Michael C. Friedman

Memory and metamemory for inverted words: Illusions of competency and desirable difficulties

Research regarding how people monitor their learning has shown that ease of processing strongly guides people’s judgments of learning (JOLs). However, the desirable difficulties concept (Bjork, 1994) suggests that studying information that is less fluent can result in greater learning. Currently, it is unclear whether people are aware of the potential benefits of desirable difficulties during learning. To address this, in Experiment 1, participants studied inverted and upright words and also made JOLs. While participants’ JOLs did not differ for inverted and upright words, recall was greater for inverted words. Experiment 2 used several study–test cycles in which participants could potentially learn about the beneficial effects of processing inverted words with task experience, and similar results were obtained. Thus, reading inverted words requires processing that enhances recall, but memory predictions do not differentiate between upright and inverted words. We interpret these results in terms of processing fluency, desirable difficulties, and theories of metacognitive monitoring.

Selecting Valuable Information to Remember: Age-Related Differences and Similarities in Self-Regulated Learning

It is often necessary to selectively attend to important information, at the expense of less important information, especially if you know you cannot remember large amounts of information. The present study examined how younger and older adults select valuable information to study, when given unrestricted choices about how to allocate study time. Participants were shown a display of point values ranging from 1-30. Participants could choose which values to study, and the associated word was then shown. Study time, and the choice to restudy words, was under the participants control during the 2-minute study session. Overall, both age groups selected high value words to study and studied these more than the lower value words. However, older adults allocated a disproportionately greater amount of study time to the higher-value words, and age-differences in recall were reduced or eliminated for the highest value words. In addition, older adults capitalized on recency effects in a strategic manner, by studying high-value items often but also immediately before the test. A multilevel mediation analysis indicated that participants strategically remembered items with higher point value, and older adults showed similar or even stronger strategic process that may help to compensate for poorer memory. These results demonstrate efficient (and different) metacognitive control operations in younger and older adults, which can allow for strategic regulation of study choices and allocation of study time when remembering important information. The findings are interpreted in terms of life span models of agenda-based regulation and discussed in terms of practical applications.

Predicting memory benefits in the production effect: the use and misuse of self-generated distinctive cues when making judgments of learning

The production effect occurs when reading a word aloud leads to better memory for the item, relative to words that are read silently. In the present study, we assessed the degree to which judgments of learning (JOLs) are sensitive to the production effect, to determine whether people are aware of how distinctive cues can enhance memory. If the act of saying a word aloud is used as a cue for later memorability, then JOLs should be sensitive to production. Experiment 1 demonstrated that this was the case, as participants provided higher JOLs for produced items than for those read silently. This pattern of JOLs was also evident when participants silently mouthed words (Exp. 2). In Experiment 3, participants instead made a nonunique response as the production component (saying “yes” instead of the word itself). JOLs were still higher under production, although memory performance did not differ from that in a silent condition. The results suggest that the presence of both specific and nonspecific self-generated cues is used to make metacognitive judgments, likely due to the high accessibility of this information, but that participants are not precisely aware of how distinctiveness enhances encoding and retrieval. Such findings have implications for how distinctiveness is perceived by learners and for what cues would appropriately be incorporated when predicting future memory performance.

Are we aware of our ability to forget? Metacognitive predictions of directed forgetting

It is often important to accurately predict not only what information we will later remember, but also what information we are likely to forget. The present research examined these abilities in the context of item-method directed forgetting, to determine whether people are aware of their strategic control of remembering and forgetting, as well as what cues are used when making metacognitive judgments. Participants studied words, each of which was followed by a cue to remember (R) or forget (F) the word for an upcoming test, and also made predictions of how likely they would be to later recall each word. When asked to recall all of the words, regardless of cue, both recall and predicted recall were fairly sensitive to the R or F instructions, despite some overconfidence. A similar and stronger pattern was found when words were assigned positive or negative point values as cues to remember or forget. These findings suggest that item-based cues to remember or forget information can be successfully utilized when making metacognitive judgments, and that people are fairly aware of the control they have over both remembering and forgetting information.

Recurrent patterns of DNA copy number alterations in tumors reflect metabolic selection pressures

Copy number alteration (CNA) profiling of human tumors has revealed recurrent patterns of DNA amplifications and deletions across diverse cancer types. These patterns are suggestive of conserved selection pressures during tumor evolution but cannot be fully explained by known oncogenes and tumor suppressor genes. Using a pan‐cancer analysis of CNA data from patient tumors and experimental systems, here we show that principal component analysis‐defined CNA signatures are predictive of glycolytic phenotypes, including 18F‐fluorodeoxy‐glucose (FDG) avidity of patient tumors, and increased proliferation. The primary CNA signature is enriched for p53 mutations and is associated with glycolysis through coordinate amplification of glycolytic genes and other cancer‐linked metabolic enzymes. A pan‐cancer and cross‐species comparison of CNAs highlighted 26 consistently altered DNA regions, containing 11 enzymes in the glycolysis pathway in addition to known cancer‐driving genes. Furthermore, exogenous expression of hexokinase and enolase enzymes in an experimental immortalization system altered the subsequent copy number status of the corresponding endogenous loci, supporting the hypothesis that these metabolic genes act as drivers within the conserved CNA amplification regions. Taken together, these results demonstrate that metabolic stress acts as a selective pressure underlying the recurrent CNAs observed in human tumors, and further cast genomic instability as an enabling event in tumorigenesis and metabolic evolution.

Memory for medication side effects in younger and older adults: The role of subjective and objective importance

Older adults often experience memory impairments, but sometimes they can use selective processing and schematic support to remember important information. In the present experiments, we investigated the degrees to which younger and healthy older adults remembered medication side effects that were subjectively or objectively important to remember. Participants studied a list of common side effects and rated how negative these effects would be if they were to experience them, and they were then given a free recall test. In Experiment 1, the severity of the side effects ranged from mild (e.g., itching) to severe (e.g., stroke), and in Experiment 2, certain side effects were indicated as being critical to remember (i.e., “contact your doctor if you experience this”). We observed no age differences in terms of free recall of the side effects, and older adults remembered more severe side effects than mild effects. However, older adults were less likely to recognize the critical side effects on a later recognition test, relative to younger adults. These findings suggest that older adults can selectively remember medication side effects but have difficulty identifying familiar but potentially critical side effects, and this has implications for monitoring medication use in older age.

JUN dependency in distinct early and late BRAF inhibition adaptation states of melanoma.

A prominent mechanism of acquired resistance to BRAF inhibitors in BRAFV600-mutant melanoma is associated with the upregulation of receptor tyrosine kinases. Evidences suggested that this resistance mechanism is part of a more complex cellular adaptation process. Using an integrative strategy, we found this mechanism to invoke extensive transcriptomic, (phospho-) proteomic and phenotypic alterations that accompany a cellular transition to a de-differentiated, mesenchymal and invasive state. Even short-term BRAF-inhibitor exposure leads to an early adaptive, differentiation state change—characterized by a slow-cycling, persistent state. The early persistent state is distinct from the late proliferative, resistant state. However, both differentiation states share common signaling alterations including JUN upregulation. Motivated by the similarities, we found that co-targeting of BRAF and JUN is synergistic in killing fully resistant cells; and when used up-front, co-targeting substantially impairs the formation of the persistent subpopulation. We confirmed that JUN upregulation is a common response to BRAF inhibitor treatment in clinically treated patient tumors. Our findings demonstrate that events shared between early- and late-adaptation states provide candidate up-front co-treatment targets.

On the Transfer of Prior Tests or Study Events to Subsequent Study

Tests, as learning events, are often more effective than are additional study opportunities, especially when recall is tested after a long retention interval. To what degree, though, do prior test or study events support subsequent study activities? We set out to test an implication of Bjork and Bjorks (1992) new theory of disuse-that, under some circumstances, prior study may facilitate subsequent study more than does prior testing. Participants learned English-Swahili translations and then underwent a practice phase during which some items were tested (without feedback) and other items were restudied. Although tested items were better recalled after a 1-week delay than were restudied items, this benefit did not persist after participants had the opportunity to study the items again via feedback. In fact, after this additional study opportunity, items that had been restudied earlier were better recalled than were items that had been tested earlier. These results suggest that measuring the memorial consequences of testing requires more than a single test of retention and, theoretically, a consideration of the differing status of initially recallable and nonrecallable items.

False memory and importance: Can we prioritize encoding without consequence?

Given the large amount of information that we encounter, we often must prioritize what information we attempt to remember. Although critical for everyday functioning, relatively little research has focused on how people prioritize the encoding of information. Recent research has shown that people can and do selectively remember information assigned with higher, relative to lower, importance. However, the mechanisms underlying this prioritization process and the consequences of these processes are still not well understood. In the present study, we sought to better understand these prioritization processes and whether implementing these processes comes at the cost of memory accuracy, by increasing false memories. We used a modified form of the Deese/Roediger–McDermott (DRM) paradigm, in which participants studied DRM lists, with each list paired with low, medium, or high point values. In Experiment 1, encoding higher values led to more false memories than did encoding lower values, possibly because prioritizing information enhanced relational processing among high-value words. In Experiment 2, disrupting relational processing selectively reduced false memories for high-value words. Finally, in Experiment 3, facilitating relational processing selectively increased false memories for low-value words. These findings suggest that while prioritizing information can enhance true memory, this process concomitantly increases false memories. Furthermore, the mechanism underlying these prioritization processes depends on the ability to successfully engage in relational processing. Thus, how we prioritize the encoding of incoming information can come at a cost in terms of accurate memory.

I owe you: age-related similarities and differences in associative memory for gains and losses

ABSTRACT Older adults often experience associative memory impairments but can sometimes remember important information. The current experiments investigate potential age-related similarities and differences associate memory for gains and losses. Younger and older participants were presented with faces and associated dollar amounts, which indicated how much money the person “owed” the participant, and were later given a cued recall test for the dollar amount. Experiment 1 examined face-dollar amount pairs while Experiment 2 included negative dollar amounts to examine both gains and losses. While younger adults recalled more information relative to older adults, both groups were more accurate in recalling the correct value associated with high-value faces compared to lower-value faces and remembered gist-information about the values. However, negative values (losses) did not have a strong impact on recall among older adults versus younger adults, illustrating important associative memory differences between younger and older adults.