The presence of fear: How subjective fear, not physiological changes, shapes the experience of presence.

When we become engrossed in novels, films, games, or even our own wandering thoughts, we can feel present in a reality distinct from the real world. Although this subjective sense of presence is, presumably, a ubiquitous aspect of conscious experience, the mechanisms that produce it are unknown. Correlational studies conducted in virtual reality have shown that we feel more present when we are afraid, motivating claims that physiological changes contribute to presence; however, such causal claims remain to be evaluated. Here, we report two experiments that test the causal role of subjective and physiological components of fear (i.e., activation of the sympathetic nervous system) in generating presence. In Study 1, we validated a virtual reality simulation capable of inducing fear. Participants rated their emotions while they crossed a wooden plank that appeared to be suspended above a city street; at the same time, we recorded heart rate and skin conductance levels. Height exposure increased ratings of fear, presence, and both measures of sympathetic activation. Although presence and fear ratings were correlated during height exposure, presence and sympathetic activation were unrelated. In Study 2, we manipulated whether the plank appeared at height or at ground level. We also captured participants' movements, which revealed that alongside increases in subjective fear, presence, and sympathetic activation, participants also moved more slowly at height relative to controls. Using a mediational approach, we found that the relationship between height exposure and presence on the plank was fully mediated by self-reported fear, and not by sympathetic activation. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Emotion in motion: perceiving fear in the behaviour of individuals from minimal motion capture displays.

The ability to quickly and accurately recognise emotional states is adaptive for numerous social functions. Although body movements are a potentially crucial cue for inferring emotions, few studies have studied the perception of body movements made in naturalistic emotional states. The current research focuses on the use of body movement information in the perception of fear expressed by targets in a virtual heights paradigm. Across three studies, participants made judgments about the emotional states of others based on motion-capture body movement recordings of those individuals actively engaged in walking a virtual plank at ground-level or 80 stories above a city street. Results indicated that participants were reliably able to differentiate between height and non-height conditions (Studies 1 & 2), were more likely to spontaneously describe target behaviour in the height condition as fearful (Study 2) and their fear estimates were highly calibrated with the fear ratings from the targets (Studies 1-3). Findings show that VR height scenarios can induce fearful behaviour and that people can perceive fear in minimal representations of body movement.

The Promises and Pitfalls of Virtual Reality.

Increasingly, Virtual Reality technologies are finding a place in psychology and behavioral neuroscience labs. Immersing participants in virtual worlds enables researchers to investigate empirical questions in realistic or imaginary environments while measuring a wide range of behavioral responses, without sacrificing experimental control. In this chapter, we aim to provide a balanced appraisal of VR research methods. We describe how VR can help advance psychological science by opening pathways for addressing many pernicious challenges currently facing science (e.g., direct replication, prioritizing ecological validity). We also outline a range of unique and perhaps unanticipated obstacles and provide practical recommendations to overcome them.

Walk the plank! Using mobile electroencephalography to investigate emotional lateralization of immersive fear in virtual reality.

Most studies on emotion processing induce emotions through images or films. However, this method lacks ecological validity, limiting generalization to real-life emotion processing. More realistic paradigms using virtual reality (VR) may be better suited to investigate authentic emotional states and their neuronal correlates. This pre-registered study examines the neuronal underpinnings of naturalistic fear, measured using mobile electroencephalography (EEG). Seventy-five healthy participants walked across a virtual plank which extended from the side of a skyscraper-either 80 storeys up (the negative condition) or at street level (the neutral condition). Subjective ratings showed that the negative condition induced feelings of fear. Following the VR experience, participants passively viewed negative and neutral images from the international affective picture system (IAPS) outside of VR. We compared frontal alpha asymmetry between the plank and IAPS task and across valence of the conditions. Asymmetry indices in the plank task revealed greater right-hemispheric lateralization during the negative VR condition, relative to the neutral VR condition and to IAPS viewing. Within the IAPS task, no significant asymmetries were detected. In summary, our findings indicate that immersive technologies such as VR can advance emotion research by providing more ecologically valid ways to induce emotion.

Laterality indices consensus initiative (LICI): A Delphi expert survey report on recommendations to record, assess, and report asymmetry in human behavioural and brain research.

Laterality indices (LIs) quantify the left-right asymmetry of brain and behavioural variables and provide a measure that is statistically convenient and seemingly easy to interpret. Substantial variability in how structural and functional asymmetries are recorded, calculated, and reported, however, suggest little agreement on the conditions required for its valid assessment. The present study aimed for consensus on general aspects in this context of laterality research, and more specifically within a particular method or technique (i.e., dichotic listening, visual half-field technique, performance asymmetries, preference bias reports, electrophysiological recording, functional MRI, structural MRI, and functional transcranial Doppler sonography). Experts in laterality research were invited to participate in an online Delphi survey to evaluate consensus and stimulate discussion. In Round 0, 106 experts generated 453 statements on what they considered good practice in their field of expertise. Statements were organised into a 295-statement survey that the experts then were asked, in Round 1, to independently assess for importance and support, which further reduced the survey to 241 statements that were presented again to the experts in Round 2. Based on the Round 2 input, we present a set of critically reviewed key recommendations to record, assess, and report laterality research for various methods.

Emotional responding to overt and subtle social exclusion among young women who engage in non-suicidal self-injury.

People who engage in non-suicidal self-injury (NSSI) consistently report greater emotion reactivity and dysregulation than their peers. However, evidence that these self-reports reflect an amplified emotional response under controlled conditions is limited. Here we test the effects of both subtle and overt social exclusion, to determine whether self-reported emotion dysregulation reflects responses to real-time emotional challenge for people who self-injure. We recruited 100 young women with past-year NSSI and 100 without NSSI to an online experiment. Participants took part in a baseline social inclusion ball-tossing game, followed by either an overt or subtle social exclusion ball-tossing game, while we measured negative mood and belongingness. Despite reporting greater emotion reactivity (d = 1.40) and dysregulation (d = 1.63) than controls, women with past-year NSSI showed no differences in negative mood or belongingness ratings in response to either overt or subtle social exclusion. Within the NSSI group, exploratory analyses found greater endorsement of intrapersonal functions predicted greater negative mood following social exclusion (ß = 0.19). Given that amplified emotional responding is central to prominent theoretical models of NSSI, findings highlight the need to better understand the divergence in findings between self-reported emotion dysregulation and real-time emotional responding among people who self-injure.

Lateralized Learning to Solve Complex Boolean Problems.

Modern classifier systems can effectively classify targets that consist of simple patterns. However, they can fail to detect hierarchical patterns of features that exist in many real-world problems, such as understanding speech or recognizing object ontologies. Biological nervous systems have the ability to abstract knowledge from simple and small-scale problems in order to then apply it to resolve more complex problems in similar and related domains. It is thought that lateral asymmetry of biological brains allows modular learning to occur at different levels of abstraction, which can then be transferred between tasks. This work develops a novel evolutionary machine-learning (EML) system that incorporates lateralization and modular learning at different levels of abstraction. The results of analyzable Boolean tasks show that the lateralized system has the ability to encapsulate underlying knowledge patterns in the form of building blocks of knowledge (BBK). Lateralized abstraction transforms complex problems into simple ones by reusing general patterns (e.g., any parity problem becomes a sequence of the 2-bit parity problem). By enabling abstraction in evolutionary computation, the lateralized system is able to identify complex patterns (e.g., in hierarchical multiplexer (HMux) problems) better than existing systems.

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.

Proactive Control of Emotional Distraction: Evidence From EEG Alpha Suppression.

Biased attention towards emotional stimuli is adaptive, as it facilitates responses to important threats and rewards. An unfortunate consequence is that emotional stimuli can become potent distractors when they are irrelevant to current goals. How can this distraction be overcome despite the bias to attend to emotional stimuli? Recent studies show that distraction by irrelevant flankers is reduced when distractor frequency is high, even if they are emotional. A parsimonious explanation is that the expectation of frequent distractors promotes the use of proactive control, whereby attentional control settings can be altered to minimize distraction before it occurs. It is difficult, however, to infer proactive control on the basis of behavioral data alone. We therefore measured neural indices of proactive control while participants performed a target-detection task in which irrelevant peripheral distractors (either emotional or neutral) could appear either frequently (on 75% of trials) or rarely (on 25% of trials). We measured alpha power during the pre-stimulus period to assess proactive control and during the post-stimulus period to determine the consequences of control for subsequent processing. Pre-stimulus alpha power was tonically suppressed in the high, compared to low, distractor frequency condition, regardless of expected distractor valence, indicating sustained use of proactive control. In contrast, post-stimulus alpha suppression was reduced in the high-frequency condition, suggesting that proactive control reduced the need for post-stimulus adjustments. Our findings indicate that a sustained proactive control strategy accounts for the reduction in both emotional and non-emotional distraction when distractors are expected to appear frequently.

Universal Patterns in Color-Emotion Associations Are Further Shaped by Linguistic and Geographic Proximity.

Many of us "see red," "feel blue," or "turn green with envy." Are such color-emotion associations fundamental to our shared cognitive architecture, or are they cultural creations learned through our languages and traditions? To answer these questions, we tested emotional associations of colors in 4,598 participants from 30 nations speaking 22 native languages. Participants associated 20 emotion concepts with 12 color terms. Pattern-similarity analyses revealed universal color-emotion associations (average similarity coefficient r = .88). However, local differences were also apparent. A machine-learning algorithm revealed that nation predicted color-emotion associations above and beyond those observed universally. Similarity was greater when nations were linguistically or geographically close. This study highlights robust universal color-emotion associations, further modulated by linguistic and geographic factors. These results pose further theoretical and empirical questions about the affective properties of color and may inform practice in applied domains, such as well-being and design.

Response inhibition to emotional faces is modulated by functional hemispheric asymmetries linked to handedness.

Effective response inhibition requires efficient bottom-up perceptual processing and effective top-down inhibitory control. To investigate the role of hemispheric asymmetries in these processes, 49 right- and 50 left-handers completed a tachistoscopic Go/Nogo task with positive and negative emotional faces while ERPs were recorded. Frontal resting state EEG asymmetry was assessed as a marker of individual differences in prefrontal inhibitory networks. Results supported a dependency of inhibitory processing on early lateralized processes. As expected, right-handers showed a stronger N170 over the right hemisphere, and better response inhibition when faces were projected to the right hemisphere. Left-handers showed a stronger N170 over the left hemisphere, and no behavioural asymmetry. Asymmetries in response inhibition were also valence-dependent, with better inhibition of responses to negative faces when projected to the right, and better inhibition of responses to positive faces when projected to the left hemisphere. Frontal asymmetry was not related to handedness, but did modulate response inhibition depending on valence. Consistent with the asymmetric inhibition model (Grimshaw & Carmel, 2014), greater right frontal activity was associated with better response inhibition to positive than to negative faces; subjects with greater left frontal activity showed an opposite trend. These findings highlight the interplay between bottom-up and top-down processes in explaining hemispheric asymmetries in response inhibition.

Reduction of emotional distraction during target processing by attentional manipulations.

Previous research has demonstrated that fully irrelevant distractors - i.e., not sharing any feature with the target - capture our attention and modulate our responses. In the present study, we explored this interference by irrelevant distractors in a series of three experiments wherein the emotional valence of distractors (negative vs. neutral valence) was manipulated along with endogenous and exogenous attention. We aimed at jointly investigating - within the same paradigm - the possible modulations over the interference effect by these three critical variables in a systematic way. Although we replicated the interference effect by distractors previously reported in Martín-Arévalo et al. (2015), results showed no attentional and only weak emotional valence modulations over the interference effect. We discuss the possible boundary conditions underlying the absence (or weakness) of modulations over the interference effect by distractors observed in our experiments.

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.].

Fleeting reliability in the dot-probe task.

In a dot-probe task, two cues-one emotional and one neutral-are followed by a probe in one of their locations. Faster responses to probes co-located with the emotional stimulus are taken as evidence of attentional bias. Several studies indicate that such attentional bias measures have poor reliability, even though ERP studies show that people reliably attend to the emotional stimulus. This inconsistency might arise because the emotional stimulus captures attention briefly (as indicated by ERP), but cues appear for long enough that attention can be redistributed before the probe onset, causing RT measures of bias to vary across trials. We tested this hypothesis by manipulating SOA (stimulus onset asynchrony between onset of the cues and onset of the probe) in a dot-probe task using angry and neutral faces. Across three experiments, the internal reliability of behavioural biases was significantly greater than zero when probes followed faces by 100 ms, but not when the SOA was 300, 500, or 900 ms. Thus, the initial capture of attention shows some level of consistency, but this diminishes quickly. Even at the shortest SOA internal reliability estimates were poor, and not sufficient to justify the use of the task as an index of individual differences in attentional bias.

Fundamental or forgotten? Is Pierre Paul Broca still relevant in modern neuroscience?

The ability to speak is a unique human capacity, but where is it located in our brains? This question is closely connected to the pioneering work of Pierre Paul Broca in the 1860s. Based on post-mortem observations of aphasic patients' brains, Broca located language production in the 3rd convolution of the left frontal lobe and thus reinitiated the localizationist view of brain functions. However, contemporary neuroscience has partially rejected this view in favor of a network-based perspective. This leads to the question, whether Broca's findings are still relevant today. In this mini-review, we discuss current and historical implications of Broca's work by focusing on his original contribution and contrasting it with contemporary knowledge. Borrowing from Broca's famous quote, our review shows that humans indeed "speak with the left hemisphere"- but Broca's area is not the sole "seat of articulatory language".

New insights on real-world human face recognition.

Humans are supposedly expert in face recognition. Because of limitations in existing research paradigms, little is known about how faces become familiar in the real world, or the mechanisms that distinguish good from poor recognizers. Here, we capitalized on several unique features of the TV series Game of Thrones to develop a highly challenging test of face recognition that is ecologically grounded yet controls for important factors that affect familiarity. We show that familiarization with faces and reliable person identification require much more exposure than previously suggested. Recognition is impaired by the mere passage of time and simple changes in appearance, even for faces we have seen frequently. Good recognizers are distinguished not by the number of faces they recognize, but by their ability to reject novel faces as unfamiliar. Importantly, individuals with superior recognition abilities also forget faces and are not immune to identification errors. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

Beyond frontal alpha: investigating hemispheric asymmetries over the EEG frequency spectrum as a function of sex and handedness.

Frontal alpha EEG asymmetry, an indirect marker of asymmetries in relative frontal brain activity, are widely used in research on lateralization of emotional processing. While most authors focus on frontal electrode pairs (e.g., F3/F4 or F7/F8), several recent studies have indicated that EEG asymmetries can also be observed outside the frontal lobe and in frequency bands other than alpha. Because the focus of most EEG asymmetry research is on the correlations between asymmetry and other traits, much less is known about the distribution of patterns of asymmetry at the population level. To systematically assess these asymmetries in a representative sample, we determined EEG asymmetries across the head in the alpha, beta, delta and theta frequency bands in 235 healthy adults. We found significant asymmetries in all four frequency bands and across several brain areas, indicating that EEG asymmetries are not limited to frontal alpha. Asymmetries were not modulated by sex. They were modulated by direction of hand preference, with stronger right-handedness predicting greater right (relative to left) alpha power, or greater left (relative to right) activity. Taken together, the present results show that EEG asymmetries other than frontal alpha represent markers of asymmetric brain function that should be explored further.

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.