Assessing the influence of emotional expressions on perceptual sensitivity to faces overcoming interocular suppression.

Detecting faces and identifying their emotional expressions are essential for social interaction. The importance of expressions has prompted suggestions that some emotionally relevant facial features may be processed unconsciously, and it has been further suggested that this unconscious processing yields preferential access to awareness. Evidence for such preferential access has predominantly come from reaction times in the breaking continuous flash suppression (bCFS) paradigm, which measures how long it takes different stimuli to overcome interocular suppression. For instance, it has been claimed that fearful expressions break through suppression faster than neutral expressions. However, in the bCFS procedure, observers can decide how much information they receive before committing to a report, so although their responses may reflect differential detection sensitivity, they may also be influenced by differences in decision criteria, stimulus identification, and response production processes. Here, we employ a procedure that directly measures sensitivity for both face detection and identification of facial expressions, using predefined exposure durations. We apply diverse psychophysical approaches-forced-choice localization, presence/absence detection, and staircase-based threshold measurement; across six experiments, we find that emotional expressions do not alter detection sensitivity to faces as they break through CFS. Our findings constrain the possible mechanisms underlying previous findings: faster reporting of emotional expressions' breakthrough into awareness is unlikely to be due to the presence of emotion affecting perceptual sensitivity; the source of such effects is likely to reside in one of the many other processes that influence response times. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

The importance of awareness in face processing: A critical review of interocular suppression studies.

Human faces convey essential information for understanding others' mental states and intentions. The importance of faces in social interaction has prompted suggestions that some relevant facial features such as configural information, emotional expression, and gaze direction may promote preferential access to awareness. This evidence has predominantly come from interocular suppression studies, with the most common method being the Breaking Continuous Flash Suppression (bCFS) procedure, which measures the time it takes different stimuli to overcome interocular suppression. However, the procedures employed in such studies suffer from multiple methodological limitations. For example, they are unable to disentangle detection from identification processes, their results may be confounded by participants' response bias and decision criteria, they typically use small stimulus sets, and some of their results attributed to detecting high-level facial features (e.g., emotional expression) may be confounded by differences in low-level visual features (e.g., contrast, spatial frequency). In this article, we review the evidence from the bCFS procedure on whether relevant facial features promote access to awareness, discuss the main limitations of this very popular method, and propose strategies to address these issues.

Gaze direction and face orientation modulate perceptual sensitivity to faces under interocular suppression.

Faces convey information essential for social interaction. Their importance has prompted suggestions that some facial features may be processed unconsciously. Although some studies have provided empirical support for this idea, it remains unclear whether these findings were due to perceptual processing or to post-perceptual decisional factors. Evidence for unconscious processing of facial features has predominantly come from the Breaking Continuous Flash Suppression (b-CFS) paradigm, which measures the time it takes different stimuli to overcome interocular suppression. For example, previous studies have found that upright faces are reported faster than inverted faces, and direct-gaze faces are reported faster than averted-gaze faces. However, this procedure suffers from important problems: observers can decide how much information they receive before committing to a report, so their detection responses may be influenced by differences in decision criteria and by stimulus identification. Here, we developed a new procedure that uses predefined exposure durations, enabling independent measurement of perceptual sensitivity and decision criteria. We found higher detection sensitivity to both upright and direct-gaze (compared to inverted and averted-gaze) faces, with no effects on decisional factors. For identification, we found both greater sensitivity and more liberal criteria for upright faces. Our findings demonstrate that face orientation and gaze direction influence perceptual sensitivity, indicating that these facial features may be processed unconsciously.

Reporting in Experimental Philosophy: Current Standards and Recommendations for Future Practice.

Recent replication crises in psychology and other fields have led to intense reflection about the validity of common research practices. Much of this reflection has focussed on reporting standards, and how they may be related to the questionable research practices that could underlie a high proportion of irreproducible findings in the published record. As a developing field, it is particularly important for Experimental Philosophy to avoid some of the pitfalls that have beset other disciplines. To this end, here we provide a detailed, comprehensive assessment of current reporting practices in Experimental Philosophy. We focus on the quality of statistical reporting and the disclosure of information about study methodology. We assess all the articles using quantitative methods (n = 134) that were published over the years 2013-2016 in 29 leading philosophy journals. We find that null hypothesis significance testing is the prevalent statistical practice in Experimental Philosophy, although relying solely on this approach has been criticised in the psychological literature. To augment this approach, various additional measures have become commonplace in other fields, but we find that Experimental Philosophy has adopted these only partially: 53% of the papers report an effect size, 28% confidence intervals, 1% examined prospective statistical power and 5% report observed statistical power. Importantly, we find no direct relation between an article's reporting quality and its impact (numbers of citations). We conclude with recommendations for authors, reviewers and editors in Experimental Philosophy, to facilitate making research statistically-transparent and reproducible.

"There Is No (Where a) Face Like Home": Recognition and Appraisal Responses to Masked Facial Dialects of Emotion in Four Different National Cultures.

The theory of universal emotions suggests that certain emotions such as fear, anger, disgust, sadness, surprise and happiness can be encountered cross-culturally. These emotions are expressed using specific facial movements that enable human communication. More recently, theoretical and empirical models have been used to propose that universal emotions could be expressed via discretely different facial movements in different cultures due to the non-convergent social evolution that takes place in different geographical areas. This has prompted the consideration that own-culture emotional faces have distinct evolutionary important sociobiological value and can be processed automatically, and without conscious awareness. In this paper, we tested this hypothesis using backward masking. We showed, in two different experiments per country of origin, to participants in Britain, Chile, New Zealand and Singapore, backward masked own and other-culture emotional faces. We assessed detection and recognition performance, and self-reports for emotionality and familiarity. We presented thorough cross-cultural experimental evidence that when using Bayesian assessment of non-parametric receiver operating characteristics and hit-versus-miss detection and recognition response analyses, masked faces showing own cultural dialects of emotion were rated higher for emotionality and familiarity compared to other-culture emotional faces and that this effect involved conscious awareness.

Evidence for a minimal role of stimulus awareness in reversal of threat learning.

In an ever-changing environment, survival depends on learning which stimuli represent threat, and also on updating such associations when circumstances shift. It has been claimed that humans can acquire physiological responses to threat-associated stimuli even when they are unaware of them, but the role of awareness in updating threat contingencies remains unknown. This complex process-generating novel responses while suppressing learned ones-relies on distinct neural mechanisms from initial learning, and has only been shown with awareness. Can it occur unconsciously? Here, we present evidence that threat reversal may not require awareness. Participants underwent classical threat conditioning to visual stimuli that were suppressed from awareness. One of two images was paired with an electric shock; halfway through the experiment, contingencies were reversed and the shock was paired with the other image. Despite variations in suppression across participants, we found that physiological responses reflected changes in stimulus-threat pairings independently of stimulus awareness. These findings suggest that unconscious affective processing may be sufficiently flexible to adapt to changing circumstances.

Monetary and non-monetary rewards reduce attentional capture by emotional distractors.

Irrelevant emotional stimuli often capture attention, disrupting ongoing cognitive processes. In two experiments, we examined whether availability of rewards (monetary and non-monetary) can prevent this attentional capture. Participants completed a central letter identification task while attempting to ignore negative, positive, and neutral distractor images that appeared above or below the targets on 25% of trials. Distraction was indexed by slowing on distractor-present trials. Half the participants completed the task with no performance-contingent reward, while the other half earned points for fast and accurate performance. In Experiment 1, points translated into monetary reward, but in Experiment 2, points had no monetary value. In both experiments, reward reduced capture by emotional distractors, showing that even non-monetary reward can aid attentional control. These findings suggest that motivation encourages use of effective cognitive control mechanisms that effectively prevent attentional capture, even when distractors are emotional.

Erratum: Dissociating the physiological components of unconscious emotional responses.

[This corrects the article DOI: 10.1093/nc/nix021.][This corrects the article DOI: 10.1093/nc/nix021.].

Reward elicits cognitive control over emotional distraction: Evidence from pupillometry.

Attention is biased toward emotional stimuli, even when they are irrelevant to current goals. Motivation, elicited by performance-contingent reward, reduces behavioural emotional distraction. In emotionally neutral contexts, reward is thought to encourage use of a proactive cognitive control strategy, altering anticipatory attentional settings to more effectively suppress distractors. The current preregistered study investigates whether a similar proactive shift occurs even when distractors are highly arousing emotional images. We monitored pupil area, an online measure of both cognitive and emotional processing, to examine how reward influences the time course of control. Participants (n = 110) identified a target letter flanking an irrelevant central image. Images were meaningless scrambles on 75% of trials; on the remaining 25%, they were intact positive (erotic), negative (mutilation), or neutral images. Half the participants received financial rewards for fast and accurate performance, while the other half received no performance-contingent reward. Emotional distraction was greater than neutral distraction, and both were attenuated by reward. Consistent with behavioural findings, pupil dilation was greater following emotional than neutral distractors, and dilation to intact distractors (regardless of valence) was decreased by reward. Although reward did not enhance tonic pupil dilation (an index of sustained proactive control), exploratory analyses showed that reward altered the time course of control-eliciting a sharp, rapid, increase in dilation immediately preceding stimulus onset (reflecting dynamic use of anticipatory control), that extended until well after stimulus offset. These findings suggest that reward alters the time course of control by encouraging proactive preparation to rapidly disengage from emotional distractors.

Similar but separate systems underlie perceptual bistability in vision and audition.

The dynamics of perceptual bistability, the phenomenon in which perception switches between different interpretations of an unchanging stimulus, are characterised by very similar properties across a wide range of qualitatively different paradigms. This suggests that perceptual switching may be triggered by some common source. However, it is also possible that perceptual switching may arise from a distributed system, whose components vary according to the specifics of the perceptual experiences involved. Here we used a visual and an auditory task to determine whether individuals show cross-modal commonalities in perceptual switching. We found that individual perceptual switching rates were significantly correlated across modalities. We then asked whether perceptual switching arises from some central (modality-) task-independent process or from a more distributed task-specific system. We found that a log-normal distribution best explained the distribution of perceptual phases in both modalities, suggestive of a combined set of independent processes causing perceptual switching. Modality- and/or task-dependent differences in these distributions, and lack of correlation with the modality-independent central factors tested (ego-resiliency, creativity, and executive function), also point towards perceptual switching arising from a distributed system of similar but independent processes.

The importance of awareness for understanding language.

Is consciousness required for high level cognitive processes, or can the unconscious mind perform tasks that are as complex and difficult as, for example, understanding a sentence? Recent work has argued that, yes, the unconscious mind can: Sklar et al. (2012) found that sentences, masked from consciousness using the technique of continuous flash suppression (CFS), broke into awareness more rapidly when their meanings were more unusual or more emotionally negative, even though processing the sentences' meaning required unconsciously combining each word's meaning. This has motivated the important claim that consciousness plays little-to-no functional role in high-level cognitive operations. Here, we aimed to replicate and extend these findings, but instead, across 10 high-powered studies, we found no evidence that the meaning of a phrase or word could be understood without awareness. We did, however, consistently find evidence that low-level perceptual features, such as sentence length and familiarity of alphabet, could be processed unconsciously. Our null findings for sentence processing are corroborated by a meta-analysis that aggregates our studies with the prior literature. We offer a potential explanation for prior positive results through a set of computational simulations, which show how the distributional characteristics of this type of CFS data, in particular its skew and heavy tail, can cause an elevated level of false positive results when common data exclusion criteria are applied. Our findings thus have practical implication for analyzing such data. More importantly, they suggest that consciousness may well be required for high-level cognitive tasks such as understanding language. (PsycINFO Database Record

Motivation enhances control of positive and negative emotional distractions.

Using cognitive control to ignore distractions is essential for successfully achieving our goals. In emotionally-neutral contexts, motivation can reduce interference from irrelevant stimuli by enhancing cognitive control. However, attention is commonly biased towards emotional stimuli, making them potent distractors. Can motivation aid control of emotional distractions, and does it do so similarly for positive and negative stimuli? Here, we examined how task motivation influences control of distraction from positive, negative, and neutral scenes. Participants completed a simple perceptual task while attempting to ignore task-irrelevant images. One group received monetary reward for fast and accurate task performance; another (control) group did not. Overall, both negative (mutilation) and positive (erotic) images caused greater slowing of responses than neutral images of people, but emotional distraction was reduced with reward. Crucially, despite the different motivational directions associated with negative and positive stimuli, reward reduced negative and positive distraction equally. Our findings suggest that motivation may encourage the use of a sustained proactive control strategy that can effectively reduce the impact of emotional distraction.

Contrasting reactive and proactive control of emotional distraction.

Attending to emotional stimuli is often beneficial, because they provide important social and environmental cues. Sometimes, however, current goals require that we ignore them. To what extent can we control emotional distraction? Here we show that the ability to ignore emotional distractions depends on the type of cognitive control that is engaged. Participants completed a simple perceptual task at fixation while irrelevant images appeared peripherally. In 2 experiments, we manipulated the proportion of trials in which images appeared, to encourage use of either reactive control (rare distractors) or proactive control (frequent distractors). Under reactive control, both negative and positive images were more distracting than neutral images, even though they were irrelevant and appeared in unattended locations. However, under proactive control, distraction by both emotional and neutral images was eliminated. Proactive control was triggered by the meaning, and not the location, of distracting images. Our findings argue against simple bottom-up or top-down explanations of emotional distraction, and instead show how the flexible use of cognitive control supports adaptive processing of emotional distractors. (PsycINFO Database Record

Dissociating the physiological components of unconscious emotional responses.

Conscious emotional processing is characterized by a coordinated set of responses across multiple physiological systems. Although emotional stimuli can evoke certain physiological responses even when they are suppressed from awareness, it is not known whether unconscious emotional responses comprise a similar constellation or are confined to specific systems. To compare physiological responses to emotional stimuli with and without awareness, we measured a range of responses while participants viewed positive, negative and neutral images that were accompanied by noise bursts to elicit startle reflexes. We measured four responses simultaneously - skin conductance and heart rate changes in response to the images themselves; and startle eye-blink and post-auricular reflexes in response to the noise bursts that occurred during image presentation. For half of the participants, the images were masked from awareness using continuous flash suppression. The aware group showed the expected pattern of response across physiological systems: emotional images (regardless of valence) evoked larger skin conductance responses (SCRs) and greater heart rate deceleration than neutral images, negative images enhanced eye-blink reflexes and positive images enhanced post-auricular reflexes. In contrast, we found a striking dissociation between measures for the unaware group: typical modulation of SCRs and post-auricular reflexes, but no modulation of heart rate deceleration or eye-blink reflexes. Our findings suggest that although some physiological systems respond to emotional stimuli presented outside of awareness, conscious emotional processing may be characterized by a broad and coordinated set of responses across systems.

An asymmetric inhibition model of hemispheric differences in emotional processing.

Two relatively independent lines of research have addressed the role of the prefrontal cortex in emotional processing. The first examines hemispheric asymmetries in frontal function; the second focuses on prefrontal interactions between cognition and emotion. We briefly review each perspective and highlight inconsistencies between them. We go on to describe an alternative model that integrates approaches by focusing on hemispheric asymmetry in inhibitory executive control processes. The asymmetric inhibition model proposes that right-lateralized executive control inhibits processing of positive or approach-related distractors, and left-lateralized control inhibits negative or withdrawal-related distractors. These complementary processes allow us to maintain and achieve current goals in the face of emotional distraction. We conclude with a research agenda that uses the model to generate novel experiments that will advance our understanding of both hemispheric asymmetries and cognition-emotion interactions.

When Pinocchio's nose does not grow: belief regarding lie-detectability modulates production of deception.

Does the brain activity underlying the production of deception differ depending on whether or not one believes their deception can be detected? To address this question, we had participants commit a mock theft in a laboratory setting, and then interrogated them while they underwent functional MRI (fMRI) scanning. Crucially, during some parts of the interrogation participants believed a lie-detector was activated, whereas in other parts they were told it was switched-off. We were thus able to examine the neural activity associated with the contrast between producing true vs. false claims, as well as the independent contrast between believing that deception could and could not be detected. We found increased activation in the right amygdala and inferior frontal gyrus (IFG), as well as the left posterior cingulate cortex (PCC), during the production of false (compared to true) claims. Importantly, there was a significant interaction between the effects of deception and belief in the left temporal pole and right hippocampus/parahippocampal gyrus, where activity increased during the production of deception when participants believed their false claims could be detected, but not when they believed the lie-detector was switched-off. As these regions are associated with binding socially complex perceptual input and memory retrieval, we conclude that producing deceptive behavior in a context in which one believes this deception can be detected is associated with a cognitively taxing effort to reconcile contradictions between one's actions and recollections.

Weight and see: loading working memory improves incidental identification of irrelevant faces.

Are task-irrelevant stimuli processed to a level enabling individual identification? This question is central both for perceptual processing models and for applied settings (e.g., eye-witness testimony). Lavie's load theory proposes that working memory actively maintains attentional prioritization of relevant over irrelevant information. Loading working memory thus impairs attentional prioritization, leading to increased processing of task-irrelevant stimuli. Previous research has shown that increased working memory load leads to greater interference effects from response-competing distractors. Here we test the novel prediction that increased processing of irrelevant stimuli under high working memory load should lead to a greater likelihood of incidental identification of entirely irrelevant stimuli. To test this, we asked participants to perform a word-categorization task while ignoring task-irrelevant images. The categorization task was performed during the retention interval of a working memory task with either low or high load (defined by memory set size). Following the final experimental trial, a surprise question assessed incidental identification of the irrelevant image. Loading working memory was found to improve identification of task-irrelevant faces, but not of building stimuli (shown in a separate experiment to be less distracting). These findings suggest that working memory plays a critical role in determining whether distracting stimuli will be subsequently identified.