representations

Navigated routes can be recalled by remembering a schematic layout or with additional sensory and perceptual details, engaging episodic memory processes. In this study, we contrasted the effects of these remembering approaches on retrieving real-world navigated routes, the impact on flexibly using familiar route information and on learning new spatial representations. In a within-subjects design, participants were oriented to recall familiar routes under two remembering conditions-a detail condition that promoted episodic memory processes and a gist condition in which routes were recalled via schematic processes. In each condition, participants performed two subsequent navigation tasks. They first described solutions to navigation problems that involved the recalled familiar route (e.g., navigating around a road block or to a new destination) and then learned and recalled a route within a novel spatial environment. All navigation descriptions were scored for the number of spatial references, entities, and sensory descriptions. We report the following findings. First, when describing the familiar routes, more details were generated in the detail condition, but a higher proportion of these details were spatial references in the gist condition. Route descriptions in the gist condition also relied more on egocentric spatial representations than in the detail condition. Next, when solving navigation problems in the familiar environment, solution routes were described with more details in the detail condition and deviated less from the familiar route than in the gist condition. Finally, the detail condition led to the preferential encoding of entity and sensory descriptive details of new spatial representations. These findings suggest that activating episodic processes at retrieval has distinct effects on how familiar information can be flexibly used and how new spatial representations are formed.

The Effects of Age on the Neural Correlates of Recollection Success, Recollection-Related Cortical Reinstatement, and Post-Retrieval Monitoring

Functional magnetic resonance imaging (fMRI) was used to investigate whether age-related differences in episodic memory performance are accompanied by a reduction in the specificity of recollected information. We addressed this question by comparing recollection-related cortical reinstatement in young and older adults. At study, subjects viewed objects and concrete words, making 1 of 2 different semantic judgments depending on the study material. Test items were words that corresponded to studied words or the names of studied objects. Subjects indicated whether each test item was recollected, familiar, or novel. Reinstatement of information differentiating the encoding tasks was quantified both with a univariate analysis of the fMRI signal and with a multivoxel pattern analysis, using a classifier that had been trained to discriminate between the 2 classes of study episode. The results of these analyses converged to suggest that reinstatement did not differ according to age. Thus, there was no evidence that specificity of recollected information was reduced in older individuals. Additionally, there were no age effects in the magnitude of recollection-related modulations in regional activity or in the neural correlates of post-retrieval monitoring. Taken together, the findings suggest that the neural mechanisms engaged during successful episodic retrieval can remain stable with advancing age.

Creativity and Memory: Effects of an Episodic-Specificity Induction on Divergent Thinking

People produce more episodic details when imagining future events and solving means-end problems after receiving an episodic-specificity induction-brief training in recollecting details of a recent event-than after receiving a control induction not focused on episodic retrieval. Here we show for the first time that an episodic-specificity induction also enhances divergent creative thinking. In Experiment 1, participants exhibited a selective boost on a divergent-thinking task (generating unusual uses of common objects) after a specificity induction compared with a control induction; by contrast, performance following the two inductions was similar on an object association task thought to involve little divergent thinking. In Experiment 2, we replicated the specificity-induction effect on divergent thinking using a different control induction, and also found that participants performed similarly on a convergent-thinking task following the two inductions. These experiments provide novel evidence that episodic memory is involved in divergent creative thinking.

The retrieval context of intervening tasks influences subsequent memory in younger and older adults

BACKGROUND/STUDY CONTEXT: What people remember can be shaped by how they access and evaluate their memories as well as by events that happen after the original experience. This study examined how thinking about events in different ways after their occurrence can influence younger and older adults' memory for what really occurred.

METHODS

Younger adults (ages 18-22) and older adults (ages 65-88) saw and imagined pictures of objects and later evaluated each object 0, 1, or 3 times on a task that either required them to remember the objects in a general way (old or new?), in a more specific manner (perceived, imagined, or new?), or that required thinking about objects without regard to whether or how they were earlier experienced (e.g., judging their function or frequency in everyday life).

RESULTS

RESULTS showed that probing items multiple times on the intervening tasks increased the number of items younger and older adults successfully remembered later but also increased source misattributions of claiming to have seen objects that were really imagined, with older adults showing lower recall but higher source errors. Exposure to items on the nonretrieval intervening tasks negatively affected later source memory, and remembering items without explicitly considering their source increased source errors even more that did the non-retrieval-based intervening tasks.

CONCLUSIONS

These findings illustrate the negative impact of thinking about and nondiscriminately remembering past events on subsequent memory accuracy.

The neural correlates of gist-based true and false recognition

When information is thematically related to previously studied information, gist-based processes contribute to false recognition. Using functional MRI, we examined the neural correlates of gist-based recognition as a function of increasing numbers of studied exemplars. Sixteen participants incidentally encoded small, medium, and large sets of pictures, and we compared the neural response at recognition using parametric modulation analyses. For hits, regions in middle occipital, middle temporal, and posterior parietal cortex linearly modulated their activity according to the number of related encoded items. For false alarms, visual, parietal, and hippocampal regions were modulated as a function of the encoded set size. The present results are consistent with prior work in that the neural regions supporting veridical memory also contribute to false memory for related information. The results also reveal that these regions respond to the degree of relatedness among similar items, and implicate perceptual and constructive processes in gist-based false memory.

Recall of remote episodic memories can appear deficient because of a gist-based retrieval orientation

Determining whether patients with amnesia can succeed in remembering their distant past has pivotal implications for theories of memory storage. However, various factors influence recall. We speculated that some patients with anterograde amnesia adopt a gist-based retrieval orientation for memories from all time periods, thereby exaggerating remote recall deficits. We tested whether an experimentally induced gist-based retrieval orientation could indeed hinder remote recall. Healthy individuals described photographs of complex scenes (e.g., of a cluttered desk) either with many words or few words (detail- or gist-based manipulation, respectively). They subsequently recalled autobiographical events and produced less episodic information after engaging the gist-based compared to the detail-based orientation. These results demonstrate the ease with which a gist-based orientation can produce apparent recall impairments. Deficits in remote episodic recall, and in future-event imagining, must thus be interpreted in light of habitual tendencies toward gist-based retrieval that some amnesic patients may exhibit.