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Although the role of the medial temporal lobe (MTL) and the hippocampus in episodic memory is well established, there is emerging evidence that these regions play a broader role in cognition, specifically in temporal processing. However, despite strong evidence that the hippocampus plays a critical role in sequential processing, the involvement of the MTL in timing per se is poorly understood. In the present study, we investigated whether patients with MTL damage exhibit differential performance on a temporal distance memory task. Critically, we manipulated context shifts, or boundaries, which have been shown to interfere with associative binding, leading to increases in subjective temporal distance. We predicted that patients with MTL damage would show impaired binding across boundaries and thus fail to show temporal expansion. Consistent with this hypothesis, unilateral patients failed to show a temporal expansion effect, and bilateral patients actually exhibited the reverse effect, suggesting a critical role for the MTL in binding temporal information across boundaries. Furthermore, patients were impaired overall on both the temporal distance memory task and recognition memory, but not on an independent, short-timescale temporal perception task. Interestingly, temporal distance performance could be independently predicted by performance on recognition memory and the short temporal perception task. Together, these data suggest that distinct mnemonic and temporal processes may influence long interval temporal memory and that damage to the MTL may impair the ability to integrate episodic and temporal information in memory. [ABSTRACT FROM AUTHOR]

Previous work highlighted a critical role for top–down goals in shifting memory organization, namely, through studying the downstream influences of event segmentation and task switching on free recall. Here, we extend these frameworks into the realm of motivation, by comparing how threat motivation influences memory organization by capturing free recall dynamics. In Study 1, we manipulated individuals' motivation to successfully encode information by the threat of exposure to aversive sounds for forgetting. In Study 2, we conducted a parallel study manipulating motivation via instruction rather than threat, allowing us to examine changes directly related to threat motivation. Our findings showed that motivation to avoid threat broadly enhances memory for items presented within a threatening context, regardless of whether items were directly associated with the threat or not. Concurrently, these memory enhancements coincide with a decrease in the organization of memory around motivationally relevant features. These results highlight the importance of considering motivational valence when conceptualizing memory organization within adaptive memory frameworks. [ABSTRACT FROM AUTHOR]

Humans have an outstanding ability to generalize from past experiences, which requires parsing continuously experienced events into discrete, coherent units, and relating them to similar past experiences. Time is a key element in this process; however, how temporal information is used in generalization remains unclear. Latent-cause inference provides a Bayesian framework for clustering experiences, by building a world model in which related experiences are generated by a shared cause. Here, we examine how temporal information is used in latent-cause inference, using a novel task in which participants see "microbe" stimuli and explicitly report the latent cause ("strain") they infer for each microbe. We show that humans incorporate time in their inference of latent causes, such that recently inferred latent causes are more likely to be inferred again. In particular, a "persistent" model, in which the latent cause inferred for one observation has a fixed probability of continuing to cause the next observation, explains the data significantly better than two other time-sensitive models, although extensive individual differences exist. We show that our task and this model have good psychometric properties, highlighting their potential use for quantifying individual differences in computational psychiatry or in neuroimaging studies. [ABSTRACT FROM AUTHOR]

Our experience of time can feel dilated or compressed, rather than reflecting true "clock time." Although many contextual factors influence the subjective perception of time, it is unclear how memory accessibility plays a role in constructing our experience of and memory for time. Here, we used a combination of behavioral and functional MRI measures in healthy young adults (N = 147) to ask the question of how memory is incorporated into temporal duration judgments. Behaviorally, we found that event boundaries, which have been shown to disrupt ongoing memory integration processes, result in the temporal compression of duration judgments. Additionally, using a multivoxel pattern similarity analysis of functional MRI data, we found that greater temporal pattern change in the left hippocampus within individual trials was associated with longer duration judgments. Together, these data suggest that mnemonic processes play a role in constructing representations of time. [ABSTRACT FROM AUTHOR]

Although the stream of information we encounter is continuous, our experiences tend to be discretized into meaningful clusters, altering how we represent our past. Event segmentation theory proposes that clustering ongoing experience in this way is adaptive in that it promotes efficient online processing as well as later reconstruction of relevant information. A growing literature supports this theory by demonstrating its important behavioral consequences. Yet the exact mechanisms of segmentation remain elusive. Here, we provide a brief overview of how event segmentation influences ongoing processing, subsequent memory retrieval, and decision making as well as some proposed underlying mechanisms. We then explore how beliefs, or inferences, about what generates our experience may be the foundation of event cognition. In this inference‐based framework, experiences are grouped together according to what is inferred to have generated them. Segmentation then occurs when the inference changes, creating an event boundary. This offers an alternative to dominant theories of event segmentation, allowing boundaries to occur independent of perceptual change and even when transitions are predictable. We describe how this framework can reconcile seemingly contradictory empirical findings (e.g., memory can be biased toward both extreme episodes and the average of episodes). Finally, we discuss open questions regarding how time is incorporated into the inference process. Shin and DuBrow propose that a key principle driving event segmentation relates to causal analyses: specifically, that experiences that are attributed as having the same underlying cause are grouped together into an event. This offers an alternative to accounts of segmentation based on prediction error. [ABSTRACT FROM AUTHOR]

Individuals value the opportunity to make choices and exert control over their environment. This perceived sense of agency has been shown to have broad influences on cognition, including preference, decision-making, and valuation. However, it is unclear whether perceived control influences memory. Using a combined behavioral and functional magnetic resonance imaging approach, we investigated whether imbuing individuals with a sense of agency over their learning experience influences novel memory encoding. Participants encoded objects during a task that manipulated the opportunity to choose. Critically, unlike previous work on active learning, there was no relationship between individuals' choices and the content of memoranda. Despite this, we found that the opportunity to choose resulted in robust, reliable enhancements in declarative memory. Neuroimaging results revealed that anticipatory activation of the striatum, a region associated with decision-making, valuation, and exploration, correlated with choice-induced memory enhancements in behavior. These memory enhancements were further associated with interactions between the striatum and hippocampus. Specifically, anticipatory signals in the striatum when participants are alerted to the fact that they will have to choose one of two memoranda were associated with encoding success effects in the hippocampus on a trial-by-trial basis. The precedence of the striatal signal in these interactions suggests a modulatory relationship of the striatum over the hippocampus. These findings not only demonstrate enhanced declarative memory when individuals have perceived control over their learning but also support a novel mechanism by which these enhancements emerge. Furthermore, they demonstrate a novel context in which mesolimbic and declarative memory systems interact. [ABSTRACT FROM AUTHOR]

Making sense of previous experience requires remembering the order in which events unfolded in time. Prior work has implicated the hippocampus and medial temporal lobe cortex in memory for temporal information associated with individual episodes. However, the processes involved in encoding and retrieving temporal information across extended sequences is relatively poorly understood. Here we used fMRI during the encoding and retrieval of extended sequences to test specific predictions about the type of information used to resolve temporal order and the role of the hippocampus in this process. Participants studied sequences of images of celebrity faces and common objects followed by a recency discrimination test. The main conditions of interest were pairs of items that had been presented with three intervening items, half of which included an intervening category shift. During encoding, hippocampal pattern similarity across intervening items was associated with subsequent successful order memory. To test for evidence of associative retrieval, we trained a classifier to discriminate encoding patterns associated with faces versus objects and applied the classifier on fMRI patterns during recency discrimination. We found evidence that the category content of intervening items was reactivated during recency judgments, and this was related to hippocampal encoding-retrieval similarity. A follow-up behavioral priming experiment revealed additional evidence for intervening item reinstatement during temporal order judgments. Reinstatement did not differ according to whether the items occurred within a single context or across context boundaries. Thus, these data suggest that inter-item associative encoding and retrieval mediated by the hippocampus contribute to temporal order memory. [ABSTRACT FROM AUTHOR]