Beware the eyes behind the mask: The capture and hold of selective attention by backward masked fearful eyes

Fearful facial expressions are important social indicators of environmental threat. Among the various features of a fearful face, the eyes appear to be particularly important for recognizing and responding to these social cues. One way in which fearful faces facilitate observers’ behavior is by automatically capturing attention. This is true for both consciously and nonconsciously processed fearful faces. Recent research suggests that consciously processed fearful eyes alone are sufficient to capture observers’ attention. However, it is unknown as to whether or not nonconsciously processed, backward masked, fearful eyes are sufficient to facilitate spatial attention. To test this possibility, two dot-probe experiments with masked fearful eye stimuli were performed. In Experiment 1, we found that, relative to scrambled eyes, masked fearful eyes facilitate attentional orienting and delay attentional disengagement. In Experiment 2, we replicated this effect when comparing backward masked fearful to neutral eyes. Thus, the data suggest that nonconscious fearful eyes facilitate spatial attention through facilitated orienting and delayed disengagement.     

Masked fearful faces modulate the orienting of covert spatial attention

Dot probe studies indicate that masked fearful faces modulate spatial attention. However, without a baseline to compare congruent and incongruent reaction times, it is unclear which aspect(s) of attention (orienting or disengagement) is affected. Additionally, backward masking studies commonly use a neutral face as the mask stimulus. This method results in greater perceptual inconsistencies for fearful as opposed to neutral faces. Therefore, it is currently unclear whether the effects of backward masked fearful faces are due to the fearful nature of the face or perceptual inconsistencies. Equally unclear, is whether this spatial attention effect is due to orienting or disengagement. Two modified dot probe experiments with neutral (closed mouth in Experiment 1) and smiling (open mouth in Experiment 2) masks were used to determine the role of perceptual inconsistencies in mediating the spatial attention effects elicited by masked fearful faces. The results indicate that masked fearful faces modulate the orienting of spatial attention, and it appears that this effect is due to the fearful nature of the face rather than perceptual inconsistencies between the initial faces and masks.     

Spatial attention-related modulation of the N170 by backward masked fearful faces

Facial expressions are a basic form of non-verbal communication that convey important social information to others. The relevancy of this information is highlighted by findings that backward masked facial expressions facilitate spatial attention. This attention effect appears to be mediated through a neural network consisting of the amygdala, anterior cingulate, and visual cortex. However, a direct investigation of the neural time course associated with orienting to such stimuli has yet to be performed. In the current investigation, a backward masked fearful face dot-probe task was performed while ERPs were recorded. Reaction time results suggest that spatial attention is captured by backward masked fearful faces and attention is focused at the location of the fear stimulus. Masked right visual field fearful faces enhanced the N170 amplitudes of contralateral occipito-temporal electrodes. The rapid contralateral N170 enhancement was positively correlated with participants’ behavioral index of spatial attention. Thus, backward masked fearful face-elicited spatial attention facilitates behavior and modulates the early stage of facial processing reflected by the N170.     

Attentional bias to brief threat-related faces revealed by saccadic eye movements

According to theories of emotion and attention, we are predisposed to orient rapidly toward threat. However, previous examination of attentional cueing by threat showed no enhanced capture at brief durations, a finding that may be related to the sensitivity of the manual response measure used. Here we investigated the time course of orienting attention toward fearful faces in the exogenous cueing task. Cue duration (20 ms or 100 ms) and response mode (saccadic or manual) were manipulated. In the saccade mode, both enhanced attentional capture and impaired disengagement from fearful faces were evident and limited to 20 ms, suggesting that saccadic cueing effects emerge rapidly and are short lived. In the manual mode, fearful faces impacted only upon the disengagement component of attention at 100 ms, suggesting that manual cueing effects emerge over longer periods of time. Importantly, saccades could reveal threat biases at brief cue durations consistent with current theories of emotion and attention.     

Selective attention and avoidance on a pictorial cueing task during stress in clinically anxious and depressed participants

Although it is well established that attentional biases exist in anxious populations, the specific components of visual orienting towards and away from emotional stimuli are not well delineated. The present study was designed to examine these processes. We used a modified spatial cueing task to assess the speed of engagement and disengagement from supraliminal and masked pictorial cues depicting threat, dysphoria, or neutral content in 36 clinically anxious, 41 depressed and 41 control participants. Participants were randomly assigned to a stress or neutral condition. During stress, anxious participants were slow to disengage from masked left hemifield pictures depicting threat or dysphoria, but were quick to disengage from supraliminal threat pictures. Information processing in anxious participants during stress was characterized by early selective attention of emotional stimuli, occurring prior to full conscious awareness, followed by effortful avoidance of threat. Depressed participants were distinct from the anxious group, displaying selective attention for stimuli depicting dysphoria, but not threat, during the neutral condition. In sum, attentional biases in clinical populations are associated with difficulties in the disengagement component of visual orienting. Further, a vigilant-avoidant pattern of attentional bias may represent a strategic attempt to compensate for the early activation of a fear response.     

Attending to the fear in your eyes: Facilitated orienting and delayed disengagement

Fearful facial expressions convey threat-related information and automatically elicit modulations in spatial attention. The eye-region appears to be a particularly important feature for recognising and responding to fearful faces. However, it is unknown as to whether or not fearful eyes initiate modulations in spatial attention. In the current study, three dot-probe experiments with fearful and neutral eye stimuli were performed. The results of Experiment 1 demonstrate that fearful eyes capture spatial attention through facilitated attentional orienting to threat and delayed attentional disengagement from threat. In Experiments 2 and 3, these attentional effects were replicated, while ruling out the influence of overall size/shape and brightness differences between fearful and neutral eyes, respectively. Thus, fearful eye-whites appear to be a salient feature of fearful facial expressions that elicit modulations in spatial attention.     

Links between rapid ERP responses to fearful faces and conscious awareness

To study links between rapid ERP responses to fearful faces and conscious awareness, a backward‐masking paradigm was employed where fearful or neutral target faces were presented for different durations and were followed by a neutral face mask. Participants had to report target face expression on each trial. When masked faces were clearly visible (200 ms duration), an early frontal positivity, a later more broadly distributed positivity, and a temporo‐occipital negativity were elicited by fearful relative to neutral faces, confirming findings from previous studies with unmasked faces. These emotion‐specific effects were also triggered when masked faces were presented for only 17 ms, but only on trials where fearful faces were successfully detected. When masked faces were shown for 50 ms, a smaller but reliable frontal positivity was also elicited by undetected fearful faces. These results demonstrate that early ERP responses to fearful faces are linked to observers' subjective conscious awareness of such faces, as reflected by their perceptual reports. They suggest that frontal brain regions involved in the construction of conscious representations of facial expression are activated at very short latencies.     

Anxiety sensitivity: the role of conscious awareness and selective attentional bias to physical threat

Selective attentional biases were examined amongst individuals varying in levels of physical anxiety sensitivity. The dot-probe paradigm was used to examine attention towards anxiety symptomatology, social threat and positive words. Stimuli were presented above (unmasked) and below (masked) the level of conscious awareness. High physical anxiety sensitivity was associated with attentional vigilance for anxiety symptomatology words in both unmasked and masked conditions. For positive words, however, those high in anxiety sensitivity were found to avoid such stimuli when they were masked, whereas they exhibited a relative vigilance when unmasked. If the differences between awareness conditions are reliable, then the impact of the automatic vigilance for threat might be modified by conscious attempts to direct attention towards other types of stimuli.     

Attentional bias to threat: Roles of trait anxiety, stressful events, and awareness

Attentional biases for threat stimuli were assessed in high and low trait anxious subjects (n = 66) using a probe detection task. To examine the effects of trait anxiety and situational stressors, each subject was tested three times: Under no stress, laboratory-induced stress, and examination-induced stress. To evaluate the role of awareness, half the word stimuli were presented very briefly (14 msec) and masked, and the other half were presented for 500 msec without a mask. Results showed that high trait anxious subjects under exam stress showed an attentional bias towards unmasked threat stimuli compared with low trait subjects. This effect was not found under lab-induced stress, suggesting that the attentional bias for unmasked threat in high trait subjects may be a function of a prolonged stressor, rather than a transient increase in state anxiety. The results from the masked exposure condition were not predicted; high trait anxious subjects shifted attention towards the spatial location of threat words despite lack of awareness of their lexical content, but this bias was only apparent in the no-stress condition. The results are discussed in relation to recent cognitive theories of anxiety.     

The involvement of distinct visual channels in rapid attention towards fearful facial expressions

This paper reports five experiments demonstrating that the low spatial frequency components of faces are critical to the production of rapid attentional responses towards fearful facial expressions. In our main experiments, low spatial frequency (LSF) or high spatial frequency (HSF) face pairs, consisting of one fearful and one neutral expression, were presented on a computer screen for a brief period. Participants were required to identify as quickly as possible the orientation of a bar target that immediately replaced one of the faces. Responses were faster when targets replaced the location of LSF fearful faces, compared with LSF neutral faces. By contrast, there were no differences between responses to targets replacing HSF fearful versus HSF neutral faces. This facilitation in spatial orienting occurred specifically with short time intervals between faces and target, and is consistent with a rapid processing of fear cues from LSF inputs that can serve to guide attention towards threat events.     

Through the eyes of anxiety: Dissecting threat bias via emotional-binocular rivalry

An extensive body of research has demonstrated that anxious individuals abnormally process threat-related content. Yet, the manner in which clinical anxiety affects the selection of threatening signals and their maintenance within consciousness is yet to be explored. The present study used an emotional binocular rivalry (e-BR) procedure, in which pictures of faces depicting either fearful or neutral expressions competed with pictures of a house for conscious perception. We assumed that first- or cumulative-preferred perception of faces with fearful over neutral expression (i.e., initial or sustained threat bias, respectively) stand for preferential selection or maintenance of fear content in awareness, correspondingly. Unmedicated patients with social anxiety disorder (SAD) and panic disorder (PAD) were compared to healthy controls for threat-related perceptual biases in the e-BR. At first perception of face, both SAD and PAD patients showed a greater initial threat bias than healthy controls. In contrast, at cumulative dwell-time of face, patient groups demonstrated a diminished sustained threat bias relative to healthy controls, yet in a different manner. SAD patients showed a sustained threat bias, though it was smaller than in healthy controls. Furthermore, increased levels of reported anxiety among SAD patients were associated with enhanced sustained perception of neutral faces. PAD patients, on the other hand, showed no sustained threat bias and a diminished cumulative perception of fearful faces with increased levels of anxiety traits. These findings indicate that anxiety disorders commonly involve an initially enhanced selection of threat signals into awareness, followed by disorder-specific manifestation of diminished preferred maintenance of threat in awareness. (PsycINFO Database Record (c) 2012 APA, all rights reserved).     

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.     

Associations between attentional biases to fearful faces and social-emotional development in infants with and without an older sibling with autism

During the first year of life, infants become increasingly attuned to facial emotion, with heightened sensitivity to faces conveying threat observed by age seven months as illustrated through attentional biases (e.g., slower shifting away from fearful faces). Individual differences in these cognitive attentional biases have been discussed in relation to broader social-emotional functioning, and the current study examines these associations in infants with an older sibling with autism spectrum disorder (ASD), a group with an elevated likelihood of a subsequent ASD diagnosis (ELA; n = 33), and a group of infants with no family history of ASD who are at low likelihood of ASD (LLA; n = 24). All infants completed a task measuring disengagement of attention from faces at 12 months (fearful, happy, neutral), and caregivers completed the Infant-Toddler Social and Emotional Assessment at 12, 18, and/or 24 months. For the full sample, greater fear bias in attention disengagement at 12 months related to more internalizing behaviors at 18 months, and this was driven by the LLA infants. When examining groups separately, findings revealed that LLA with a greater fear bias had more difficult behaviors at 12, 18, and 24 months; in contrast, ELA showed the opposite pattern, and this was most pronounced for ELA who later received an ASD diagnosis. These preliminary group-level findings suggest that heightened sensitivity to fearful faces might serve an adaptive function in children who later receive an ASD diagnosis, but in infants with no family history of ASD, increased biases might reflect a marker of social-emotional difficulties.     

Selective attention for masked and unmasked threatening words in anxiety: Effects of trait anxiety, state anxiety and awareness

We investigated the effects of awareness on selective attention for masked and unmasked verbal threat material using a computerised version of the emotional Stroop. Participants were assigned to the high trait anxious (HTA) and low trait anxious (LTA) groups on the basis of questionnaire scores, and state anxiety was manipulated within participants through the threat of electric shock. To investigate the effects of awareness on responses to threat, the mode of exposure was blocked such that half the participants received masked trials before the unmasked trials, whereas the other half received the reverse order. The results revealed that there was no difference between the HTA and LTA groups in responses to threat for those who received the masked trials before the unmasked trials. However, when unmasked trials were presented before the masked trials HTA individuals were significantly slower to respond to both masked and unmasked threat words compared to the LTA group, and these effects were not further modified by participants' state anxiety status. The results are discussed in terms of the automatic nature of threat processing in anxiety.     

Effects of long-term meditation practice on attentional biases towards emotional faces: An eye-tracking study

Attentional biases towards affective stimuli reflect an individual balance of appetitive and aversive motivational systems. Vigilance in relation to threatening information reflects emotional imbalance, associated with affective and somatic problems. It is known that meditation practice significantly improves control of attention, which is considered to be a tool for adaptive emotional regulation. In this regard, the main aim of the present study was to evaluate the influence of meditation on attentional bias towards neutral and emotional facial expressions. Eyes were tracked while 21 healthy controls and 23 experienced meditators (all males) viewed displays consisting of four facial expressions (neutral, angry, fearful and happy) for 10 s. Measures of biases in initial orienting and maintenance of attention were assessed. No effects were found for initial orienting biases. Meditators spent significantly less time viewing angry and fearful faces than control subjects. Furthermore, meditators selectively attended to happy faces whereas control subjects showed attentional biases towards both angry and happy faces. In sum we can conclude that long-term meditation practice adaptively affects attentional biases towards motivationally significant stimuli and that these biases reflect positive mood and predominance of appetitive motivation.     

低自尊个体注意偏向的ERP研究

本研究以高兴、愤怒和中性面孔图片为实验材料,采用空间线索任务,借助事件相关电位技术(ERP)探讨低自尊个体注意偏向的内在机制及生理基础,即从电生理的角度,探讨注意偏向的内在机制是反映了注意的快速定向还是注意的解脱困难,亦或是既有快速注意定向又伴随注意的解脱困难。行为数据发现,高低自尊个体在有效提示下的反应显著快于无效提示条件。脑电数据发现,无效提示条件下,愤怒面孔后的靶子比高兴和中性面孔后的靶子在低自尊个体中诱发了更大的P1和更小的N1波幅,有效提示下无显著差异;高自尊个体在N1和P1波幅上无显著结果。晚期P300成分上,无效提示比有效提示诱发了更正的波幅,未发现自尊相关的显著差异。结果表明,低自尊个体对评价性威胁信息(愤怒)的注意偏向是对威胁信息(愤怒)的注意解脱困难。     

Attention for emotional faces under restricted awareness revisited: do emotional faces automatically attract attention?

Theoretical models of attention for affective information have assigned a special status to the cognitive processing of emotional facial expressions. One specific claim in this regard is that emotional faces automatically attract visual attention. In three experiments, the authors investigated attentional cueing by angry, happy, and neutral facial expressions that were presented under conditions of limited awareness. In these experiments, facial expressions were presented in a masked (14 ms or 34 ms, masked by a neutral face) and unmasked fashion (34 ms or 100 ms). Compared with trials containing neutral cues, delayed responding was found on trials with emotional cues in the unmasked, 100-ms condition, suggesting stronger allocation of cognitive resources to emotional faces. However, in both masked and unmasked conditions, the hypothesized cueing of visual attention to the location of emotional facial expression was not found. In contrary, attentional cueing by emotional faces was less strong compared with neutral faces in the unmasked, 100-ms condition. These data suggest that briefly presented emotional faces influence cognitive processing but do not automatically capture visual attention.     

Effects of mask use and other-race on face perception,emotion recognition,and social distancing during the COVID-19 pandemic

We tested the effect of mask use and other-race effect on (a) face recognition, (b) recognition of facial expressions, and (c) social distance. Caucasian subjects were tested in a matching-to-sample paradigm with either masked or unmasked Caucasian and Asian faces. The participants exhibited the best performance in recognizing an unmasked face condition and the poorest to recognize a masked face that they had seen earlier without a mask. Accuracy was poorer for Asian faces than Caucasian faces. The second experiment presented Asian or Caucasian faces having emotional expressions, with and without masks. The participants' emotion recognition performance decreased for masked faces. From the most accurately to least accurately recognized emotions were as follows: happy, neutral, disgusted, fearful. Performance was poorer for Asian stimuli compared to Caucasian. In Experiment 3 the same participants indicated the social distance they would prefer with each pictured person. They preferred a wider distance with unmasked faces compared to masked faces. Distance from farther to closer was as follows: disgusted, fearful, neutral, and happy. They preferred wider social distance for Asian compared to Caucasian faces. Altogether, findings indicated that during the COVID-19 pandemic mask wearing decreased recognition of faces and emotional expressions, negatively impacting communication among people from different ethnicities.     

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.     

Genetic polymorphisms of the dopamine and serotonin systems modulate the neurophysiological response to feedback and risk taking in healthy humans

Genetic differences in the dopamine and serotonin systems have been suggested as potential factors underlying interindividual variability in risk taking and in brain activation during the processing of feedback. Here, we studied the effects of dopaminergic (dopamine transporter [DAT1], catecholamine-O-methyltransferase val158met [COMT]) and serotonergic (serotonin transporter [5HTTLPR]) polymorphisms on risk taking and brain responses following feedback in 60 healthy female subjects. The subjects completed a well-established experimental gambling paradigm while an electroencephalogram was recorded. During the task, risk-taking behavior and prefrontal brain responses (feedback-related negativity [FRN]) following monetary gains and losses were assessed. FRN amplitudes were enhanced for nine-repeat-allele carriers of the DAT1 and short-allele carriers of 5HTTLPR, which are both presumably linked to less transporter activity and higher neurotransmitter levels. Moreover, nine-repeat DAT1 carriers displayed a trend toward increased risk taking in general, whereas 5HTTLPR short-allele carriers showed decreased risk taking following gains. COMT val158met genotype was unrelated to FRN amplitude and average risk taking. However, COMT met/met carriers showed a pronounced feedback P3 amplitude independent of valence, and a gradual increase in risk taking during the gambling task. In sum, the present findings underline the importance of genetic variability in the dopamine and serotonin systems regarding the neurophysiology of feedback processing.