Interaction of prime and target in the subliminal affective priming effect

It has been found that an emotional stimulus such as a facial expression presented subliminally can affect subsequent information processing and behavior, usually by shifting evaluation of a subsequent stimulus to a valence congruent with the previous stimulus. This phenomenon is called subliminal affective priming. The present study was conducted to replicate and expand previous findings by investigating interaction of primes and targets in the affective priming effect. Two conditions were used. Prime (subliminal presentation 35 msec.) of an angry face of a woman and a No Prime control condition. Just after presentation of the prime, an ambiguous angry face or an emotionally neutral face was presented above the threshold of awareness (500 msec.). 12 female undergraduate women judged categories of facial expressions (Anger, Neutral, or Happiness) for the target faces. Analysis indicated that the Anger primes significantly facilitated judgment of anger for the ambiguous angry faces; however, the priming effect of the Anger primes was not observed for neutral faces. Consequently, the present finding suggested that a subliminal affective priming effect should be more prominent when affective valence of primes and targets is congruent.     

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.     

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.     

Contextual influences of emotional speech prosody on face processing: How much is enough?

The influence of emotional prosody on the evaluation of emotional facial expressions was investigated in an event-related brain potential (ERP) study using a priming paradigm, the facial affective decision task. Emotional prosodic fragments of short (200-msec) and medium (400-msec) duration were presented as primes, followed by an emotionally related or unrelated facial expression (or facial grimace, which does not resemble an emotion). Participants judged whether or not the facial expression represented an emotion. ERP results revealed an N400-like differentiation for emotionally related prime-target pairs when compared with unrelated prime-target pairs. Faces preceded by prosodic primes of medium length led to a normal priming effect (larger negativity for unrelated than for related prime-target pairs), but the reverse ERP pattern (larger negativity for related than for unrelated prime-target pairs) was observed for faces preceded by short prosodic primes. These results demonstrate that brief exposure to prosodic cues can establish a meaningful emotional context that influences related facial processing; however, this context does not always lead to a processing advantage when prosodic information is very short in duration.     

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.     

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.     

Boundary conditions for the influence of unfamiliar non-target primes in unconscious evaluative priming: The moderating role of attentional task sets

Evaluative priming by masked emotional stimuli that are not consciously perceived has been taken as evidence that affective stimulus evaluation can also occur unconsciously. However, as masked priming effects were small and frequently observed only for familiar primes that there also presented as visible targets in an evaluative decision task, priming was thought to reflect primarily response activation based on acquired S–R associations and not evaluative semantic stimulus analysis. The present study therefore assessed across three experiments boundary conditions for the emergence of masked evaluative priming effects with unfamiliar primes in an evaluative decision task and investigated the role of the frequency of target repetition on priming with pictorial and verbal stimuli. While familiar primes elicited robust priming effects in all conditions, priming effects by unfamiliar primes were reliably obtained for low repetition (pictures) or unrepeated targets (words), but not for targets repeated at a high frequency. This suggests that unfamiliar masked stimuli only elicit evaluative priming effects when the task set associated with the visible target involves evaluative semantic analysis and is not based on S–R triggered responding as for high repetition targets. The present results therefore converge with the growing body of evidence demonstrating attentional control influences on unconscious processing.     

Emotional context influences access of visual stimuli to anxious individuals' awareness

Anxiety has been associated with enhanced unconscious processing of threat and attentional biases towards threat. Here, we focused on the phenomenology of perception in anxiety and examined whether threat-related material more readily enters anxious than non-anxious individuals' awareness. In six experiments, we compared the stimulus exposures required for each anxiety group to become objectively or subjectively aware of masked facial stimuli varying in emotional expression. Crucially, target emotion was task irrelevant. We found that high trait-anxiety individuals required less sensory evidence (shorter stimulus exposure times) to become aware of the face targets. This anxiety-based difference was observed for fearful faces in all experiments, but with non-threat faces, it emerged only when these were presented among threatening faces. Our findings suggest a prominent role for affective context in high-anxiety individuals' conscious perception of visual stimuli. Possible mechanisms underlying the influence of context in lowering awareness thresholds in anxious individuals are discussed.     

The amygdala is involved in affective priming effect for fearful faces

The object of this study was to investigate whether the amygdala is involved in affective priming effect after stimuli are encoded unconsciously and consciously. During the encoding phase, each masked face (fearful or neutral) was presented to participants six times for 17ms each, using a backward masking paradigm. During the retrieval phase, participants made a fearful/neutral judgment for each face. Half of the faces had the same valence as that seen during encoding (congruent condition) and the other half did not (incongruent condition). Participants were divided into unaware and aware groups based on their subjective and objective awareness assessments. The fMRI results showed that during encoding, the amygdala elicited stronger activation for fearful faces than neutral faces but differed in the hemisphere according to the awareness level. During retrieval, the amygdala showed a significant repetition priming effect, with the congruent faces producing less activation than the incongruent faces, especially for fearful faces. These data suggest that the amygdala is important in unconscious retrieving of memories for emotional faces whether they are encoded consciously or unconsciously.     

What is a nice smile like that doing in a place like this? Automatic affective responses to environments influence the recognition of facial expressions

An affective priming paradigm with pictures of environmental scenes and facial expressions as primes and targets, respectively, was employed in order to investigate the role of natural (e.g., vegetation) and built elements (e.g., buildings) in eliciting rapid affective responses. In Experiment 1, images of environmental scenes were digitally manipulated to make continua of priming pictures with a gradual increase of natural elements (and a decrease of built elements). The primes were followed by presentations of facial expressions of happiness and disgust as to-be-recognized target stimuli. The recognition times of happy faces decreased and the recognition times of disgusted faces increased as the quantity of natural/built material present in the primes increased/decreased. The physical changes also influenced the evaluated restorativeness and affective valence of the primes. In Experiment 2, the primes used in Experiment 1 were manipulated in such a way that they were void of any recognizable natural or built elements but contained either similar colours or similar shapes as primes in Experiment 1. This time the results showed no effect of priming. These results were interpreted to give support for a view that the priming effect by environmental pictures is due to the primes representing environmental scenes and not due to the presence of certain low-level colour or shape information in the primes. In all, the present results provide evidence that perception of environmental scenes elicits automatic affective responses and influences recognition of facial expressions.     

A functional disconnection between spoken and visual word recognition: evidence from unconscious priming.

The goal of the present study is to assess whether there is an automatic and obligatory activation of the phonological lexicon upon the presentation of a written word under unconscious processing conditions. We use a cross-modal version of the masked repetition priming procedure introduced by Forster and Davis (Journal of Experimental Psychology: Learning, Memory, and Cognition 10 (1984) 680) which consists of priming a spoken word by its written equivalent under masked conditions. These trials are randomly mixed with within-modal (visual-visual) repetition priming control trials. Our results show that cross-modal priming effects are absent unless primes are consciously perceived, as assessed by d' scores obtained with a letter/pseudo discrimination task. In contrast, priming effects within the written modality are observed under conscious as well as unconscious processing conditions. We conclude that the systems underlying written and spoken word processing are, respectively, autonomous and connected only under conscious conditions.     

Conscious and unconscious face recognition is improved by high-frequency rTMS on pre-motor cortex

Simulation process and mirroring mechanism appear to be necessary to the recognition of emotional facial expressions. Prefrontal areas were found to support this simulation mechanism. The present research analyzed the role of premotor area in processing emotional faces with different valence (positive vs. negative faces), considering both conscious and unconscious pathways. High-frequency rTMS (10 Hz) stimulation was applied to prefrontal area to induce an activation response when overt (conscious) and covert (unconscious) processing was implicated. Twenty-two subjects were asked to detect emotion/no emotion (anger, fear, happiness, neutral). Error rates (ERs) and response times (RTs) were considered in response to the experimental conditions. ERs and RTs decreased in case of premotor brain activation, specifically in response to fear, for both conscious and unconscious condition. The present results highlight the role of the premotor system for facial expression processing, supporting the existence of two analogous mechanisms for conscious and unconscious condition.     

Stronger suboptimal than optimal affective priming?

The finding of stronger affective priming in less conscious (suboptimal) conditions than in fully conscious (optimal) conditions (S. T. Murphy & R. B. Zajonc, 1993) is theoretically important because it contradicts notions that emotions are primarily reflected by conscious states. In 2 experiments, this pattern of results was obtained. Happy and angry faces were presented both optimally and suboptimally and were masked by unknown ideographs. In Experiment 1, instructions for the conscious and less conscious affective priming conditions were matched, and affective ratings of ideographs were determined. In Experiment 2, a more implicit affective measure (facial electromyography of musculus zygomaticus major and musculus corrugator supercilii) served as the dependent variable. Stronger suboptimal than optimal affective priming was found in both experiments. It is concluded that stronger suboptimal than optimal processing is characteristic for affective processing and that it can also be found when instructions are matched and when a more implicit measure is assessed.     

Nervous Instability and Genius: Military and Political Leaders

Participants (N = 106) performed an affective priming task with facial primes that varied in their skin tone and facial physiognomy, and, which were presented either in color or in gray-scale. Participants' racial evaluations were more positive for Eurocentric than for Afrocentric physiognomy faces. Light skin tone faces were evaluated more positively than dark skin tone faces, but the magnitude of this effect depended on the mode of color presentation. The results suggest that in affective priming tasks, faces might not be processed holistically, and instead, visual features of facial priming stimuli independently affect implicit evaluations.     

Masked emotional priming: A double dissociation between direct and indirect effects reveals non-conscious processing of emotional information beyond valence

We demonstrate non-conscious processing beyond valence by employing the masked emotional priming paradigm (Rohr, Degner, & Wentura, 2012) with a stimulus-onset asynchrony (SOA) variation. Emotional faces were briefly presented and directly masked, followed by the target face, using a SOA of either 43 ms or 143 ms. Targets were categorized as happy, angry, fearful, or sad. With short SOA, we replicated the differentiated priming effect within the negative domain (i.e., angry differentiate from fearful/sad). A direct test of prime awareness indicated that primes could not be discriminated consciously in this condition. With long SOA, however, we did not observe the priming effect whereas the direct test indicated some degree of conscious processing. Thus, indirect effects dissociated from direct effects in our study, an indication for non-conscious processing. Thereby, the present study provides evidence for non-conscious processing of emotional information beyond a simple positive-negative differentiation.     

Processing emotional facial expressions: The role of anxiety and awareness

In this paper, the role of self-reported anxiety and degree of conscious awareness as determinants of the selective processing of affective facial expressions is investigated. In two experiments, an attentional bias toward fearful facial expressions was observed, although this bias was apparent only for those reporting high levels of trait anxiety and only when the emotional face was presented in the left visual field. This pattern was especially strong when the participants were unaware of the presence of the facial stimuli. In Experiment 3, a patient with right-hemisphere brain damage and visual extinction was presented with photographs of faces and fruits on unilateral and bilateral trials. On bilateral trials, it was found that faces produced less extinction than did fruits. Moreover, faces portraying a fearful or a happy expression tended to produce less extinction than did neutral expressions. This suggests that emotional facial expressions may be less dependent on attention to achieve awareness. The implications of these results for understanding the relations between attention, emotion, and anxiety are discussed.     

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.     

非自主闯入焦虑发生的机制：阈下启动效应的实验研究

本研究采用阈下情感启动范式, 研究威胁信息启动效应及其特质焦虑的调节作用,旨在揭示焦虑非自主闯入性特点形成的机制。实验在随机的三种条件下（阈上/阈下/基线）给38名被试呈现两种目标词（威胁词和中性词）,其中基线条件不呈现目标词;之后要求被试在回避目标词的条件下完成组词任务,结果：（1）无论是中性词还是威胁词,被试阈下条件下目标词的击中率显著高于基线条件;（2）特质焦虑对阈下启动效应起着调节作用：高焦虑组被试威胁词的启动效应显著高于中性词,低焦虑组被试中性词的启动效应显著高于威胁词。结论：阈下启动效应显著,高特质焦虑组个体对威胁信息的无意识加工会增强对威胁信息的意识加工,产生闯入性想法,导致焦虑非自主闯入性的特点。     

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.