不同愉悦度面孔阈下情绪启动效应:来自ERP的证据

采用事件相关电位技术,研究阈下情绪启动效应。实验中的因素是阈下呈现的情绪启动面孔的愉悦度,分为高、低两个水平。被试的任务是对中性靶刺激面孔进行情绪判断。结果发现:被试在对靶刺激进行情绪判断时出现与启动刺激愉悦度趋于一致的启动效应;低愉悦度面孔作启动刺激条件下N1和P2的波幅显著大于高愉悦度面孔作为启动刺激的条件;不同愉悦度情绪面孔的阈下启动效应是由于启动刺激影响了对靶刺激的知觉加工所致。     

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。     

Effect of calories on appetite for palatable food in obese and nonobese humans.

Palatable food stimuli were presented to 11 obese and 11 nonobese male human subjects (in three experiments) 1 hr after ingestion of 900-calorie liquid lunches and (on separate days) indentically tasting 450-calorie liquid lunches of equal volume. Salivary responses to the presentation of the stimuli (i.e., appetite) by the nonobese were inhibited by the high-calorie meal, but those by the obses were less inhibited. Hunger ratings were unaffected by calories in either group. Food stimuli were rated as more appetizing by the nonobese after high-calorie meals, but not so by the obese. Parallels with animal findings suggest that salivary responses reflect lateral hypothalamic activity.     

Priming effects on the N400 in the affective priming paradigm with facial expressions of emotion

We studied the effect of facial expression primes on the evaluation of target words through a variant of the affective priming paradigm. In order to make the affective valence of the faces irrelevant to the task, the participants were assigned a double prime–target task in which they were unpredictably asked either to identify the gender of the face or to evaluate whether the word was pleasant or unpleasant. Behavioral and electrophysiological (event-related potential, or ERP) indices of affective priming were analyzed. Temporal and spatial versions of principal components analyses were used to detect and quantify those ERP components associated with affective priming. Although no significant behavioral priming was observed, electrophysiological indices showed a reverse priming effect, in the sense that the amplitude of the N400 was higher in response to congruent than to incongruent negative words. Moreover, a late positive potential (LPP), peaking around 700 ms, was sensitive to affective valence but not to prime–target congruency. This pattern of results is consistent with previous accounts of ERP effects in the affective priming paradigm that have linked the LPP with evaluative priming and the N400 with semantic priming. Our proposed explanation of the N400 priming effects obtained in the present study is based on two assumptions: a double check of affective stimuli in terms of valence and specific emotion content, and the differential specificities of facial expressions of positive and negative emotions.     

Affective Expectations Influence Neural Responses to Stressful Images in Soldiers

In the present study, we examined how expectations about the affective valence of an event influence immediate neurocognitive responses to the event. Both neutral images and negative images displaying war photos were shown to active duty military personnel undergoing predeployment training. Expectations regarding the affective content of upcoming images were manipulated by means of abstract visual cues that were valid only 75% of the time. Besides providing greater ecological validity, inclusion of invalid cues enabled us to examine separately, effects of the expected and actual valence of the images. Neurocognitive responses within the first second after image presentation were examined using the late positive potential (LPP), a noninvasive measure of brain electrical activity known to index affective processes. Negative images evoked an enhanced LPP relative to neutral images over central-parietal and right anterior electrode sites. Both the central-parietal and anterior LPP were found, likewise, to be modulated by expected valence. Expectation of negative versus neutral images led to an enhanced central-parietal LPP and an attenuated anterior LPP over both hemispheres independent of image valence. These findings are interpreted in terms of the allocation of attention to motivationally salient events, affective interpretation of those events, and induced affective/motivational states. By helping to characterize affective responses to acute stress and the regulation of those responses by psychological context, our study contributes to a basic understanding of how such regulation may become disordered and may aid in the development of targets for therapeutic interventions.     

面部表情加工的ERP成分

面部表情加工的ERP成分主要包括P1 (80~120 ms)、N170 (120~200 ms), 早期后部负电位(Early Posterior Negativity, EPN, 200~300 ms)和晚期正成分(Late Positive Potential, LPP, 300 ms以后)。这些成分代表了表情加工的不同阶段, 具有不同的心理含义。P1成分只对威胁类表情(恐惧, 厌恶和愤怒)敏感, 反映了对威胁面孔的快速探测, 具有自动加工的性质。N170成分与表情结构信息的编码有关, 同样具有自动加工的性质。EPN反映了对情绪信息的选择性注意, 具有情绪普遍性, 情绪场景图片和表情刺激都会对它产生影响, 在特定的条件下具有自动加工的性质。LPP则反映了对情绪信息的高级认知加工, 较易受注意控制的影响。在对上述成分的特性了解的基础上, 将来的研究应该探索以下问题：(1) P1是否受表情威胁程度的影响？(2) N170受到哪些自上而下因素的影响？(3)那些不能影响N170成分, 却能影响EPN成分的表情刺激是否被当成了普通的情绪刺激来看待？(4)表情加工引发的LPP是否能具有自动加工的性质？(5)不同的基本表情类型(如恐惧和厌恶)是否具有特异性的ERP成分？     

Slower eating rate reduces the food intake of men, but not women: implications for behavioral weight control

This study tested a central tenet of behavioral weight control: does slower eating rate reduce food intake and positively affect appetite ratings. This study used direct behavioral observation of participants' (n=48; 25BMI35) eating behavior using Universal Eating Monitors. Food intake and ratings of "desire to eat" (collected each minute during meals) were represented as a function of time. Based on an acclimation meal, participants' eating rate was modified by instructing them to eat a bite of food when prompted by a computer, which generated three types of meals: (1) baseline (eating rate was the same as the acclimation meal), (2) reduced-rate (eating rate was reduced by 50%), and (3) combined-rate (eating rate at the beginning of the meal was identical to that of the acclimation meal, subsequently eating rate was reduced by 50%). All meals were ad libitum. Slower eating rate during the reduced-rate and combined-rate meals resulted in less food intake compared to the baseline meal for men, but not women. Ratings of desire to eat, normalized for the amount of food consumed, were lower during the combined-rate meal for men and women. Thus, this basic premise of behavioral weight control was supported for men, but not for women.     

ELECTROCORTICAL DIFFERENTIATION OF EVALUATIVE AND NONEVALUATIVE CATEGORIZATIONS

Abstract— The evaluative categorizations that underlie affective and attitudinal judgments have often been equated with non-evaluative categorizations despite the central importance of evaluative processes for survival In the present experiment, a late positive potential (LPP) of the event-related brain potential elicited when participants evaluatively categorized food items as positive or nonpositive was compared with the LPP elicited when participants semantically (i e., nonevaluatively) categorized food items as vegetable or nonvegetable Results revealed that evaluative categorizations evoked an LPP that was relatively larger over the right than the left scalp regions compared with the LPP evoked by nonevaluative categorizations. This finding provides evidence regarding the differences in neural and cognitive processes involved in evaluative and nonevaluative categorizations.     

Unlearned appetite controls: watersnakes (Nerodia) take smaller meals when they have the choice

Studies of appetite in mammals emphasize that meal size is learned, but lactation and parental care constrain testing of naive individuals. Neonatal reptiles, in contrast, are self-sufficient foragers. The authors examined the effect of prey size on meal size in primivorous (at first feeding) northern watersnakes (Nerodia sipedon). When offered an excess of small prey (2%-20% of snake mass), neonates ate significantly smaller meals (M = 23.5% of snake mass) than when offered a single huge item (range = 32%-55%). The authors conclude that (a) the taking of smaller meals is not a learned effect, (b) there may be a satiety threshold for meal size rather than a target, (c) oropharyngeal stimuli may provide satiety cues, and (d) huge meals may have fitness costs.     

Food intake with an antiobesity drug (sibutramine) versus placebo and rorschach data: a crossover within-subjects study

We related the effect of the satiety enhancing drug sibutramine (Meridia, Reductil) on food intake to Rorschach Comprehensive System (Exner, 1991, 1993) personality factors. A placebo-controlled crossover, within-subjects design (n = 36) was used. Food intake after 2 weeks in the sibutramine and placebo conditions was assessed with a test meal using the VIKTOR (Cabmek, Stockholm, Sweden) setup, a computerized eating monitor. Building on baseline VIKTOR measurements, we had earlier studied the microstructure of eating (Elfhag, Barkeling, Carlsson, & Rossner, 2003). In this study, a model including Afr, MOR, and Populars could explain the variance in the effect of sibutramine. Sibutramine may reduce food intake in single test meals for participants whose appetite is prompted by external stimuli including food cues, suggested by the Affective ratio. Distress related to the body in obesity seen in damaged self-imagery (MOR) and adjustment to social expectations (Populars) could also have a moderating effect on the participants' consumption of test meals in an experimental design. Bodily concern (An + Xy) was also related to sibutramine response in univariate analyses.     

Conflict and surrender during sentence processing: an ERP study of syntax-semantics interaction

Recent ERP studies report that implausible verb-argument combinations can elicit a centro-parietal P600 effect (e.g., "The hearty meal was devouring …"; Kim & Osterhout, 2005). Such eliciting conditions do not involve outright syntactic anomaly, deviating from previous reports of P600. Kim and Osterhout (2005) attributed such P600 effects to structural reprocessing that occurs when syntactic cues fail to support a semantically attractive interpretation ('meal' as the Agent of 'devouring') and the syntactic cues are overwhelmed; the sentence is therefore perceived as syntactically ill-formed. The current study replicated such findings and also found that altering the syntactic cues in such situations of syntax-semantics conflict (e.g., "The hearty meal would devour …") affects the conflict's outcome. P600s were eliminated when sentences contained syntactic cues that required multiple morphosyntactic steps to "repair". These sentences elicited a broad, left-anterior negativity at 300-600ms (LAN). We interpret the reduction in P600 amplitude in terms of "resistance" of syntactic cues to reprocessing. We speculate that the LAN may be generated by difficulty retrieving an analysis that satisfies both syntactic and semantic cues, which results when syntactic cues are strong enough to resist opposing semantic cues. This pattern of effects is consistent with partially independent but highly interactive syntactic and semantic processing streams, which often operate collaboratively but can compete for influence over interpretation.     

Childhood maltreatment is associated with increased neural response to ambiguous threatening facial expressions in adulthood: Evidence from the late positive potential

Childhood maltreatment increases lifetime vulnerability for psychopathology. One proposed mechanism for this association is that early maltreatment increases vigilance for and attention to subtle threat cues, persisting outside of the environment in which maltreatment occurs. To test this possibility, the present study examined neural responses to ambiguous and nonambiguous threatening facial expressions in a sample of 25 adults reporting a history of low-to-moderate levels of abuse in childhood and 46 reporting no or low levels of childhood maltreatment. The measure of neural response used was the late positive potential (LPP), a neural marker of sustained attention to motivationally salient information that is sensitive to subtle variation in emotional content. Participants passively viewed angry–neutral and fearful–neutral face blends and rated emotional intensity for each face. In the maltreated group, as fearful faces increased in emotional intensity, the LPP similarly increased, suggesting increased sensitivity to subtle variation in threatening content. Moreover, the LPP at each level of emotional intensity was not related to current symptoms of anxiety and depression. However, contrary to our hypotheses, adults with a history of abuse did not rate angry or fearful faces as more threatening, nor did they exhibit a larger LPP to angry faces, compared to controls. These findings suggest that childhood maltreatment may be associated with increased sensitivity to ambiguous threatening information in adulthood.     

The persistence of attention to emotion: brain potentials during and after picture presentation

Emotional stimuli have been shown to elicit increased perceptual processing and attentional allocation. The late positive potential (LPP) is a sustained P300-like component of the event-related potential that is enhanced after the presentation of pleasant and unpleasant pictures as compared with neutral pictures. In this study, the LPP was measured using dense array electroencephalograph both before and after pleasant, neutral, and unpleasant images to examine the time course of attentional allocation toward emotional stimuli. Results from 17 participants confirmed that the LPP was larger after emotional than neutral images and that this effect persisted for 800 ms after pleasant picture offset and at least 1,000 ms after unpleasant picture offset. The persistence of increased attention after unpleasant compared to pleasant stimuli is consistent with the existence of a negativity bias. Overall, these results indicate that attentional capture of emotion continues well beyond picture presentation and that this can be measured with the LPP. Implications and directions for future research are discussed.     

Sex differences in asymmetrically perceiving the intensity of facial expressions.

Emotional facial expressions are often asymmetrical, with the left half of the face typically displaying the stronger affective intensity cues. During facial perception, however, most right-handed individuals are biased toward facial affect cues projecting to their own left visual hemifield. Consequently, mirror-reversed faces are typically rated as more emotionally intense than when presented normally. Mirror-reversal permits the most intense side of the expresser's face to project to the visual hemifield biased for processing facial affect cues. This study replicated the mirror-reversal effect in 21 men and 49 women (aged 18-52 yr.) using a videotaped free viewing presentation but also showed the effect of facial orientation is moderated by the sex of the perceiver. The mirror-reversal effect was significant only for men but not for women, suggesting possible sex differences in cerebral organization of systems for facial perception.     

Sensory-specific satiety is intact in amnesics who eat multiple meals

What is the relationship between memory and appetite? We explored this question by examining preferences for recently consumed food in patients with amnesia. Although the patients were unable to remember having eaten, and were inclined to eat multiple meals, we found that sensory-specific satiety was intact in these patients. The data suggest that sensory-specific satiety can occur in the absence of explicit memory for having eaten and that impaired sensory-specific satiety does not underlie the phenomenon of multiple-meal eating in amnesia. Overeating in amnesia may be due to disruption of learned control by physiological aftereffects of a recent meal or to problems utilizing internal cues relating to nutritional state.     

参考选择影响情绪加工相关的ERPs

研究采用情绪图片观看任务,考察双耳乳突参考、全脑平均参考和参考电极标准化技术（Reference electrode standardization technique, REST）对情绪相关ERP成分在波幅、统计功效、内部一致性方面的影响,以及参考选择对ERP伪迹剔除率的影响。结果显示,双耳乳突参考下颞区EPN的波幅显著小于REST和全脑平均参考下的结果,而在顶区LPP上表现出完全相反的结果。此外,双耳乳突和全脑平均参考下更可能检测到P2上负性和中性图片波幅间的差异,而REST和全脑平均参考下更可能检测到EPN的“正性偏向”效应。未来研究应结合以往文献和特定成分谨慎选择参考类型。     

Children prenatally exposed to maternal anxiety devote more attentional resources to neutral pictures

Maternal anxiety during pregnancy can negatively affect fetal neurodevelopment, predisposing the offspring to a higher risk of behavioral and emotional problems later in life. The current study investigates the association between maternal anxiety during pregnancy and child affective picture processing using event‐related brain potentials (ERPs). Mothers reported anxiety during the second trimester using the anxiety subscale of the Symptom Checklist (SCL‐90). At age 4 years, child affective picture processing (N = 86) was measured by recording ERPs during viewing of neutral, pleasant, and unpleasant pictures selected from the International Affective Pictures System. The late positive potential (LPP)—an ERP component reflecting individual differences in affective processing—was used as child outcome. The expected positive association between maternal anxiety and LPP amplitude for unpleasant pictures was not found. Nevertheless, we found a positive association between maternal anxiety during pregnancy and LPP amplitudes for neutral pictures in the middle and late time window at anterior locations (all p < .05). These associations remained significant after adjusting for maternal postnatal anxiety and gestational age at birth and after FDR correction for multiple comparisons. Our study provides neurophysiological evidence that children prenatally exposed to higher maternal anxiety devote more attentional resources to neutral pictures, but not to unpleasant pictures. Possibly, these children show enhanced vigilance for threat when viewing neutral pictures. Although useful in dangerous environments, this enhanced vigilance may predispose children prenatally exposed to higher maternal anxiety to developing behavioral and/or emotional problems later in life. A video abstract of this article can be viewed at: https://www.youtube.com/watch?v=kEzYi6IS2HA     

Task-dependent evaluative processing of moral and emotional content during comprehension: An ERP study

Recently, we showed that when participants passively read about moral transgressions (e.g., adultery), they implicitly engage in the evaluative (good–bad) categorization of incoming information, as indicated by a larger event-related brain potential (ERP) positivity to immoral than to moral scenarios (Leuthold, Kunkel, Mackenzie, & Filik in Social, Cognitive, and Affective Neuroscience, 10, 1021–1029, 2015). Behavioral and neuroimaging studies indicated that explicit moral tasks prioritize the semantic-cognitive analysis of incoming information but that implicit tasks, as used in Leuthold et al. (Social, Cognitive, and Affective Neuroscience, 10, 1021–1029, 2015), favor their affective processing. Therefore, it is unclear whether an affective categorization process is also involved when participants perform explicit moral judgments. Thus, in two experiments, we used similarly constructed morality and emotion materials for which their moral and emotional content had to be inferred from the context. Target sentences from negative vs. neutral emotional scenarios and from moral vs. immoral scenarios were presented using rapid serial visual presentation. In Experiment 1, participants made moral judgments for moral materials and emotional judgments for emotion materials. Negative compared to neutral emotional scenarios elicited a larger posterior ERP positivity (LPP) about 200 ms after critical word onset, whereas immoral compared to moral scenarios elicited a larger anterior negativity (500–700 ms). In Experiment 2, where the same emotional judgment to both types of materials was required, a larger LPP was triggered for both types of materials. These results accord with the view that morality scenarios trigger a semantic-cognitive analysis when participants explicitly judge the moral content of incoming linguistic information but an affective evaluation when judging their emotional content.     

Mothers’ neural responses to infant faces are associated with activation of the maternal care system and observed intrusiveness with their own child

Certain infant facial characteristics, referred to as baby schema, are thought to automatically trigger parenting behavior and affective orientation toward infants. Electroencephalography (EEG) is well suited to assessing the intuitive nature and temporal dynamics of parenting responses, due to its millisecond temporal resolution. Little is known, however, about the relations between neural processing of infant cues and actual parenting behavior in a naturalistic setting. In the present study we examined the event-related potentials (ERPs) of mothers (N = 33) watching infant faces of varying attractiveness, in relation to activation of the maternal care system and the mothers’ observed parenting behavior (sensitivity, nonintrusiveness) with their own child (2–6 years old). The results revealed that, irrespective of the cuteness of the infant face, mothers’ neural processing of infant faces involved both early P1 and P2 components (related to orienting/detecting processes) and late positive potentials (LPPs; related to more controlled cognitive evaluation/attentional engagement). Increased early detection and processing of infant faces (reflected by P1 and P2 activity) was related to increased activation of the parental care system. In later stages of face processing, increased attentional engagement with infant faces (as reflected by LPP activity) was associated with more intrusiveness of a mother with her own child during interaction. These findings suggest that individual variations in responses to infant stimuli are associated with individual differences in parental care system activation and parenting quality. Furthermore, the parental care system might be activated relatively automatically, but actual parenting and caregiving behavior requires more conscious control.     

A large-scale comparison of prospective and retrospective memory development from childhood to middle age

We present the first large-scale comparison of prospective memory (PM) and retrospective memory (RM) from 8 to 50 years of age (N?=?318,614). Participants in an Internet study were asked to remember to click on a smiley face (single-trial event-based PM test) and to indicate whether/where a picture had changed from study to test (single-trial RM test), in both cases after retention intervals filled with working-memory tests and questionnaires. Both PM and RM improved during childhood; however, whereas maximal PM was reached by teenagers, with approximately linear decline through the 20s–40s, RM continued to improve through the 20s and 30s. On both tests, females outperformed males and achieved maximal success at earlier ages. Strikingly, 10–11-year-old girls performed significantly better than females in their late 20s on the PM test. The presence of the smiley face at encoding and temporal uncertainty (expecting it “later” rather than at the “end” of the test) both benefited PM; these effects decreased and increased, respectively, from childhood to middle age. The findings demonstrate that in a cross-sectional study (a) developmental trajectories are qualitatively different between PM and RM, and (b) the relative influence of PM cues differs between younger and older ages.