Memory enhancement for emotional words is attributed to both valence and arousal

We do not memorize items in our surroundings with equal priority. Previous literature has widely shown that emotional stimuli are better remembered than neutral stimuli. However, given emotional stimuli and neutral stimuli often differ in both valence and arousal dimensions, it remains unclear whether the enhancement effects can be attributed to valence, or just to arousal. Importantly, most prior studies relied on a relatively small number of stimuli and non-emotional factors such as word length, imageability and other confounds were hard to control. To address these challenges, we analyzed multiple large databases of recognition memory and free recall tasks from previous research by items with many lexical and semantic covariates included, examining the effects of valence or arousal when controlling for each other. Our results showed a U-shaped relationship between valence and memory performance for both recognition and free recall, and a linear relationship between arousal and memory performance for both tasks. These findings showed that the memory enhancement effects can be attributed to both valence and arousal. We demonstrated these effects with generalizability across many stimuli and controlled for non-emotional factors. Together, these findings disentangle the contribution of valence and arousal in emotional memory enhancement effects and provide insights for current major theories of emotional memory.

Motivated with joy or anxiety: Does approach-avoidance goal framing elicit differential reward-network activation in the brain?

Psychological research on human motivation repeatedly observed that approach goals (i.e., goals to attain success) increase task enjoyment and intrinsic motivation more strongly than avoidance goals (i.e., goals to avoid failure). The present study sought to address how the reward network in the brain-including the striatum and ventromedial prefrontal cortex-is involved when individuals engage in the same task with a focus on approach or avoidance goals. Participants reported stronger positive emotions when they focused on approach goals, but stronger anxiety and disappointment when they focused on avoidance goals. The fMRI analyses revealed that the reward network in the brain showed similar levels of activity to cues predictive of approach and avoidance goals. In contrast, the two goal states were associated with different patterns of activity in the visual cortex, hippocampus, and cerebellum during success and failure outcomes. Representation similarity analysis further revealed shared and different representations within the striatum and vmPFC between the approach and avoidance goal states, suggesting both the similarity and uniqueness of the mechanisms behind the two goal states. In addition, the distinct patterns of activation in the striatum were associated with distinct subjective experiences participants reported between the approach and the avoidance conditions. These results suggest the importance of examining the pattern of striatal activity in understanding the mechanisms behind different motivational states in humans.

Developmental trajectories of achievement emotions in mathematics during adolescence

This study examined how adolescents' emotions in mathematics develop over time. Growth curve modeling was applied to longitudinal data collected annually from 2002 to 2006 (Grades 5-9; N = 3425 German adolescents; Mage  = 11.7, 15.6 years at the first and last waves, respectively; 50.0% female). Results indicated that enjoyment and pride decreased over time (Glass's Δs = -.86, -.71). In contrast, negative emotions exhibited more complex patterns: Anger, boredom, and hopelessness increased (Δs = .52, .79, .26), shame decreased (Δ = -.12), and anxiety remained stable (Δ = .00). These change trajectories of emotions were associated with change trajectories of perceived control, intrinsic value, achievement value, and achievement in mathematics. Implications and future directions are discussed.

Metacognition of curiosity: People underestimate the seductive lure of non-instrumental information

Curiosity - the desire to seek information - is fundamental for learning and performance. Studies on curiosity have shown that people are intrinsically motivated to seek information even if it does not bring an immediate tangible benefit (i.e., non-instrumental information), but little is known as to whether people have the metacognitive capability to accurately monitor their motivation for seeking information. We examined whether people can accurately predict their own non-instrumental information-seeking behavior. Across six experiments (Experiments 1A-1E and 2, total N = 579), participants predicted that they would engage in information-seeking behavior less frequently than they actually did, suggesting that people tend to underestimate the motivational lure of curiosity. Overall, there was no consistent statistical evidence that this underestimation was altered by contextual factors (e.g., the cost to seek information). These results were consistent with the theoretical account that it is difficult for people to make sense of the internally rewarding value of information in advance.

Uncertainty drives exploration of negative information across younger and older adults

Although individuals generally avoid negative information, recent research documents that they voluntarily explore negative information to resolve uncertainty. However, it remains unclear (a) whether uncertainty facilitates exploration similarly when exploration is expected to lead to negative, neutral, or positive information, and (b) whether older adults seek negative information to reduce uncertainty like younger adults do. This study addresses the two issues across four experimental studies (N = 407). The results indicate that individuals are more likely to expose themselves to negative information when uncertainty is high. In contrast, when information was expected to be neutral or positive, the uncertainty surrounding it did not significantly alter individuals' exploration behavior. Furthermore, we found that uncertainty increased the exploration of negative information in both older and younger adults. In addition, both younger and older adults chose to explore negative information to reduce uncertainty, even when there were positive or neutral alternatives. In contrast to the age-related similarities in these behavioral measures, older adults demonstrated reduced scores in questionnaires on sensation seeking and curiosity, relative to their counterparts who were younger. These results suggest that information uncertainty has a selective facilitation effect on exploration for negative information and that normal aging does not alter this tendency, despite age-related reductions in self-reported measures of personality traits relevant to information seeking.

Longitudinal Association between Maternal Autonomy Support and Controlling Parenting and Adolescents' Depressive Symptoms

Most studies on autonomy support and controlling parenting rely on children's perceptions, despite the limitations of this approach. This study investigated congruency between autonomy support and controlling parenting reported by mothers and adolescents and their association with adolescents' depressive symptoms via basic psychological needs satisfaction. Participants included 408 Japanese mother-adolescent (M_age = 13.73, SD = 0.90, 52% female) pairs who completed a questionnaire at two time points four months apart. Results demonstrated low to moderate levels of mother-adolescent agreement. Cross-lagged regression models revealed that mothers' reported autonomy support positively predicted adolescents' basic psychological needs satisfactions, which was negatively associated with depressive symptoms. The independent roles of parenting reported by mothers and adolescents for adolescents' well-being were discussed.

Heart Rate Variability Covaries with Amygdala Functional Connectivity During Voluntary Emotion Regulation

The Neurovisceral Integration Model posits that shared neural networks support the effective regulation of emotions and heart rate, with heart rate variability (HRV) serving as an objective, peripheral index of prefrontal inhibitory control. Prior neuroimaging studies have predominantly examined both HRV and associated neural functional connectivity at rest, as opposed to contexts that require active emotion regulation. The present study sought to extend upon previous resting-state functional connectivity findings, examining task-related HRV and corresponding amygdala functional connectivity during a cognitive reappraisal task. Seventy adults (52 older and 18 younger adults, 18-84 years, 51% male) received instructions to cognitively reappraise negative affective images during functional MRI scanning. HRV measures were derived from a finger pulse signal throughout the scan. During the task, younger adults exhibited a significant inverse association between HRV and amygdala-medial prefrontal cortex (mPFC) functional connectivity, in which higher task-related HRV was correlated with weaker amygdala-mPFC coupling, whereas older adults displayed a slight positive, albeit non-significant correlation. Furthermore, voxelwise whole-brain functional connectivity analyses showed that higher task-based HRV was linked to weaker right amygdala-posterior cingulate cortex connectivity across older and younger adults, and in older adults, higher task-related HRV correlated positively with stronger right amygdala-right ventrolateral prefrontal cortex connectivity. Collectively, these findings highlight the importance of assessing HRV and neural functional connectivity during active regulatory contexts to further identify neural concomitants of HRV and adaptive emotion regulation.

Transmission of Basic Psychological Need Satisfaction Between Parents and Adolescents: The Critical Role of Parental Perceptions

Although studies have documented the importance of basic psychological need satisfaction in parent–child relationships, a gap remains in understanding how parent and adolescent need satisfaction are associated. Using two longitudinal intergenerational data sets (200 parent–adolescent dyads and 408 mother–adolescent dyads; two waves), we examined whether (a) parents’ need satisfaction predicts adolescents’ need satisfaction (parental needs effect), (b) adolescents’ need satisfaction predicts parents’ need satisfaction (child’s needs effect), and (c) parental perception of adolescent’s need satisfaction predicts adolescents’ need satisfaction (parental perception effect). Findings from cross-lagged path models analogous to actor–partner interdependence models only supported parental perception effects: Parents’ T1 perception of their adolescent’s need satisfaction predicted their adolescent’s T2 self-reported need satisfaction, especially for autonomy and competence needs. Findings highlight the importance of parents’ perceptions, which may benefit the design of new interventions for basic psychological needs.

Memory of the U.K.'s 2016 EU referendum: The effects of valence on the long-term measures of a public event

Emotional public events, relative to nonemotional ones, are typically remembered more accurately, more vividly, and with more confidence. However, the majority of previous studies investigating this have focused on negative public events and less is known about positive ones. The current study examined whether positive and negative public events were remembered in a similar manner by assessing individuals' memory for the time when they learned the results of the United Kingdom's 2016 Referendum on its European Union (EU) membership. Participants included U.K. participants who voted to leave the EU in the referendum and found the event highly positive, U.K. participants who voted to remain in the EU and found the event highly negative, and U.S. participants who did not vote and found the event neutral. Data from a total of 851 participants were assessed at four time points over the course of 16 months. Growth curve modeling showed that differences in memory between participants in the Remain group (who reported the highest levels of negative emotion) and those in the Leave group (who reported the highest levels of positive emotion) emerged over time. Specifically, Remain participants maintained higher levels of memory consistency than Leave participants, whereas Leave participants maintained higher levels of memory confidence than Remain participants. These results indicate that positive and negative public events are remembered differently, such that negative valence enhances memory accuracy, while positive valence results in overconfidence. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Parental perception matters: Reciprocal relations between adolescents' depressive symptoms and parental perceptions

A large body of research has shown that parents play a vital role in the development of adolescents' depression. However, previous research has overlooked the effects of a potentially critical factor, namely, parental perceptions, and beliefs about adolescents' depression. The present study examined whether parental perceptions of an adolescent's depressive symptoms predict longitudinal changes in adolescents' symptoms (i.e., the parental perception effect). The longitudinal relationship between adolescents' depressive symptoms and parental perceptions of the adolescents' symptoms was analyzed in three independent groups of parent-adolescent pairs (in total N = 1,228). Parental perception and monitoring effects were found in Studies 1B and 2 only in the depressive mood subscale. While a decreased enjoyment subscale showed a perception effect in Study 1A, we obtained null results from other studies. We synthesized the results by applying meta-analytic structural equation modeling to obtain a more robust estimate. The analysis qualified both perception and monitoring effects in both subscales. Our results suggest that when parents believe that their adolescent child is depressed, adolescents are cognitively biased by their parental perceptions over time, resulting in more severe depressive symptoms. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Summary-statistics-based power analysis: A new and practical method to determine sample size for mixed-effects modeling

This article proposes a summary-statistics-based power analysis-a practical method for conducting power analysis for mixed-effects modeling with two-level nested data (for both binary and continuous predictors), complementing the existing formula-based and simulation-based methods. The proposed method bases its logic on conditional equivalence of the summary-statistics approach and mixed-effects modeling, paring back the power analysis for mixed-effects modeling to that for a simpler statistical analysis (e.g., one-sample t test). Accordingly, the proposed method allows us to conduct power analysis for mixed-effects modeling using popular software such as G*Power or the pwr package in R and, with minimum input from relevant prior work (e.g., t value). We provide analytic proof and a series of statistical simulations to show the validity and robustness of the summary-statistics-based power analysis and show illustrative examples with real published work. We also developed a web app (https://koumurayama.shinyapps.io/summary_statistics_based_power/) to facilitate the utility of the proposed method. While the proposed method has limited flexibilities compared with the existing methods in terms of the models and designs that can be appropriately handled, it provides a convenient alternative for applied researchers when there is limited information to conduct power analysis. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

The effect of low-intensity exercise on emotional and cognitive engagement in the classroom

This study examined whether engaging in physical exercise during a university class would have beneficial effect on students' learning motivation. One hundred and forty-nine participants took part in a psychology class over nine weeks (one lesson per week); for each lesson, participants engaged in a three-minute physical activity (low-intensity aerobic exercise) or control activity (watching a video), about 20 min after the lesson started. Participants reported higher vigour and lower fatigue during the class when they exercised than when they engaged in control activities. These findings suggest the utility of incorporating a short exercise activity in university settings to enhance students' classroom motivation.

Cortical thickness and resting-state cardiac function across the lifespan: A cross-sectional pooled mega-analysis

Understanding the association between autonomic nervous system [ANS] function and brain morphology across the lifespan provides important insights into neurovisceral mechanisms underlying health and disease. Resting-state ANS activity, indexed by measures of heart rate [HR] and its variability [HRV] has been associated with brain morphology, particularly cortical thickness [CT]. While findings have been mixed regarding the anatomical distribution and direction of the associations, these inconsistencies may be due to sex and age differences in HR/HRV and CT. Previous studies have been limited by small sample sizes, which impede the assessment of sex differences and aging effects on the association between ANS function and CT. To overcome these limitations, 20 groups worldwide contributed data collected under similar protocols of CT assessment and HR/HRV recording to be pooled in a mega-analysis (N = 1,218 (50.5% female), mean age 36.7 years (range: 12-87)). Findings suggest a decline in HRV as well as CT with increasing age. CT, particularly in the orbitofrontal cortex, explained additional variance in HRV, beyond the effects of aging. This pattern of results may suggest that the decline in HRV with increasing age is related to a decline in orbitofrontal CT. These effects were independent of sex and specific to HRV; with no significant association between CT and HR. Greater CT across the adult lifespan may be vital for the maintenance of healthy cardiac regulation via the ANS-or greater cardiac vagal activity as indirectly reflected in HRV may slow brain atrophy. Findings reveal an important association between CT and cardiac parasympathetic activity with implications for healthy aging and longevity that should be studied further in longitudinal research.

The Role of Cognitive Control in Age-Related Changes in Well-Being

Maintaining emotional well-being in late life is crucial for achieving successful and healthy aging. While previous research from Western cultures has documented that emotional well-being improves as individuals get older, previous research provided mixed evidence on the effects of age on well-being in Eastern Asian cultures. However, previous studies in East Asia do not always take into account the effects of cognitive control—an ability which has been considered as a key to enable older adults to regulate their emotions. In the current study, we tested whether cognitive control abilities interact with age in determining individuals’ well-being in 59 Japanese females (age range: 26–79; M_age = 64.95). Participants’ mental health and mental fatigue were tracked for 5 years together with their cognitive control abilities. We found that as individuals became older, they showed improved mental health and decreased mental fatigue. In addition, we found a quadratic effect of age on mental fatigue, which was further qualified by baseline cognitive control abilities. Specifically, in those who had a lower level of cognitive control abilities, mental fatigue declined until the mid-60s, at which point it started increasing (a U-shape effect). In contrast, in those who had a higher level of cognitive control ability, mental fatigue showed a steady decrease with age even after their mid-60s. These results suggest that whether advancing age is associated with positive vs. negative changes in well-being depends on cognitive control abilities, and that preserved cognitive control is a key to maintain well-being in late life.

Closer to critical resting-state neural dynamics in individuals with higher fluid intelligence

According to the critical brain hypothesis, the brain is considered to operate near criticality and realize efficient neural computations. Despite the prior theoretical and empirical evidence in favor of the hypothesis, no direct link has been provided between human cognitive performance and the neural criticality. Here we provide such a key link by analyzing resting-state dynamics of functional magnetic resonance imaging (fMRI) networks at a whole-brain level. We develop a data-driven analysis method, inspired from statistical physics theory of spin systems, to map out the whole-brain neural dynamics onto a phase diagram. Using this tool, we show evidence that neural dynamics of human participants with higher fluid intelligence quotient scores are closer to a critical state, i.e., the boundary between the paramagnetic phase and the spin-glass (SG) phase. The present results are consistent with the notion of "edge-of-chaos" neural computation.

Emotional arousal amplifies competitions across goal-relevant representation: A neurocomputational framework

Emotional arousal often facilitates memory for some aspects of an event while impairing memory for other aspects of the same event. Across three experiments, we found that emotional arousal amplifies competition among goal-relevant representations, such that arousal impairs memory for multiple goal-relevant representations while enhancing memory for solo goal-relevant information. We also present a computational model to explain the mechanisms by which emotional arousal can modulate memory in opposite ways via the local/synaptic-level noradrenergic system. The model is based on neurophysiological observations that norepinephrine (NE) released under emotional arousal is locally controlled by glutamate levels, resulting in different NE effects across regions, gating either long-term potentiation or long-term depression by activating different adrenergic receptors depending on NE concentration levels. This model successfully replicated behavioral findings from the three experiments. These findings suggest that the NE's local effects are key in determining the effects of emotion on memory.

Advanced Aging Enhances the Positivity Effect in Memory: Due to Cognitive Control or Age-Related Decline in Emotional Processing?

Older adults typically remember more positive than negative information compared to their younger counterparts; a phenomenon referred to as the ‘positivity effect.’ According to the socioemotional selectivity theory (SST), the positivity effect derives from the age-related motivational shift towards attaining emotionally meaningful goals which become more important as the perception of future time becomes more limited. Cognitive control mechanisms are critical in achieving such goals and therefore SST predicts that the positivity effect is associated with preserved cognitive control mechanisms in older adults. In contrast, the aging-brain model suggests that the positivity effect is driven by an age-related decline in the amygdala which is responsible for emotional processing and emotional learning. The aim of the current research was to address whether the age-related positivity effect is associated with cognitive control or impaired emotional processing associated with aging. We included older old adults, younger old adults and younger adults and tested their memory for emotional stimuli, cognitive control and amygdala-dependent fear conditioned responses. Consistent with prior research, older adults, relative to younger adults, demonstrate better memory for positive over negative images. We further found that within a group of older adults, the positivity effect increases as a function of age, such that older old adults demonstrated a greater positivity effect compared to younger older adults. Furthermore, the positivity effect in older old adults was associated with preserved cognitive control, supporting the prediction of SST. Contrary to the prediction of the aging-brain model, participants across all groups demonstrated similar enhanced skin conductance responses to fear conditioned stimuli – responses known to rely on the amygdala. Our results support SST and suggest that the positivity effect in older adults is achieved by the preserved cognitive control mechanisms and is not a reflection of the impaired emotional function associated with age.

Beyond Self-Report: A Review of Physiological and Neuroscientific Methods to Investigate Consumer Behavior

The current paper investigates the value and application of a range of physiological and neuroscientific techniques in applied marketing research and consumer science, highlighting new insights from research in social psychology and neuroscience. We review measures of sweat secretion, heart rate, facial muscle activity, eye movements, and electrical brain activity, using techniques including skin conductance, pupillometry, eyetracking, and magnetic brain imaging. For each measure, after a brief explanation of the underlying technique, we illustrate concepts and mechanisms that the measure allows researchers in marketing and consumer science to investigate, with a focus on consumer attitudes and behavior. By providing reviews on recent research that applied these methods in consumer science and relevant related fields, we also highlight methodological and theoretical strengths and limitations, with an emphasis on ecological validity. We argue that the inclusion of physiological and neuroscientific techniques can advance consumer research by providing insights into the often unconscious mechanisms underlying consumer behavior. Therefore, such technologies can help researchers and marketing practitioners understand the mechanisms of consumer behavior and improve predictions of consumer behavior.

Age-related changes in the ease of dynamical transitions in human brain activity

Executive functions, a set of cognitive processes that enable flexible behavioral control, are known to decay with aging. Because such complex mental functions are considered to rely on the dynamic coordination of functionally different neural systems, the age-related decline in executive functions should be underpinned by alteration of large-scale neural dynamics. However, the effects of age on brain dynamics have not been firmly formulated. Here, we investigate such age-related changes in brain dynamics by applying "energy landscape analysis" to publicly available functional magnetic resonance imaging data from healthy younger and older human adults. We quantified the ease of dynamical transitions between different major patterns of brain activity, and estimated it for the default mode network (DMN) and the cingulo-opercular network (CON) separately. We found that the two age groups shared qualitatively the same trajectories of brain dynamics in both the DMN and CON. However, in both of networks, the ease of transitions was significantly smaller in the older than the younger group. Moreover, the ease of transitions was associated with the performance in executive function tasks in a doubly dissociated manner: for the younger adults, the ability of executive functions was mainly correlated with the ease of transitions in the CON, whereas that for the older adults was specifically associated with the ease of transitions in the DMN. These results provide direct biological evidence for age-related changes in macroscopic brain dynamics and suggest that such neural dynamics play key roles when individuals carry out cognitively demanding tasks.

Arousal increases neural gain via the locus coeruleus-norepinephrine system in younger adults but not in older adults

In younger adults, arousal amplifies attentional focus to the most salient or goal-relevant information while suppressing other information. A computational model of how the locus coeruleus-norepinephrine (LC-NE) system can implement this increased selectivity under arousal and an fMRI study comparing how arousal affects younger and older adults' processing indicate that the amplification of salient stimuli and the suppression of non-salient stimuli are separate processes, with aging affecting suppression without impacting amplification under arousal. In the fMRI study, arousal increased processing of salient stimuli and decreased processing of non-salient stimuli for younger adults. In contrast, for older adults, arousal increased processing of both low and high salience stimuli, generally increasing excitatory responses to visual stimuli. Older adults also showed decline in LC functional connectivity with frontoparietal networks that coordinate attentional selectivity. Thus, among older adults, arousal increases the potential for distraction from non-salient stimuli.

Clustering Coefficients for Correlation Networks

Graph theory is a useful tool for deciphering structural and functional networks of the brain on various spatial and temporal scales. The clustering coefficient quantifies the abundance of connected triangles in a network and is a major descriptive statistics of networks. For example, it finds an application in the assessment of small-worldness of brain networks, which is affected by attentional and cognitive conditions, age, psychiatric disorders and so forth. However, it remains unclear how the clustering coefficient should be measured in a correlation-based network, which is among major representations of brain networks. In the present article, we propose clustering coefficients tailored to correlation matrices. The key idea is to use three-way partial correlation or partial mutual information to measure the strength of the association between the two neighboring nodes of a focal node relative to the amount of pseudo-correlation expected from indirect paths between the nodes. Our method avoids the difficulties of previous applications of clustering coefficient (and other) measures in defining correlational networks, i.e., thresholding on the correlation value, discarding of negative correlation values, the pseudo-correlation problem and full partial correlation matrices whose estimation is computationally difficult. For proof of concept, we apply the proposed clustering coefficient measures to functional magnetic resonance imaging data obtained from healthy participants of various ages and compare them with conventional clustering coefficients. We show that the clustering coefficients decline with the age. The proposed clustering coefficients are more strongly correlated with age than the conventional ones are. We also show that the local variants of the proposed clustering coefficients (i.e., abundance of triangles around a focal node) are useful in characterizing individual nodes. In contrast, the conventional local clustering coefficients were strongly correlated with and therefore may be confounded by the node's connectivity. The proposed methods are expected to help us to understand clustering and lack thereof in correlational brain networks, such as those derived from functional time series and across-participant correlation in neuroanatomical properties.

Brain structural concomitants of resting state heart rate variability in the young and old: evidence from two independent samples

Previous research has shown associations between brain structure and resting state high-frequency heart rate variability (HF HRV). Age affects both brain structure and HF HRV. Therefore, we sought to examine the relationship between brain structure and HF HRV as a function of age. Data from two independent studies were used for the present analysis. Study 1 included 19 older adults (10 males, age range 62-78 years) and 19 younger adults (12 males, age range 19-37). Study 2 included 23 older adults (12 males; age range 55-75) and 27 younger adults (17 males; age range 18-34). The root-mean-square of successive R-R-interval differences (RMSSD) from ECG recordings was used as time-domain measure of HF HRV. MRI scans were performed on a 3.0-T Siemens Magnetom Trio scanner. Cortical reconstruction and volumetric segmentation were performed with the Freesurfer image analysis suite, including 12 regions as regions of interests (ROI). Zero-order and partial correlations were used to assess the correlation of RMSSD with cortical thickness in selected ROIs. Lateral orbitofrontal cortex (OFC) cortical thickness was significantly associated with RMSSD. Further, both studies, in line with previous research, showed correlations between RMSSD and anterior cingulate cortex (ACC) cortical thickness. Meta-analysis on adjusted correlation coefficients from individual studies confirmed an association of RMSSD with the left rostral ACC and the left lateral OFC. Future longitudinal studies are necessary to trace individual trajectories in the association of HRV and brain structure across aging.

Arousal amplifies biased competition between high and low priority memories more in women than in men: The role of elevated noradrenergic activity

Recent findings indicate that emotional arousal can enhance memory consolidation of goal-relevant stimuli while impairing it for irrelevant stimuli. According to one recent model, these goal-dependent memory tradeoffs are driven by arousal-induced release of norepinephrine (NE), which amplifies neural gain in target sensory and memory processing brain regions. Past work also shows that ovarian hormones modulate activity in the same regions thought to support NE's effects on memory, such as the amygdala, suggesting that men and women may be differentially susceptible to arousal's dual effects on episodic memory. Here, we aimed to determine the neurohormonal mechanisms that mediate arousal-biased competition processes in memory. In a competitive visuo-attention task, participants viewed images of a transparent object overlaid on a background scene and explicitly memorized one of these stimuli while ignoring the other. Participants then heard emotional or neutral audio-clips and provided a subjective arousal rating. Hierarchical generalized linear modeling (HGLM) analyses revealed that greater pre-to-post task increases in salivary alpha-amylase (sAA), a biomarker of noradrenergic activity, was associated with significantly greater arousal-enhanced memory tradeoffs in women than in men. These sex-dependent effects appeared to result from phasic and background noradrenergic activity interacting to suppress task-irrelevant representations in women but enhancing them in men. Additionally, in naturally cycling women, low ovarian hormone levels interacted with increased noradrenergic activity to amplify memory selectivity independently of emotion-induced arousal. Together these findings suggest that increased noradrenergic transmission enhances preferential consolidation of goal-relevant memory traces according to phasic arousal and ovarian hormone levels in women.

Resting-state networks associated with cognitive processing show more age-related decline than those associated with emotional processing

Correlations in activity across disparate brain regions during rest reveal functional networks in the brain. Although previous studies largely agree that there is an age-related decline in the "default mode network," how age affects other resting-state networks, such as emotion-related networks, is still controversial. Here we used a dual-regression approach to investigate age-related alterations in resting-state networks. The results revealed age-related disruptions in functional connectivity in all 5 identified cognitive networks, namely the default mode network, cognitive-auditory, cognitive-speech (or speech-related somatosensory), and right and left frontoparietal networks, whereas such age effects were not observed in the 3 identified emotion networks. In addition, we observed age-related decline in functional connectivity in 3 visual and 3 motor/visuospatial networks. Older adults showed greater functional connectivity in regions outside 4 out of the 5 identified cognitive networks, consistent with the dedifferentiation effect previously observed in task-based functional magnetic resonance imaging studies. Both reduced within-network connectivity and increased out-of-network connectivity were correlated with poor cognitive performance, providing potential biomarkers for cognitive aging.

Noradrenergic mechanisms of arousal's bidirectional effects on episodic memory

Arousal's selective effects on cognition go beyond the simple enhancement of emotional stimuli, sometimes enhancing and other times impairing processing of proximal neutral information. Past work shows that arousal impairs encoding of subsequent neutral stimuli regardless of their top-down priority via the engagement of β-adrenoreceptors. In contrast, retrograde amnesia induced by emotional arousal can flip to enhancement when preceding neutral items are prioritized in top-down attention. Whether β-adrenoreceptors also contribute to this retrograde memory enhancement of goal-relevant neutral stimuli is unclear. In this pharmacological study, we administered 40mg of propranolol or 40mg of placebo to healthy young adults to examine whether emotional arousal's bidirectional effects on declarative memory relies on β-adrenoreceptor activation. Following pill intake, participants completed an emotional oddball task in which they were asked to prioritize a neutral object appearing just before an emotional or neutral oddball image within a sequence of 7 neutral objects. Under placebo, emotional oddballs impaired memory for lower priority oddball+1 objects but had no effect on memory for high priority oddball-1 objects. Propranolol blocked this anterograde amnesic effect of arousal. Emotional oddballs also enhanced selective memory trade-offs significantly more in the placebo than drug condition, such that high priority oddball-1 objects were more likely to be remembered at the cost of their corresponding lower priority oddball+1 objects under arousal. Lastly, those who recalled more high priority oddball-1 objects preceding an emotional versus neutral oddball image showed greater increases in salivary alpha-amylase, a biomarker of noradrenergic system activation, across the task. Together these findings suggest that different noradrenergic mechanisms contribute to the anterograde and retrograde mnemonic effects of arousal on proximal neutral memoranda.

Thinking about a limited future enhances the positivity of younger and older adults' recall: Support for socioemotional selectivity theory

Compared with younger adults, older adults have a relative preference to attend to and remember positive over negative information. This is known as the "positivity effect," and researchers have typically evoked socioemotional selectivity theory to explain it. According to socioemotional selectivity theory, as people get older they begin to perceive their time left in life as more limited. These reduced time horizons prompt older adults to prioritize achieving emotional gratification and thus exhibit increased positivity in attention and recall. Although this is the most commonly cited explanation of the positivity effect, there is currently a lack of clear experimental evidence demonstrating a link between time horizons and positivity. The goal of the current research was to address this issue. In two separate experiments, we asked participants to complete a writing activity, which directed them to think of time as being either limited or expansive (Experiments 1 and 2) or did not orient them to think about time in a particular manner (Experiment 2). Participants were then shown a series of emotional pictures, which they subsequently tried to recall. Results from both studies showed that regardless of chronological age, thinking about a limited future enhanced the relative positivity of participants' recall. Furthermore, the results of Experiment 2 showed that this effect was not driven by changes in mood. Thus, the fact that older adults' recall is typically more positive than younger adults' recall may index naturally shifting time horizons and goals with age.

Heart rate variability is associated with amygdala functional connectivity with MPFC across younger and older adults

The ability to regulate emotion is crucial to promote well-being. Evidence suggests that the medial prefrontal cortex (mPFC) and adjacent anterior cingulate (ACC) modulate amygdala activity during emotion regulation. Yet less is known about whether the amygdala-mPFC circuit is linked with regulation of the autonomic nervous system and whether the relationship differs across the adult lifespan. The current study tested the hypothesis that heart rate variability (HRV) reflects the strength of mPFC-amygdala interaction across younger and older adults. We recorded participants' heart rates at baseline and examined whether baseline HRV was associated with amygdala-mPFC functional connectivity during rest. We found that higher HRV was associated with stronger functional connectivity between the amygdala and the mPFC during rest across younger and older adults. In addition to this age-invariant pattern, there was an age-related change, such that greater HRV was linked with stronger functional connectivity between amygdala and ventrolateral PFC (vlPFC) in younger than in older adults. These results are in line with past evidence that vlPFC is involved in emotion regulation especially in younger adults. Taken together, our results support the neurovisceral integration model and suggest that higher heart rate variability is associated with neural mechanisms that support successful emotional regulation across the adult lifespan.

Type I error inflation in the traditional by-participant analysis to metamemory accuracy: a generalized mixed-effects model perspective

In order to examine metacognitive accuracy (i.e., the relationship between metacognitive judgment and memory performance), researchers often rely on by-participant analysis, where metacognitive accuracy (e.g., resolution, as measured by the gamma coefficient or signal detection measures) is computed for each participant and the computed values are entered into group-level statistical tests such as the t test. In the current work, we argue that the by-participant analysis, regardless of the accuracy measurements used, would produce a substantial inflation of Type I error rates when a random item effect is present. A mixed-effects model is proposed as a way to effectively address the issue, and our simulation studies examining Type I error rates indeed showed superior performance of mixed-effects model analysis as compared to the conventional by-participant analysis. We also present real data applications to illustrate further strengths of mixed-effects model analysis. Our findings imply that caution is needed when using the by-participant analysis, and recommend the mixed-effects model analysis.

Emotional arousal amplifies the effects of biased competition in the brain

The arousal-biased competition model predicts that arousal increases the gain on neural competition between stimuli representations. Thus, the model predicts that arousal simultaneously enhances processing of salient stimuli and impairs processing of relatively less-salient stimuli. We tested this model with a simple dot-probe task. On each trial, participants were simultaneously exposed to one face image as a salient cue stimulus and one place image as a non-salient stimulus. A border around the face cue location further increased its bottom-up saliency. Before these visual stimuli were shown, one of two tones played: one that predicted a shock (increasing arousal) or one that did not. An arousal-by-saliency interaction in category-specific brain regions (fusiform face area for salient faces and parahippocampal place area for non-salient places) indicated that brain activation associated with processing the salient stimulus was enhanced under arousal whereas activation associated with processing the non-salient stimulus was suppressed under arousal. This is the first functional magnetic resonance imaging study to demonstrate that arousal can enhance information processing for prioritized stimuli while simultaneously impairing processing of non-prioritized stimuli. Thus, it goes beyond previous research to show that arousal does not uniformly enhance perceptual processing, but instead does so selectively in ways that optimizes attention to highly salient stimuli.

Memory suppression can help people "unlearn" behavioral responses--but only for nonemotional memories

When encountering reminders of memories that we prefer not to think about, we often try to exclude those memories from awareness. Past studies have revealed that such suppression attempts can reduce the subsequent recollection of unwanted memories. In the present study, we examined whether the inhibitory effects extend even to associated behavioral responses. Participants learned cue-target pairs for emotional and nonemotional targets and were additionally trained in behavioral responses for each cue. Afterward, they were shown the cues and instructed either to think or to avoid thinking about the targets without performing any behaviors. In a final test phase, behavioral performance was tested for all of the cues. When the targets were neutral, participants' attempts to avoid retrieval reduced accuracy and increased reaction times in generating behavioral responses associated with cues. By contrast, behavioral performance was not affected by suppression attempts when the targets were emotional. These results indicate that controlling unwanted recollection is powerful enough to inhibit associated behavioral responses-but only for nonemotional memories.

Emotion strengthens high-priority memory traces but weakens low-priority memory traces

When people encounter emotional events, their memory for those events is typically enhanced. But it has been unclear how emotionally arousing events influence memory for preceding information. Does emotional arousal induce retrograde amnesia or retrograde enhancement? The current study revealed that this depends on the top-down goal relevance of the preceding information. Across three studies, we found that emotional arousal induced by one image facilitated memory for the preceding neutral item when people prioritized that neutral item. In contrast, an emotionally arousing image impaired memory for the preceding neutral item when people did not prioritize that neutral item. Emotional arousal elicited by both negative and positive pictures showed this pattern of enhancing or impairing memory for the preceding stimulus depending on its priority. These results indicate that emotional arousal amplifies the effects of top-down priority in memory formation.

Association learning for emotional harbinger cues: when do previous emotional associations impair and when do they facilitate subsequent learning of new associations?

Neutral cues that predict emotional events (emotional harbingers) acquire emotional properties and attract attention. Given the importance of emotional harbingers for future survival, it is desirable to flexibly learn new facts about emotional harbingers when needed. However, recent research revealed that it is harder to learn new associations for emotional harbingers than cues that predict non-emotional events (neutral harbingers). In the current study, we addressed whether this impaired association learning for emotional harbingers is altered by one's awareness of the contingencies between cues and emotional outcomes. Across 3 studies, we found that one's awareness of the contingencies determines subsequent association learning of emotional harbingers. Emotional harbingers produced worse association learning than neutral harbingers when people were not aware of the contingencies between cues and emotional outcomes, but produced better association learning when people were aware of the contingencies. These results suggest that emotional harbingers do not always suffer from impaired association learning and can show facilitated learning depending on one's contingency awareness.

Age-related similarities and differences in brain activity underlying reversal learning

The ability to update associative memory is an important aspect of episodic memory and a critical skill for social adaptation. Previous research with younger adults suggests that emotional arousal alters brain mechanisms underlying memory updating; however, it is unclear whether this applies to older adults. Given that the ability to update associative information declines with age, it is important to understand how emotion modulates the brain processes underlying memory updating in older adults. The current study investigated this question using reversal learning tasks, where younger and older participants (age ranges 19–35 and 61–78, respectively) learn a stimulus–outcome association and then update their response when contingencies change. We found that younger and older adults showed similar patterns of activation in the frontopolar OFC and the amygdala during emotional reversal learning. In contrast, when reversal learning did not involve emotion, older adults showed greater parietal cortex activity than did younger adults. Thus, younger and older adults show more similarities in brain activity during memory updating involving emotional stimuli than during memory updating not involving emotional stimuli.

Automatic ability attribution after failure: a dual process view of achievement attribution

Causal attribution has been one of the most influential frameworks in the literature of achievement motivation, but previous studies considered achievement attribution as relatively deliberate and effortful processes. In the current study, we tested the hypothesis that people automatically attribute their achievement failure to their ability, but reduce the ability attribution in a controlled manner. To address this hypothesis, we measured participants’ causal attribution belief for their task failure either under the cognitive load (load condition) or with full attention (no-load condition). Across two studies, participants attributed task performance to their ability more in the load than in the no-load condition. The increased ability attribution under cognitive load further affected intrinsic motivation. These results indicate that cognitive resources available after feedback play crucial roles in determining causal attribution belief, as well as achievement motivations.

Amygdala functional connectivity with medial prefrontal cortex at rest predicts the positivity effect in older adults' memory

As people get older, they tend to remember more positive than negative information. This age-by-valence interaction has been called "positivity effect." The current study addressed the hypotheses that baseline functional connectivity at rest is predictive of older adults' brain activity when learning emotional information and their positivity effect in memory. Using fMRI, we examined the relationship among resting-state functional connectivity, subsequent brain activity when learning emotional faces, and individual differences in the positivity effect (the relative tendency to remember faces expressing positive vs. negative emotions). Consistent with our hypothesis, older adults with a stronger positivity effect had increased functional coupling between amygdala and medial PFC (MPFC) during rest. In contrast, younger adults did not show the association between resting connectivity and memory positivity. A similar age-by-memory positivity interaction was also found when learning emotional faces. That is, memory positivity in older adults was associated with (a) enhanced MPFC activity when learning emotional faces and (b) increased negative functional coupling between amygdala and MPFC when learning negative faces. In contrast, memory positivity in younger adults was related to neither enhanced MPFC activity to emotional faces, nor MPFC-amygdala connectivity to negative faces. Furthermore, stronger MPFC-amygdala connectivity during rest was predictive of subsequent greater MPFC activity when learning emotional faces. Thus, emotion-memory interaction in older adults depends not only on the task-related brain activity but also on the baseline functional connectivity.

Both younger and older adults have difficulty updating emotional memories

OBJECTIVE

The main purpose of the study was to examine whether emotion impairs associative memory for previously seen items in older adults, as previously observed in younger adults.

METHOD

Thirty-two younger adults and 32 older adults participated. The experiment consisted of 2 parts. In Part 1, participants learned picture-object associations for negative and neutral pictures. In Part 2, they learned picture-location associations for negative and neutral pictures; half of these pictures were seen in Part 1 whereas the other half were new. The dependent measure was how many locations of negative versus neutral items in the new versus old categories participants remembered in Part 2.

RESULTS

Both groups had more difficulty learning the locations of old negative pictures than of new negative pictures. However, this pattern was not observed for neutral items.

DISCUSSION

Despite the fact that older adults showed overall decline in associative memory, the impairing effect of emotion on updating associative memory was similar between younger and older adults.

Effects of interferon-α-transduced tumor cell vaccines and blockade of programmed cell death-1 on the growth of established tumors

Interferon-alpha (IFN-α) has strong antitumor effects, and IFN-α gene therapy has been used clinically against some cancers. In this study, we evaluated the efficacy of the combination of IFN-α-transduced tumor cell vaccines and programmed cell death 1 (PD-1) blockade, and investigated the mechanisms of the antitumor effects of the combined therapy. A poorly immunogenic murine colorectal cancer cell line, MC38, was transduced to overexpress IFN-α. In a therapeutic model, parental tumor-bearing mice were inoculated with MC38-IFNα cells and an anti-PD-1 antagonistic antibody. Analyses of immunohistochemistry and tumor-specific lysis were performed. The outgrowth of the established tumors was significantly reduced in mice treated with the combination of IFN-α and anti-PD-1. Immunohistochemical analyses of the therapeutic model showed marked infiltration of CD4(+) cells and CD8(+) cells in the established MC38 tumors of mice treated with both IFN-α and anti-PD-1. Significant tumor-specific cytolysis was detected when splenocytes of mice that were treated with both IFN-α and anti-PD-1 were used as effector cells. These results suggest that blockade of the PD-1 PD-ligand enhanced the Th1-type antitumor immune responses induced by IFN-α. The combination of IFN-α gene-transduced tumor cell vaccines and PD-1 blockade may be a possible candidate for a cancer vaccine for clinical trials.

Differential brain activity during emotional versus nonemotional reversal learning

The ability to change an established stimulus-behavior association based on feedback is critical for adaptive social behaviors. This ability has been examined in reversal learning tasks, where participants first learn a stimulus-response association (e.g., select a particular object to get a reward) and then need to alter their response when reinforcement contingencies change. Although substantial evidence demonstrates that the OFC is a critical region for reversal learning, previous studies have not distinguished reversal learning for emotional associations from neutral associations. The current study examined whether OFC plays similar roles in emotional versus neutral reversal learning. The OFC showed greater activity during reversals of stimulus-outcome associations for negative outcomes than for neutral outcomes. Similar OFC activity was also observed during reversals involving positive outcomes. Furthermore, OFC activity is more inversely correlated with amygdala activity during negative reversals than during neutral reversals. Overall, our results indicate that the OFC is more activated by emotional than neutral reversal learning and that OFC's interactions with the amygdala are greater for negative than neutral reversal learning.

Differential interference effects of negative emotional states on subsequent semantic and perceptual processing

Past studies have revealed that encountering negative events interferes with cognitive processing of subsequent stimuli. The present study investigates whether negative events affect semantic and perceptual processing differently. Presentation of negative pictures produced slower reaction times than neutral or positive pictures in tasks that require semantic processing, such as natural or man-made judgments about drawings of objects, commonness judgments about objects, and categorical judgments about pairs of words. In contrast, negative picture presentation did not slow down judgments in subsequent perceptual processing (e.g., color judgments about words, size judgments about objects). The subjective arousal level of negative pictures did not modulate the interference effects on semantic or perceptual processing. These findings indicate that encountering negative emotional events interferes with semantic processing of subsequent stimuli more strongly than perceptual processing, and that not all types of subsequent cognitive processing are impaired by negative events.

How reward and emotional stimuli induce different reactions across the menstrual cycle

Despite widespread belief that moods are affected by the menstrual cycle, researchers on emotion and reward have not paid much attention to the menstrual cycle until recently. However, recent research has revealed different reactions to emotional stimuli and to rewarding stimuli across the different phases of the menstrual cycle. The current paper reviews the emerging literature on how ovarian hormone fluctuation during the menstrual cycle modulates reactions to emotional stimuli and to reward. Behavioral and neuroimaging studies in humans suggest that estrogen and progesterone have opposing influences. That is, it appears that estrogen enhances reactions to reward, but progesterone counters the facilitative effects of estrogen and decreases reactions to rewards. In contrast, reactions to emotionally arousing stimuli (particularly negative stimuli) appear to be decreased by estrogen but enhanced by progesterone. Potential factors that can modulate the effects of the ovarian hormones (e.g., an inverse quadratic function of hormones' effects; the structural changes of the hippocampus across the menstrual cycle) are also discussed.

Age differences in brain activity during emotion processing: reflections of age-related decline or increased emotion regulation?

Despite the fact that physical health and cognitive abilities decline with aging, the ability to regulate emotion remains stable and in some aspects improves across the adult life span. Older adults also show a positivity effect in their attention and memory, with diminished processing of negative stimuli relative to positive stimuli compared with younger adults. The current paper reviews functional magnetic resonance imaging studies investigating age-related differences in emotional processing and discusses how this evidence relates to two opposing theoretical accounts of older adults' positivity effect. The aging-brain model [Cacioppo et al. in: Social Neuroscience: Toward Understanding the Underpinnings of the Social Mind. New York, Oxford University Press, 2011] proposes that older adults' positivity effect is a consequence of age-related decline in the amygdala, whereas the cognitive control hypothesis [Kryla-Lighthall and Mather in: Handbook of Theories of Aging, ed 2. New York, Springer, 2009; Mather and Carstensen: Trends Cogn Sci 2005;9:496-502; Mather and Knight: Psychol Aging 2005;20:554-570] argues that the positivity effect is a result of older adults' greater focus on regulating emotion. Based on evidence for structural and functional preservation of the amygdala in older adults and findings that older adults show greater prefrontal cortex activity than younger adults while engaging in emotion-processing tasks, we argue that the cognitive control hypothesis is a more likely explanation for older adults' positivity effect than the aging-brain model.

Gender differences in reward-related decision processing under stress

Recent research indicates gender differences in the impact of stress on decision behavior, but little is known about the brain mechanisms involved in these gender-specific stress effects. The current study used functional magnetic resonance imaging (fMRI) to determine whether induced stress resulted in gender-specific patterns of brain activation during a decision task involving monetary reward. Specifically, we manipulated physiological stress levels using a cold pressor task, prior to a risky decision making task. Healthy men (n = 24, 12 stressed) and women (n = 23, 11 stressed) completed the decision task after either cold pressor stress or a control task during the period of cortisol response to the cold pressor. Gender differences in behavior were present in stressed participants but not controls, such that stress led to greater reward collection and faster decision speed in males but less reward collection and slower decision speed in females. A gender-by-stress interaction was observed for the dorsal striatum and anterior insula. With cold stress, activation in these regions was increased in males but decreased in females. The findings of this study indicate that the impact of stress on reward-related decision processing differs depending on gender.

Updating existing emotional memories involves the frontopolar/orbito-frontal cortex in ways that acquiring new emotional memories does not

In life, we must often learn new associations to people, places, or things we already know. The current fMRI study investigated the neural mechanisms underlying emotional memory updating. Nineteen participants first viewed negative and neutral pictures and learned associations between those pictures and other neutral stimuli, such as neutral objects and encoding tasks. This initial learning phase was followed by a memory updating phase, during which participants learned picture-location associations for old pictures (i.e., pictures previously associated with other neutral stimuli) and new pictures (i.e., pictures not seen in the first phase). There was greater frontopolar/orbito-frontal (OFC) activity when people learned picture-location associations for old negative pictures than for new negative pictures, but frontopolar OFC activity did not significantly differ during learning locations of old versus new neutral pictures. In addition, frontopolar activity was more negatively correlated with the amygdala when participants learned picture-location associations for old negative pictures than for new negative or old neutral pictures. Past studies revealed that the frontopolar OFC allows for updating the affective values of stimuli in reversal learning or extinction of conditioning [e.g., Izquierdo, A., & Murray, E. A. Opposing effects of amygdala and orbital PFC lesions on the extinction of instrumental responding in macaque monkeys. European Journal of Neuroscience, 22, 2341-2346, 2005]; our findings suggest that it plays a more general role in updating associations to emotional stimuli.

[Reoperation through right thoracotomy for mitral regurgitation after coronary artery bypass grafting; report of a case]

A 53-year-old male patient developed severe mitral regurgitation 6 years after coronary artery bypass grafting (CABG) with a left internal thoracic artery and 2 saphenous veins. The left ventriculography showed severe mitral regurgitation and slight decrease in left ventricular function. The coronary arteriography showed all grafts being patent. The median re-sternotomy was avoided because of the risk for injury of bypass grafts, and the right anterolateral thoracotomy was chosen. Mitral valve replacement was performed under moderate hypothermia and ventricular fibrillation without aortic cross clamping. The postoperative course was uneventful. Right anterolateral thoracotomy is considered to be a superior approach to the mitral valve surgery in the patients with previous CABG.

Semantic self-knowledge and episodic self-knowledge: independent or interrelated representations?

In this study of the structure of self-knowledge, we examined priming effects for the recall of personal episodes in order to investigate whether abstract trait knowledge and personal episodes are independent mental representations. We found that accessing similar abstract representations of traits facilitated a faster recall of related personal episodes than did accessing irrelevant abstract representations of traits (Experiments 1 and 2), reading a nonword prime (Experiments 2 and 3), accessing knowledge of one's mother (Experiment 3), or accessing semantic knowledge (Experiment 3). Contrary to previous findings, which indicated that abstract trait knowledge is represented independently of related personal episodes (e.g., Klein & Loftus, 1993; Tulving, 1993), our results suggest that abstract trait knowledge is associated with personal episodes, and therefore that semantic self-knowledge is associated with episodic self-knowledge in long-term self-knowledge.