Divided attention enhances explicit but not implicit conceptual memory: an item-specific account of the attentional boost effect

The Attentional Boost Effect (ABE) refers to the counterintuitive finding that words encoded with to-be-responded targets in a divided-attention condition are remembered better than words encoded with distractors. Previous studies suggested that the ABE-related enhancement of verbal memory depends upon the activation of abstract lexical representations. In the present study, we extend this hypothesis by embedding it in the context of a broader perspective, which proposes that divided attention in the ABE paradigm affects item-specific, but not relational, processing. To this purpose, we examined the ABE in the matched tasks of category-cued recall (CCRT: explicit memory) and category exemplar generation (CEGT: implicit memory). In addition, study time was varied (500, 1500 or 4000?ms), to further determine whether the attentional boost manipulation could influence late-phase elaborative processing. In agreement with the predictions of the item-specific account, the results showed that exemplars encoded with targets were recalled better than exemplars encoded with distractors in the CCRT, but not in the CEGT. Moreover, performance in the CCRT increased with study time, whereas the size of the ABE-related enhancement tended to decrease, further confirming that this effect hinges upon early phase encoding processes.     

The effect of presentation rate on implicit sequence learning in aging

Implicit sequence learning is thought to be preserved in aging when the to-be learned associations are first-order; however, when associations are second-order, older adults (OAs) tend to experience deficits as compared to young adults (YAs). Two experiments were conducted using a first (Experiment 1) and second-order (Experiment 2) serial-reaction time task. Stimuli were presented at a constant rate of either 800 milliseconds (fast) or 1200 milliseconds (slow). Results indicate that both age groups learned first-order dependencies equally in both conditions. OAs and YAs also learned second-order dependencies, but the learning of lag-2 information was significantly impacted by the rate of presentation for both groups. OAs showed significant lag-2 learning in slow condition while YAs showed significant lag-2 learning in the fast condition. The sensitivity of implicit sequence learning to the rate of presentation supports the idea that OAs and YAs different processing speeds impact the ability to build complex associations across time and intervening events.     

Accessibility and characteristics of memories of the future

Recent research suggests that some imagined future events are encoded in memory, leading to the formation of “memories of the future”. However, questions remain regarding the exact components of future event simulations that are encoded and the factors that determine their accessibility. To address these questions, the present study investigated memory for previously imagined future events using both free and cued recall tasks. The results showed that most future event simulations were successfully encoded and remained available in memory after a one week delay, but only some of them were readily accessible, whereas others could only be accessed when relevant cues were provided. Persons and locations were particularly well remembered, suggesting that these components are central to the simulation and memorisation of future events. We also found that memory for future event simulations was related to the clarity and familiarity of represented persons, the subjective feelings of pre-experience and mental time travel, the importance of imagined events to personal goals, and their emotional intensity during the initial simulation phase. Taken together, these findings expand our understanding of the formation, accessibility, and characteristics of memories of the future.     

The effect of the order in which episodic autobiographical memories versus autobiographical knowledge are shared on feelings of closeness

Autobiographical memories (AMs) can be used to create and maintain closeness with others [Alea, N., &; Bluck, S. (2003). Why are you telling me that? A conceptual model of the social function of autobiographical memory. Memory, 11(2), 165–178]. However, the differential effects of memory specificity are not well established. Two studies with 148 participants tested whether the order in which autobiographical knowledge (AK) and specific episodic AM (EAM) are shared affects feelings of closeness. Participants read two memories hypothetically shared by each of four strangers. The strangers first shared either AK or an EAM, and then shared either AK or an EAM. Participants were randomly assigned to read either positive or negative AMs from the strangers. Findings suggest that people feel closer to those who share positive AMs in the same way they construct memories: starting with general and moving to specific.     

Should you Sleep on it? The Effects of Overnight Sleep on Subjective Preference‐based Choice

Conventional wisdom and studies of unconscious processing suggest that sleeping on a choice may improve decision making. Although sleep has been shown to benefit several cognitive tasks, including problem solving, its impact on everyday choices remains unclear. Here we explore the effects of ‘sleeping on it’ on preference‐based decisions among multiple options. In two studies, individuals viewed several attributes describing a set of items and were asked to select their preferred item after a 12‐hour interval that either contained sleep or was spent fully awake. After an overnight period including sleep, individuals showed increases in positive perceptions of the choice set. This finding contrasts with previous research showing that sleep selectively enhances recall for negative information. In addition, this increase in positive recall did not translate into a greater desire to purchase their preferred item or into an overall benefit for choice satisfaction. Time‐of‐day controls were used to confirm that the observed effects could not be explained by circadian influences. Thus, we show that people may feel more positive about the choice options but not more confident about the choice after ‘sleeping on’ a subjective decision. We discuss how the valence of recalled choice set information may be important in understanding the effects of sleep on multi‐attribute decision making and suggest several avenues for future research. Copyright © 2015 John Wiley & Sons, Ltd.     

Successfully controlling intrusive memories is harder when control must be sustained

After unpleasant events, people often experience intrusive memories that undermine their peace of mind. In response, they often suppress these unwanted memories from awareness. Such efforts may fail, however, when inhibitory control demands are high due to the need to sustain control, or when fatigue compromises inhibitory capacity. Here we examined how sustained inhibitory demand affected intrusive memories in the Think/No-Think paradigm. To isolate intrusions, participants reported, trial-by-trial, whether their preceding attempt to suppress retrieval had triggered retrieval of the memory they intended to suppress. Such counter-intentional retrievals provide a laboratory model of the sort of involuntary retrieval that may underlie intrusive memories. Using this method, we found that longer duration trials increased the probability of an intrusion. Moreover, on later No-Think trials, control over intrusions suddenly declined, with longer trial durations triggering more relapses of items that had been previously been purged. Thus, the challenges of controlling retrieval appear to cause a decline in control over time, due to a change in state, such as fatigue. These findings raise the possibility that characteristics often true of people with psychiatric disorders – such as compromised sleep, and increased demand on control – may contribute to difficulties in suppressing intrusive memories.     

Impact of age-relevant goals on future thinking in younger and older adults

This study investigated how personal goals influence age differences in episodic future thinking. Research suggests that personal goals change with age and like autobiographical memory, future thinking is thought to be organised and impacted by personal goals. It was hypothesised that cueing older adults with age-relevant goals should modulate age differences in episodic details and may also influence phenomenological characteristics of imagined scenarios. Healthy younger and older adults completed the Future Thinking Interview [Addis, D. R., Wong, A. T., & Schacter, D. L. (2008). Age-related changes in the episodic simulation of future events. Psychological Science, 19(1), 33–41. doi:10.1111/j.1467-9280.2008.02043.x] adapted to activate age-appropriate goals. Narratives were scored with an established protocol to obtain objective measures of episodic and semantic details. Subjective features such as emotionality and personal significance showed age differences as a function of goal domain while other features (e.g., vividness) were unaffected. However, consistent with prior reports, older adults produced fewer episodic details than younger adults and this was not modulated by goal domain. The results do not indicate that goal activation affects level of episodic detail. With respect to phenomenological aspects of future thinking, however, younger adults show more sensitivity to goal activation, compared with older adults.     

Inconsistent-handed advantage in episodic memory extends to paragraph-level materials

Past research using handedness as a proxy for functional access to the right hemisphere demonstrates that individuals who are mixed/inconsistently handed outperform strong/consistently handed individuals when performing episodic recall tasks. However, research has generally been restricted to stimuli presented in a list format. In the present paper, we present two studies in which participants were presented with paragraph-level material and then asked to recall material from the passages. The first study was based on a classic study looking at retroactive interference with prose materials. The second was modelled on a classic experiment looking at perspective taking and the content of memory. In both studies, the classic effects were replicated and the general finding that mixed/inconsistent-handers outperform strong/consistent-handers was replicated. This suggests that considering degree of handedness may be an empirically useful means of reducing error variance in paradigms looking at memory for prose level material.     

Usage of semantic representations in recognition memory

Meanings of words facilitate false acceptance as well as correct rejection of lures in recognition memory tests, depending on the experimental context. This suggests that semantic representations are both directly and indirectly (i.e., mediated by perceptual representations) used in remembering. Studies using memory conjunction errors (MCEs) paradigms, in which the lures consist of component parts of studied words, have reported semantic facilitation of rejection of the lures. However, attending to components of the lures could potentially cause this. Therefore, we investigated whether semantic overlap of lures facilitates MCEs using Japanese Kanji words in which a whole-word image is more concerned in reading. Experiments demonstrated semantic facilitation of MCEs in a delayed recognition test (Experiment 1), and in immediate recognition tests in which participants were prevented from using phonological or orthographic representations (Experiment 2), and the salient effect on individuals with high semantic memory capacities (Experiment 3). Additionally, analysis of the receiver operating characteristic suggested that this effect is attributed to familiarity-based memory judgement and phantom recollection. These findings indicate that semantic representations can be directly used in remembering, even when perceptual representations of studied words are available.