Theta and alpha band oscillations during value-directed strategic processing

Perceptual contrast reduces the judgments of learning of small-font words and increases the judgments of learning of large-font words compared with the no-contrast conditions

The font-size effect on judgments of learning (JOLs) refers to large-font words being rated as more memorable than small ones when required to predict memory performance during the study phase. This study examines perceptual contrast as the prerequisite for this font-size effect on JOLs and explores how perceptual contrast leads to this effect. In Experiment 1, perceptual contrast was achieved by inserting words with one font (e.g., 18 pt) into a series of words with another font (e.g., 70 pt) at a particular proportion (1:4). In Experiment 2, perceptual contrast was manipulated by presenting two different font words up and down in a pair. The results of both experiments showed that: (1) participants rated higher JOLs for large than small fonts under the contrast conditions, but the JOL difference between the two fonts was not significant under the no-contrast conditions; (2) the JOLs of small-font words under the contrast conditions was reduced compared with the no-contrast conditions, but the JOLs of large-font words under the contrast conditions was increased compared with the no-contrast conditions. These results indicated that perceptual contrast was the prerequisite for the font-size effect on JOLs. The reason for this effect is that, compared to no-contrast conditions, perceptual contrast reduces the JOLs of small-font words while increasing the JOLs of large-font words. This study may deepen researchers' understanding of the mechanism of the font-size effect on JOLs and help educators effectively guide students to learn.

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 perceptual processing fluency and value on metacognition and remembering

Previous research has indicated that perceptual processing fluency significantly affects metacognitive predictions of performance but not learning outcomes. In the present study, we examined the differential impact of perceptual processing fluency and an item's value on metacognition and recall. We presented participants with words visually and audibly, with each word paired with a point value counting towards participants' scores if recalled. The words were either highly perceptually fluent (large font, loud volume) or less perceptually fluent (small font, low volume). Results revealed that both metacognitive monitoring (JOLs) and recall were sensitive to perceptual processing fluency as well as value, but the magnitude of the effect of value was significantly greater than that of font size. Specifically, high-value words were better remembered than low-value words, regardless of fluency, and participants' judgments mapped onto their selectivity for valuable information. Thus, the current study revealed the differential effects of intrinsic and extrinsic cues on metacognitive monitoring and later remembering such that the cues that can influence monitoring in certain encoding conditions become less impactful when pitted against other intrinsic cues in different encoding conditions.

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.

The role of attention and ageing in the retrieval dynamics of value-directed remembering

For memory to be efficient, people need to remember important information. This involves selective encoding and retrieval operations to maximise the recall of valuable information at the expense of less important information. While past research has examined this in terms of strategic encoding operations, we investigated differences in the dynamics of retrieval in value-directed remembering tasks with younger adults under full and divided attention during encoding as well as in older adults. Participants typically initiated recall with the first presented, last presented, or highest valued words and also strategically organised retrieval according to information value such that high-value words tended to be recalled before low-value words. However, the average value of older adults' first recalled word was greater than that of younger adults, likely contributing to their enhanced selectivity. In addition, there were no differences in lag-conditional-response probabilities in younger adults under full or divided attention, but older adults showed impairments in the retrieval of items sharing contextual features with nearby items, while younger adults relied more on temporal-contextual cues to recall words. Together, this study suggests that both strategic encoding and strategic retrieval operations contribute to selectivity for valuable information and older adults may be able to maximise retrieval operations despite displaying impairments in temporal binding during encoding and an overall recall deficit.

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.

Strategic encoding and enhanced memory for positive value-location associations

People often need to remember the location of important objects or events, and also to remember locations that are associated with negative objects. In the current study, we examined how both positive and negative items might be selectively remembered in the visuospatial domain. Participants studied number-items ranging from -25 to +25 indicating point values in a grid display and were instructed to maximize their score (a summation of correctly remembered positive and negative information; incorrectly placed negative items resulted in a subtraction from the overall score). Items were presented in a sequential, simultaneous (Experiment 1), or self-regulated format (Experiment 2) where participants controlled which items to study and the length of study time per item. In Experiment 1, participants selectively recalled high-magnitude over low-magnitude items, but also displayed a positivity preference in memory. In Experiment 2, we were able to determine whether this positivity preference was a result of bottom-up, automatic, or top-down strategic processes. Results indicated that participants explicitly chose to study positive items more frequently and for more total time relative to negative items, suggesting a deliberate strategy to focus on positive information. This bias for highly positive information suggests an overt points-gained approach, as opposed to a loss-aversion approach, to remembering value in the visuospatial domain.

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.

Effects of Traditional vs. iPad-Enhanced Aerobic Exercise on Wayfinding Efficacy and Cognition: A Pilot Randomized Controlled Trial

The purpose of this pilot study was to test the feasibility and efficacy of an iPad-enhanced aerobic exercise intervention designed to enhance wayfinding efficacy and performance and relevant cognitive functioning among middle-aged adults at risk for cognitive impairment. Twenty-seven low active adults (21 females) aged 45 to 62 years (51.22 ± 5.20) participated in a ten-week randomized controlled trial. Participants were randomized to an iPad-enhanced aerobic exercise group (experimental group) or an aerobic exercise-only group (control group) following baseline assessment. Both groups exercised at 50% to 75% of age-predicted heart rate maximum for 30 to 50 min/d, 2 d/wk for 10 weeks. During aerobic exercise, the experimental group engaged in virtual tours delivered via iPad. Baseline and post-intervention assessments of wayfinding self-efficacy, wayfinding task performance, cognitive functioning, electroencephalogram (EEG), and psychosocial questionnaires were administered. The results suggest that ten weeks of iPad-enhanced, moderately intense aerobic exercise had specific effects on wayfinding self-efficacy; however, no statistical differences were found between groups on the behavioral wayfinding task or spatial memory performance at follow-up. Performance scores on an inhibitory attentional-control cognitive assessment revealed significant differences between groups, favoring the experimental group (p < 0.05). Virtual reality-enhanced aerobic exercise may prove to be an effective method for improving cognitive function and increasing confidence to navigate real-world scenarios among individuals at risk of cognitive impairment.