时间间隔对面部表情唤醒度阈下情绪启动的影响

采用3×4混合实验设计,研究了启动刺激与靶刺激的时间间隔对面部表情唤醒度阈下情绪启动效应的影响,实验因素为启动刺激的唤醒度和时间间隔。结果发现,当时间间隔为200ms、300ms、500ms时,出现了阈下情绪启动效应,时间间隔为700ms时,启动效应消失。上述结果表明阈下情绪启动效应可在唤醒度维度上实现,但此效应只能在启动刺激与靶刺激间隔时间较短的情况下出现。     

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。     

Test-retest reliability of subliminal facial affective priming

Since the seminal 1993 demonstrations o f Murphy an d Zajonc, researchers have replicated and extended findings concerning subliminal affective priming. So far, however, no data on test-retest reliability of affective priming effects are available. A subliminal facial affective priming task was administered to 22 healthy individuals (15 women and 7 men) twice about 7 wk. apart. Happy and sad facial expressions were used as affective primes and neutral Chinese ideographs served as target masks, which had to be evaluated. Neutral facial primes and a no-face condition served as baselines. All participants reported not having seen any of the prime faces at either testing session. Priming scores for affective faces compared to the baselines were computed. Acceptable test-retest correlations (rs) of up to .74 were found for the affective priming scores. Although measured almost 2 mo. apart, subliminal affective priming seems to be a temporally stable effect.     

Face recognition and emotional valence: processing without awareness by neurologically intact participants does not simulate covert recognition in prosopagnosia

Covert face recognition in neurologically intact participants was investigated with the use of very brief stimulus presentation to prevent awareness of the stimulus. In Experiment 1, skin conductance response (SCR) to photographs of celebrity and unfamiliar faces was recorded; the faces were displayed for 220 msec and for 17 msec in a within-participants design. SCR to faces presented for 220 msec was larger and more likely to occur with familiar faces than with unfamiliar faces. Face familiarity did not affect the SCR to faces presented for 17 msec. SCR was larger for faces of good than for faces of evil celebrities presented for 17 msec, but valence did not affect SCR to faces displayed for 220 msec. In Experiment 2, associative priming was found in a face familiarity decision task when the prime face was displayed for 220 msec, but no facilitation occurred when primes were presented for 17 msec. In Experiment 3, participants were able to differentiate evil and good faces presented without awareness in a two-alternative forced-choice decision. The results provide no evidence of familiarity detection outside awareness in normal participants and suggest that, contrary to previous research, very brief presentation to neurologically intact participants is not a useful model for the types of covert recognition found in prosopagnosia. However, a response based on affective valence appears to be available from brief presentation.     

Differential priming effect for subliminal fear and disgust facial expressions

Compared to neutral or happy stimuli, subliminal fear stimuli are known to be well processed through the automatic pathway. We tried to examine whether fear stimuli could be processed more strongly than other negative emotional stimuli using a modified subliminal affective priming paradigm. Twenty-six healthy subjects participated in two separated sessions. Fear, disgust and neutral facial expressions were adopted as primes, and 50% happy facial stimuli were adopted as a target to let only stronger negative primes reveal a priming effect. Participants were asked to appraise the affect of target faces in the affect appraisal session and to appraise the genuineness of target faces in the genuineness appraisal session. The genuineness instruction was developed to help participants be sensitive to potential threats. In the affect appraisal, participants judged 50% happy target faces significantly more 'unpleasant' when they were primed by fear faces than primed by 50% happy control faces. In the genuineness appraisal, participants judged targets significantly more 'not genuine' when they were primed by fear and disgust faces than primed by controls. These findings suggest that there may be differential priming effects between subliminal fear and disgust expressions, which could be modulated by a sensitive context of potential threat.     

No evidence for subliminal affective priming with emotional facial expression primes

The present study investigated whether facial expressions of emotion presented outside consciousness awareness will elicit evaluative responses as assessed in affective priming. Participants were asked to evaluate pleasant and unpleasant target words that were preceded by masked or unmasked schematic (Experiment 1) or photographic faces (Experiments 1 and 2) with happy or angry expressions. They were either required to perform the target evaluation only or to perform the target evaluation and to name the emotion expressed by the face prime. Prime-target interval was 300 ms in Experiment 1 and 80 ms in Experiment 2. Naming performance confirmed the effectiveness of the masking procedure. Affective priming was evident after unmasked primes in tasks that required naming of the facial expressions for schematic and photographic faces and after unmasked primes in tasks that did not require naming for photographic faces. No affective priming was found after masked primes. The present study failed to provide evidence for affective priming with masked face primes, however, it indicates that voluntary attention to the primes enhances affective priming.     

情绪背景对面部表情识别的影响及其作用机制

正确识别面部表情对成功的社会交往有重要意义。面部表情识别受到情绪背景的影响。本文首先介绍了情绪背景对面部表情识别的增强作用,主要表现为视觉通道的情绪一致性效应和跨通道情绪整合效应;然后介绍了情绪背景对面部表情识别的阻碍作用,主要表现为情绪冲突效应和语义阻碍效应;接着介绍了情绪背景对中性和歧义面孔识别的影响,主要表现为背景的情绪诱发效应和阈下情绪启动效应;最后对现有研究进行了总结分析,提出了未来研究的建议。     

Right hemispheric dominance in processing of unconscious negative emotion

Right hemispheric dominance in unconscious emotional processing has been suggested, but remains controversial. This issue was investigated using the subliminal affective priming paradigm combined with unilateral visual presentation in 40 normal subjects. In either left or right visual fields, angry facial expressions, happy facial expressions, or plain gray images were briefly presented as negative, positive, and control primes, followed by a mosaic mask. Then nonsense target ideographs were presented, and the subjects evaluated their partiality toward the targets. When the stimuli were presented in the left, but not the right, visual fields, the negative primes reduced the subjects' liking for the targets, relative to the case of the positive or control primes. These results provided behavioral evidence supporting the hypothesis that the right hemisphere is dominant for unconscious negative emotional processing.     

Right hemispheric dominance in processing of unconscious negative emotion

Right hemispheric dominance in unconscious emotional processing has been suggested, but remains controversial. This issue was investigated using the subliminal affective priming paradigm combined with unilateral visual presentation in 40 normal subjects. In either left or right visual fields, angry facial expressions, happy facial expressions, or plain gray images were briefly presented as negative, positive, and control primes, followed by a mosaic mask. Then nonsense target ideographs were presented, and the subjects evaluated their partiality toward the targets. When the stimuli were presented in the left, but not the right, visual fields, the negative primes reduced the subjects’ liking for the targets, relative to the case of the positive or control primes. These results provided behavioral evidence supporting the hypothesis that the right hemisphere is dominant for unconscious negative emotional processing.     

Stimulus/response learning in masked congruency priming of faces: Evidence for covert mental classifications?

Reaction times for categorization of a probe face according to its sex or fame were contrasted as a function of whether the category of a preceding, sandwich-masked prime face was congruent or incongruent. Prime awareness was measured by the ability to later categorize the primes, and this was close to chance and typically uncorrelated with priming. When prime faces were never presented as visible probes within a test, priming was not reliable; when prime faces were also seen as probes, priming was only reliable if visible and masked presentation of faces were interleaved (not simply if primes had been visible in a previous session). In the latter case, priming was independent of experimentally induced face–response or face–category contingencies, ruling out any simple form of stimulus–response learning. We conclude that the reliable masked congruency priming reflects bindings between stimuli and multiple, abstract classifications that can be generated both overtly and covertly.     

Recognition advantage of happy faces in extrafoveal vision: Featural and affective processing

Happy, surprised, disgusted, angry, sad, fearful, and neutral facial expressions were presented extrafoveally (2.5° away from fixation) for 150 ms, followed by a probe word for recognition (Experiment 1) or a probe scene for affective valence evaluation (Experiment 2). Eye movements were recorded and gaze-contingent masking prevented foveal viewing of the faces. Results showed that (a) happy expressions were recognized faster than others in the absence of fixations on the faces, (b) the same pattern emerged when the faces were presented upright or upside-down, (c) happy prime faces facilitated the affective evaluation of emotionally congruent probe scenes, and (d) such priming effects occurred at 750 but not at 250 ms prime–probe stimulus–onset asynchrony. This reveals an advantage in the recognition of happy faces outside of overt visual attention, and suggests that this recognition advantage relies initially on featural processing and involves processing of positive affect at a later stage.     

Depth of facial expression processing depends on stimulus visibility: Behavioral and electrophysiological evidence of priming effects

Participants performed a priming task during which emotional faces served as prime stimuli and emotional words served as targets. Prime-target pairs were congruent or incongruent, and two levels of prime visibility were obtained by varying the duration of the masked primes. To probe a neural signature of the impact of the masked primes, lateralized readiness potentials (LRPs) were recorded over motor cortex. In the high-visibility condition, responses to word targets were faster when the prime-target pairs were congruent than when they were incongruent, providing evidence of priming effects. In line with the behavioral results, the electrophysiological data showed that high-visibility face primes resulted in LRP differences between congruent and incongruent trials, suggesting that prime stimuli initiated motor preparation. Contrary to the above pattern, no evidence for reaction time or LRP differences was observed in the low-visibility condition, revealing that the depth of facial expression processing is dependent on stimulus visibility.     

An anxiety-related bias in semantic activation when processing threat/neutral homographs

Three experiments are reported comparing high and low-trait anxious subjects in terms of their patterns of semantic activation in response to ambiguous primes, with one threat-related and one neutral meaning. Such primes were followed by targets related to either their threat or neutral meaning, or by unrelated targets, in a lexical decision task. Experiments 1 to 3 employed stimulus onset asynchronies (SOAs) of 750 msec, 500 msec, and 1250 msec, respectively. At 500-msec SOA all subjects showed facilitation for both meanings. At 750-msec SOA the only significant priming effect was that for the threat-related meaning in the high-anxiety group, and a similar trend was found at 1250-msec SOA. Consideration of the patterns of priming for targets following ambiguous threat/neutral primes suggest that at the longer SOAs, high-anxiety subjects consciously “lock on” to a threatening interpretation if one has been made available by earlier automatic spreading activation.     

Masked emotional priming beyond global valence activations

An immense body of research demonstrates that emotional facial expressions can be processed unconsciously. However, it has been assumed that such processing takes place solely on a global valence-based level, allowing individuals to disentangle positive from negative emotions but not the specific emotion. In three studies, we investigated the specificity of emotion processing under conditions of limited awareness using a modified variant of an affective priming task. Faces with happy, angry, sad, fearful, and neutral expressions were presented as masked primes for 33 ms (Study 1) or 14 ms (Studies 2 and 3) followed by emotional target faces (Studies 1 and 2) or emotional adjectives (Study 3). Participants' task was to categorise the target emotion. In all three studies, discrimination of targets was significantly affected by the emotional primes beyond a simple positive versus negative distinction. Results indicate that specific aspects of emotions might be automatically disentangled in addition to valence, even under conditions of subjective unawareness.     

Processing emotional category congruency between emotional facial expressions and emotional words

Facial expressions are critical for effective social communication, and as such may be processed by the visual system even when it might be advantageous to ignore them. Previous research has shown that categorising emotional words was impaired when faces of a conflicting valence were simultaneously presented. In the present study, we examined whether emotional word categorisation would also be impaired when faces of the same (negative) valence but different emotional category (either angry, sad or fearful) were simultaneously presented. Behavioural results provided evidence for involuntary processing of basic emotional facial expression category, with slower word categorisation when the face and word categories were incongruent (e.g., angry word and sad face) than congruent (e.g., angry word and angry face). Event-related potentials (ERPs) time-locked to the presentation of the word–face pairs also revealed that emotional category congruency effects were evident from approximately 170 ms after stimulus onset.     

Masked emotional priming beyond global valence activations

An immense body of research demonstrates that emotional facial expressions can be processed unconsciously. However, it has been assumed that such processing takes place solely on a global valence-based level, allowing individuals to disentangle positive from negative emotions but not the specific emotion. In three studies, we investigated the specificity of emotion processing under conditions of limited awareness using a modified variant of an affective priming task. Faces with happy, angry, sad, fearful, and neutral expressions were presented as masked primes for 33 ms (Study 1) or 14 ms (Studies 2 and 3) followed by emotional target faces (Studies 1 and 2) or emotional adjectives (Study 3). Participants’ task was to categorise the target emotion. In all three studies, discrimination of targets was significantly affected by the emotional primes beyond a simple positive versus negative distinction. Results indicate that specific aspects of emotions might be automatically disentangled in addition to valence, even under conditions of subjective unawareness.     

Spatial frequency filtered images reveal differences between masked and unmasked processing of emotional information

High and low spatial frequency information has been shown to contribute differently to the processing of emotional information. In three priming studies using spatial frequency filtered emotional face primes, emotional face targets, and an emotion categorization task, we investigated this issue further. Differences in the pattern of results between short and masked, and short and long unmasked presentation conditions emerged. Given long and unmasked prime presentation, high and low frequency primes triggered emotion-specific priming effects. Given brief and masked prime presentation in Experiment 2, we found a dissociation: High frequency primes caused a valence priming effect, whereas low frequency primes yielded a differentiation between low and high arousing information within the negative domain. Brief and unmasked prime presentation in Experiment 3 revealed that subliminal processing of primes was responsible for the pattern observed in Experiment 2. The implications of these findings for theories of early emotional information processing are discussed.     

Processing emotional category congruency between emotional facial expressions and emotional words

Facial expressions are critical for effective social communication, and as such may be processed by the visual system even when it might be advantageous to ignore them. Previous research has shown that categorising emotional words was impaired when faces of a conflicting valence were simultaneously presented. In the present study, we examined whether emotional word categorisation would also be impaired when faces of the same (negative) valence but different emotional category (either angry, sad or fearful) were simultaneously presented. Behavioural results provided evidence for involuntary processing of basic emotional facial expression category, with slower word categorisation when the face and word categories were incongruent (e.g., angry word and sad face) than congruent (e.g., angry word and angry face). Event-related potentials (ERPs) time-locked to the presentation of the word-face pairs also revealed that emotional category congruency effects were evident from approximately 170 ms after stimulus onset.     

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.     

Stimulus/response learning in masked congruency priming of faces: evidence for covert mental classifications?

Reaction times for categorization of a probe face according to its sex or fame were contrasted as a function of whether the category of a preceding, sandwich-masked prime face was congruent or incongruent. Prime awareness was measured by the ability to later categorize the primes, and this was close to chance and typically uncorrelated with priming. When prime faces were never presented as visible probes within a test, priming was not reliable; when prime faces were also seen as probes, priming was only reliable if visible and masked presentation of faces were interleaved (not simply if primes had been visible in a previous session). In the latter case, priming was independent of experimentally induced face-response or face-category contingencies, ruling out any simple form of stimulus-response learning. We conclude that the reliable masked congruency priming reflects bindings between stimuli and multiple, abstract classifications that can be generated both overtly and covertly.