Effects of aging on value-directed modulation of semantic network activity during verbal learning

Memory and automatic processing of valuable information in younger and older adults

People often engage in the selective remembering of valuable or important information, whether strategic and/or automatic. We examined potential age-related differences in the automatic processing of value during encoding on later remembering by presenting participants with words paired with point values (range: 1-10 twice or 1-20) to remember for a later test. On the first three lists, participants were told that they would receive the points associated with each word if they recalled it on the test (their goal was to maximize their score). On the last three lists, we told participants that all words were worth the same number of points if recalled on the tests, thus making the point value paired with each word meaningless. Results revealed that selective memory may be impaired in older adults using procedures with larger value ranges. Additionally, we demonstrated that the automatic effects of value may have a greater effect on younger adults relative to older adults, but there may be instances where older adults also exhibit these automatic effects. Finally, strategic and automatic processes may not be related within each learner, suggesting that these processes may rely on different cognitive mechanisms. This indicates that these processes could be underpinned by distinct cognitive mechanisms: strategic processes might engage higher-level cognitive operations like imagery, while automatic processes appear to be more perceptually driven.

Memory selectivity in older age

Memory often declines with age, but older adults can off-set memory challenges by selectively remembering important information. When encountering large amounts of information and knowing that memory is limited, older adults may choose to focus on what is most important and forget less relevant details. Prioritizing what to remember becomes essential when memory is limited, and influences what information can be off-loaded. While forgetting can be frustrating and consequential, a lifetime of these experiences may help older adults learn to focus on strategically remembering important information and life events. Curiosity and emotion may also guide what older adults remember, such that selective remembering can be an adaptive way to use memory efficiently in older age.

Goal-directed remembering in older adults

Compared to younger adults, older adults show a reduced difference in memory between items they are directed to remember and items they are directed to forget. This effect may result from increased processing of goal-irrelevant information in aging. In contrast, healthy older adults are often able to selectively remember valuable information, suggesting preservation of goal-directed encoding in aging. Here, we examined how value may differentially affect directed-forgetting and memory for irrelevant details for younger and older adults in a value-directed remembering task. In Experiment 1, participants studied words paired with a directed-forgetting cue and a point-value they earned for later recognition. Participants' memory was then tested, either after an 8-min or 24-hr retention interval. In Experiment 2 words were presented in two colors and the recognition test assessed whether the participant could retrieve the incidentally-presented point value and the color of each recognized words. In both experiments, older and younger adults displayed a comparable ability to selectively encode valuable items. However, older adults showed a reduced directed-forgetting effect compared to younger adults that was maintained across the 24-hr retention interval. In Experiment 2, older adults showed both intact directed-forgetting and similar incidental detail retrieval compared to younger adults. These findings suggest that older adults maintained selectivity to value, demonstrating that aging does not impact the differential encoding of valuable information. Furthermore, younger and older adults may be similarly goal-directed in terms of item features to encode, but that instructions to forget presented items are less effective in older adults.

The interactive effect of external rewards and self-determined choice on memory

Both external motivational incentives (e.g., monetary reward) and internal motivational incentives (e.g., self-determined choice) have been found to promote memory, but much less is known about how these two types of incentives interact with each other to affect memory. The current study (N = 108) examined how performance-dependent monetary rewards affected the role of self-determined choice in memory performance, also known as the choice effect. Using a modified and better controlled version of the choice paradigm and manipulating levels of reward, we demonstrated an interactive effect between monetary reward and self-determined choice on 1-day delayed memory performance. Specifically, the choice effect on memory decreased when we introduced the performance-dependent external rewards. These results are discussed in terms of understanding how external and internal motivators interact to impact learning and memory.

Does point value structure influence measures of memory selectivity?

ABSTRACTIn reward-based learning and value-directed remembering, many different value structures for the to-be-remembered information have been used by researchers. I was interested in whether different scoring structures used in a value-directed remembering task impact measures of memory selectivity. Participants studied lists of words paired with point values and some lists included words paired with values ranging from 1 to 20, 1 to 10 (repeating twice), either a high value (10 points) or a low value (1 point), and either a high value (10 points), a medium value (5 points) or a low value (1 point). Results suggest that (1) in tests of free recall, if using a continuous value scale, the range of values matters in terms of selective memory, (2) analysing the selectivity index can yield different results than modelling item-level recall using point values (and the latter may be a preferable approach), (3) measures of selectivity using different value structures may lack construct validity when testing memory via recognition tests, and (4) the effect of value on memory is much larger on recall than recognition tests. Thus, I suggest that researchers carefully consider and justify the value structure used when examining selective memory for valuable information in list learning tasks.

Reward network dysfunction is associated with cognitive impairment after stroke

Stroke survivors not only suffer from severe motor, speech and neurocognitive deficits, but in many cases also from a "lack of pleasure" and a reduced motivational level. Especially apathy and anhedonic symptoms can be linked to a dysfunction of the reward system. Rewards are considered as important co-factor for learning, so the question arises as to why and how this affects the rehabilitation of stroke patients. We investigated reward behaviour, learning ability and brain network connectivity in acute (3-7d) mild to moderate stroke patients (n = 28) and age-matched healthy controls (n = 26). Reward system activity was assessed using the Monetary Incentive Delay task (MID) during magnetoencephalography (MEG). Coherence analyses were used to demonstrate reward effects on brain functional network connectivity. The MID-task showed that stroke survivors had lower reward sensitivity and required greater monetary incentives to improve performance and showed deficits in learning improvement. MEG-analyses showed a reduced network connectivity in frontal and temporoparietal regions. All three effects (reduced reward sensitivity, reduced learning ability and altered cerebral connectivity) were found to be closely related and differed strongly from the healthy group. Our results reinforce the notion that acute stroke induces reward network dysfunction, leading to functional impairment of behavioural systems. These findings are representative of a general pattern in mild strokes and are independent of the specific lesion localisation. For stroke rehabilitation, these results represent an important point to identify the reduced learning capacity after stroke and to implement individualised recovery exercises accordingly.

Establishing a causal role for left ventrolateral prefrontal cortex in value-directed memory encoding with high-definition transcranial direct current stimulation

One critical approach for promoting the efficiency of memory is to adopt selective encoding strategies to prioritize more valuable information. Past neuroimaging studies have shown that value-directed modulation of verbal memory depends heavily on the engagement of left-lateralized semantic processing regions, particularly in the ventrolateral prefrontal cortex (VLPFC). In the present study, we used high-definition transcranial direct current stimulation (HD-tDCS) to seek evidence for a causal role of left VLPFC in supporting the memory advantage for high-value items. Three groups of healthy young adult participants were presented with lists of words to remember, with each word accompanied by an arbitrarily assigned point value. During the first session, all participants received sham stimulation as they encoded five lists of 30 words each. Two of these lists were immediately tested with free recall, with feedback given to allow participants to develop metacognitive insight and strategies to maximize their point total. The second session had the exact same structure as the first, but the groups differed in whether they received continued sham stimulation (N = 22) or anodal stimulation of the left VLPFC (N = 21) or right VLPFC (N = 20). Those lists not tested with immediate recall were tested with recognition judgments after a one-day delay. Since no brain stimulation was applied during this Day 2 test, any performance differences can be attributed to the effects of stimulation on Day 1 encoding processes. Anodal stimulation of left VLPFC significantly boosted participants' memory encoding selectivity. In comparison, no such effect was seen in participants who received right VLPFC or sham stimulation. Estimates of recollection- and familiarity-based responding revealed that left VLPFC stimulation specifically amplified the effects of item value on recollection. These results demonstrate a causal role for left VLPFC in the implementation of selective value-directed encoding strategies, putatively by boosting deep semantic processing of high-value words. Our findings also provide further evidence on the hemispheric lateralization of value-directed verbal memory encoding.

Value-directed memory selectivity relies on goal-directed knowledge of value structure prior to encoding in young and older adults

People are generally able to selectively attend and remember high-value over low-value information. Here, we investigated whether young and older adults would display typical value-based memory selectivity effects for to-be-learned item-value associations when goal-directed information about the meaning of associated values was presented before and after encoding. In two experiments, both young and older adults were presented with one (Experiment 1) or multiple (Experiment 2) lists of words that were arbitrarily paired with different numerical values (e.g., "door-8") or font colors (e.g., "door" presented in red), which indicated each word's value. In Experiment 1, participants were told that the numerical value indicated the relative importance of each item either before they studied the list (preencoding), after they studied it (postencoding), or not at all (no value control instructions). Older adults were significantly more selective in the preencoding condition relative to the other conditions, whereas younger adults were not selective in any condition on this single-list (numerical) value task of Experiment 1. In Experiment 2, young and older adults were tested on four additional lists of both pre- and postencoding trials each after studying and recalling four lists of words without any value instructions. Results from Experiment 2 revealed that both young and older adults selectively prioritized high-value words on the preencoding trials, but not on postencoding trials, on this color-based categorical (low-medium-high) value task. The present study highlights a critical role of goal-directed knowledge of value-based instructions prior to encoding to facilitate typically observed value-directed memory selectivity for important information. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Effect of retrieval reward on episodic recognition with different difficulty: ERP evidence

Previous studies found that the reward effect is stronger in more difficult retrieval tasks of item memory. However, it remains unclear whether the effect of reward is influenced by the memory task difficulty level in the source memory. We investigated the effects and neural mechanisms of the processing depth during encoding and rewards at retrieval on the item and source memory using event-related potentials (ERPs). Participants were required to carry out the congruity-judgment (deep processing) and size-judgment (shallow processing) tasks during encoding, and they completed separate object and background tests (half presented with reward) immediately after encoding. The results revealed that congruity-judgment (compare to size-judgment) task had longer response time in encoding phase, and evoked significantly greater reward differences at Prs (the hit rate minus the false alarm rate) in item retrieval, and the reward (relative to no reward) significantly improved recognition accuracy in source retrieval. ERP results also showed that congruity-judgment (compare to size-judgment) task evoked the larger N170, P3a, LPP and a decreased P3b of the stimuli in encoding phase, and elicited the wider distribution of LPC and LPN reward effects (i.e., the average amplitudes under the reward condition were significantly more positive than under the non-reward condition) in item retrieval, and the reward effects at FN400, LPC, and LPN were found only in the congruity-judged items with optimal difficulty in source retrieval. The results suggest that reward at retrieval evoked a greater boost in the congruity-judged stimuli, whether in item or source retrieval, which maybe be related to their optimal retrieval difficulty (Pr is closer to medium 0.50). This meant that the reward is more effective in memory retrieval with optimal difficulty.

Value-directed remembering in first-episode schizophrenia

OBJECTIVE

Memory deficits in individuals with schizophrenia are well-established, but less is known about how schizophrenia affects metacognitive processes such as metamemory. We investigated metamemory ability using the value-directed remembering task, which assesses the degree to which participants use value cues to guide their learning of a list of items (i.e., their memory selectivity).

METHOD

Participants were patients undergoing treatment following a recent first episode of schizophrenia (n = 20) and demographically comparable healthy controls (n = 18). Participants viewed six lists of 24 words where each word was paired with either a low value (1-3 points) or a high value (10-12 points), and they were instructed to maximize their score on free recall tests given after each list. After the final free recall test, participants completed a recognition test where they gave remember/know judgments.

RESULTS

On tests of free recall, patients showed reduced memory selectivity relative to healthy controls. On the recognition test, patients failed to show an effect of value on recognition of nonrecalled words, in contrast to healthy controls, who showed a significant value effect that was characterized by greater "remember" judgments. Patients initially overestimated their memory capacity but were able to adjust their estimates to be more accurate based on task experience. Patients' self-reports of memory selectivity were unrelated to their actual memory selectivity.

CONCLUSIONS

Patients with first-episode schizophrenia had substantial impairments on the value-directed remembering task, but areas of preserved metamemory ability were also observed. These findings have potential implications for cognitive training interventions. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

Still Wanting to Win: Reward System Stability in Healthy Aging

Healthy aging is accompanied by multi-faceted changes. Especially within the brain, healthy aging exerts substantial impetus on core parts of cognitive and motivational networks. Rewards comprise basic needs, such as food, sleep, and social contact. Thus, a functionally intact reward system remains indispensable for elderly people to cope with everyday life and adapt to their changing environment. Research shows that reward system function is better preserved in the elderly than most cognitive functions. To investigate the compensatory mechanisms providing reward system stability in aging, we employed a well-established reward paradigm (Monetary Incentive Delay Task) in groups of young and old participants while undergoing EEG measurement. As a new approach, we applied EEG connectivity analyses to assess cortical reward-related network connectivity. At the behavioral level, our results confirm that the function of the reward system is preserved in old age. The mechanisms identified for maintaining reward system function in old age do not fit into previously described models of cognitive aging. Overall, older adults exhibit lower reward-related connectivity modulation, higher reliance on posterior and right-lateralized brain areas than younger adults, and connectivity modulation in the opposite direction than younger adults, with usually greater connectivity during non-reward compared to reward conditions. We believe that the reward system has unique compensatory mechanisms distinct from other cognitive functions, probably due to its etymologically very early origin. In summary, this study provides important new insights into cortical reward network connectivity in healthy aging.

Encoding tasks moderated the reward effect on brain activity during memory retrieval

Previous studies have explored the effects of retrieval reward and depth of processing in encoding on recognition, but it remains unclear whether and how reward and depth of processing during encoding influence recognition. We investigated the effect and neural mechanisms of encoding reward and processing depth on recognition using event-related potentials (ERPs) in this study. In the study phase, participants were asked to perform two encoding tasks: congruity-judgment (deep processing) and size-judgment (shallow processing) in reward and no-reward conditions. The test phases included object (item) and background (source) tests. The results of item retrieval showed that the accuracy of rewarded items was higher than that of unrewarded items only in the congruity-judgment task, and the reward effect (the average amplitudes in the reward condition were significantly more positive than those in the no-reward condition) in the 300–500 and 500–700 ms were greater in the congruity-judgment task than in the size-judgment task. The results of source retrieval showed that the accuracy of rewarded items was higher than that of unrewarded items, that the difference in the size-judgment task was significantly larger, and that the reward effect in the 300–500 and 500–700 ms were greater in the size-judgment task than in the congruity-judgment task. In conclusion, the encoding task moderated the reward effect in item and source memory.

Disrupted Value-Directed Strategic Processing in Individuals with Mild Cognitive Impairment: Behavioral and Neural Correlates

Value-directed strategic processing involves attending to higher-value information while inhibiting lower-value information. This preferential processing is relatively preserved in cognitively normal older adults but is impaired in individuals with dementia. No studies have investigated whether value-directed strategic processing is disrupted in earlier stages of cognitive decline, namely, mild cognitive impairment (MCI). The current study examined behavioral and EEG differences in value-directed strategic processing between 18 individuals with MCI and 18 cognitively normal older controls using a value-directed list learning task. Behaviorally, individuals with MCI recalled fewer total and high-value words compared to controls, but no group differences were observed in low-value word recall. Neurally, individuals with MCI had reduced theta synchronization relative to controls between 100 and 200 ms post-stimulus. Greater alpha desynchronization was observed for high- versus low-value words between 300 and 400 ms in controls but not in the MCI group. The groups showed some processing similarities, with greater theta synchronization for low-value words between 700 and 800 ms and greater alpha desynchronization for high-value words between 500 and 1100 ms. Overall, value-directed strategic processing was compromised in individuals with MCI on both behavioral and neural measures relative to controls. These findings add to the growing body of literature on differences between typical cognitive aging and MCI.

The effect of external store reliance on actual and predicted value-directed remembering

We often rely on external devices to store to-be-remembered information in our everyday lives (e.g., writing grocery lists, setting reminders), yet there is limited research about how certain information (i.e., valuable information) may be differentially encoded when we rely on our internal memory versus an external store. Across three preregistered experiments, we examined the effect of relying on an external store on the recall of high-value and low-value information. In Experiments 1a and 1b, we presented participants with words associated with point values and examined mean recall performance during two critical trials in which the external store was not available: (1) a trial in which participants were told that they would have access to an external memory store at test (told-external-store) and (2) a trial in which participants were told that they would not have access to their external store at test (told-no-external-store). In Experiment 2, we explored participants' metacognitive predictions of performance on the recall test. Critically, across all of the experiments, we found that the value effect (i.e., better recall for valuable information) was significantly reduced when individuals were told that they could rely on an external store. The same pattern was present in participant's metacognitive judgements. Together, these results suggest that when relying on external stores, individuals forgo (to some extent, at least) selective encoding by value and that individuals might be aware of this change in strategy.

Selective memory disrupted in intra-modal dual-task encoding conditions

Given natural memory limitations, people can generally attend to and remember high-value over low-value information even when cognitive resources are depleted in older age and under divided attention during encoding, representing an important form of cognitive control. In the current study, we examined whether tasks requiring overlapping processing resources may impair the ability to selectively encode information in dual-task conditions. Participants in the divided-attention conditions of Experiment 1 completed auditory tone-distractor tasks that required them to discriminate between tones of different pitches (audio-nonspatial) or auditory channels (audio-spatial), while studying items in different locations in a grid (visual-spatial) differing in reward value. Results indicated that, while reducing overall memory accuracy, neither cross-modal auditory distractor task influenced participants' ability to selectively encode high-value items relative to a full attention condition, suggesting maintained cognitive control. Participants in Experiment 2 studied the same important visual-spatial information while completing demanding color (visual-nonspatial) or pattern (visual-spatial) discrimination tasks during study. While the cross-modal visual-nonspatial task did not influence memory selectivity, the intra-modal visual-spatial secondary task eliminated participants' sensitivity to item value. These results add novel evidence of conditions of impaired cognitive control, suggesting that the effectiveness of top-down, selective encoding processes is attenuated when concurrent tasks rely on overlapping processing resources.

Memory and Reward-Based Learning: A Value-Directed Remembering Perspective

The ability to prioritize valuable information is critical for the efficient use of memory in daily life. When information is important, we engage more effective encoding mechanisms that can better support retrieval. Here, we describe a dual-mechanism framework of value-directed remembering in which both strategic and automatic processes lead to differential encoding of valuable information. Strategic processes rely on metacognitive awareness of effective deep encoding strategies that allow younger and healthy older adults to selectively remember important information. In contrast, some high-value information may also be encoded automatically in the absence of intention to remember, but this may be more impaired in older age. These different mechanisms are subserved by different neural substrates, with left-hemisphere semantic processing regions active during the strategic encoding of high-value items, and automatic enhancement of encoding of high-value items may be supported by activation of midbrain dopaminergic projections to the hippocampal region. Expected final online publication date for the Annual Review of Psychology, Volume 73 is January 2022. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

Developmental change in prefrontal cortex recruitment supports the emergence of value-guided memory

Prioritizing memory for valuable information can promote adaptive behavior across the lifespan, but it is unclear how the neurocognitive mechanisms that enable the selective acquisition of useful knowledge develop. Here, using a novel task coupled with functional magnetic resonance imaging, we examined how children, adolescents, and adults (N = 90) learn from experience what information is likely to be rewarding, and modulate encoding and retrieval processes accordingly. We found that the ability to use learned value signals to selectively enhance memory for useful information strengthened throughout childhood and into adolescence. Encoding and retrieval of high- vs. low-value information was associated with increased activation in striatal and prefrontal regions implicated in value processing and cognitive control. Age-related increases in value-based lateral prefrontal cortex modulation mediated the relation between age and memory selectivity. Our findings demonstrate that developmental increases in the strategic engagement of the prefrontal cortex support the emergence of adaptive memory.

Value-directed memory effects on item and context memory

The ability to prioritize learning some information over others when that information is considered important or valuable is known as value-directed remembering. In these experiments, we investigate how value influences different aspects of memory, including item memory (memory for the to-be-learned materials) and context memory (memory for peripheral details that occurred when studying items) to get a better understanding of how people prioritize learning information. In this investigation, participants encoded words associated with a range of values (binned into higher, medium, and lower value in Experiment 1, and into higher and lower value in Experiment 2) for a subsequent memory test that measured item memory (Is this item old or new?) as well as both objective context memory (memory for an objectively verifiable contextual detail: In which voice was this item spoken?) and subjective context memory (How many visual, auditory, and extraneous thoughts/feelings can you remember associated with this item?). Results indicated that value influenced item memory but had no effect on objective context memory in both Experiments. In Experiment 2, results showed better subjective context memory for multiple episodic details for higher-value relative to lower-value materials. Overall, these findings suggest that value has a strong influence over some aspects of memory, but not others. This work gives a richer understanding of how people prioritize learning more important over less important information.

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.

The influence of rewards on incidental memory: more does not mean better

Studies have revealed that rewards promote long-term memory, even in an incidental way. However, most previous studies using the incidental paradigm have included two reward levels, and it is still not clear how the reward magnitude influences memory. Adopting the incidental paradigm and three reward levels, the current study revealed that the reward magnitude impacted 1-d delayed episodic memory in a nonlinear, inverted U-shaped pattern. An additional experiment showed that there was no reward effect in immediate episodic memory. Our results support the dopaminergic memory consolidation theory and further imply that the reward magnitude needs to be considered in the theory.

Reward motivation influences response bias on a recognition memory task

Reward-motivated memory has been studied extensively in psychology and neuroscience. Many recognition studies follow the same type of paradigm: stimuli are cued at encoding with high or low reward values which indicate the amount the stimulus is worth if successfully recognized on a subsequent memory test. Each incorrect endorsement of a lure at retrieval is penalized with an arbitrary value between the high and low reward value, resulting in a single false alarm rate. Studies employing this type of paradigm have reported higher hit rates for high value items compared to low value items, but generally hit rate is the only measure of memory that is reported as a function of reward value. It is currently not clear what aspects of the experimental design lead to these memory effects, and other measures, like discriminability and response bias, cannot be properly calculated when there is only a single false alarm rate, but we hypothesize that these are also susceptible to motivational manipulations. To test how reward anticipation might influence memory and response bias in this type of task, we created a novel paradigm that allowed us to calculate both by associating rewards with categories (indoor vs. outdoor scenes), thus calculating separate false alarm rate as well as hit rate at each level of reward. We report results of three experiments that varied rewards and penalties for correct and error responses for the category items. In two experiments, we replicated prior findings of higher hit rates for high compared to low reward items, but consistently across three experiments, when d' was calculated, we found no difference in memory discriminability as a function of reward. Further, Experiment 1 we found that response bias was more conservative for low reward items: participants were more likely to endorse a 'new' response to low compared to high reward items. This effect was significantly reduced in Experiment 2 and eliminated in Experiment 3 when the reward-penalty structure was manipulated to reduce bias. Our findings reveal that reward motivation can influence decisional biases thought to be independent of memory processes. The amount of the reward value for correct responses and the amount of the penalty for incorrect responses should be considered when designing experimental paradigms to study motivation-cognition interactions.

Influence of Reward Motivation on Directed Forgetting in Younger and Older Adults

An important feature of the memory system is the ability to forget, but aging is associated with declines in the ability to intentionally forget potentially due to declines in cognitive control. Despite cognitive deficits, older adults are sensitive to affective manipulations, such as reward motivation, and reward anticipation can improve older adults' memory performance. The goal of the current studies was to examine the effect of reward motivation on directed remembering and forgetting. Participants were healthy CloudResearch/Turk Prime workers aged 18-35 and 60-85. In Experiment 1, we conducted a typical item-method directed forgetting task using neutral words presented one at a time followed by a to-be-remembered (TBR) or to-be-forgotten (TBF) cue. A recognition memory test followed that included all words from the encoding task, as well as new words. We replicated prior findings of better memory for TBR compared to TBF items, but not typical age-related differences in recognition of TBF items. In Experiments 2-4, we repeated this paradigm except that in the second block of trials, each word was presented with a high ($0.75) or low ($0.01) reward cue indicating the value that could be earned if the item was successfully Remembered or Forgotten (depending on cue). During recognition, correct responses to target items (both TBR and TBF) resulted in the associated reward, but incorrect "old" responses resulted in a loss of $0.50. In three experiments, high rewards led to better memory for younger and older adults compared to low rewards, regardless of the directed cue to remember or forget the word. In Experiments 3 and 4, older adults showed typical deficits in directed forgetting, but this was across reward conditions. For older adults, there was no evidence that including reward motivation improved cognitive control abilities as high value reward anticipation did not improve directed forgetting. Instead, in line with hypotheses, high compared to low value reward anticipation leads to engagement of processes that result in better memory regardless of the TBR or TBF cue, and reward anticipation bolsters memory in a relatively automatic, rather than strategic, fashion that overrides one's ability to cognitively control encoding processes.

Losing Money and Motivation: Effects of Loss Incentives on Motivation and Metacognition in Younger and Older Adults

Incentives are usually expected to increase motivation and cognitive control and to thereby improve performance. A small but growing number of studies have begun to investigate whether the effects of incentive on cognitive performance differ for younger vs. older adults. Most have used attention and cognitive control paradigms, trial-wise implementation of incentive condition, and gain incentives (reward), with only a very few investigating the effects of loss incentives. The present study takes a complementary approach: We tested younger and older adults in a working memory paradigm with loss incentives implemented session-wide (between subjects). We also included self-report measures to ask how loss incentive affected participants’ perceptions of the mental demand of the task, as well as their perceived effort, frustration, motivation, distraction, and metacognitive judgments of how well they had performed. This allowed us to test the disparate predictions of different theoretical views: the intuitive hypothesis that incentive should increase motivation and performance, the motivational shift proposal that older adults are especially motivated to avoid losses (Freund and Ebner, 2005), a heuristic “positivity effect” perspective that older adults ignore losses (Brassen et al., 2012; Williams et al., 2017), and a more nuanced view that suggests that when negative information is unavoidable and increases perceived costs, older adults may instead disengage from the situation (Charles, 2010; Hess, 2014). The results seemed most consistent with the more nuanced view of the positivity effect. While neither group showed incentive-related performance differences, both younger and older adults reported greater perceived demand and frustration under loss incentive, especially in the most challenging conditions. Loss incentive increased the accuracy of immediate metacognitive judgments, but reduced the accuracy of later, more global judgments of competency for older adults. Self-report measures suggested that the loss incentive manipulation was distracting to young adults and demotivating for older adults. The results suggest a need for caution in generalizing from existing studies to everyday life, and that additional studies parameterizing critical aspects of task design and incentive manipulation are needed to fully understand how incentives affect cognition and motivation in younger and older adults.

Investigating EEG theta and alpha oscillations as measures of value-directed strategic processing in cognitively normal younger and older adults

Value-directed strategic processing is an ability that appears to be relatively preserved with aging, but the neurophysiological mechanisms underlying strategic processing in older adults are not well understood. The current study examined age-related spectral power differences in EEG oscillations linked to processing of high-value versus low-value information in a value-directed strategic processing task in 24 younger adults (mean age: 22.4 ± 1.2 years) and 24 older adults (mean age: 63.2 ± 6.4 years). Both groups exhibited comparable strategic processing ability behaviorally with preferential recall of high- compared to low-value words. Both groups exhibited comparable theta band power with greater synchronization for low- compared to high-value words, but age-related differences in processing were noted in alpha band power. Older adults showed more prolonged alpha desynchronization for high- compared to low-value words relative to younger adults. This neurophysiological modulation in the alpha band in older adults might reflect a compensatory neural mechanism or increased effort linked to selective engagement of neural resources, allowing them to perform similarly to younger adults behaviorally on a value-directed strategic processing task.

Assessing Relationships Among Impulsive Sensation Seeking, Reward Circuitry Activity, and Risk for Psychopathology: A Functional Magnetic Resonance Imaging Replication and Extension Study

BACKGROUND

High trait impulsive sensation seeking (ISS), the tendency to engage in behavior without forethought and to seek out new or extreme experiences, is a transdiagnostic risk factor for externalizing and mood disorders, particularly bipolar disorder. We published a positive association between trait ISS and reward expectancy-related activity in the left ventrolateral prefrontal cortex (L vlPFC) and the ventral striatum. We aimed to replicate this finding and extend it by testing for mediation effects of ISS on relationships between reward expectancy-related activity and measures denoting hypomania.

METHODS

A transdiagnostic sample of 127 adults, 18 to 25 years of age, completed a card-guessing functional magnetic resonance imaging task as well as measures of ISS (inattention, motor impulsivity, fun seeking, positive and negative urgency) and the Moods Spectrum as a measure of hypomania. An original sample of 98 was included for confirmatory and mediation analyses.

RESULTS

We replicated a positive relationship between reward expectancy-related L vlPFC activity and negative urgency, an ISS component (β = .28, t = 2.44, p = .0169). We combined these data with the original sample, confirming this finding (β = .27, t = 2.41, p = .0184). Negative urgency statistically mediated the relationship between reward expectancy-related L vlPFC activity and Moods Spectrum factors associated with hypomania. No other associations between ISS measures and reward expectancy-related activity were replicated.

CONCLUSIONS

We replicated findings showing that reward expectancy-related L vlPFC activity is a biomarker for negative urgency, the tendency to react with frustration during distressing conditions. Negative urgency also statistically mediated the relationship between L vlPFC activity and measures indicative of hypomanic symptoms.

Intact strategic retrieval processes in older adults: no evidence for age-related deficits in source-constrained retrieval

Aging is thought to involve impairments to cognitive control functions that support episodic memory, for example by enabling people to strategically constrain their retrieval search towards a specific context ("source") in order to facilitate retrieval of goal-relevant memories. The "memory-for-foils" paradigm investigates source-constrained retrieval by assessing whether incidental encoding of new foils during an old/new recognition test differs depending on the type of processing that was previously used during study of the old items in the test. If it does, it suggests that people process foils differently as a result of engaging in source-constrained retrieval attempts. Young adults typically show differences in incidental encoding foils, but such differences have not been found in older adults. Here, we compared source-constrained retrieval and reward effects on incidental foil encoding between younger and older adults, to assess if age-related reductions in strategic retrieval processing are accompanied by differences in responsiveness to external rewards. The results showed only minor effects of rewards on memory processing, in younger adults only. Contrary to prior findings, older adults had equivalent overall memory performance and spontaneously constrained retrieval to the same extent as the young group, showing that aging-related impairments to strategic retrieval processes are not inevitable.

Neural correlates underlying the effect of reward value on recognition memory

The prioritized encoding and retrieval of valuable information is an essential aspect of human memory. We used electroencephalography (EEG) to determine which of two hypothesized processes underlies the influence of reward value on episodic memory. One hypothesis is that value engages prefrontal executive control processes, so that valuable stimuli engage an elaborative rehearsal strategy that benefits memory. A second hypothesis is that value acts through the reward-related midbrain dopamine system to modulate synaptic plasticity in hippocampal and cortical efferents, thereby benefiting memory encoding. We used a value-directed recognition memory (VDR) paradigm in which participants encoded words assigned different point values and aimed to maximize the point value of subsequently recognized words. Subjective states of recollection (i.e., “remember”) and familiarity (i.e., “know”) were assessed at retrieval. Words assigned higher values at study were recognized more effectively than words assigned lower values, due to increased “remember” responses but no difference in “know” responses. Greater value was also associated with larger amplitudes of an EEG component at retrieval that indexes recollection (parietal old/new component), but had no relationship with a component that indexes familiarity (FN400 component). During encoding, we assessed a late frontal positivity (frontal slow wave, FSW) that has been related to elaborative rehearsal strategies and an early parietal component (P3) thought to index dopamine driven attention allocation. Our findings indicate that the effect of value on recognition memory is primarily driven by the dopamine-driven reward valuation system (P3) with no discernible effect on rehearsal processes (FSW).

Age-related differences in metacognition for memory capacity and selectivity

Background: We compared two types of metacognitive monitoring in younger and older adults: metacognitive accuracy for their overall memory performance and their ability to selectively remember high-value information. Method: Participants studied words paired with point values and were asked to maximise their point score. In Experiment 1, they predicted how many words they would remember while in Experiment 2, they predicted how many points they would earn. Results: In Experiment 1, while younger adults were accurate in their predictions, older adults were overconfident in the number of words they would recall throughout the task. In Experiment 2, however, both younger and older adults were equally accurate when predicting the amount of points they would earn after some task experience. Conclusions: While younger adults may have higher metacognitive accuracy for their capacity, older adults can accurately assess their ability to selectively remember information, suggesting potentially separate metacognitive mechanisms that are differentially affected by aging.

Theta and alpha band oscillations during value-directed strategic processing

Strategic processing allows for value-based preferential encoding of information. Event-related spectral perturbations can provide insights into neural processes linked to the different aspects of strategic processing. This study examined theta and alpha band power differences linked to processing of high- versus low-value information. Thirty-three young adults (17 F; mean age: 21.2 ± 1.5 years) completed a value-directed word list learning task. The task consisted of five word lists that each contained a unique set of high- and low-value words that were visually presented one at a time and EEG corresponding to these words were examined. To encourage strategic processing, participants were informed that after each list they would be asked to recall as many words as possible with their goal being to maximize their score. Overall, participants recalled more high-value words for each of the five lists as compared to low-value words, which supports that participants engaged in strategic processing. Frontal theta band power showed greater positivity during processing of low- compared to high-value words, whereas parietal alpha band power showed greater negativity during processing of high- compared to low-value words. These findings suggest that theta and alpha bands index different aspects of strategic processing, namely inhibition and selective attention, and have future applications for understanding the effects of aging and brain diseases/disorders.

Separate Memory-Enhancing Effects of Reward and Strategic Encoding

Memory encoding for important information can be enhanced both by reward anticipation and by intentional strategies. These effects are hypothesized to depend on distinct neural mechanisms, yet prior work has provided only limited evidence for their separability. We aimed to determine whether reward-driven and strategic mechanisms for prioritizing important information are separable, even if they may also interact. We examined the joint operation of both mechanisms using fMRI measures of brain activity. Participants learned abstract visual images in a value-directed recognition paradigm. On each trial, two novel images were presented simultaneously in different screen quadrants, one arbitrarily designated as high point value and one as low value. Immediately after each block of 16 study trials, the corresponding point rewards could be obtained in a test of item recognition and spatial location memory. During encoding trials leading to successful subsequent memory, especially of high-value images, increased activity was observed in dorsal frontoparietal and lateral occipitotemporal cortex. Furthermore, activity in a network associated with reward was higher during encoding when any image, of high or low value, was subsequently remembered. Functional connectivity between right medial temporal lobe and right ventral tegmental area, measured via psychophysiological interaction, was also greater during successful encoding regardless of value. Strategic control of memory, as indexed by successful prioritization of the high-value image, affected activity in dorsal posterior parietal cortex as well as connectivity between this area and right lateral temporal cortex. These results demonstrate that memory can be strengthened by separate neurocognitive mechanisms for strategic control versus reward-based enhancement of processing.

White matter integrity in brain structures supporting semantic processing is associated with value-directed remembering in older adults

White matter microstructure changes substantially in aging. To better understand how the integrity of white matter structures supports the selective learning of rewarding material, 23 healthy older adults were tested on a value-directed remembering task. This task involved successive free recall word lists where items differed in importance, as denoted by value cues preceding each word. White matter structure was measured using diffusion tensor imaging (DTI). We found that greater structural integrity (as measured by lower mean diffusivity) in left inferior fronto-occipital fasciculus was associated with greater recall for high-value items, but not low-value items. Older adults with greater structural integrity in a tract involved in semantic processing are thus able to more successfully encode high-value items for subsequent recall. However, unlike prior findings in younger adults, older adults' memory for high value-items was not significantly correlated with the structural integrity of the uncinate fasciculus, nor with the strength of anatomical connectedness between the bilateral nucleus accumbens to ventral tegmental area reward pathway. These structural imaging findings add support to recent functional neuroimaging demonstrations that value-related modulation of memory in older adults depends heavily on brain circuits implicated in controlled processing of semantic knowledge.

Divided Attention Selectively Impairs Value-Directed Encoding

In the present study, we examined the effect of value-directed encoding on recognition memory and how various divided attention tasks at encoding alter value-directed remembering. In the first experiment, participants encoded words that were assigned either high or low point values in multiple study-test phases. The points corresponded to the value the participants could earn by successfully recognizing the words in an upcoming recognition memory task. Importantly, participants were instructed that their goal was to maximize their score in this memory task. The second experiment was modified such that while studying the words participants simultaneously completed a divided attention task (either articulatory suppression or random number generation). The third experiment used a non-verbal tone detection divided attention task (easy or difficult versions). Subjective states of recollection (i.e., “Remember”) and familiarity (i.e., “Know”) were assessed at retrieval in all experiments. In Experiment 1, high value words were recognized more effectively than low value words, and this difference was primarily driven by increases in “Remember” responses with no difference in “Know” responses. In Experiment 2, the pattern of subjective judgment results from the articulatory suppression condition replicated Experiment 1. However, in the random number generation condition, the effect of value on recognition memory was lost. This same pattern of results was found in Experiment 3 which implemented a different variant of the divided attention task. Overall, these data suggest that executive processes are used when encoding valuable information and that value-directed improvements to memory are not merely the result of differential rehearsal.

Memory Recall for High Reward Value Items Correlates With Individual Differences in White Matter Pathways Associated With Reward Processing and Fronto-Temporal Communication

When given a long list of items to remember, people typically prioritize the memorization of the most valuable items. Prior neuroimaging studies have found that cues denoting the presence of high value items can lead to increased activation of the mesolimbic dopaminergic reward circuit, including the nucleus accumbens (NAcc) and ventral tegmental area (VTA), which in turn results in up-regulation of medial temporal lobe encoding processes and better memory for the high value items. Value cues may also trigger the use of elaborative semantic encoding strategies which depend on interactions between frontal and temporal lobe structures. We used diffusion tensor imaging (DTI) to examine whether individual differences in anatomical connectivity within these circuits are associated with value-induced modulation of memory. DTI data were collected from 19 adults who also participated in an functional magnetic resonanceimaging (fMRI) study involving a value-directed memory task. In this task, subjects encoded words with arbitrarily assigned point values and completed free recall tests after each list, showing improved recall performance for high value items. Motivated by our prior fMRI finding of increased recruitment of left-lateralized semantic network regions during the encoding of high value words (Cohen et al., 2014), we predicted that the robustness of the white matter pathways connecting the ventrolateral prefrontal cortex (VLPFC) with the temporal lobe might be a determinant of recall performance for high value items. We found that the mean fractional anisotropy (FA) of each subject’s left uncinate fasciculus (UF), a fronto-temporal fiber bundle thought to play a critical role in semantic processing, correlated with the mean number of high value, but not low value, words that subjects recalled. Given prior findings on reward-induced modulation of memory, we also used probabilistic tractography to examine the white matter pathway that links the NAcc to the VTA. We found that the number of fibers projecting from left NAcc to VTA was reliably correlated with subjects’ selectivity index, a behavioral measure reflecting the degree to which recall performance was impacted by item value. Together, these findings help to elucidate the neuroanatomical pathways that support verbal memory encoding and its modulation by value.

Narrative Discourse in Young and Older Adults: Behavioral and NIRS Analyses

Discourse comprehension is at the core of communication capabilities, making it an important component of elderly populations' quality of life. The aim of this study is to evaluate changes in discourse comprehension and the underlying brain activity. Thirty-six participants read short stories and answered related probes in three conditions: micropropositions, macropropositions and situation models. Using near-infrared spectroscopy (NIRS), the variation in oxyhemoglobin (HbO₂) and deoxyhemoglobin (HbR) concentrations was assessed throughout the task. The results revealed that the older adults performed with equivalent accuracy to the young ones at the macroproposition level of discourse comprehension, but were less accurate at the microproposition and situation model levels. Similar to what is described in the compensation-related utilization of neural circuits hypothesis (CRUNCH) model, older participants tended to have greater activation in the left dorsolateral prefrontal cortex while reading in all conditions. Although it did not enable them to perform similarly to younger participants in all conditions, this over-activation could be interpreted as a compensation mechanism.

The effects of value on context-item associative memory in younger and older adults

Valuable items are often remembered better than items that are less valuable by both older and younger adults, but older adults typically show deficits in binding. Here, we examine whether value affects the quality of recognition memory and the binding of incidental details to valuable items. In Experiment 1, participants learned English words each associated with a point-value they earned for correct recognition with the goal of maximizing their score. In Experiment 2, value was manipulated by presenting items that were either congruent or incongruent with an imagined state of physiological need (e.g., hunger). In Experiment 1, point-value was associated with enhanced recollection in both age groups. Memory for the color associated with the word was in fact reduced for high-value recollected items compared with low-value recollected items, suggesting value selectively enhances binding of task-relevant details. In Experiment 2, memory for learned images was enhanced by value in both age groups. However, value differentially enhanced binding of an imagined context to the item in younger and older adults, with a strong trend for increased binding in younger adults only. These findings suggest that value enhances episodic encoding in both older and younger adults but that binding of associated details may be reduced for valuable items compared to less valuable items, particularly in older adults. (PsycINFO Database Record

Strategic value-directed learning and memory in Alzheimer's disease and behavioural-variant frontotemporal dementia

In healthy adults, the ability to prioritize learning of highly valued information is supported by executive functions and enhances subsequent memory retrieval for this information. In Alzheimer's disease (AD) and behavioural-variant frontotemporal dementia (bvFTD), marked deficits are evident in learning and memory, presenting in the context of executive dysfunction. It is unclear whether these patients show a typical memory bias for higher valued stimuli. We administered a value-directed word-list learning task to AD (n = 10) and bvFTD (n = 21) patients and age-matched healthy controls (n = 22). Each word was assigned a low, medium or high point value, and participants were instructed to maximize the number of points earned across three learning trials. Participants' memory for the words was assessed on a delayed recall trial, followed by a recognition test for the words and corresponding point values. Relative to controls, both patient groups showed poorer overall learning, delayed recall and recognition. Despite these impairments, patients with AD preferentially recalled high-value words on learning trials and showed significant value-directed enhancement of recognition memory for the words and points. Conversely, bvFTD patients did not prioritize recall of high-value words during learning trials, and this reduced selectivity was related to inhibitory dysfunction. Nonetheless, bvFTD patients showed value-directed enhancement of recognition memory for the point values, suggesting a mismatch between memory of high-value information and the ability to apply this in a motivationally salient context. Our findings demonstrate that value-directed enhancement of memory may persist to some degree in patients with dementia, despite pronounced deficits in learning and memory.

Human aging reduces the neurobehavioral influence of motivation on episodic memory

The neural circuitry mediating the influence of motivation on long-term declarative or episodic memory formation is delineated in young adults, but its status is unknown in healthy aging. We examined the effect of reward and punishment anticipation on intentional declarative memory formation for words using an event-related functional magnetic resonance imaging (fMRI) monetary incentive encoding task in twenty-one younger and nineteen older adults. At 24-hour memory retrieval testing, younger adults were significantly more likely to remember words associated with motivational cues than neutral cues. Motivational enhancement of memory in younger adults occurred only for recollection ("remember" responses) and not for familiarity ("familiar" responses). Older adults had overall diminished memory and did not show memory gains in association with motivational cues. Memory encoding associated with monetary rewards or punishments activated motivational (substantia nigra/ventral tegmental area) and memory-related (hippocampus) brain regions in younger, but not older, adults during the target word periods. In contrast, older and younger adults showed similar activation of these brain regions during the anticipatory motivational cue interval. In a separate monetary incentive delay task that did not require learning, we found evidence for relatively preserved striatal reward anticipation in older adults. This supports a potential dissociation between incidental and intentional motivational processes in healthy aging. The finding that motivation to obtain rewards and avoid punishments had reduced behavioral and neural influence on intentional episodic memory formation in older compared to younger adults is relevant to life-span theories of cognitive aging including the dopaminergic vulnerability hypothesis.

Adaptive scaling of reward in episodic memory: a replication study

Reward is thought to enhance episodic memory formation via dopaminergic consolidation. Bunzeck, Dayan, Dolan, and Duzel [(2010). A common mechanism for adaptive scaling of reward and novelty. Human Brain Mapping, 31, 1380–1394] provided functional magnetic resonance imaging (fMRI) and behavioural evidence that reward and episodic memory systems are sensitive to the contextual value of a reward—whether it is relatively higher or lower—as opposed to absolute value or prediction error. We carried out a direct replication of their behavioural study and did not replicate their finding that memory performance associated with reward follows this pattern of adaptive scaling. An effect of reward outcome was in the opposite direction to that in the original study, with lower reward outcomes leading to better memory than higher outcomes. There was a marginal effect of reward context, suggesting that expected value affected memory performance. We discuss the robustness of the reward memory relationship to variations in reward context, and whether other reward-related factors have a more reliable influence on episodic memory.

Explaining the forgetting bias effect on value judgments: The influence of memory for a past test

People often feel that information that was forgotten is less important than remembered information. Prior work has shown that participants assign higher importance to remembered information while undervaluing forgotten information. The current study examined two possible accounts of this finding. In three experiments, participants studied lists of words in which each word was randomly assigned a point value denoting the value of remembering the word. Following the presentation of each list participants engaged in a free recall test. After the presentation of all lists participants were shown each of the words they had studied and asked to recall the point value that was initially paired with each word. Experiment 1 tested a fluency-based account by presenting items for value judgments in a low-fluency or high-fluency format. Experiment 2 examined whether value judgments reflect attributions based on the familiarity of an item when value judgments are made. Finally, in Experiment 3, we evaluated whether participants believe that forgotten words are less important by having them judge whether an item was initially recalled or forgotten prior to making a value judgment. Manipulating the fluency of an item presented for judgment had no influence on value ratings (Experiment 1) and familiarity exerted a limited influence on value judgments (Experiment 2). More importantly, participants' value judgments appeared to reflect a theory that remembered information is more valuable than forgotten information (Experiment 3). Overall, the present work suggests that individuals may apply a theory about remembering and forgetting to retrospectively assess the value of information.

Test expectancy and memory for important information

Prior research suggests that learners study and remember information differently depending upon the type of test they expect to later receive. The current experiments investigate how testing expectations impact the study of and memory for valuable information. Participants studied lists of words ranging in value from 1 to 10 points with the goal being to maximize their score on a later memory test. Half of the participants were told to expect a recognition test after each list, whereas the other half were told to expect a recall test. After several lists of receiving tests congruent with expectations, participants studying for a recognition test instead received an unexpected recall test. In Experiment 1, participants who had studied for a recognition test recalled less of the valuable information than participants anticipating the recall format. These participants continued to attend less to item value on future (expected) recall tests than participants who had only ever experienced recall testing. When the recognition tests were made more demanding in Experiment 2, value-based recall improved relative to Experiment 1: though memory for the valuable information remained superior when participants studied with the expectation of having to recall the information, there were no longer significant differences after accounting for recall testing experience. Thus, recall-based testing encouraged strategic, value-based encoding and enhanced retrieval of important information, whereas recognition testing in some cases limited value-based study and memory. These results extend prior work concerning the impact of testing expectations on memory, offering further insight into how people study important information. (PsycINFO Database Record

Free recall test experience potentiates strategy-driven effects of value on memory

People tend to show better memory for information that is deemed valuable or important. By one mechanism, individuals selectively engage deeper, semantic encoding strategies for high value items (Cohen, Rissman, Suthana, Castel, & Knowlton, 2014). By another mechanism, information paired with value or reward is automatically strengthened in memory via dopaminergic projections from midbrain to hippocampus (Shohamy & Adcock, 2010). We hypothesized that the latter mechanism would primarily enhance recollection-based memory, while the former mechanism would strengthen both recollection and familiarity. We also hypothesized that providing interspersed tests during study is a key to encouraging selective engagement of strategies. To test these hypotheses, we presented participants with sets of words, and each word was associated with a high or low point value. In some experiments, free recall tests were given after each list. In all experiments, a recognition test was administered 5 minutes after the final word list. Process dissociation was accomplished via remember/know judgments at recognition, a recall test probing both item memory and memory for a contextual detail (word plurality), and a task dissociation combining a recognition test for plurality (intended to probe recollection) with a speeded item recognition test (to probe familiarity). When recall tests were administered after study lists, high value strengthened both recollection and familiarity. When memory was not tested after each study list, but rather only at the end, value increased recollection but not familiarity. These dual process dissociations suggest that interspersed recall tests guide learners' use of metacognitive control to selectively apply effective encoding strategies. (PsycINFO Database Record