Free recall test experience potentiates strategy-driven effects of value on memory.

People tend to show better memory for information that is deemed valuable or important. By one mechanism, individuals selectively engage deeper, semantic encoding strategies for high value items (Cohen, Rissman, Suthana, Castel, & Knowlton, 2014). By another mechanism, information paired with value or reward is automatically strengthened in memory via dopaminergic projections from midbrain to hippocampus (Shohamy & Adcock, 2010). We hypothesized that the latter mechanism would primarily enhance recollection-based memory, while the former mechanism would strengthen both recollection and familiarity. We also hypothesized that providing interspersed tests during study is a key to encouraging selective engagement of strategies. To test these hypotheses, we presented participants with sets of words, and each word was associated with a high or low point value. In some experiments, free recall tests were given after each list. In all experiments, a recognition test was administered 5 minutes after the final word list. Process dissociation was accomplished via remember/know judgments at recognition, a recall test probing both item memory and memory for a contextual detail (word plurality), and a task dissociation combining a recognition test for plurality (intended to probe recollection) with a speeded item recognition test (to probe familiarity). When recall tests were administered after study lists, high value strengthened both recollection and familiarity. When memory was not tested after each study list, but rather only at the end, value increased recollection but not familiarity. These dual process dissociations suggest that interspersed recall tests guide learners' use of metacognitive control to selectively apply effective encoding strategies. (PsycINFO Database Recor

Enhancing the Ecological Validity of fMRI Memory Research Using Virtual Reality

Functional magnetic resonance imaging (fMRI) is a powerful research tool to understand the neural underpinnings of human memory. However, as memory is known to be context-dependent, differences in contexts between naturalistic settings and the MRI scanner environment may potentially confound neuroimaging findings. Virtual reality (VR) provides a unique opportunity to mitigate this issue by allowing memories to be formed and/or retrieved within immersive, navigable, visuospatial contexts. This can enhance the ecological validity of task paradigms, while still ensuring that researchers maintain experimental control over critical aspects of the learning and testing experience. This mini-review surveys the growing body of fMRI studies that have incorporated VR to address critical questions about human memory. These studies have adopted a variety of approaches, including presenting research participants with VR experiences in the scanner, asking participants to retrieve information that they had previously acquired in a VR environment, or identifying neural correlates of behavioral metrics obtained through VR-based tasks performed outside the scanner. Although most such studies to date have focused on spatial or navigational memory, we also discuss the promise of VR in aiding other areas of memory research and facilitating research into clinical disorders

Distributed representations in memory: Insights from functional brain imaging. Annu Rev Psychol 63

Abstract Forging new memories for facts and events, holding critical details in mind on a moment-to-moment basis, and retrieving knowledge in the service of current goals all depend on a complex interplay between neural ensembles throughout the brain. Over the past decade, researchers have increasingly utilized powerful analytical tools (e.g., multivoxel pattern analysis) to decode the information represented within distributed functional magnetic resonance imaging activity patterns. In this review, we discuss how these methods can sensitively index neural representations of perceptual and semantic content and how leverage on the engagement of distributed representations provides unique insights into distinct aspects of memory-guided behavior. We emphasize that, in addition to characterizing the contents of memories, analyses of distributed patterns shed light on the processes that influence how information is encoded, maintained, or retrieved, and thus inform memory theory. We conclude by highlighting open questions about memory that can be addressed through distributed pattern analyses

Behavioral representational similarity analysis reveals how episodic learning is influenced by and reshapes semantic memory

Abstract While semantic and episodic memory have been shown to influence each other, uncertainty remains as to how this interplay occurs. We introduce a behavioral representational similarity analysis approach to assess whether semantic space can be subtly re-sculpted by episodic learning. Eighty participants learned word pairs that varied in semantic relatedness, and learning was bolstered via either testing or restudying. Next-day recall is superior for semantically related pairs, but there is a larger benefit of testing for unrelated pairs. Analyses of representational change reveal that successful recall is accompanied by a pulling together of paired associates, with cue words in semantically related (but not unrelated) pairs changing more across learning than target words. Our findings show that episodic learning is associated with systematic and asymmetrical distortions of semantic space which improve later recall by making cues more predictive of targets, reducing interference from potential lures, and establishing novel connections within pairs

Evidence of memory from brain data.

Much courtroom evidence relies on assessing witness memory. Recent advances in brain imaging analysis techniques offer new information about the nature of autobiographical memory and introduce the potential for brain-based memory detection. In particular, the use of powerful machine-learning algorithms reveals the limits of technological capacities to detect true memories and contributes to existing psychological understanding that all memory is potentially flawed. This article first provides the conceptual foundation for brain-based memory detection as evidence. It then comprehensively reviews the state of the art in brain-based memory detection research before establishing a framework for admissibility of brain-based memory detection evidence in the courtroom and considering whether and how such use would be consistent with notions of justice. The central question that this interdisciplinary analysis presents is: if the science is sophisticated enough to demonstrate that accurate, veridical memory detection is limited by biological, rather than technological, constraints, what should that understanding mean for broader legal conceptions of how memory is traditionally assessed and relied upon in legal proceedings? Ultimately, we argue that courtroom admissibility is presently a misdirected pursuit, though there is still much to be gained from advancing our understanding of the biology of human memory

Neurocognitive mechanisms of real-world autobiographical memory retrieval: insights from studies using wearable camera technology.

In recent years, investigation into the cognitive and neural mechanisms of autobiographical memory has been aided by the use of experimental paradigms incorporating wearable camera technology. By effortlessly capturing first-person images of one's life events, these cameras provide a rich set of naturalistic stimuli that can later be used to trigger the recall of specific episodes. Here, we chronicle the development and progression of such studies in behavioral and neuroimaging examinations of both clinical and nonclinical adult populations. Experiments examining the effects of periodic review of first-person images of life events have documented enhancements of autobiographical memory retrieval. Such benefits are most pronounced in patients with memory impairments, but there is mounting evidence that cognitively healthy individuals may benefit as well. Findings from functional magnetic resonance imaging experiments using wearable camera stimuli as retrieval probes have produced results that, although largely consistent with the broader episodic memory literature, have significantly extended prior findings concerning the underlying mnemonic processes and the neural representation of autobiographical information. Taken together, wearable camera technology provides a unique opportunity for studies of autobiographical memory to more closely approximate real-world conditions, thus offering enhanced ecological validity and opening up new avenues for experimental work