Lifetime familiarity cue effects for autobiographical memory.

Recollecting an autobiographical memory requires a cue to initiate processes related to accessing and then elaborating on a past personal experience. Prior work has shown that the familiarity of a cue can influence the autobiographical memory retrieval process. Extending this work, we tested how familiarity accrued from cumulative lifetime exposures associated with the cue-as well as associated semantic knowledge-can affect how we access and remember autobiographical memories. In Experiment 1, we measured reaction times to access and report memories in response to cue words. In Experiment 2 we examined the details with which participants described memories in response to cue words. For both experiments, participants provided estimates of lifetime exposure and semantic knowledge for each cue. In Experiment 1, we found a cue's lifetime exposure, independent of semantic knowledge, led to quicker memory access. In Experiment 2, we found the lifetime exposure and semantic knowledge of a cue interactively affected the specificity of a described autobiographical memory. These results provide new evidence that the amount of lifetime exposure associated with a cue, both independently and interactively with semantic knowledge, influences how autobiographical memories are accessed and described.Clinical trial This was not a clinical trial.Trial Registration Number (TRN) N/A.

The Neural Corelates of Constructing Conceptual and Perceptual Representations of Autobiographical Memories.

Contemporary neurocognitive frameworks propose that conceptual and perceptual content of autobiographical memories-personal past experiences-are processed by dissociable neural systems. Other work has proposed a central role of the anterior hippocampus in initially constructing autobiographical memories, regardless of the content. Here, we report on an fMRI study that utilized a repeated retrieval paradigm to test these ideas. In an MRI scanner, participants retrieved autobiographical memories at three timepoints. During the third retrieval, participants either shifted their focus to the conceptual content of the memory, the perceptual content of the memory, or retrieved the memory as they had done so on previous trials. We observed stronger anterior hippocampal activity for the first retrieval compared with later retrievals, regardless of whether there was a shift in content in those later trials. We also found evidence for separate cortical systems when constructing autobiographical memories with a focus on conceptual or perceptual content. Finally, we found that there was common engagement between later retrievals that required a shift toward conceptual content and the initial retrieval of a memory. This final finding was explored further with a behavioral experiment that provided evidence that focusing on conceptual content of a memory guides memory construction, whereas perceptual content adds precision to a memory. Together, these findings suggest there are distinct content-oriented cortical systems that work with the anterior hippocampus to construct representations of autobiographical memories.

Comparing neural activity during autobiographical memory retrieval between younger and older adults: An ALE meta-analysis.

Aging changes autobiographical memory (AM), yet the neural correlates of these changes are poorly understood, likely due to methodological variability across studies. We conducted a quantitative meta-analysis using activation likelihood estimation (GingerALE 3.0.2) to identify regions AM retrieval engaged in younger and older adults across 45 studies (Nyounger = 24 studies, 357 participants, 349 foci; Nolder = 21 studies, 299 participants, 356 foci), considering methodological differences in cueing AMs (i.e., using generic vs. specific/personalized cues). Both age-groups commonly engaged a left-lateralized pattern of brain activity that included the hippocampus, retrosplenial/posterior cingulate cortex, and angular gyrus. Younger adults showed enhanced right posterior cingulate cortical activity, while older adults presented with bilateral activity in the hippocampus, and enhanced activity in left middle temporal gyrus, precuneus, and retrosplenial cortex. Exploratory analyses indicated that age-related commonalties and differences in brain activity depended on the method of AM cuing. These findings suggest that key regions of AM retrieval are preserved in older age, yet subtle changes exist, especially depending on how AMs are cued.

Reduced anterior hippocampal and ventromedial prefrontal activity when repeatedly retrieving autobiographical memories.

Research has reported that repeatedly retrieving a novel or imagined event representation reduces activity within brain regions critical for constructing mental scenarios, namely the anterior hippocampus and ventromedial prefrontal cortex (vmPFC). The primary aim of this investigation was to test if this pattern reported for imagined events would be found when repeatedly recollecting autobiographical memories. Twenty-four participants retrieved 12 pre-selected autobiographical memories four times while undergoing an fMRI scan. We used a region of interest approach to investigate how the anterior and posterior hippocampus as well as cortical regions critical for memory retrieval-the vmPFC and the posterior cingulate cortex (PCC)-are affected by repeated retrievals. This analysis revealed an effect in the bilateral anterior hippocampi and vmPFC, but not the posterior hippocampus nor the PCC, with activity decreasing in these regions as a function of repeated retrievals. A multivariate analytic approach (Partial Least Squares) was used to assess whole-brain patterns of neural activity associated with repeated retrievals. This analysis revealed one pattern of neural activity associated with the initial retrieval of a memory (e.g., inferior frontal and temporal lobe regions) and a separate pattern of activity associated with later retrievals that was distributed primarily across the lateral parietal cortices. These findings suggest that the anterior hippocampus and the vmPFC support the episodic construction of an autobiographical memory the first time it is retrieved and that alternate nonconstructive processes support its subsequent retrieval shortly thereafter.

Conceptual similarity alters the impact of context shifts on temporal memory.

Past work has shown that changes in encoding contexts (context shifts) act as boundaries across encountered items and can impair temporal memory. We address two questions about this effect: whether conceptual similarity among contexts creating a boundary can alleviate temporal memory impairments and if this effect holds for different forms of contexts (spatial vs. categorical). In a between-subjects design, participants studied the order of sequentially presented faces (items), each presented with an associated context. One group was shown images of a room (spatial) and the other images of a dessert (categorical) as the context. For both, boundaries between contexts with overlapping (similar) or non-overlapping (distinct) conceptual features were introduced. At test, participants performed a recency judgment for pairs of items that crossed or did not cross a context boundary at encoding and recalled whether they were encoded within the same, similar, or distinct context. For both groups, recency judgments were more accurate for item pairs from similar than distinct contexts, but memory for the context relationship between items was more accurate for items from distinct than similar contexts. Our findings suggest that conceptual knowledge impacts how events are parsed during encoding and affects temporal associations formed in episodic memory.

Trait-Level Variability in Attention Modulates Mind Wandering and Academic Achievement.

Although mind wandering remains ubiquitous in daily life, the processes that underlie and sustain this behavior remain poorly understood. Across two experiments, we studied the role of intrinsic temperament traits, which shape stable behavioral processes, in moderating the association between mind wandering and the real-life functional outcome of academic success. In Experiment 1, participants completed the Mind Wandering Questionnaire, the Adult Temperament Questionnaire, and reported their grade for the highest degree completed or in progress. Individuals with traits of low Effortful control, high Negative affect, and low Extraversion indicated more mind wandering. Effortful control moderated the relationship between mind wandering and academic success, with higher tendency for mind wandering associated with higher academic achievement for individuals with high Effortful control, and lower academic achievement for those with low Effortful control. Experiment 2 confirmed these links using the visual metronome response task, an objective measure of mind wandering. Together, these results suggest that the intrinsic temperament trait of Effortful control represents one of the key mechanisms behind the functional influence of mind wandering on real-life outcomes. This work places an innate ability to control attention at the very core of real life success, and highlights the need for studying mind wandering through an interdisciplinary lens that brings together cognitive, biological, social, and clinical theories in order to understand the fundamental mechanisms that drive this behavior.

Retrieval orientation alters neural activity during autobiographical memory recollection.

When an autobiographical memory is retrieved, the underlying memory representation is constructed by flexibly activating a broad neural network. As such, the content used to reconstruct a memory can bias activity within this neural network. Here, we tested the hypothesis that focusing on the conceptual and contextual aspects of a memory to construct a memory representation will recruit distinct neural subsystems. To test this hypothesis, we measured neural activity as participants retrieved memories under retrieval orientations that biased remembering towards these elements of a past autobiographical experience. In an MRI scanner, participants first retrieved autobiographical memories and then were re-oriented towards the conceptual or contextual elements of that memory. They then used this re-oriented content (conceptual or contextual elements) to access and elaborate upon a new autobiographical memory. Confirming our hypothesis, we found a neural dissociation between these retrieval orientation conditions that aligned with established models of memory. We also found evidence that this neural dissociation was most prominent when the re-oriented mnemonic content was used to access a new memory. Altogether, the reported results provide critical insight into how and when retrieval orientations alter neural support for autobiographical memory retrieval and inform on the neural organization of autobiographical knowledge.

Constructing autobiographical events within a spatial or temporal context: a comparison of two targeted episodic induction techniques.

Recalling and imagining autobiographical experiences involves constructing event representations within spatiotemporal contexts. We tested whether generating autobiographical events within a primarily spatial (where the event occurred) or temporal (the sequence of actions that occurred) context affected how the associated mental representation was constructed. We leveraged the well-validated episodic specificity induction (ESI) technique, known to influence the use of episodic processes on subsequent tasks, to develop variants that selectively enhance spatial or temporal processing. We tested the effects of these inductions on the details used to describe past and future autobiographical events. We first replicated the standard ESI effect, showing that ESI enhances generating episodic details, particularly those that are perception-based, when describing autobiographical events (Experiment 1). We then directly compared the effects of the spatial and temporal inductions (Experiment 2 and 3). When describing autobiographical events, spatial induction enhanced generating episodic details, specifically perception-based details, compared to the control or temporal inductions. A greater proportion of the episodic details generated after the temporal induction were gist-based than after the spatial induction, but this proportion did not differ from a control induction. Thus, using a spatial or temporal framework for autobiographical event generation alters the associated details that are accessed.

A Neurocognitive Perspective on the Forms and Functions of Autobiographical Memory Retrieval.

Autobiographical memory retrieval involves constructing mental representations of personal past episodes by associating together an array of details related to the retrieved event. This construction process occurs flexibly so that the event details can be associated together in different ways during retrieval. Here, we propose that differences in how this association occurs support a division in autobiographical remembering. We first review theories of autobiographical memory organization that suggest that episodic details of an experience are processed along a gradient of abstraction. This organization allows for the same autobiographical event to be recalled as either a conceptualized or perceptually-based episodic memory. We then use neuroimaging evidence to show how this division within episodic autobiographical memory is also present in the brain, both at a network level and within the hippocampus. Specifically, we suggest that the anterior and posterior hippocampus are obligatorily tuned towards constructing conceptual vs. perceptual episodic representations of autobiographical memories. Finally, we discuss the directive purpose of this proposed division of episodic remembering by reviewing decision scenarios that benefit from recalling the past as a conceptual vs. a perceptual episode. Conceptual remembering is useful to guide ambiguous decisions that have yet to be encountered whereas perceptual remembering is useful to guide decisions for well-structured tasks that have been previously experienced. We emphasize that the ability to shift between conceptual and perceptual forms of remembering, by virtue of hippocampal specialization, during decision-making and other memory-guided actions is the key to adaptive behavior.