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The brain processes underlying impairing effects of emotional arousal on associative memory were previously attributed to two dissociable routes using high-resolution fMRI of the MTL (Madan et al. 2017). Extrahippocampal MTL regions supporting associative encoding of neutral pairs suggested unitization; conversely, associative encoding of negative pairs involved compensatory hippocampal activity. Here, whole-brain fMRI revealed prefrontal contributions: dmPFC was more involved in hippocampal-dependent negative pair learning and vmPFC in extrahippocampal neutral pair learning. Successful encoding of emotional memory associations may require emotion regulation/conflict resolution (dmPFC), while neutral memory associations may be accomplished by anchoring new information to prior knowledge (vmPFC).

Entrepreneurial journalism has its genesis in the disruption shaking up the media landscape. As news organizations struggle to adapt to their evolving ecosystem, they look to new generations of journalists to drive progress. As educators, we have a responsibility to help prepare students to thrive in the evolving journalism ecosystem.

It would be profoundly important if reconsolidation research in animals and other memory domains generalized to human episodic memory. A 3-d-list-discrimination procedure, based on free recall of objects, with a contextual reminder cue (the testing room), has been thought to demonstrate reconsolidation of human episodic memory (as noted in a previous study). Our goal was to replicate the central result, a high intrusion rate during recall of the target list, and evaluate the reconsolidation account relative to an alternative account, based on state-dependent learning and interference. First, replication was not straightforward (Experiment 1). Second, using a very unique, highly salient context (Experiment 2), the method produced a qualitative replication, but it was small in magnitude. A critical assumption of the reconsolidation account, that the target list is reactivated and destabilized during re-exposure to the study context, was not supported (Experiment 3). Although troubling for the reconsolidation account, the findings can be easily accommodated by an alternative account that does not assume additional neurobiological processes underlying the destabilization of consolidated memories, instead explaining intrusion rates simply in terms of well-established cognitive effects, such as item-to-context binding and interference during retrieval.

Early verbal-memory researchers assumed participants represent memory of a pair of unrelated items with 2 independent, separately modifiable, directional associations. However, memory for pairs of unrelated words (A-B) exhibits associative symmetry: a near-perfect correlation between accuracy on forward (A??) and backward (??B) cued recall. This was viewed as arguing against the independent-associations hypothesis and in favor of the hypothesis that associations are remembered as holistic units. Here we test the Holistic Representation hypothesis further by examining cued recall of compound words. If we suppose preexisting words are more unitized than novel associations, the Holistic Representation hypothesis predicts compound words (e.g., ROSE BUD) will have a higher forward-backward correlation than novel compounds (e.g., BRIEF TAX). We report the opposite finding: Compound words, as well as noncompound words, exhibited less associative symmetry than novel compounds. This challenges the Holistic Representation account of associative symmetry. Moreover, preexperimental associates (positional family size) influenced associative symmetry--but asymmetrically: Increasing family size of the last constituent increasing decoupled forward and backward recall, but family size of the 1st constituent had no such effect. In short, highly practiced, meaningful associations exhibit associative asymmetry, suggesting associative symmetry is not diagnostic of holistic representations but, rather, is a characteristic of ad hoc associations. With additional learning, symmetric associations may be replaced by directional, independently modifiable associations as verbal associations become embedded within a rich knowledge structure.

This study was designed to assess the effects of acute exercise on performance of a paired associate learning (PAL) test, an operationalization of hippocampal-dependent associative memory. Participants performed a PAL test and then ran on a treadmill (exercise group, n = 52) or solved Sudoku puzzles (control group, n = 54). Participants returned 2, 5, or 8 hr later to perform a second, different, PAL test. PAL scores for the control group did not change over time. Similarly, scores on tests taken 2 and 5 hr after exercise were not different from baseline or control data. Scores on tests taken 8 hr after exercise, however, fell significantly below baseline (by 8.6%) and control (by 9.8%) scores. These data demonstrate that acute exercise can negatively affect the encoding and retrieval of new information even hours after the exercise bout, which should be a consideration when designing exercise programs to enhance, and not hinder, learning. [ABSTRACT FROM AUTHOR]

Emotionally arousing information is remembered better than neutral information. This enhancement effect has been shown for memory for items. In contrast, studies of association-memory have found both impairments and enhancements of association-memory by arousal. We aimed to resolve these conflicting results by using a cued-recall paradigm combined with a model-based data analysis method (Madan, Glaholt, & Caplan, 2010) that simultaneously obtains separate estimates of arousal effects on memory for associations and memory for items. Participants studied sequentially presented words in pairs that were pure (NEGATIVE-NEGATIVE or NEUTRAL-NEUTRAL) or mixed (NEGATIVE-NEUTRAL or NEUTRAL-NEGATIVE). Cued recall tests had NEUTRAL or NEGATIVE probes and NEUTRAL or NEGATIVE targets. We found impaired memory for associations involving negative words despite enhanced item-memory (more retrievable targets). A category-list control condition explained away the item-memory enhancement but could not explain the impairment of association-memory due to arousal. A second experiment with identical structure but using higher arousing taboo words revealed increased cued recall of taboo than neutral words. However, this was exclusively mediated by item-memory effects with neither enhancement nor impairment of association-memory. Thus, although cued recall was lower for pure negative pairs and higher for pure taboo pairs, our modeling approach determined a different locus of action for these memory impairing or increasing effects: Although item memory was increased by arousal, association-memory was impaired by moderately arousing, negative words and unaffected by taboo words. Our results suggest that previous results reporting an enhancement of association-memory due to arousal may have instead been solely driven by enhanced item-memory. (Contains 4 tables and 6 figures.)

Word properties like imageability and word frequency improve cued recall of verbal paired-associates. We asked whether these enhancements follow simply from prior effects on item-memory, or also strengthen associations between items. Participants studied word pairs varying in imageability or frequency: pairs were "pure" (high-high, low-low) or "mixed" (high-low, low-high) where "high" and "low" refer to imageability or frequency values and are probed with forward (A-?) and backward (?-B) cues. Probabilistic model fits to the data suggested that imageability primarily improved retrieval of associations, but frequency primarily improved recall of target items. All pair types exhibited a high correlation between forward and backward probe accuracy, a measure of holistic learning (Kahana, 2002), which extends the boundary conditions of holistic association-memory and challenges Paivio's (1971) suggestion that holistic learning depends critically on imagery. In sum, item properties can boost association-memory beyond simply boosting target retrievability. (Contains 3 tables and 8 figures.)

By having subjects drive a virtual taxicab through a computer-rendered town, we examined how landmark and layout information interact during spatial navigation. Subject-drivers searched for passengers, and then attempted to take the most efficient route to the requested destinations (one of several target stores). Experiment 1 demonstrated that subjects rapidly learn to find direct paths from random pickup locations to target stores. Experiment 2 varied the degree to which landmark and layout cues were preserved across two successively learned towns. When spatial layout was preserved, transfer was low if only target stores were altered, and high if both target stores and surrounding buildings were altered, even though in the latter case all local views were changed. This suggests that subjects can rapidly acquire a survey representation based on the spatial layout of the town and independent of local views, but that subjects will rely on local views when present, and are harmed when associations between previously learned landmarks are disrupted. We propose that spatial navigation reflects a hierarchical system in which either layout or landmark information is sufficient for orienting and wayfinding; however, when these types of cues conflict, landmarks are preferentially used.

Paired associates and serial list memory are typically investigated separately. An "isolation principle" (J. B. Caplan, 2005) was proposed to explain behavior in both paradigms by using a single model, in which serial list and paired associates memory differ only in how isolated pairs of items are from interference from other studied items. In the present study, 2 experiments identify a critical dissociation between the 2 paradigms, challenging this unified account. Specifically, forward and backward probes were highly correlated for pairs and less so for short lists (triples). The authors asked whether the isolation principle could quantitatively accommodate this type of dissociation. A simulation confirmed that a single model incorporating the isolation principle can adequately explain this and other dissociations, supporting the common processes view.

The congruity effect is a highly replicated feature of comparative judgments, and has been recently found in memory judgments of relative temporal order. Specifically, asking "Which came earlier?" versus "Which came later?" facilitates response times and sometimes error rates on judgments toward the beginning or end of the list, respectively. This suggests memory judgments of relative temporal order may be part of a broader class of comparative judgments. If so, the same congruity effect should also be found with the English alphabet, despite the alphabet being a longer, semantic-memory list, with forward directional encoding. A large-sample study (N = 340) produced a clear congruity effect in response time and even error rate (when controlled for response time). The large number of serial positions afforded by the alphabet enabled us to test a repertoire of mathematical models instantiating four distinct mechanisms of the congruity effect, against the empirical serial-position effects. The best-performing model assumed a response bias toward a discrete set of letters conceived of as "early" versus "late," respectively, an account that had previously been ruled out for typical comparative-judgment paradigms. In contrast, models implementing congruity effect mechanisms supported for conventional comparative judgment paradigms (based on reference-point theory or positional discriminability) produced quantitatively poorer fits, with more curvilinear serial-position effects that deviated from the data. The congruity effect thus extends to long, highly directional semantic-memory lists. However, qualitatively different serial-position effects across models suggest that, despite the superficial similarity, there are probably several quite different mechanisms that produce congruity effects, which may, in turn, depend on specific task characteristics. [ABSTRACT FROM AUTHOR]

Whereas both human and animal lesion and human neuroimaging studies have implicated the hippocampus in memory for associations, some studies find preserved associative memory following hippocampal damage. Starting with a classic summed similarity model of item recognition, we can account for associative recognition without assuming a specific hippocampally-mediated associative process. We add one key assumption: that one item can influence activation of another item's features. Feature-strength patterns, evaluated for each probe item individually, are then diagnostic of whether an item was paired with one item versus another. We suggest that feature-level inference, without explicit storage of associations, may play a critical role in associative recognition tasks. [ABSTRACT FROM AUTHOR]

If two associations share an item, one may be remembered at the expense of the other (BC recalled but not AB). Here, we identify the neural processes by which this competition materializes and is resolved. We analyzed fMRI signal while participants studied sets of pairs that reliably induced pair-to-pair associative interference, but which participants could not fully resolve. Precuneus activity tracked retrieval of previous pairs during study of later overlapping pairs. This retrieval apparently produced interference by diverting study resources from the currently displayed pair. However, when activity in ventromedial prefrontal cortex, as well as anterior subregions of the hippocampus, was present while the earlier pair had been studied, interference was reversed, and both pairs were likely to be recalled. Angular gyrus and mid-frontal activity were related to interference resolution once the participant had seen both pairs. Taken together, associations compete via precuneus-mediated competitive retrieval, but ventromedial prefrontal cortex may neutralize this by ensuring that when the earlier association is remembered while studying the later pair, memories of the two pairs can overcome interference likely via activity in mid-frontal cortex and angular gyrus. [ABSTRACT FROM AUTHOR]

For Phil Richardson, it began with a simple question. How do albatross soar so effortlessly, flying around the world without flapping their wings? On an expedition in 1997 to the [...]

Memory champions remember vast amounts of information in order and at first encounter by associating each study item to an anchor within a scaffold – a pre-learned, structured memory. The scaffold provides direct-access retrieval cues. Dominated by the familiar-route scaffold (Method of Loci), researchers have little insight into what characteristics of scaffolds make them effective, nor whether individual differences might play a role. We compared participant-generated mnemonic scaffolds: (a) familiar routes (Loci), (b) autobiographical stories (Story), (c) parts of the human body (Body), and (d) routine activities (Routine Activity). Loci, Body, and Story Scaffolds benefited serial recall over Control (no scaffold). The Body and Loci Scaffold were equally superior to the other scaffolds. Measures of visual imagery aptitude and vividness and body responsiveness did not predict accuracy. A second experiment tested whether embodiment could be responsible for the high level of effectiveness of the Body Scaffold; this was not supported. In short, mnemonic scaffolds are not equally effective and embodied cognition may not directly contribute to memory success. The Body Scaffold may be a strong alternative to the Method of Loci and may enhance learning for most learners, including those who do not find the Method of Loci useful. [ABSTRACT FROM AUTHOR]

Author(s): Arne D. Ekstrom [1]; Michael J. Kahana (corresponding author) [1]; Jeremy B. Caplan [1]; Tony A. Fields [2]; Eve A. Isham [2]; Ehren L. Newman [1]; Itzhak Fried (corresponding [...]

Theta activity takes place in distinct, task-dependent episodes, according to research based on subdural recordings from epileptic patients learning to navigate computer-generated mazes. Theta oscillations take place during spatial navigation. The oscillations are visually striking against a complex background signal. It is probable that theta oscillations are significant in human spatial cognition, as they become more frequent in long mazes and during retrieval.