Recognition memory for emotional faces in amnestic mild cognitive impairment: An event-related potential study

ABSTRACT

This study examined the temporal course of emotional face recognition in amnestic mild cognitive impairment (aMCI). Patients and healthy controls (HC) performed a face recognition task, giving old/new responses to previously studied and novel faces displaying a negative or neutral expression. In aMCI patients, recognition accuracy was preserved for negative faces. Event-related potentials (ERPs) revealed disease-related changes in early perceptual components but not in ERP indices of explicit recognition. Specifically, aMCI patients showed impaired recognition effects for negative faces on the amplitudes of N170 and P2, suggesting deficient memory-related processing of negative faces at the stage of structural encoding and during an early recognition stage at which faces are individuated, respectively. Moreover, while a right-lateralized emotion effect specifically observed for correctly recognized faces on the amplitude of N170 was absent in aMCI, a similar emotion effect for successfully recognized faces on P2 was preserved in the patients, albeit with a different distribution. This suggests that in aMCI facilitated processing of successfully recognized emotional faces starts later in the processing sequence. Nonetheless, an early frontal old/new effect confined to negative faces and a parietal old/new effect unaffected by facial emotion were observed in both groups. This indicates that familiarity and conceptual priming processes may specifically contribute to recognition of negative faces in older adults and that aMCI patients can recruit the same retrieval mechanisms as controls, despite disease-related changes on early perceptual ERP components.     

Age-related changes in amplitude,latency and specialization of ERP responses to faces and watches

ABSTRACT

Healthy aging is associated with impairments in face recognition. While earlier research suggests that these impairments arise during memory retrieval, more recent findings suggest that earlier mechanisms, at the perceptual stage, may also be at play. However, results are often inconsistent and very few studies have included a non-face control stimulus to facilitate interpretation of results with respect to the implication of specialized face mechanisms vs. general cognitive factors. To address these issues, P100, N170 and P200 event-related potentials (ERPs) were measured during processing of faces and watches. For faces, age-related differences were found for P100, N170 and P200 ERPs. For watches, age-related differences were found for N170 and P200 ERPs. Older adults showed less selective and less lateralized N170 responses to faces, suggesting that ERPs can detect age-related de-differentiation of specialized face networks. We conclude that age-related impairments in face recognition arise in part from difficulties in the earliest perceptual stages of visual information processing. A working model is presented based on coarse-to-fine analysis of visually similar exemplars.     

The neurophysiological correlates of face processing in adults and children with Asperger's syndrome

Past research has found evidence for face and emotional expression processing differences between individuals with Asperger's syndrome (AS) and neurotypical (NT) controls at both the neurological and behavioural levels. The aim of the present study was to examine the neurophysiological basis of emotional expression processing in children and adults with AS relative to age- and gender-matched NT controls. High-density event-related potentials were recorded during explicit processing of happy, sad, angry, scared, and neutral faces. Adults with AS were found to exhibit delayed P1 and N170 latencies and smaller N170 amplitudes in comparison to control subjects for all expressions. This may reflect impaired holistic and configural processing of faces in AS adults. However, these differences were not observed between AS and control children. This may result from incomplete development of the neuronal generators of these ERP components and/or early intervention.     

The development of emotional face processing during childhood

Our facial expressions give others the opportunity to access our feelings, and constitute an important nonverbal tool for communication. Many recent studies have investigated emotional perception in adults, and our knowledge of neural processes involved in emotions is increasingly precise. Young children also use faces to express their internal states and perceive emotions in others, but little is known about the neurodevelopment of expression recognition. The goal of the current study was to determine the normal development of facial emotion perception. We recorded ERPs in 82 children 4 to 15 years of age during an implicit processing task with emotional faces. Task and stimuli were the same as those used and validated in an adult study; we focused on the components that showed sensitivity to emotions in adults (P1, N170 and frontal slow wave). An effect of the emotion expressed by faces was seen on the P1 in the youngest children. With increasing age this effect disappeared while an emotional sensitivity emerged on N170. Early emotional processing in young children differed from that observed in the adolescents, who approached adults. In contrast, the later frontal slow wave, although showing typical age effects, was more positive for neutral and happy faces across age groups. Thus, despite the precocious utilization of facial emotions, the neural processing involved in the perception of emotional faces develops in a staggered fashion throughout childhood, with the adult pattern appearing only late in adolescence.     

The association of physical activity to occipito-temporal processing during face recognition

ObjectivesThis study examined the association between physical activity level and primitive cognitive processing during a face recognition task in young adults, a topic that has received little attention.DesignCross-sectional.MethodsThe face recognition task required participants to respond to famous faces but not respond to unfamiliar faces. Task performance and several occipito-temporal event-related brain potentials reflecting the various stages of face processing, from perceptual encoding (N170) to recognition (N250 and face-N400), were assessed during the face recognition task.ResultsAlthough analyses revealed no significant group differences in behavioral performance measures, neuroelectric data showed different time courses of face recognition processes between groups. Active individuals exhibited larger N250 amplitude, reflecting an early stage of facial recognition, for famous relative to unfamiliar faces, whereas inactive individuals did not exhibit such a difference.ConclusionsThese findings are suggestive of a possible association between physical activity and relatively early, primitive cognitive processes.     

Alexithymia and levels of processing: Evidence for an overall deficit in remembering emotion words

Alexithymia is a multifaceted personality construct that is thought to reflect a deficit in the cognitive processing of emotions. The effects of low vs. high Alexithymia, neutral vs. positive vs. negative words processed, and perceptual vs. semantic processing on memory were investigated in a group of 82 students using the levels of processing paradigm and the Remember/Know procedure. No differences were observed between low and high Alexithymia students when neutral material was considered. However, for both levels of processing, high Alexithymia students recalled fewer emotion words (both positive and negative) when “Remember” responses were considered. “Know” responses were comparable across Alexithymia groups. The deficit in the ability to consciously access emotional material (the “Remember” responses) may help explain the impaired regulation of intense emotional states by high Alexithymia individuals.     

Event-related potentials to schematic faces in social phobia

Social phobia has been associated with an attentional bias for angry faces. This study aimed at further characterising this attentional bias by investigating reaction times, heart rates, and ERPs while social phobics, spider phobics, and controls identified either the colour or the emotional quality of angry, happy, or neutral schematic faces. The emotional expression of angry faces did not interfere with the processing of their colour in social phobics, and heart rate, N170 amplitude and parietal late positive potentials (LPPs) of these subjects were also no different from those of non-phobic subjects. However, social phobics showed generally larger P1 amplitudes than non-phobic controls with spider phobic subjects in between. No general threat advantage for angry faces was found. All groups identified neutral schematic faces faster and showed larger late positive amplitudes to neutral than to emotional faces. Furthermore, in all groups the N170 was modulated by the emotional quality of faces. This effect was most pronounced in the emotion identification task.     

知觉负载对负性分心面孔的知觉加工和记忆的影响

本研究采用视觉搜索和意外再认记忆任务,结合事件相关电位技术,考察知觉负载对负性分心面孔的知觉加工和记忆的影响。在视觉搜索任务中,行为上恐惧分心面孔在高负载下干扰任务。ERP结果上,恐惧比中性分心面孔诱发更大的N170和N250;在低负载下恐惧比中性分心面孔诱发更大的N700,在高负载下没有差异。在意外再认记忆中,个体对低负载下的恐惧分心面孔表现出记忆。这些结果说明负性分心物在早期是自动化加工;晚期加工受知觉负载的调节,负载越低对负性分心物的过滤越少,存在对负性分心物的记忆偏向。     

On the Relationship Between Interoceptive Awareness and Alexithymia: Is Interoceptive Awareness Related to Emotional Awareness?

Interoceptive awareness (IA) is associated with emotional experience, the processing of emotional stimuli, and activation of brain structures that monitor the internal visceral and emotional state of the organism. Alexithymia is characterized by difficulties in identifying and describing one's emotions and externally oriented thinking (EOT) and reflects impairments in emotional awareness and the regulation of emotions. This study examined the relationship between alexithymia and IA in a healthy population of N=155 persons. A well-validated heartbeat perception task to measure interoceptive awareness, the Toronto Alexithymia Scale (TAS-20) and a depression questionnaire (BDI-2) were administered to 88 women and 67 men. IA was inversely associated with all features of alexithymia in the whole sample. When considering sex differences, IA turned out to be a relevant negative predictor for the EOT subscale only in men. This large sample investigation in a nonclinical population indicates that IA represents a relevant negative predictor for alexithymia.     

儿童与成人对社会和非社会正性情绪刺激脑电反应特征比较

采用事件相关电位技术探究不同年龄群体社会与非社会正性情绪刺激加工是否具有差异。研究发现：在P2成分上,成人在情绪刺激下诱发的波幅大于儿童;N2成分上,儿童在三种情绪刺激条件下波幅无显著差异。成人在社会性情绪刺激条件下诱发的脑电波幅大于在中性情绪刺激条件和非社会情绪刺激条件下诱发波幅;在LPP早、中、晚时间窗中,儿童的LPP波幅大于成人。由此,儿童与成人在社会和非社会正性情绪刺激加工上存在明显差异。     

Attention to faces modulates early face processing during low but not high face discriminability

In the present study, we investigated whether attention to faces results in sensory gain modulation. Participants were cued to attend either to faces or to scenes in superimposed face—scene images for which face discriminability was manipulated parametrically. The face-sensitive N170 event-related potential component was used as a measure of early face processing. Attention to faces modulated N170 amplitude, but only when faces were not highly discriminable. Additionally, directing attention to faces modulated later processing (~230—300 msec) for all discriminability levels. These results demonstrate that attention to faces can modulate perceptual processing of faces at multiple stages of processing, including early sensory levels. Critically, the early attentional benefit is present only when the “face signal” (i.e., the perceptual quality of the face) in the environment is suboptimal.     

Electrophysiological correlates of emotional face processing after mild traumatic brain injury in preschool children

Evidence suggests that social skills are affected by childhood mild traumatic brain injury (mTBI), but the neural and affective substrates of these difficulties are still underexplored. In particular, nothing is known about consequences on the perception of emotional facial expressions, despite its critical role in social interactions and the importance of the preschool period in the development of this ability. This study thus aimed to investigate the electrophysiological correlates of emotional facial expressions processing after early mTBI. To this end, 18 preschool children (mean age 53 ± 8 months) who sustained mTBI and 15 matched healthy controls (mean age 55 ± 11 months) were presented with pictures of faces expressing anger, happiness, or no emotion (neutral) while event-related potentials (ERP) were recorded. The main results revealed that P1 amplitude was higher for happy faces than for angry faces, and that N170 latency was shorter for emotional faces than for neutral faces in the control group only. These findings suggest that preschool children who sustain mTBI do not present the early emotional effects that are observed in healthy preschool children at visuospatial and visual expertise stages. This study provides new evidence regarding the consequences of childhood mTBI on socioemotional processing, by showing alterations of emotional facial expressions processing, an ability known to underlie social competence and appropriate social interactions.     

Emotional face prediction in rejection sensitive individuals: Evidence from event-related potentials

Human beings live in an uncertain world, but they continuously generate top-down predictions about emotional face information of other people around them. Although the prediction processing has repeatedly been investigated in the literature of prediction, little is known about the impact of rejection sensitive (RS) on individuals’ emotional face prediction. To this end, high and low RS participants were asked to perform an identification task of emotional faces in which target faces were shown in either an angry or happy expression while their brain responses were recorded using an event-related potential (ERP) technique. The behavioral results suggested an effect of emotional face prediction. For the P100 component, low RS participants showed longer P100 peak latencies in the left than right hemisphere when they viewed predictable emotional faces. In addition, low RS participants showed larger N170 mean amplitudes for angry compared to happy faces when they perceived unpredictable faces, but not when these faces were predictable. This presumably reflected a sensibility to angry faces in the unpredictable trails. Interestingly, high RS participants did not demonstrate such a N170 difference, suggesting that high RS participants showed a reduced sensitivity to unpredictable angry faces. Furthermore, angry faces triggered increased LPP mean amplitudes compared to happy faces, which was consistent with the results of other ERP studies examining the processing of emotional faces. Finally, we observed significant negative correlations between behavioral and ERP prediction effect, indicating one consistency between the behavioral and electrophysiological data.     

Early processing of emotional faces in children with autism: An event-related potential study

Social deficits are one of the most striking manifestations of autism spectrum disorders (ASDs). Among these social deficits, the recognition and understanding of emotional facial expressions has been widely reported to be affected in ASDs. We investigated emotional face processing in children with and without autism using event-related potentials (ERPs). High-functioning children with autism (n = 15, mean age = 10.5 ± 3.3 years) completed an implicit emotional task while visual ERPs were recorded. Two groups of typically developing children (chronological age-matched and verbal equivalent age-matched [both ns = 15, mean age = 7.7 ± 3.8 years]) also participated in this study. The early ERP responses to faces (P1 and N170) were delayed, and the P1 was smaller in children with autism than in typically developing children of the same chronological age, revealing that the first stages of emotional face processing are affected in autism. However, when matched by verbal equivalent age, only P1 amplitude remained affected in autism. Our results suggest that the emotional and facial processing difficulties in autism could start from atypicalities in visual perceptual processes involving rapid feedback to primary visual areas and subsequent holistic processing.     

Facial identity and emotional expression as predictors during economic decisions

Two sources of information most relevant to guide social decision making are the cooperative tendencies associated with different people and their facial emotional displays. This electrophysiological experiment aimed to study how the use of personal identity and emotional expressions as cues impacts different stages of face processing and their potential isolated or interactive processing. Participants played a modified trust game with 8 different alleged partners, and in separate blocks either the identity or the emotions carried information regarding potential trial outcomes (win or loss). Behaviorally, participants were faster to make decisions based on identity compared to emotional expressions. Also, ignored (nonpredictive) emotions interfered with decisions based on identity in trials where these sources of information conflicted. Electrophysiological results showed that expectations based on emotions modulated processing earlier in time than those based on identity. Whereas emotion modulated the central N1 and VPP potentials, identity judgments heightened the amplitude of the N2 and P3b. In addition, the conflict that ignored emotions generated was reflected on the N170 and P3b potentials. Overall, our results indicate that using identity or emotional cues to predict cooperation tendencies recruits dissociable neural circuits from an early point in time, and that both sources of information generate early and late interactive patterns.     

The role of spatial attention in the processing of facial expression: An ERP study of rapid brain responses to six basic emotions

To investigate the time course of emotional expression processing, we recorded ERP responses to stimulus arrays containing neutral versus angry, disgusted, fearful, happy, sad, or surprised faces. In one half of the experiment, the task was to discriminate emotional and neutral facial expressions. Here, an enhanced early frontocentral positivity was elicited in response to emotional as opposed to neutral faces, followed by a broadly distributed positivity and an enhanced negativity at lateral posterior sites. These emotional expression effects were very similar for all six basic emotional expressions. In the other half of the experiment, attention was directed away from the faces toward a demanding perceptual discrimination task. Under these conditions, emotional expression effects were completely eliminated, demonstrating that brain processes involved in the detection and analysis of facial expression require focal attention. The face-specific N170 component was unaffected by any emotional expression, supporting the hypothesis that structural encoding and expression analysis are independent processes.     

Effects of implicit power motive on the processing of anger faces: An event-related potential study

Implicit motives are one form of motivation that regulates cognitive and emotional processing. In this study, we investigated the impact of implicit power motive (nPower) on the processing of anger faces. Event-related potentials were recorded while high- and low-nPower individuals performed a face version of an emotion Stroop task comprised of anger and neutral faces. It was found that nPower does not modify early perceptual and attentional components (P2 and N2), but a later component is affected. Indeed, power-motivated participants showed enhanced P3/LPPs (Late positive potentials) amplitude compared to low-nPower subjects, in response to anger stimuli. These findings demonstrate that anger faces have greater salience for high-nPower individuals and are subject to a more salient, conscious processing.     

Men appear more lateralized when noticing emotion in male faces

Empirical tests of the "right hemisphere dominance" versus "valence" theories of emotion processing are confounded by known sex differences in lateralization. Moreover, information about the sex of the person posing an emotion might be processed differently by men and women because of an adaptive male bias to notice expressions of threat and vigilance in other male faces. The purpose of this study was to investigate whether sex of poser and emotion displayed influenced lateralization in men and women by analyzing "laterality quotient" scores on a test which depicts vertically split chimeric faces, formed with one half showing a neutral expression and the other half showing an emotional expression. We found that men (N = 50) were significantly more lateralized for emotions indicative of vigilance and threat (happy, sad, angry, and surprised) in male faces relative to female faces and compared to women (N = 44). These data indicate that sex differences in functional cerebral lateralization for facial emotion may be specific to the emotion presented and the sex of face presenting it.     

Glucose regulation and face recognition deficits in older adults: the role of attention

The present study investigated the perceptual, attentional, and memory processes underlying face recognition deficits observed in older adults with impaired glucoregulation. Participants were categorized as good glucoregulators or poor glucoregulators on the basis of an oral glucose tolerance test. Using event-related potential (ERP) methodology, 23 participants (62–88 years) performed a 2-stimulus oddball task. Participants were asked to rate and memorize 10 “target” faces, which were then presented amongst 120 unfamiliar foils. Behavioral results indicated that good glucoregulators were significantly more accurate at recognizing target faces. ERP markers of early visual perception (P1 and N170 components) and memory formation (P3 component) were unaffected by glucoregulatory efficiency. The P2 component, an index of attentional processing, was larger and delayed in the poor glucoregulators. To the best of our knowledge, this study is the first to suggest that face recognition deficits in poor glucoregulators may be due to impairments in attentional processing.     

Emotional scenes elicit more pronounced self-reported emotional experience and greater EPN and LPP modulation when compared to emotional faces

Emotional faces and scenes carry a wealth of overlapping and distinct perceptual information. Despite widespread use in the investigation of emotional perception, expressive face and evocative scene stimuli are rarely assessed in the same experiment. Here, we evaluated self-reports of arousal and pleasantness, as well as early and late event-related potentials (e.g., N170, early posterior negativity [EPN], late positive potential [LPP]) as subjects viewed neutral and emotional faces and scenes, including contents representing anger, fear, and joy. Results demonstrate that emotional scenes were rated as more evocative than emotional faces, as only scenes produced elevated self-reports of arousal. In addition, viewing scenes resulted in more extreme ratings of pleasantness (and unpleasantness) than did faces. EEG results indicate that both expressive faces and emotional scenes evoke enhanced negativity in the N170 component, while the EPN and LPP components show significantly enhanced modulation only by scene, relative to face stimuli. These data suggest that viewing emotional scenes results in a more pronounced emotional experience that is associated with reliable modulation of visual event-related potentials that are implicated in emotional circuits in the brain.