High reward makes items easier to remember, but harder to bind to a new temporal context

Learning through reward is central to adaptive behavior. Indeed, items are remembered better if they are experienced while participants expect a reward, and people can deliberately prioritize memory for high- over low-valued items. Do memory advantages for high-valued items only emerge after deliberate prioritization in encoding? Or, do reward-based memory enhancements also apply to unrewarded memory tests and to implicit memory? First, we tested for a high-value memory advantage in unrewarded implicit- and explicit-tests (Experiment 1). Participants first learned high or low-reward values of 36 words, followed by unrewarded lexical decision and free-recall tests. High-value words were judged faster in lexical decision, and more often recalled in free recall. These two memory advantages for high-value words were negatively correlated suggesting at least two mechanisms by which reward value can influence later item-memorability. The ease with which the values were originally acquired explained the negative correlation: people who learned values earlier showed reward effects in implicit memory whereas people who learned values later showed reward effects in explicit memory. We then asked whether a high-value advantage would persist if trained items were linked to a new context (Experiments 2a and 2b). Following the same value training as in Experiment 1, participants learned lists composed of previously trained words mixed with new words, each followed by free recall. Thus, participants had to retrieve words only from the most recent list, irrespective of their values. High- and low-value words were recalled equally, but low-value words were recalled earlier than high-value words and high-value words were more often intruded (proactive interference). Thus, the high-value advantage holds for implicit- and explicit-memory, but comes with a side effect: High-value items are more difficult to relearn in a new context. Similar to emotional arousal, reward value can both enhance and impair memory

Emotional arousal impairs association-memory: roles of amygdala and hippocampus

Emotional arousal is well-known to enhance memory for individual items or events, whereas it can impair association memory. The neural mechanism of this association memory impairment by emotion is not known: In response to emotionally arousing information, amygdala activity may interfere with hippocampal associative encoding (e.g., via prefrontal cortex). Alternatively, emotional information may be harder to unitize, resulting in reduced availability of extra-hippocampal medial temporal lobe support for emotional than neutral associations. To test these opposing hypotheses, we compared neural processes underlying successful and unsuccessful encoding of emotional and neutral associations. Participants intentionally studied pairs of neutral and negative pictures (Experiments 1–3). We found reduced association-memory for negative pictures in all experiments, accompanied by item-memory increases in Experiment 2. High-resolution fMRI (Experiment 3) indicated that reductions in associative encoding of emotional information are localizable to an area in ventral-lateral amygdala, driven by attentional/salience effects in the central amygdala. Hippocampal activity was similar during both pair types, but a left hippocampal cluster related to successful encoding was observed only for negative pairs. Extra-hippocampal associative memory processes (e.g., unitization) were more effective for neutral than emotional materials. Our findings suggest that reduced emotional association memory is accompanied by increases in activity and functional coupling within the amygdala. This did not disrupt hippocampal association-memory processes, which indeed were critical for successful emotional association memory formation

Reduced associative memory for negative information: impact of confidence and interactive imagery during study

Although item-memory for emotional information is enhanced, memory for associations between items is often impaired for negative, emotionally arousing compared to neutral information. We tested two possible mechanisms underlying this impairment, using picture pairs: 1) higher confidence in one’s own ability to memorise negative information may cause participants to under-study negative pairs; 2) better interactive imagery for neutral pairs could facilitate associative memory for neutral pairs more than for negative pairs. Tested with associative recognition, we replicated the impairment of associative memory for negative pairs. We also replicated the result that confidence in future memory (judgments of learning) was higher for negative than neutral pairs. Inflated confidence could not explain the impairment of associative recognition memory: Judgements of learning were positively correlated with associative memory success for both negative and neutral pairs. However, neutral pairs were rated higher in their conduciveness to interactive imagery than negative pairs, and this difference in interactive imagery showed a robust relationship to the associative memory difference. Thus, associative memory reductions for negative information are not due to differences in encoding effort. Instead, interactive imagery may be less effective for encoding of negative than neutral pairs

Crime in Context: Utilizing Risk Terrain Modeling and Conjunctive Analysis of Case Configurations to Explore the Dynamics of Criminogenic Behavior Settings.

Risk terrain modeling (RTM) is a geospatial crime analysis tool designed to diagnose environmental risk factors for crime and identify the places where their spatial influence is collocated to produce vulnerability for illegal behavior. However, the collocation of certain risk factors’ spatial influences may result in more crimes than the collocation of a different set of risk factors’ spatial influences. Absent from existing RTM outputs and methods is a straightforward method to compare these relative interactions and their effects on crime. However, as a multivariate method for the analysis of discrete categorical data, conjunctive analysis of case configurations (CACC) can enable exploration of the interrelationships between risk factors’ spatial influences and their varying effects on crime occurrence. In this study, we incorporate RTM outputs into a CACC to explore the dynamics among certain risk factors’ spatial influences and how they create unique environmental contexts, or behavior settings, for crime at microlevel places. We find that most crime takes place within a few unique behavior settings that cover a small geographic area and, further, that some behavior settings were more influential on crime than others. Moreover, we identified particular environmental risk factors that aggravate the influence of other risk factors. We suggest that by focusing on these microlevel environmental crime contexts, police can more efficiently target their resources and further enhance place-based approaches to policing that fundamentally address environmental features that produce ideal opportunities for crime

How the physical landscape of the urban environment affects drug dealing

Many illegal drugs are sold in open air markets on the street. But what determines where drug transactions take place? In new research, Jeremy D. Barnum, Walter L. Campbell, Sarah Trocchio, Joel M. Caplan, and Leslie W. Kennedy examine how drug dealers and buyers can take advantage of features of the urban environment in Chicago to find more effective places to make drug deals. Assessing 28 of these environmental features, they find that drug deals were much more likely to take place near to foreclosures, problem landlords and broken street lighting. They write that their findings could be used to inform more place-based policing strategies aimed at tackling drug markets

Value bias of verbal memory

© 2019 Elsevier Inc. A common finding is that items associated with higher reward value are subsequently remembered better than items associated with lower value. A confounding factor is that when a higher value stimuli is presented, this typically signals to participants that it is now a particularly important time to engage in the task. When this was controlled, Madan, Fujiwara, Gerson, and Caplan (2012) still found a large value-bias of memory. Their value-learning procedure, however, explicitly pitted high- against low-value words. Our novel value-learning procedure trained words one at a time, avoiding direct competition between words, but with no difference in words signalling participants to engage in the task. Results converged on null effects of value on subsequent free recall accuracy. Re-analyses attributed Madan et al.’s value-bias to competition between choice items that were paired during learning. Value may not bias memory if it does not signal task importance or induce inter-item competition

Effectiveness of the method of loci is only minimally related to factors that should influence imagined navigation

The method of loci is arguably the most famous mnemonic strategy and is highly effective for memorising lists of non-spatial information in order. As described and instructed, this strategy apparently relies on a spatial/navigational metaphor. The user imagines moving through an environment, placing (study) and reporting (recall) list items along the way. However, whether the method relies critically on this spatial/navigation metaphor is unknown. An alternative hypothesis is that the navigation component is superfluous to memory success, and the method of loci is better viewed as a special case of a larger class of imagery-based peg strategies. Training participants on three virtual environments varying in their characteristics (an apartment, an open field, and a radial-arm maze), we asked participants to use each trained environment as the basis of the method of loci to learn five 11-word lists. Performance varied significantly across environment. However, the effects were small in magnitude. Further tests suggested that navigation-relevant knowledge and ability were not major determinants of success in verbal memory, even for participants who were confirmed to have been compliant with the strategy. These findings echo neuroimaging findings that navigation-based cognition does occur during application of the method of loci, but imagined navigation is unlikely to be directly responsible for its effectiveness. Instead, the method of loci may be best viewed as a variant of peg methods