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

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.

The effect of value on context and target recollection in memory for truth and falsity

Memory for truth and falsity has recently been investigated from the perspective of the dual-recollection theory, showing better context and target recollection for truth than falsity. In this paper, we examine whether these memory effects obtained for true statements are similar to the value effect, whereby true statements are given higher priority in encoding. For this purpose, we implemented value-directed remembering (VDR) into the conjoint-recognition paradigm. In our first experiment, the primary goal was to verify how VDR influences the processes defined by dual-recollection theory. At study, prioritized/important items were linked to higher numerical values (e.g., 10), while unimportant ones had lower values (e.g., 1). At test, the participants' task was to recognize whether a particular sentence was important, unimportant, or new. We found that both context and target recollection were better for important items. In the second experiment, the main goal was to study the combined effects of importance and veracity on memory. In the between-subjects design, participants were monetarily rewarded for memorizing true or false sentences. The results demonstrated differences in the ability to prioritize truth over falsity. Specifically, we found a substantial increase in context recollection for prioritized true information but not for prioritized false information. Moreover, we found higher context recollection for true than false sentences in the true-prioritized condition, but not in the false-prioritized condition. These results indicated that people are able to prioritize true information better than false, and suggested that memory for truth may be a special case of the value effect.

The limited memory of value following value directed encoding

Items associated with higher values during encoding are later recognized and recalled better than are lower valued items. During recall paradigms, these value directed encoding (VDE) effects heavily depend upon learned strategies acquired during repeated testing with earnings feedback. However, because VDE effects also occur in single test recognition designs, precluding such learning, it has been suggested that high value may automatically induce good encoding. We tested this by manipulating encoding instructions (Experiments 1a and 1b) and manipulating concurrent levels of processing (LOP) requirements during encoding (Experiment 2a and 2b). Two main findings emerged. First, subject initiated strategies played a dominant role in VDE effects with little evidence for automaticity. This was demonstrated in Experiment 1 by a more than three-fold increase in the VDE recognition effect when instructions specifically encouraged selective elaboration of high-value items. It was also shown by the complete elimination of VDE recognition effects in Experiment 2 when LOP tasks were concurrently performed during encoding. Critically, the blocking of VDE effects occurred even though a catch trial procedure verified that value was being processed during encoding and remained even when subjects had unlimited time to process the materials during encoding. Second, the data showed, for the first time, that when subjects attempted to specify the value of recognized items, they heavily depended upon a recognition heuristic in which increases in recognition strength, even when nondiagnostic, were inferred to reflect high encoding value. The tendency for subjects to conflate recognition strength and value may have important implications for behavioral economics.

Age-Related Differences in Overcoming Interference When Selectively Remembering Important Information

We examined the effects of interference on value-based memory in younger and older adults by presenting participants with lists of words paired with point values counting toward their score if recalled. In Experiment 1, we created a situation where there was a buildup of interference such that participants could recall words from any studied list to earn points. However, to increase participants' motivation to combat interference, we told participants that if they recalled words from previously studied lists, those words would be worth double the original point value of the word. In Experiment 2, to examine age-related differences in the absence of any interference, participants studied and were tested on the same set of words throughout several study-test cycles. The buildup of interference caused by participants needing to recall both just-studied and previously studied words in Experiment 1 impaired selectivity in older adults relative to younger adults and this effect was particularly pronounced when considering the recall of just prior-list words. However, in the absence of interference, there was not an overall recall deficit or any selectivity impairments in older adults. Thus, proactive and retroactive interference seem to be largely responsible for age-related deficits in selective memory for important information.

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.

Contributions of transient and sustained reward to memory formation

Reward benefits to memory formation have been robustly linked to dopaminergic activity. Despite the established characterization of dopaminergic mechanisms as operating at multiple timescales, potentially supporting distinct functional outcomes, the temporal dynamics by which reward might modulate memory encoding are just beginning to be investigated. In the present study, we leveraged a mixed block/event experimental design to disentangle transient and sustained reward influences on task engagement and subsequent recognition memory in an adapted monetary-incentive-encoding (MIE) paradigm. Across three behavioral experiments, transient and sustained reward modulation of item and context memory was probed, at both 24-h and ~ 15-min retention intervals, to investigate the importance of overnight consolidation. In general, we observed that transient reward was associated with enhanced item memory encoding, while sustained reward modulated response speed but did not appear to benefit subsequent recognition accuracy. Notably, reward effects on item memory performance and response speed were somewhat inconsistent across the three experiments, with suggestions that RT speeding might also be related to time on task, and we did not observe reward modulation of context memory performance or amplification of reward benefits to memory by overnight consolidation. Taken together, the observed pattern of behavior is consistent with potentially distinct roles for transient and sustained reward in memory encoding and cognitive performance and suggests that further investigation of the temporal dynamics of dopaminergic contributions to memory formation will advance the understanding of motivated memory.

Can neural correlates of encoding explain the context dependence of reward-enhanced memory?

Selective encoding can be studied by manipulating how valuable it is for participants to remember specific stimuli, for instance, by varying the monetary reward participants receive for recalling a particular stimulus in a subsequent memory test. It would be reasonable for participants to strategically attend more to high-reward items compared to low-reward items in mixed list contexts, but to attend both types of items equally in pure list contexts, where all items are of equal value. Reward-enhanced memory may be driven by automatic dopaminergic interactions between reward circuitry and the hippocampus and thus be insensitive to list context; or it may be driven by meta-cognitive strategies, and thus context-dependent. We contrasted these alternatives by manipulating list composition and tracked selective encoding through multiple EEG measures of attention and rehearsal. Behavioral results were context-dependent, such that recall of high-reward items was increased only in mixed lists. This result and aspects of the recall dynamics confirm predictions of the eCMR (emotional Context Maintenance and Retrieval) model. The power of ssVEPs was lower for high-reward items regardless of list composition, suggesting decreased visual processing of high-reward stimuli and that ssVEPs may index the modulation of context-to-item associations predicted by eCMR. By contrast, reward modulated the amplitude of Late Positive Potential and Frontal Slow Wave only in mixed lists. Taken together, the results provide evidence that reward-enhanced memory is caused by an interplay between strategic processes applied when high- and low-reward items compete for cognitive resources during encoding and context-dependent mechanisms operating during recall.

Instructed motivational states bias reinforcement learning and memory formation

Motivation influences goals, decisions, and memory formation. Imperative motivation links urgent goals to actions, narrowing the focus of attention and memory. Conversely, interrogative motivation integrates goals over time and space, supporting rich memory encoding for flexible future use. We manipulated motivational states via cover stories for a reinforcement learning task: The imperative group imagined executing a museum heist, whereas the interrogative group imagined planning a future heist. Participants repeatedly chose among four doors, representing different museum rooms, to sample trial-unique paintings with variable rewards (later converted to bonus payments). The next day, participants performed a surprise memory test. Crucially, only the cover stories differed between the imperative and interrogative groups; the reinforcement learning task was identical, and all participants had the same expectations about how and when bonus payments would be awarded. In an initial sample and a preregistered replication, we demonstrated that imperative motivation increased exploitation during reinforcement learning. Conversely, interrogative motivation increased directed (but not random) exploration, despite the cost to participants' earnings. At test, the interrogative group was more accurate at recognizing paintings and recalling associated values. In the interrogative group, higher value paintings were more likely to be remembered; imperative motivation disrupted this effect of reward modulating memory. Overall, we demonstrate that a prelearning motivational manipulation can bias learning and memory, bearing implications for education, behavior change, clinical interventions, and communication.

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 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).

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.

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.

Alpha oscillatory power decreases are associated with better memory for higher valued information

Items associated with high value are often better remembered. Value may increase attention toward item in context associations. Alpha oscillations (8-13 Hz) are thought to underlie attention and their observation may reveal the role attention plays in value-based memory. In the current study, EEG is used to record brain activity while participants (n = 30) completed a source recognition memory task where items were associated with either high or low value backgrounds to determine whether greater attentional resources are deployed when encoding high value information. Participants demonstrated better memory for objects associated with high value backgrounds. Alpha oscillatory power in occipital/temporal brain regions exhibited greater desynchronization when encoding objects associated with high value that were later successfully recalled compared to those associated with low value. In addition, beta oscillatory power in midfrontal brain regions exhibited greater desynchronization during successful recall of high value objects compared to low value objects. Together these results suggest that more attentional resources are used to encode information that is associated with high value, which increases the likelihood of later successful memory recall.

The effect of value on long-term associative memory

Items with high value are often remembered better than those with low value. It is not clear, however, whether this value effect extends to the binding of associative details (e.g., word colour) in episodic memory. Here, we explored whether value enhances memory for associative information in two different scenarios that might support a more effective process of binding between identity and colour. Experiment 1 examined incidental binding between item and colour using coloured images of familiar objects, whereas Experiment 2 examined intentional learning of word colour. In both experiments, increasing value led to improvements in memory for both item and colour, and these effects persisted after approximately 24 hr. Experiment 3a and Experiment 3b replicated the value effect on intentional word–colour memory from Experiment 2 while also demonstrating this effect to be less reliable when word colour is incidental to the encoding phase. Thus, value-directed prioritisation can facilitate episodic associative memory when conditions for binding are optimised through the use of appropriate to-be remembered materials and encoding conditions.

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.

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.

Expected Value of Reward Predicts Episodic Memory for Incidentally Learnt Reward-Item Associations

In this paper, we draw connections between reward processing and cognition by behaviourally testing the implications of neurobiological theories of reward processing on memory. Single-cell neurophysiology in non-human primates and imaging work in humans suggests that the dopaminergic reward system responds to different components of reward: expected value; outcome or prediction error; and uncertainty of reward (Schultz et al., 2008). The literature on both incidental and motivated learning has focused on understanding how expected value and outcome—linked to increased activity in the reward system—lead to consolidation-related memory enhancements. In the current study, we additionally investigate the impact of reward uncertainty on human memory. The contribution of reward uncertainty—the spread of the reward probability distribution irrespective of the magnitude—has not been previously examined. To examine the effects of uncertainty on memory, a word-learning task was introduced, along with a surprise delayed recognition memory test. Using Bayesian model selection, we found evidence only for expected value as a predictor of memory performance. Our findings suggest that reward uncertainty does not enhance memory for individual items. This supports emerging evidence that an effect of uncertainty on memory is only observed in high compared to low risk environments.

Words in larger font are perceived as more important: explaining the belief that font size affects memory

Words presented in larger font size are considered more memorable and rated with higher judgments of learning (JOLs). One explanation for this phenomenon is that people believe that font size affects memory. However, it is not clear why people hold this belief. One alternative is that font size represents importance, with larger fonts implying more relevant information. More important information is judged as more memorable and is, in fact, better remembered. In Experiments 1 and 2 we presented words in small (18 points) and extra-large font (250 points) and found higher JOLs and higher judgments of importance with extra-large fonts. A mediation analysis showed that importance accounted for 21-23% of the effect of font size on JOLs. In Experiment 3, we tested whether processing fluency was higher with the extra-large font. In a lexical decision task, participants were slower at detecting words and non-words with extra-large than small font, which is the opposite of what the processing fluency hypothesis predicts. This result shows that the font-size effect persists even in conditions in which perceived fluency should be lower. In sum, this research explained the belief that font size affects memory because words in larger fonts are considered more important.

Memory Beliefs Drive the Memory Bias on Value-based Decisions

For many value-based decisions, people need to retrieve relevant information from their memory. In our previous work, we have shown that memory biases decisions in the sense that better-memorized choice options are preferred, even if these options are comparatively unattractive. However, the cognitive mechanisms that drive this memory bias remain unclear. In the current pre-registered study, we tested the hypothesis that the memory bias arises because people believe they remember better options more often than worse options. Specifically, we predicted a positive correlation between the memory bias on value-based decisions and the belief in value-dependent memory performance. This prediction was confirmed. Additional exploratory analyses revealed that memory performance was indeed higher for more attractive options, indicating that letting decisions be influenced by memory can be an adaptive strategy. However, the memory bias persisted after correcting for this effect, suggesting that it is not simply an artifact of unequal memory performance. Our results highlight a critical influence of beliefs on behavior and add to an emerging understanding of the role of memory in shaping value-based decisions.

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.

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.