The mnemonic effect of choice

Temporary ambiguity and memory for the context of spoken language in adults with moderate-severe traumatic brain injury

Language is processed incrementally, with addressees considering multiple candidate interpretations as speech unfolds, supporting the retention of these candidate interpretations in memory. For example, after interpreting the utterance, "Click on the striped bag", listeners exhibit better memory for non-mentioned items in the context that were temporarily consistent with what was said (e.g., dotted bag), vs. not consistent (e.g., dotted tie), reflecting the encoding of linguistic context in memory. Here, we examine the impact of moderate-severe traumatic brain injury (TBI) on memory for the contexts of language use. Participants with moderate-severe TBI (N=71) and non-injured comparison participants (NC, N=85) interpreted temporarily ambiguous utterances in rich contexts. A subsequent memory test demonstrated that participants with TBI exhibited impaired memory for context items and an attenuated memory advantage for mentioned items compared to NC participants. Nonetheless, participants with TBI showed similar, although attenuated, patterns in memory for temporarily-activated items as NC participants.

Option similarity modulates the link between choice and memory

Choices made in everyday life are highly variable. Sometimes, you may find yourself choosing between two similar options (e.g., breakfast foods to eat) and other times between two dissimilar options (e.g., what to buy with a gift certificate). The goal of the present study was to understand how the similarity of choice options affects our ability to remember what we choose and what we did not choose. We hypothesized that choosing between similar as compared to dissimilar options would evoke a comparison-based strategy (evaluating options with respect to one another), fostering a relational form of encoding and leading to better memory for both the chosen and unchosen options. In Experiment 1, participants reported their strategy when choosing between pairs of similar or dissimilar options, revealing that participants were more likely to use a comparison-based strategy when faced with similar options. In Experiment 2, we tested memory after participants made choices between similar or dissimilar options, finding improved memory for both chosen and unchosen options from the similar compared to dissimilar choice trials. In Experiment 3, we examined strategy use when choosing between pairs of similar or dissimilar options and memory for these options. Replicating and extending the results of the first two experiments, we found that participants were more likely to use a comparison-based strategy when choosing between similar than dissimilar options, and that the positive effect of similarity on memory was stronger for unchosen than chosen options when controlling for strategy use. We interpret our results as evidence that option similarity impacts the mnemonic processes used during choice, altering what we encode and ultimately remember about our choices.

Memory for social media images following traumatic brain injury

PRIMARY OBJECTIVE

An emerging body of research examines the role of computer-mediated communication in supporting social connection in persons with traumatic brain injury (TBI). We examine the cognitive impacts of engaging with images posted to social media for persons with moderate-severe TBI.

RESEARCH DESIGN

Prior work shows that after viewing social media posts, adults have better memory for posts when they generate a comment about the post. We examined if persons with TBI experience a memory benefit for commented-upon social media images similar to non-injured comparison participants.

METHODS AND PROCEDURES

53 persons with moderate-to-severe TBI and 52 non-injured comparison participants viewed arrays of real social media images and were prompted to comment on some of them. After a brief delay, a surprise two-alternative forced choice recognition memory test measured memory for these images.

MAIN OUTCOMES AND RESULTS

Persons with TBI remembered social media images at above-chance levels and experienced a commenting-related memory boost much like non-injured comparison participants.

CONCLUSIONS

These findings add to a growing literature on the potential benefits of social media use in individuals with TBI and point to the benefits of active engagement for memory in social media contexts in TBI.

Does taking multiple photos lead to a photo-taking-impairment effect?

The photo-taking-impairment effect is observed when photographed information is less likely to be remembered than nonphotographed information. Three experiments examined whether this effect persists when multiple photos are taken. Experiment 1 used a within-subjects laboratory-based design in which participants viewed images of paintings and were instructed to photograph them once, five times, or not at all. Participants' memory was measured using a visual detail test, and the photo-taking-impairment effect was observed when participants took multiple photos. Experiment 2 examined the photo-taking-impairment effect using a between-subjects design. Participants either photographed all of the paintings they saw once, five times, or not at all, before being tested on their memory for the paintings. The photo-taking-impairment effect was observed in both photo-taking conditions relative to the no photo baseline. Experiment 3 replicated this pattern of results even when participants who took multiple photos were instructed to take five unique photos. These findings indicate that the photo-taking-impairment effect is robust, occurring even when multiple photos are taken, and after nonselective photo-taking.

The effect of choice on intentional and incidental memory

Recent studies have revealed that memory performance is better when participants have the opportunity to make a choice regarding the experimental task (choice condition) than when they do not have such a choice (fixed condition). These studies, however, used intentional memory tasks, leaving open the question whether the choice effect also applies to incidental memory. In the current study, we first repeated the choice effect on the 24-h delayed intentional memory performance (experiment 1). Next, using an incidental paradigm in which participants were asked to judge the category of the items instead of intentionally memorizing them, we observed the choice effect on judgment during encoding and memory performance in a 24-h delayed surprise test (experiment 2). Participants judged more accurately and quickly and had better recognition memory for items in the choice condition than for items in the fixed condition. These results are discussed in terms of the role of choice in both intentional and incidental memory.

Selecting effectively contributes to the mnemonic benefits of self-generated cues

Self-generated memory cues support recall of target information more robustly than memory cues generated by others. Across two experiments, we tested whether the benefit of self-generated cues in part reflects a meta-mnemonic effect rather than a pure generation effect. In other words, can learners select better memory cues for themselves than others can? Participants generated as many possible memory cues for each to-be-remembered target as they could and then selected the cue they thought would be most effective. Self-selected memory cues elicited better cued recall than cues the generator did not select and cues selected by observers. Critically, this effect cannot be attributed to the process of generating a cue itself because all of the cues were self-generated. Further analysis indicated that differences in cue selection arise because generators and observers valued different cue characteristics; specifically, observers valued the commonality of the cue more than the generators, while generators valued the distinctiveness of a cue more than observers. Together, results suggest that self-generated cues are effective at supporting memory, in part, because learners select cues that are tailored to their specific memory needs.

Adaptive Memory: Independent Effects of Survival Processing and Reward Motivation on Memory

Humans preferentially remember information processed for their survival relevance, a memorial benefit known as the survival processing effect. Memory is also biased towards information associated with the prospect of reward. Given the adaptiveness of these effects, they may depend on similar mechanisms. We tested whether motivation drives both effects, with reward incentives that are known to boost extrinsic motivation and survival processing perhaps stimulating intrinsic motivation. Accordingly, we manipulated survival processing and reward incentive independently during an incidental-encoding task in which participants chose between pairs of words concerning their relevance for a scenario, and examined the effects on encoding event-related potentials (ERP) activity and later performance on a surprise recall test. We hypothesized that if survival processing fosters intrinsic motivation, it should reduce the beneficial effects of extrinsic motivation (reward incentive). In contrast to this prediction, we found that reward incentive and survival processing independently improved memory and that the P300, a measure of lower-level cognitive resource allocation, was increased by reward incentive independent of survival processing. Further, survival processing and reward incentive independently increased the frontal slow wave (FSW), a measure of higher-level elaboration. These findings suggest that while survival processing and reward incentive may both increase encoding elaboration, the memory-enhancing effect of survival processing does not depend on increased intrinsic motivation. Additionally, we replicated a recent finding whereby the survival processing effect generalizes to a choice-based encoding task and further showed that the beneficial effect of choice on memory likely does not interact with either survival processing or reward.