Angry expressions strengthen the encoding and maintenance of face identity representations in visual working memory

Acquisition and generalization of emotional and neural responses to faces associated with negative and positive feedback behaviours

Faces can acquire emotional meaning by learning to associate individuals with specific behaviors. Here, we investigated emotional evaluation and brain activations toward faces of persons who had given negative or positive evaluations to others. Furthermore, we investigated how emotional evaluations and brain activation generalize to perceptually similar faces. Valence ratings indicated learning and generalization effects for both positive and negative faces. Brain activation, measured with functional magnetic resonance imaging (fMRI), showed significantly increased activation in the fusiform gyrus (FG) to negatively associated faces but not positively associated ones. Remarkably, brain activation in FG to faces to which emotional meaning (negative and positive) was successfully generalized was decreased compared to neutral faces. This suggests that the emotional relevance of faces is not simply associated with increased brain activation in visual areas. While, at least for negative conditions, faces paired with negative feedback behavior are related to potentiated brain responses, the opposite is seen for perceptually very similar faces despite generalized emotional responses.

The effect of emotion counter-regulation to anger on working memory updating

Emotion counter-regulation has been suggested as the core cognitive mechanism of automatic emotion regulation. Emotion counter-regulation not only induces an unintentional transfer of attention from the current emotional state to stimuli with the opposite valence but also prompts approach to stimuli of the opposite valence and increases response inhibition to stimuli of the same valence. Working memory (WM) updating has been shown to be related to attention selection and response inhibition. However, it remains unclear whether emotion counter-regulation would affect WM updating with emotional stimuli. In the present study, 48 participants were recruited and randomly assigned to the angry-priming group that watched highly arousing angry video clips, or the control group that watched neutral video clips. Then participants performed a two-back face identity matching task with happy and angry face pictures. Behavioral results showed higher accuracy for identity recognition of happy than of angry faces. The event-related potential (ERP) results revealed smaller P2 to angry faces than to happy faces in the control group. In the angry-priming group, there was no difference in P2 amplitude between angry and happy trials. Between groups, P2 to angry faces was larger in the priming group than in the control group. Late positive potential (LPP) was smaller for happy faces than for angry faces in the priming group, but not in the control group. These findings suggest that emotion counter-regulation affects the onset updating and maintenance of emotional face stimuli in WM.

Role of facial familiarity and emotional expression intensity in ensemble emotion perception

When looking at groups of people, we can extract information from the different faces to derive properties of the group, such as its average facial emotion, although how this average is computed remains a matter of debate. Here, we examined whether our participants' personal familiarity with the faces in the group, as well as the intensity of the facial expressions, biased ensemble perception. Participants judged the average emotional expression of ensembles of four different identities whose expressions depicted either neutral, angry, or happy emotions. For the angry and happy expressions, the intensity of the emotion could be either low (e.g., slightly happy) or high (very happy). When all the identities in the ensemble were unfamiliar, the presence of any high intensity emotional face biased ensemble perception towards its emotion. However, when a familiar face was present in the ensemble, perception was biased towards the familiar face's emotion regardless of its intensity. These findings reveal that how we perceive the average emotion of a group is influenced by both the emotional intensity and familiarity of the faces comprising the group, supporting the idea that different faces may be weighted differently in ensemble perception. These findings have important implications for the judgements we make about a group's overall emotional state may be biased by individuals within the group.

Working memory modulates the anger superiority effect in central and peripheral visual fields

Angry faces have been shown to be detected more efficiently in a crowd of distractors compared to happy faces, known as the anger superiority effect (ASE). The present study investigated whether the ASE could be modified by top-down manipulation of working memory (WM), in central and peripheral visual fields. In central vision, participants held a colour in WM for a final memory test while simultaneously performing a visual search task that required them to determine whether a face showed a different expression from other coloured faces. The colour held in WM matched either the colour of the target face (target-matching), the colour of a distractor face (distractor-matching), or neither (non-matching). Results showed that the ASE was observed when the probability of target-matching trials was low. However, when the top-down WM effect was strengthened by raising the probability of target-matching trials, the ASE in the target-matching condition was completely eliminated. Intriguingly, when the visual search task was substituted by a peripheral crowding task, similar results to central vision were found in the target-matching condition. Taken together, our findings indicate that the ASE is subject to the top-down WM effect, regardless of the visual field.

Amplification in the evaluation of multiple emotional expressions over time

Social interactions are dynamic and unfold over time. To make sense of social interactions, people must aggregate sequential information into summary, global evaluations. But how do people do this? Here, to address this question, we conducted nine studies (N = 1,583) using a diverse set of stimuli. Our focus was a central aspect of social interaction-namely, the evaluation of others' emotional responses. The results suggest that when aggregating sequences of images and videos expressing varying degrees of emotion, perceivers overestimate the sequence's average emotional intensity. This tendency for overestimation is driven by stronger memory of more emotional expressions. A computational model supports this account and shows that amplification cannot be explained only by nonlinear perception of individual exemplars. Our results demonstrate an amplification effect in the perception of sequential emotional information, which may have implications for the many types of social interactions that involve repeated emotion estimation.

EXPRESS: Attentional Load Effects on Emotional Content in Face Working Memory

This study investigated the role of attentional resources in processing emotional faces in working memory (WM). Participants memorised two face arrays with the same emotion but different identities and were required to judge whether the test face had the same identity as one of the previous faces. Concurrently during encoding and maintenance, a sequence of high-or-low pitched tones (high load) or white noise bursts (low load) was presented, and participants were required to count how many low-tones were heard. Experiments 1 and 2 used an emotional and neutral test face, respectively. Results revealed a significant WM impairment for sad and angry faces in the high load vs low load condition but not for happy faces. In Experiment 1, participants remembered happy faces better than other emotional faces. In contrast, Experiment 2 showed that performance was poorer for happy than sad faces but not for angry faces. This evidence suggests that depleting attentional resources has less impact on WM for happy faces than other emotional faces, but also that differential effects on WM for emotional faces depend on the presence or absence of emotion in the probe face at retrieval.

Cognitive deficits for facial emotions among male adolescent delinquents with conduct disorder

According to the social-cognitive theory and the social-information-processing theory, individuals with conduct disorder, a persistent and repetitive pattern of problematic behavior, might have cognitive biases toward hostile facial expressions. However, according to the optimal stimulation/arousal theory, the stimulation-seeking theory and the fearlessness theory, individuals with conduct disorder might have less fear and show less response to hostile or threatening facial expressions. To reconcile the discrepancy, we examined the cognitive biases including attentional processing and working memory processing to emotional faces among adolescents with conduct disorder. 35 male adolescent delinquents with conduct disorder and 35 age-matched delinquents without conduct disorder completed a visual search task and a delayed-match-to-sample task to examine their attentional processing and working memory processing for sad, angry, happy, and fearful faces, respectively. It was found that conduct disordered individuals searched angry and fearful faces, rather than sad and happy faces, more slowly than individuals without conduct disorder. However, no difference in mnemonic processing for facial emotions was found between groups. The results indicated that male adolescent delinquents with conduct disorder showed deficits in attentional orientation to hostile and threatening faces, supporting the optimal stimulation/arousal theory, the stimulation-seeking theory and the fearlessness theory, but not the social-cognitive theory.

Task demands determine whether shape or arousal of a stimulus modulates competition for visual working memory resources

It has been posited (Öhman, 1986) that the processing of threatening stimuli became prioritized during the course of mammalian evolution and that such objects may still enjoy an advantage in visual processing to this day. It has been well-documented that both mid-level visual features (i.e., conjunctions of low-level features) and the arousal level of threatening stimuli affect attentional allocation (Cisler & Koster, 2010; Wolfe & Horowitz, 2004). Despite this, few studies have investigated the effect these factors have on visual working memory resources. Here, we investigated these factors using a rapid serial visual presentation (RSVP) paradigm, and by manipulating mid-level features (specifically, shape: similar vs. dissimilar) and the arousal level (non-threatening vs threatening) of the stimuli. Participants watched an RSVP stream in preparation for an upcoming memory test. Then, they completed a two-alternative forced-choice recognition memory test (with semantically matched foils) wherein they had to identify which item they had seen in the RSVP stream. Our results showed that when shape was a sufficient feature to discriminate the target from the other items in the stream, there was no effect of arousal (i.e., threat level) on reaction time or accuracy during the memory test. However, when the shapes of all the stimuli in the visual stream were highly similar, an effect of arousal appeared: When the target had a different arousal level than the background items (i.e., non-targets), performance was improved. Together, the results suggest that both mid-level visual features and arousal level can modulate competition for visual working memory resources.

Medial prefrontal and occipito-temporal activity at encoding determines enhanced recognition of threatening faces after 1.5 years

Studies demonstrated that faces with threatening emotional expressions are better remembered than non-threatening faces. However, whether this memory advantage persists over years and which neural systems underlie such an effect remains unknown. Here, we employed an individual difference approach to examine whether the neural activity during incidental encoding was associated with differential recognition of faces with emotional expressions (angry, fearful, happy, sad and neutral) after a retention interval of > 1.5 years (N = 89). Behaviorally, we found a better recognition for threatening (angry, fearful) versus non-threatening (happy and neutral) faces after a delay of > 1.5 years, which was driven by forgetting of non-threatening faces compared with immediate recognition after encoding. Multivariate principal component analysis (PCA) on the behavioral responses further confirmed the discriminative recognition performance between threatening and non-threatening faces. A voxel-wise whole-brain analysis on the concomitantly acquired functional magnetic resonance imaging (fMRI) data during incidental encoding revealed that neural activity in bilateral inferior occipital gyrus (IOG) and ventromedial prefrontal/orbitofrontal cortex (vmPFC/OFC) was associated with the individual differences in the discriminative emotional face recognition performance measured by an innovative behavioral pattern similarity analysis (BPSA). The left fusiform face area (FFA) was additionally determined using a regionally focused analysis. Overall, the present study provides evidence that threatening facial expressions lead to persistent face recognition over periods of > 1.5 years, and that differential encoding-related activity in the medial prefrontal cortex and occipito-temporal cortex may underlie this effect.

Widowhood Impairs Emotional Cognition Among Elderly

Background

The negative impacts of spousal bereavement on the emotional health of the elderly (e.g., depression and anxiety) have been revealed. However, whether widowhood impairs emotional cognition among the elderly is less known. The purpose of this study is to reveal the emotional cognitive deficits among the widowed elderly.

Methods

In this study, we recruited 44 widowed elderly (WE) and 44 elder couples (non-widowed elderly, NWE) and examined their emotional cognition including attention and visual working memory, which were measured by the visual search task and delayed-match-to-sample task, respectively. Three kinds of emotional faces (i.e., sad, angry, and happy) were adopted as the attentional or mnemonic targets.

Results

It revealed that WE had a general deficit in search efficiency across emotional types, while they showed mnemonic deficits in negative faces but not positive faces. Furthermore, the modeling analysis revealed that the level of depression or state anxiety of the elderly moderated the effects of widowhood on the deficits of mnemonic processing, i.e., the deficits were only evident among WE with the high level of depression or state anxiety.

Conclusion

These findings reveal the attentional deficits in sad, angry, and happy faces and the mnemonic deficits in sad and angry faces among elderly who suffer from widowhood and point out the important role of emotional problems such as depression and state anxiety in modulating these emotional cognitive deficits.

Working Memory Performance for Differentially Conditioned Stimuli

Previous work suggests that threat-related stimuli are stored to a greater degree in working memory compared to neutral stimuli. However, most of this research has focused on stimuli with physically salient threat attributes (e.g., angry faces), failing to account for how a "neutral" stimulus that has acquired threat-related associations through differential aversive conditioning influences working memory. The current study examined how differentially conditioned safe (i.e., CS-) and threat (i.e., CS+) stimuli are stored in working memory relative to a novel, non-associated (i.e., N) stimuli. Participants (n = 69) completed a differential fear conditioning task followed by a change detection task consisting of three conditions (CS+, CS-, N) across two loads (small, large). Results revealed individuals successfully learned to distinguishing CS+ from CS- conditions during the differential aversive conditioning task. Our working memory outcomes indicated successful load manipulation effects, but no statistically significant differences in accuracy, response time (RT), or Pashler's K measures of working memory capacity between CS+, CS-, or N conditions. However, we observed significantly reduced RT difference scores for the CS+ compared to CS- condition, indicating greater RT differences between the CS+ and N condition vs. the CS- and N condition. These findings suggest that differentially conditioned stimuli have little impact on behavioral outcomes of working memory compared to novel stimuli that had not been associated with previous safe of aversive outcomes, at least in healthy populations.

Working memory guidance of visual attention to threat in offenders

Aggression and trait anger have been linked to attentional biases toward angry faces and attribution of hostile intent in ambiguous social situations. Memory and emotion play a crucial role in social-cognitive models of aggression but their mechanisms of influence are not fully understood. Combining a memory task and a visual search task, this study investigated the guidance of attention allocation toward naturalistic face targets during visual search by visual working memory (WM) templates in 113 participants who self-reported having served a custodial sentence. Searches were faster when angry faces were held in working memory regardless of the emotional valence of the visual search target. Higher aggression and trait anger predicted increased working memory modulated attentional bias. These results are consistent with the Social-Information Processing model, demonstrating that internal representations bias attention allocation to threat and that the bias is linked to aggression and trait anger.

Physical Versus Sexual Abuse as Reflected in Adolescents' Self-Figure Drawings: A Preliminary Study

Based on the lack of validated assessment tools to detect past physical or sexual abuse, the current study examines to what extent the experience of either sexual or physical abuse is reflected in self-figure drawings of adolescents at-risk. A convenience sample consists of 93 adolescents at risk between the ages of 12-17 recruited from Welfare institutes divided into three groups: Group 1 included adolescents who experienced sexual abuse, Group 2 included adolescents who experienced physical abuse but not sexual abuse, Group 3 included adolescents who experienced neither sexual abuse nor physical abuse. A self-report anonymous questionnaire that consisted of demographics, traumatic events questionnaire, and the Medical Somatic Dissociation Questionnaire (MSDQ) was administered following Ethical approval and signing of consent forms. Participants were asked to draw themselves on an A4 sheet of paper using a pencil. Five social workers who were unaware of participants' experiences assessed the drawings independently for the level of obviousness of the following indicators: face line, eyes, nose, ears, hair stand, forehead, lower body, arms, and hands. Results yielded differences in pictorial indicators (nose, hair stand, lower body) among the groups. MSDQ score was found significantly higher among sexually abused victims.

Negative and Positive Bias for Emotional Faces: Evidence from the Attention and Working Memory Paradigms

Visual attention and visual working memory (VWM) are two major cognitive functions in humans, and they have much in common. A growing body of research has investigated the effect of emotional information on visual attention and VWM. Interestingly, contradictory findings have supported both a negative bias and a positive bias toward emotional faces (e.g., angry faces or happy faces) in the attention and VWM fields. We found that the classical paradigms-that is, the visual search paradigm in attention and the change detection paradigm in VWM-are considerably similar. The settings of these paradigms could therefore be responsible for the contradictory results. In this paper, we compare previous controversial results from behavioral and neuroscience studies using these two paradigms. We suggest three possible contributing factors that have significant impacts on the contradictory conclusions regarding different emotional bias effects; these factors are stimulus choice, experimental setting, and cognitive process. We also propose new research directions and guidelines for future studies.

Source memory and social exchange in young children

Reciprocal interactions require memories of social exchanges; however, little is known about how we remember social partner actions, especially during childhood when we start forming peer-to-peer relationships. This study examined if the expectation-violation effect, which has been observed in adults' source memory, exists among 5-6-year-old children. Forty participants played a coin collection game where they either received or lost coins after being shown an individual with a smiling or angry expression. This set-up generated congruent (smiling-giver and angry-taker) versus incongruent (smiling-taker and angry-giver) conditions. In the subsequent tasks, the children were asked to recall which actions accompanied each individual. The children considered the person with incongruent conditions as being stranger than the person with congruent conditions, suggesting that the former violated the children's emotion-based expectations. However, no heightened source memory was found for the incongruent condition. Instead, children seem to better recognise the action of angry individuals than smiling individuals, suggesting that angry facial expressions are more salient for children's source memory in a social exchange.

Sad expressions during encoding enhance facial identity recognition in visual working memory in depression: Behavioural and electrophysiological evidence

BACKGROUND

Mood-congruent memory biases are prominently featured in cognitive theories of depression. However, how sad expressions during encoding affect facial identity recognition in visual working memory (WM) and the electrophysiological correlates in depressed individuals are unclear.

METHODS

Event-related potentials (ERPs) were recorded from 30 depressed participants and 31 controls during a delayed face discrimination task.

RESULTS

The depressed participants showed lower discrimination power in facial identity recognition than the controls. However, the depressed participants showed higher discrimination power in facial identity recognition for neutral probe faces preceded by sad expressions than for those preceded by happy expressions, while the controls showed no difference. Furthermore, hits (correctly recognizing studied faces) and associated vertex positive potential (VPP), P3b, and late positive potential (LPP) amplitudes were significantly higher for probe faces preceded by sad expressions than for those preceded by happy expressions in the depressed individuals, whereas the controls showed no differences. No such effects were found for correct rejections (correctly rejecting unstudied faces).

LIMITATIONS

The present study is limited due to the relatively small sample size and homogenous university population.

CONCLUSIONS

The findings suggest that for depressed individuals, sad expressions during encoding enhanced discrimination power in facial identity recognition, especially correct recognition of studied faces in visual WM, which was associated with an increase in early structural encoding and more late attentional and perceptual resources following facial identity during retrieval, reflecting a mood-congruent memory bias.

Updating facial emotional expressions in working memory: Differentiating trait anxiety and depressiveness

Individual differences in updating emotional facial expressions in working memory are not fully understood. Here we focused on the effects of high trait anxiety and high depressiveness in men and women on updating schematic emotional facial expressions (sad, angry, scheming, happy, neutral). A population representative sample of young adults was divided into four emotional disposition groups based on STAI-T and MADRS cut-offs: high anxiety (HA, n = 41), high depressiveness (HD, n = 31), high depressiveness & high anxiety (HAHD, n = 65) and control (CT, n = 155). Participants completed a 2-back task with schematic emotional faces, and valence/arousal ratings and verbal recognition tasks. A novel approach was used to separate encoding from retrieval. We found an interaction of emotional dispositions and emotional faces in updating accuracy. HD group made more errors than HA when encoding happy schematic faces. Other differences between emotional dispositions on updating measures were found but they were not specific to any emotional facial expression. Our findings suggest that there is a minor happy disadvantage in HD in contrast to HA which can be seen in lower accuracy for visual encoding of happy faces, but not in retrieval accuracy, the speed of updating, nor perception of emotional content in happy faces. These findings help to explain differences and similarities between high trait anxiety and high depressiveness in working memory and processing of facial expressions. The results are discussed in relation to prevalent theories of information processing in anxiety and depression.

Negative emotional state modulates visual working memory in the late consolidation phase

Although a considerable literature has grown up around the interactions between emotional state and visual working memory (VWM) performance, the mechanism underlying the impact of the negative emotional state on VWM remains unclear. The present study aimed to test whether the influence of emotional state is related to the early phase or late phase of VWM consolidation process. Across three experiments, we found that the negative emotional state did not affect VWM performance when the presentation time of stimuli was short. However, when the presentation time was long, the negative emotional state increased the VWM precision and reduced the VWM number. According to the two-phase model proposed by Ye et al. (2017. A two-phase model of resource allocation in visual working memory. Journal of Experimental Psychology: Learning, Memory, and Cognition, 43(10), 1557-1566. doi: 10.1037/xlm0000376), the results suggested that negative emotional state could affect the late phase of resource allocation in VWM consolidation process, but it has no impact on the early consolidation phase. The findings from this study make important contributions to the current literature regarding the emotional modulation of VWM.

A cross-cultural investigation into the influence of eye gaze on working memory for happy and angry faces

Previous long-term memory (LTM) research found that angry faces were more poorly recognised when encoded with averted vs. direct gaze, while memory for happy faces was unaffected by gaze. Contrastingly, working memory (WM) accuracy for angry faces was unaffected by gaze, but WM was enhanced for happy faces with averted vs. direct gaze. Because the LTM study was conducted in an Eastern culture (Japan) with Japanese faces, while the WM study was conducted in a Western culture (UK) with Caucasian faces, here we investigated WM further to examine whether gaze effects diverge due to cultural variation between the faces and participants. When Western participants viewed Japanese faces (Experiment 1), the happy-averted gaze advantage in WM was replicated. In contrast, Japanese participants viewing Caucasian faces (Experiment 2a) showed poorer WM for angry faces with averted vs. direct gaze, and no influence of gaze on WM for happy faces. When Japanese participants viewed Japanese faces (Experiment 2b), gaze did not modulate WM. Therefore, the way in which expression and gaze interact to influence face WM does not appear to rely on the specific memory system engaged, but instead may be attributed to cultural differences in display rules between Eastern and Western cultures.

Memory facilitation for emotional faces: Visual working memory trade-offs resulting from attentional preference for emotional facial expressions

Visual working memory (VWM) for faces is facilitated when they display negative facial expressions. The present study manipulated the emotional heterogeneity of the encoding display in a change detection task to examine whether VWM is enhanced by having a separate memory store or by a bias in the allocation of limited attentional resource. When the encoding display was emotionally heterogeneous, regardless of whether happy or fearful facial expressions were presented, memory for emotional faces increased while memory for neutral faces decreased, indicating a memory trade-off. To investigate whether this occurred as a result of preferential allocation of attentional resource towards emotional expressions over neutral ones, faces were shown sequentially in different quadrants of the display. The memory trade-off between happy and neutral faces disappeared but persisted between fearful and neutral faces at trailing serial positions. When blank intervals were inserted between faces to prevent fearful faces from having prolonged processing that consumes attentional resource that should be shared with neutral faces, the memory trade-off disappeared. Findings support the argument that emotional expressions facilitate VWM due to their bias in obtaining attentional resource but the exact mechanisms through which limited resource is allocated between happy and fearful expressions may differ.

Sad expressions during encoding attenuate recognition of facial identity in visual working memory: behavioural and electrophysiological evidence

The current study investigated how sad expressions during encoding affected recognition of facial identity in visual working memory (WM) and its electrophysiological correlates. Event-related potentials were obtained from 36 individuals during a delayed face discrimination task. The hit (correctly recognising studied faces) rates, correct rejection (CR: correctly rejecting unstudied faces) rates, sensitivity d' (discrimination power of face identity recognition), and N170 (150-200 ms), the vertex positive potential (VPP; 150-200 ms), N250 (250-300 ms), P3b (350-450 ms), and late positive potential (LPP; 550-800 ms) amplitudes elicited by the neutral probe faces (previously encoded with sad and happy expressions) during hits and CR conditions were analysed. The participants showed lower hits and CRs and therefore had a lower discrimination power for facial identity preceded by sad expressions compared to happy expressions. For hits, neutral probe faces previously encoded with sad expressions exhibited increased N170, VPP, N250, P3b and LPP amplitudes compared to amplitudes following encoding with happy expressions. For correct rejections, the ERP effect of sad/happy expressions was absent. These results indicate that sad expressions during encoding attenuated the recognition of facial identity in visual WM. The reduced facial identity recognition for previously encoded sad expressions may be associated with increased early structural encoding, more late attention and perceptual resource engagement.

Visual Working Memory for Faces and Facial Expressions as a Useful "Tool" for Understanding Social and Affective Cognition

Visual working memory (VWM) is one of the most investigated cognitive systems functioning as a hub between low- and high-level processes. Remarkably, its role in human cognitive architecture makes it a stage of crucial importance for the study of socio-affective cognition, also in relation with psychopathology such as anxiety. Among socio-affective stimuli, faces occupy a place of first importance. How faces and facial expressions are encoded and maintained in VWM is the focus of this review. Within the main theoretical VWM models, we will review research comparing VWM representations of faces and of other classes of stimuli. We will further present previous work investigating if and how both static (i.e., ethnicity, trustworthiness and identity) and changeable (i.e., facial expressions) facial features are represented in VWM. Finally, we will examine research showing qualitative differences in VWM for face representations as a function of psychopathology and personality traits. The findings that we will review are not always coherent with each other, and for this reason we will highlight the main methodological differences as the main source of inconsistency. Finally, we will provide some suggestions for future research in this field in order to foster our understanding of representation of faces in VWM and its potential role in supporting socio-affective cognition.

Recall of facial expressions and simple orientations reveals competition for resources at multiple levels of the visual hierarchy

Many studies of visual working memory have tested humans' ability to reproduce primary visual features of simple objects, such as the orientation of a grating or the hue of a color patch, following a delay. A consistent finding of such studies is that precision of responses declines as the number of items in memory increases. Here we compared visual working memory for primary features and high-level objects. We presented participants with memory arrays consisting of oriented gratings, facial expressions, or a mixture of both. Precision of reproduction for all facial expressions declined steadily as the memory load was increased from one to five faces. For primary features, this decline and the specific distributions of error observed, have been parsimoniously explained in terms of neural population codes. We adapted the population coding model for circular variables to the non-circular and bounded parameter space used for expression estimation. Total population activity was held constant according to the principle of normalization and the intensity of expression was decoded by drawing samples from the Bayesian posterior distribution. The model fit the data well, showing that principles of population coding can be applied to model memory representations at multiple levels of the visual hierarchy. When both gratings and faces had to be remembered, an asymmetry was observed. Increasing the number of faces decreased precision of orientation recall, but increasing the number of gratings did not affect recall of expression, suggesting that memorizing faces involves the automatic encoding of low-level features, in addition to higher-level expression information.

Neural measures of the causal role of observers' facial mimicry on visual working memory for facial expressions

Simulation models of facial expressions propose that sensorimotor regions may increase the clarity of facial expressions representations in extrastriate areas. We monitored the event-related potential marker of visual working memory (VWM) representations, namely the sustained posterior contralateral negativity (SPCN), also termed contralateral delay activity, while participants performed a change detection task including to-be-memorized faces with different intensities of anger. In one condition participants could freely use their facial mimicry during the encoding/VWM maintenance of the faces while in a different condition participants had their facial mimicry blocked by a gel. Notably, SPCN amplitude was reduced for faces in the blocked mimicry condition when compared to the free mimicry condition. This modulation interacted with the empathy levels of participants such that only participants with medium-high empathy scores showed such reduction of the SPCN amplitude when their mimicry was blocked. The SPCN amplitude was larger for full expressions when compared to neutral and subtle expressions, while subtle expressions elicited lower SPCN amplitudes than neutral faces. These findings provide evidence of a functional link between mimicry and VWM for faces and further shed light on how this memory system may receive feedbacks from sensorimotor regions during the processing of facial expressions.

Oscillatory correlates of prioritization of emotional stimuli in WM: The interaction between bottom-up and top-down processes

Working memory can be enhanced by directing attention to task-relevant representations. Alpha oscillations are a neural correlate of spatial attention either to the perceptual or the mnemonic domain. Specifically, an enhancement of alpha power is observed in the ipsilateral posterior cortex to the locus of attention, along with a suppression in the contralateral hemisphere. In this study we aim to unravel the contribution of bottom-up processes in the top-down guidance of attention inside WM. In this way, emotionality of the memoranda was manipulated in a retro-cue task. Behaviorally, we found a recognition advantage for emotional cued items, and significantly, that the emotionality of the non-cued items did not influence accuracy. We found that bilateral alpha power was greater for the emotional irrelevant condition, which could be reflecting the greater demands to suppress an emotional item from the focus of attention. Critically, we found that alpha power lateralization was not modulated by neither the emotionality of the cued or the non-cued items. However, we found that the latency at which alpha lateralization emerged was modulated by the emotionality of the memory representations. In conclusion, we propose that while alpha power lateralization might be reflecting a general spatial orienting mechanism, in our experiment it is influenced by the selection of relevant information within WM.

Affective Working Memory: An Integrative Psychological Construct

When people ruminate about an unfortunate encounter with a loved one, savor a long-sought accomplishment, or hold in mind feelings from a marvelous or regretfully tragic moment, what mental processes orchestrate these psychological phenomena? Such experiences typify how affect interacts with working memory, which we posit can occur in three primary ways: emotional experiences can modulate working memory, working memory can modulate emotional experiences, and feelings can be the mental representations maintained by working memory. We propose that this last mode constitutes distinct neuropsychological processes that support the integration of particular cognitive and affective processes: affective working memory. Accumulating behavioral and neural evidence suggests that affective working memory processes maintain feelings and are partially separable from their cognitive working memory counterparts. Affective working memory may be important for elucidating the contribution of affect to decision making, preserved emotional processes in later life, and mechanisms of psychological dysfunction in clinical disorders. We review basic behavioral, neuroscience, and clinical research that provides evidence for affective working memory; consider its theoretical implications; and evaluate its functional role within the psychological architecture. In sum, the perspective we advocate is that affective working memory is a fundamental mechanism of mind.

Current directions in visual working memory research: An introduction and emerging insights

Visual working memory (VWM) is a core construct in the cognitive (neuro-)sciences, assumed to serve as a hub for information exchange and thus supporting a multitude of cognitive functions related to processing visual information. Here, we give an introduction into key terms and paradigms and an overview of ongoing debates in the field, to which the articles collected in this Special Issue on 'Current Directions in Visual Working Memory Research' contribute. Our aim is to extract, from this overview, some 'emerging' theoretical insights concerning questions such as the optimal way to examine VWM, which types of mental representations contribute to performance on VWM tasks, and how VWM keeps features from the same object together and apart from features of concurrently maintained objects (the binding problem).

Trait anxiety is associated with a decreased visual working memory capacity for faces

Recent work has suggested that anxiety restricts working memory capacity, which may underlie a wide range of cognitive symptoms in anxiety. However, previous literature on the anxiety-visual working memory association yielded mixed results, with some studies demonstrating an anxiety-related increase in visual working memory capacity. In an attempt to gain a more thorough understanding of the relationship between anxiety and visual working memory maintenance function, the current study examined the influence of trait anxiety on visual working memory capacity and resolution for negative, positive, and neutral faces in a large unselected sample, by conducting two different experiments. Experiment 1 used a change-detection task to estimate visual working memory capacity, while Experiment 2 used a modified time-delay estimation task to measure memory precision. Hierarchical linear modeling was used to analyze the relationship between trait anxiety, emotional valence, and visual working memory. Results showed that trait anxiety was associated with decreased visual working memory capacity for faces in a valence-independent manner, whereas anxiety-related change in visual working memory resolution was not significant. This pattern of results was discussed in light of the theories of anxiety and visual working memory.

The impact of visual working memory capacity on the filtering efficiency of emotional face distractors

Emotional faces can serve as distractors for visual working memory (VWM) tasks. An event-related potential called contralateral delay activity (CDA) can measure the filtering efficiency of face distractors. Previous studies have investigated the influence of VWM capacity on filtering efficiency of simple neutral distractors but not of face distractors. We measured the CDA indicative of emotional face filtering during a VWM task related to facial identity. VWM capacity was measured in a separate colour change detection task, and participants were divided to high- and low-capacity groups. The high-capacity group was able to filter out distractors similarly irrespective of its facial emotion. In contrast, the low-capacity group failed in filtering the neutral and angry face distractors, while the filtering was efficient for the happy face distractors. The results indicate that potentially threatening faces are particularly difficult to filter if VWM capacity is limited.

The cost of facing fear: Visual working memory is impaired for faces expressing fear

Previous research has identified numerous factors affecting the capacity and accuracy of visual working memory (VWM). One potentially important factor is the emotionality of the stimuli to be encoded and held in VWM. We often must hold in VWM information that is emotionally charged, but much is still unknown about how the emotionality of stimuli impacts VWM performance. In the current research, we performed four studies examining the impact of fearful facial expressions on VWM for faces. Fearful expressions were found to produce a consistent cost to VWM performance. This cost was modulated by encoding time, but not set size. This cost was only present for faces in an upright orientation consistent with this cost being a product of the emotionality of the faces rather than lower-level perceptual differences between neutral and fearful faces. These findings are discussed in the context of existing theoretical accounts of the impact of emotion on information processing. We suggest that a number of competing effects drive both costs and benefits and are at play when emotional information must be stored in VWM, with the task context determining the balance between them.

Remembering who was where: A happy expression advantage for face identity-location binding in working memory

It is well established that visual working memory (WM) for face identity is enhanced when faces display threatening versus nonthreatening expressions. During social interaction, it is also important to bind person identity with location information in WM to remember who was where, but we lack a clear understanding of how emotional expression influences this. Here, we conducted two touchscreen experiments to investigate how angry versus happy expressions displayed at encoding influenced the precision with which participants relocated a single neutral test face to its original position. Maintenance interval was manipulated (Experiment 2; 1 s, 3 s, 6 s) to assess durability of binding. In both experiments, relocation accuracy was enhanced when faces were happy versus angry, and this happy benefit endured from 1-s to 6-s maintenance interval. Eye movement measures during encoding showed no convincing effects of oculomotor behavior that could readily explain the happy benefit. However, accuracy in general was improved, and the happy benefit was strongest for the last, most recent face fixated at encoding. Improved, durable binding of who was where in the presence of a happy expression may reflect the importance of prosocial navigation.

Effects of Oxytocin on Facial Expression and Identity Working Memory Are Found in Females but Not Males

Although oxytocin (OXT) has been shown to increase the ability of face perception and processing, no study has explored whether it could improve the performance of working memory for emotional expression information in males and females. Thus, we performed a double-blind, mixed-design, placebo-controlled study to investigate the effects of OXT on temporary maintenance/manipulation of facial information through a facial expression (EMO) vs. identity (ID) working memory task, both for males (N = 45) and females (N = 46). Our results showed that in female participants, OXT increased the accuracy of the recognition of faces displaying angry and happy emotions, in the EMO tasks, and also reduced the response time to negative emotional faces, in the ID task. However, the above effects were not present in male subjects. These results indicate that OXT may increase the efficiency of working memory in face processing and this trend is reflected in females rather than in males. This study provides novel evidence for the sexually dimorphic effects of OXT on social cognition.

People are better at maintaining positive than negative emotional states

Determining how people maintain positive and negative emotional states is critical to understanding emotional dynamics, individual differences in emotion, and the instrumental value of emotions. There has been a surge in interest in tasks assessing affective working memory that can examine how people maintain stimulus-independent positive and negative emotional states. In these tasks, people are asked to maintain their emotional state that was induced by an initial stimulus in order to compare that state with the state induced by a subsequent stimulus. It is unclear, however, whether measures of accuracy in this task actually reflect the success of maintaining the initial emotional state. In a series of studies, we introduce an idiographic metric of accuracy that reflects the success of emotional maintenance and use that metric to examine whether people are better at maintaining positive or negative emotional states. We demonstrate that people are generally better at maintaining positive emotional states than they are at maintaining negative emotional states (Studies 1-3). We also show that this effect is not due to decay or to spontaneous interference processes (Studies 2-3), retroactive interference processes (Studies 4-5), or reduced engagement with the initial emotional state (Study 5). Although the mechanism underlying this effect is not yet clear, our results have important implications for understanding emotional maintenance and the possible functions of positive and negative emotions. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

The processing of images of biological threats in visual short-term memory

The idea that there is enhanced memory for negatively, emotionally charged pictures was examined. Performance was measured under rapid, serial visual presentation (RSVP) conditions in which, on every trial, a sequence of six photo-images was presented. Briefly after the offset of the sequence, two alternative images (a target and a foil) were presented and participants attempted to choose which image had occurred in the sequence. Images were of threatening and non-threatening cats and dogs. The target depicted either an animal expressing an emotion distinct from the other images, or the sequences contained only images depicting the same emotional valence. Enhanced memory was found for targets that differed in emotional valence from the other sequence images, compared to targets that expressed the same emotional valence. Further controls in stimulus selection were then introduced and the same emotional distinctiveness effect obtained. In ruling out possible visual and attentional accounts of the data, an informal dual route topic model is discussed. This places emphasis on how visual short-term memory reveals a sensitivity to the emotional content of the input as it unfolds over time. Items that present with a distinctive emotional content stand out in memory.

Updating schematic emotional facial expressions in working memory: Response bias and sensitivity

It is unclear if positive, negative, or neutral emotional expressions have an advantage in short-term recognition. Moreover, it is unclear from previous studies of working memory for emotional faces whether effects of emotions comprise response bias or sensitivity. The aim of this study was to compare how schematic emotional expressions (sad, angry, scheming, happy, and neutral) are discriminated and recognized in an updating task (2-back recognition) in a representative sample of birth cohort of young adults. Schematic facial expressions allow control of identity processing, which is separate from expression processing, and have been used extensively in attention research but not much, until now, in working memory research. We found that expressions with a U-curved mouth (i.e., upwardly curved), namely happy and scheming expressions, favoured a bias towards recognition (i.e., towards indicating that the probe and the stimulus in working memory are the same). Other effects of emotional expression were considerably smaller (1-2% of the variance explained)) compared to a large proportion of variance that was explained by the physical similarity of items being compared. We suggest that the nature of the stimuli plays a role in this. The present application of signal detection methodology with emotional, schematic faces in a working memory procedure requiring fast comparisons helps to resolve important contradictions that have emerged in the emotional perception literature.

Can emotional content reduce the age gap in visual working memory? Evidence from two tasks

Ageing is associated with declines in several cognitive abilities including working memory (WM). The goal of the present study was to assess whether emotional information could reduce the age gap in the quantity and quality (precision) of representations in visual WM. Young and older adults completed a serial image recognition (SIR) task and a colour-image binding (CIB) task. Results of the SIR task showed worse performance for negative than neutral and positive images within the older group, hence enlarging the age gap in WM. In the CIB task, recall precision was lower in the old than young adults, showing an ageing decline in the quality of WM representations. Positive images tended to improve precision, but this boost was similar for both age groups. In sum, emotional content did not reduce the age gap in visual WM.

Conscious Access to Suppressed Threatening Information Is Modulated by Working Memory

Previous research has demonstrated that emotional information processing can be modulated by what is being held in working memory (WM). Here, we showed that such content-based WM effects can occur even when the emotional information is suppressed from conscious awareness. Using the delayed-match-to-sample paradigm in conjunction with continuous flash suppression, we found that suppressed threatening (fearful and angry) faces emerged from suppression faster when they matched the emotional valence of WM contents than when they did not. This effect cannot be explained by perceptual priming, as it disappeared when the faces were only passively viewed and not held in WM. Crucially, such an effect is highly specific to threatening faces but not to happy or neutral faces. Our findings together suggest that WM can modulate nonconscious emotion processing, which highlights the functional association between nonconsciously triggered emotional processes and conscious emotion representation.

Qualitative Analysis of Emotions: Fear and Thrill

People can speak, and this provides opportunities to analyze human emotions using perceived experiences communicated via language, as well as through measurement and imaging techniques that are also applicable to other higher animal species. Here I compare four qualitative methodological approaches to test if, and how, thrill depends on fear. I use eight high-risk, high-skill, real-life outdoor adventure recreation activities to provide the test circumstances. I present data from: >4000 person-days of participant observation; interviews with 40 expert practitioners; retrospective autoethnography of 50 critical incidents over 4 decades; and experimental autoethnography of 60 events. Results from different methods are congruent, but different approaches yield different insights. The principal findings are as follows. Individuals differ in their fear and thrill responses. The same individual may have different responses on different occasions. Fear boosts performance, but panic causes paralysis. Anxiety or apprehension prior to a risky action or event differs from fear experienced during the event itself. The intensity of pre-event fear generally increases with the immediacy of risk to life, and time to contemplate that risk. Fear must be faced, assessed and overcome in order to act. Thrill can occur either during or after a high-risk event. Thrill can occur without fear, and fear without thrill. Below a lower threshold of perceived risk, thrill can occur without fear. Between a lower and upper threshold, thrill increases with fear. Beyond the upper threshold, thrill vanishes but fear remains. This there is a sawtooth relation between fear and thrill. Perceived danger generates intense focus and awareness. Fear and other emotions can disappear during intense concentration and focus. Under high risk, the usual emotional sequence is fear before the action or event, then focus during the action or event, then thrill, relief, or triumph afterward. The emotionless state persists only during the most intense concentration. For events long enough to differentiate time within the events, fear and thrill can arise and fade in different fine-scale sequences.

Affective bias in visual working memory is associated with capacity

How does the affective nature of task stimuli modulate working memory (WM)? This study investigates whether WM maintains emotional information in a biased manner to meet the motivational principle of approaching positivity and avoiding negativity by retaining more approach-related positive content over avoidance-related negative content. This bias may exist regardless of individual differences in WM functionality, as indexed by WM capacity (overall bias hypothesis). Alternatively, this bias may be contingent on WM capacity (capacity-based hypothesis), in which a better WM system may be more likely to reveal an adaptive bias. In two experiments, participants performed change localisation tasks with emotional and non-emotional stimuli to estimate the number of items that they could retain for each of those stimuli. Although participants did not seem to remember one type of emotional content (e.g. happy faces) better than the other type of emotional content (e.g. sad faces), there was a significant correlation between WM capacity and affective bias. Specifically, participants with higher WM capacity for non-emotional stimuli (colours or line-drawing symbols) tended to maintain more happy faces over sad faces. These findings demonstrated the presence of a "built-in" affective bias in WM as a function of its systematic limitations, favouring the capacity-based hypothesis.

From specificity to sensitivity: affective states modulate visual working memory for emotional expressive faces

Previous findings suggest that visual working memory (VWM) preferentially remembers angry looking faces. However, the meaning of facial actions is construed in relation to context. To date, there are no studies investigating the role of perceiver-based context when processing emotional cues in VWM. To explore the influence of affective context on VWM for faces, we conducted two experiments using both a VWM task for emotionally expressive faces and a mood induction procedure. Affective context was manipulated by unpleasant (Experiment 1) and pleasant (Experiment 2) IAPS pictures in order to induce an affect high in motivational intensity (defensive or appetitive, respectively) compared to a low arousal control condition. Results indicated specifically increased sensitivity of VWM for angry looking faces in the neutral condition. Enhanced VWM for angry faces was prevented by inducing affects of high motivational intensity. In both experiments, affective states led to a switch from specific enhancement of angry expressions in VWM to an equally sensitive representation of all emotional expressions. Our findings demonstrate that emotional expressions are of different behavioral relevance for the receiver depending on the affective context, supporting a functional organization of VWM along with flexible resource allocation. In VWM, stimulus processing adjusts to situational requirements and transitions from a specifically prioritizing default mode in predictable environments to a sensitive, hypervigilant mode in exposure to emotional events.