Threat but not arousal narrows attention: evidence from pupil dilation and saccade control

The effects of emotional arousal on pupil size depend on luminance

Pupillometry is widely used to measure arousal states. The primary functional role of the pupil, however, is to respond to the luminance of visual inputs. We previously demonstrated that cognitive effort-related arousal interacted multiplicatively with luminance, with the strongest pupillary effects of arousal occurring at low-to-mid luminances (< 37 cd/m2), implying a narrow range of conditions ideal for assessing cognitive arousal-driven pupillary differences. Does this generalize to other forms of arousal? To answer this, we assessed luminance-driven pupillary response functions while manipulating emotional arousal, using well-established visual and auditory stimulus sets. At the group level, emotional arousal interacted with the pupillary light response differently from cognitive arousal: the effects occurred primarily at much lower luminances (< 20 cd/m2). Analyses at the individual-participant level revealed qualitatively distinct patterns of modulation, with a sizable number of individuals displaying no arousal response to the visual or auditory stimuli, regardless of luminance. Together, our results suggest that effects of arousal on pupil size are not monolithic: different forms of arousal exert different patterns of effects. More practically, our findings suggest that lower luminances create better conditions for measuring pupil-linked arousal, and when selecting ambient luminance levels, consideration of the arousal manipulation and individual differences is critical.

Investigating social comparison behaviour in an immersive virtual reality classroom based on eye-movement data

Higher-achieving peers have repeatedly been found to negatively impact students' evaluations of their own academic abilities (i.e., Big-Fish-Little-Pond Effect). Building on social comparison theory, this pattern is assumed to result from students comparing themselves to their classmates; however, based on existing research designs, it remains unclear how exactly students make use of social comparison information in the classroom. To determine the extent to which students (N = 353 sixth graders) actively attend and respond to social comparison information in the form of peers' achievement-related behaviour, we used eye-tracking data from an immersive virtual reality (IVR) classroom. IVR classrooms offer unprecedented opportunities for psychological classroom research as they allow to integrate authentic classroom scenarios with maximum experimental control. In the present study, we experimentally varied virtual classmates' achievement-related behaviour (i.e., their hand-raising in response to the teacher's questions) during instruction, and students' eye and gaze data showed that they actively processed this social comparison information. Students who attended more to social comparison information (as indicated by more frequent and longer gaze durations at peer learners) had less favourable self-evaluations. We discuss implications for the future use of IVR environments to study behaviours in the classroom and beyond.

How the Brain Becomes the Mind: Can Thermodynamics Explain the Emergence and Nature of Emotions?

The neural systems' electric activities are fundamental for the phenomenology of consciousness. Sensory perception triggers an information/energy exchange with the environment, but the brain's recurrent activations maintain a resting state with constant parameters. Therefore, perception forms a closed thermodynamic cycle. In physics, the Carnot engine is an ideal thermodynamic cycle that converts heat from a hot reservoir into work, or inversely, requires work to transfer heat from a low- to a high-temperature reservoir (the reversed Carnot cycle). We analyze the high entropy brain by the endothermic reversed Carnot cycle. Its irreversible activations provide temporal directionality for future orientation. A flexible transfer between neural states inspires openness and creativity. In contrast, the low entropy resting state parallels reversible activations, which impose past focus via repetitive thinking, remorse, and regret. The exothermic Carnot cycle degrades mental energy. Therefore, the brain's energy/information balance formulates motivation, sensed as position or negative emotions. Our work provides an analytical perspective of positive and negative emotions and spontaneous behavior from the free energy principle. Furthermore, electrical activities, thoughts, and beliefs lend themselves to a temporal organization, an orthogonal condition to physical systems. Here, we suggest that an experimental validation of the thermodynamic origin of emotions might inspire better treatment options for mental diseases.

Fear influences phantom sound percepts in an anechoic room

Aims and hypotheses

In an environment of absolute silence, researchers have found many of their participants to perceive phantom sounds (tinnitus). With this between-subject experiment, we aimed to elaborate on these research findings, and specifically investigated whether–in line with the fear-avoidance model of tinnitus perception and reactivity–fear or level of perceived threat influences the incidence and perceptual qualities of phantom sound percepts in an anechoic room. We investigated the potential role of individual differences in anxiety, negative affect, noise sensitivity and subclinical hearing loss. We hypothesized that participants who experience a higher level of threat would direct their attention more to the auditory system, leading to the perception of tinnitus-like sounds, which would otherwise be subaudible, and that under conditions of increased threat, narrowing of attention would lead to perceptual distortions.

Methods

In total, N = 78 normal-hearing volunteers participated in this study. In general, the study sample consisted of young, mostly female, university students. Their hearing was evaluated using gold-standard pure tone audiometry and a speech-in-noise self-test (Digit Triplet Test), which is a sensitive screening test to identify subclinical hearing loss. Prior to a four-minute stay in an anechoic room, we randomized participants block design-wise in a threat (N = 37) and no-threat condition (N = 41). Participants in the threat condition were deceived about their hearing and were led to believe that staying in the room would potentially harm their hearing temporarily. Participants were asked whether they perceived sounds during their stay in the room and rated the perceptual qualities of sound percepts (loudness and unpleasantness). They were also asked to fill-out standardized questionnaires measuring anxiety (State–Trait Anxiety Inventory), affect (Positive and Negative Affect Schedule) and noise sensitivity (Weinstein Noise Sensitivity Scale). The internal consistency of the questionnaires used was verified in our study sample and ranged between α = 0.61 and α = 0.90.

Results

In line with incidence rates reported in the literature, 74% of our participants reported having heard tinnitus-like sounds in the anechoic room. Speech-in-noise identification ability was comparable for both groups of participants. The experimental manipulation of threat was proven to be effective, as indicated by significantly higher scores on a Threat Manipulation Checklist among participants in the threat condition as compared to those in the no-threat condition (p < 0.01). Nevertheless, participants in the threat condition were as likely to report tinnitus percepts as participants in the no-threat condition (p = 1), and tinnitus percepts were not rated as being louder (p = 0.76) or more unpleasant (p = 0.64) as a function of level of threat. For participants who did experience tinnitus percepts, a higher level of threat was associated with a higher degree of experienced unpleasantness (p < 0.01). These associations were absent in those who did not experience tinnitus. Higher negative affect was only slightly associated with higher ratings of tinnitus unpleasantness (p < 0.01).

Conclusion

Whereas our threat manipulation was successful in elevating the level of fear, it did not contribute to a higher percentage of participants perceiving tinnitus-like sounds in the threat condition. However, higher levels of perceived threat were related to a higher degree of perceived tinnitus unpleasantness. The findings of our study are drawn from a rather homogenous participant pool in terms of age, gender, and educational background, challenging conclusions that are applicable for the general population. Participants generally obtained normophoric scores on independent variables of interest: they were low anxious, low noise-sensitive, and there was little evidence for the presence of subclinical hearing loss. Possibly, there was insufficient variation in scores to find effects.

Trait anxiety affects attentional bias to emotional stimuli across time: A growth curve analysis

Many studies have illustrated the close relationship between anxiety disorders and attentional functioning, but the relationship between trait anxiety and attentional bias remains controversial. This study examines the effect of trait anxiety on the time course of attention to emotional stimuli using materials from the International Affective Picture System. Participants with high vs. low trait anxiety (HTA vs. LTA) viewed four categories of pictures simultaneously: dysphoric, threatening, positive, and neutral. Their eye-movements for each emotional stimulus were recorded for static and dynamic analysis. Data were analyzed using a mixed linear model and growth curve analysis. Specifically, the HTA group showed a greater tendency to avoid threatening stimuli and more pupil diameter variation in the early period of stimulus presentation (0–7.9 s). The HTA group also showed a stronger attentional bias toward positive and dysphoric stimuli in the middle and late period of stimulus presentation (7.9–30 s). These results suggest that trait anxiety has a significant temporal effect on attention to emotional stimuli, and that this effect mainly manifests after 7 s. In finding stronger attentional avoidance of threatening stimuli and more changes in neural activity, as well as a stronger attentional bias toward positive stimuli, this study provides novel insights on the relationship between trait anxiety and selective attention.

Fatigue and Arousal Modulations Revealed by Saccade and Pupil Dynamics

Saccadic eye movements are directed to the objects of interests and enable high-resolution visual images in the exploration of the visual world. There is a trial-to-trial variation in saccade dynamics even in a simple task, possibly attributed to arousal fluctuations. Previous studies have showed that an increase of fatigue level over time, also known as time-on-task, can be revealed by saccade peak velocity. In addition, pupil size, controlled by the autonomic nervous system, has long been used as an arousal index. However, limited research has been done with regards to the relation between pupil size and saccade behavior in the context of trial-to-trial variation. To investigate fatigue and arousal effects on saccadic and pupillary responses, we used bright and emotional stimuli to evoke pupillary responses in tasks requiring reactive and voluntary saccade generation. Decreased voluntary saccade peak velocities, reduced tonic pupil size and phasic pupillary responses were observed as time-on-task increased. Moreover, tonic pupil size affected saccade latency and dynamics, with steeper saccade main sequence slope as tonic pupil size increased. In summary, saccade dynamics and tonic pupil size were sensitive to fatigue and arousal level, together providing valuable information for the understanding of human behavior.

Pupil-linked Arousal Signals in the Midbrain Superior Colliculus

The orienting response evoked by the appearance of a salient stimulus is modulated by arousal; however, neural underpinnings for the interplay between orienting and arousal are not well understood. The superior colliculus (SC), causally involved in multiple components of the orienting response including gaze and attention shifts, receives not only multisensory and cognitive inputs but also arousal-regulated inputs from various cortical and subcortical structures. To investigate the impact of moment-by-moment fluctuations in arousal on orienting saccade responses, we used microstimulation of the monkey SC to trigger saccade responses, and we used pupil size and velocity to index the level of arousal at stimulation onset because these measures correlate with changes in brain states and locus coeruleus activity. Saccades induced by SC microstimulation correlated with prestimulation pupil velocity, with higher pupil velocities on trials without evoked saccades than with evoked saccades. In contrast, prestimulation absolute pupil size did not correlate with saccade behavior. However, pupil velocity correlated with evoked saccade latency and metrics. Together, our results demonstrated that small fluctuations in arousal, indexed by pupil velocity, can modulate the saccade response evoked by SC microstimulation in awake behaving monkeys.

Impact of the COVID‐19 pandemic on inflammatory bowel disease: The role of emotional stress and social isolation

Inflammatory bowel disease (IBD) is a chronic health condition exacerbated by negative emotional stress experiences. In the current study, we examined whether the outbreak of the COVID-19 pandemic coincided with an increase in stress experiences and accordingly an aggravation of disease activity in IBD patients. Sixty-three IBD patients (30 Crohn's disease or CD, 33 ulcerative colitis) completed an online survey during the COVID-19-related lockdown, assessing clinical disease activity, disease-related quality of life, presence of functional gastrointestinal symptoms, social isolation and stress experiences. Scores were then compared to pre-lockdown baseline screening. The pandemic yielded a significant baseline-to-lockdown increase in emotional stress and social isolation. Stress increments, particularly those occasioned by interpersonal tension and excessive interpersonal proximity, were associated with a worsening of functional gastrointestinal symptoms. Exacerbations of loneliness coincided with an escalation of CD activity, functional gastrointestinal symptoms and a decline in subjective health. Lastly, COVID-19 anxiety was significantly related to CD symptom severity and social dysfunction. The findings show that shifts in IBD expression are closely linked to changes in emotional stress experiences and interpersonal relatedness. As such, they contribute to a better understanding of inter-individual differences in IBD progression and provide leads for therapeutic interventions.

Task demands determine whether shape or arousal of a stimulus modulates competition for visual working memory resources

It has been posited (Öhman, 1986) that the processing of threatening stimuli became prioritized during the course of mammalian evolution and that such objects may still enjoy an advantage in visual processing to this day. It has been well-documented that both mid-level visual features (i.e., conjunctions of low-level features) and the arousal level of threatening stimuli affect attentional allocation (Cisler & Koster, 2010; Wolfe & Horowitz, 2004). Despite this, few studies have investigated the effect these factors have on visual working memory resources. Here, we investigated these factors using a rapid serial visual presentation (RSVP) paradigm, and by manipulating mid-level features (specifically, shape: similar vs. dissimilar) and the arousal level (non-threatening vs threatening) of the stimuli. Participants watched an RSVP stream in preparation for an upcoming memory test. Then, they completed a two-alternative forced-choice recognition memory test (with semantically matched foils) wherein they had to identify which item they had seen in the RSVP stream. Our results showed that when shape was a sufficient feature to discriminate the target from the other items in the stream, there was no effect of arousal (i.e., threat level) on reaction time or accuracy during the memory test. However, when the shapes of all the stimuli in the visual stream were highly similar, an effect of arousal appeared: When the target had a different arousal level than the background items (i.e., non-targets), performance was improved. Together, the results suggest that both mid-level visual features and arousal level can modulate competition for visual working memory resources.

The concert of personality: Explaining personality functioning and coherence by personality systems interactions

Several psychological approaches concern explaining the dynamic psychological processes and mechanisms that render personality a coherent whole, a “well-sounding concert.” Building upon personality systems interactions (PSI) theory, which explains personality functioning on the basis of interactions among cognitive and affective-motivational personality systems, we demonstrate how diverse perspectives on personality coherence may functionally be integrated. To do so, we describe interactions among four cognitive personality systems considered to underlie and optimize two meta principles of personality functioning—self-growth (in terms of the integration of adverse experiences) and action control (in terms of goal pursuit). These meta principles establish different subtypes of personality coherence differentially focused by psychological perspectives. We highlight the interdisciplinary relevance and practical application of the present approach and conclude with implications for future research.

Pupil responses to dynamic negative facial expressions of emotion in infants and parents

Observing others' emotions triggers physiological arousal in infants as well as in adults, reflected in dilated pupil sizes. This study is the first to examine parents' and infants' pupil responses to dynamic negative emotional facial expressions. Moreover, the links between pupil responses and negative emotional dispositions were explored among infants and parents. Infants' and one of their parent's pupil responses to negative versus neutral faces were measured via eye tracking in 222 infants (5- to 7-month-olds, n = 77, 11- to 13-month-olds, n = 78, and 17- to 19-month-olds, n = 67) and 229 parents. One parent contributed to the pupil data, whereas both parents were invited to fill in questionnaires on their own and their infant's negative emotional dispositions. Infants did not differentially respond to negative expressions, while parents showed stronger pupil responses to negative versus neutral expressions. There was a positive association between infants' and their parent's mean pupil responses and significant links between mothers' and fathers' stress levels and their infants' pupil responses. We conclude that a direct association between pupil responses in parents and offspring is observable already in infancy in typical development. Stress in parents is related to their infants' pupillary arousal to negative emotions.

Extending the study of visual attention to a multisensory world (Charles W. Eriksen Special Issue)

Charles W. Eriksen (1923-2018), long-time editor of Perception & Psychophysics (1971-1993) - the precursor to the present journal - undoubtedly made a profound contribution to the study of selective attention in the visual modality. Working primarily with neurologically normal adults, his early research provided both theoretical accounts for behavioral phenomena as well as robust experimental tasks, including the well-known Eriksen flanker task. The latter paradigm has been used and adapted by many researchers over the subsequent decades. While Eriksen's research interests were primarily focused on situations of unimodal visual spatially selective attention, here I review evidence from those studies that have attempted to extend Eriksen's general approach to non-visual (i.e., auditory and tactile) selection and the more realistic situations of multisensory spatial attentional selection.

Attention control ability, mood state, and emotional regulation ability partially affect executive control of attention on task-irrelevant emotional stimuli

Executive control of attention is important for goal-directed behavior, and it is influenced by emotional information. This study examined the effect of stimulus valence on a color word flanker task and how individual differences within a general population may affect task performance. 119 participants completed a color word flanker task with task-irrelevant emotional information (positive, negative, neutral). This task was followed by several self-report scales that measured individual differences in attention control ability (ACS), current mood (PANAS), and emotion regulation ability (DERS). Faster reaction times and greater accuracy were associated with negative stimuli. The flanker effect was greater for negative trials than for neutral and positive trials. The greater flanker effect for negative trials was driven by decreased reaction time on negative congruent trials. A significant interaction was evident between stimulus valence and ACS score, such that reaction time was faster for negative trials than for neutral trials among those with low, average, and high ACS. However, this difference was largest for those with high ACS. Further, these relationships between attention control ability and executive control of attention were influenced by level of depressive symptoms (as measured by BDI-II). This study extends our knowledge about the relationship between executive control of attention to emotional stimuli and individual differences related to mood and attentional disorders in a general population. Study results may have important implications for theoretical models of cognitive control and task-irrelevant emotional information across individual differences.

Preprocessing pupil size data: Guidelines and code

Pupillometry has been one of the most widely used response systems in psychophysiology. Changes in pupil size can reflect diverse cognitive and emotional states, ranging from arousal, interest and effort to social decisions, but they are also widely used in clinical practice to assess patients’ brain functioning. As a result, research involving pupil size measurements has been reported in practically all psychology, psychiatry, and psychophysiological research journals, and now it has found its way into the primatology literature as well as into more practical applications, such as using pupil size as a measure of fatigue or a safety index during driving. The different systems used for recording pupil size are almost as variable as its applications, and all yield, as with many measurement techniques, a substantial amount of noise in addition to the real pupillometry data. Before analyzing pupil size, it is therefore of crucial importance first to detect this noise and deal with it appropriately, even prior to (if need be) resampling and baseline-correcting the data. In this article we first provide a short review of the literature on pupil size measurements, then we highlight the most important sources of noise and show how these can be detected. Finally, we provide step-by-step guidelines that will help those interested in pupil size to preprocess their data correctly. These guidelines are accompanied by an open source MATLAB script (available at https://github.com/ElioS-S/pupil-size). Given that pupil diameter is easily measured by standard eyetracking technologies and can provide fundamental insights into cognitive and emotional processes, it is hoped that this article will further motivate scholars from different disciplines to study pupil size.

CHAP: Open-source software for processing and analyzing pupillometry data

Pupil dilation is an effective indicator of cognitive and affective processes. Although several eyetracker systems on the market can provide effective solutions for pupil dilation measurement, there is a lack of tools for processing and analyzing the data provided by these systems. For this reason, we developed CHAP: open-source software written in MATLAB. This software provides a user-friendly graphical user interface for processing and analyzing pupillometry data. Our software creates uniform conventions for the preprocessing and analysis of pupillometry data and provides a quick and easy-to-use tool for researchers interested in pupillometry. To download CHAP or join our mailing list, please visit CHAP's website: http://in.bgu.ac.il/en/Labs/CNL/chap .

GIVE me your attention: Differentiating goal identification and goal execution components of the anti-saccade effect

The anti-saccade task is a commonly used method of assessing individual differences in cognitive control. It has been shown that a number of clinical disorders are characterised by increased anti-saccade cost. However, it remains unknown whether this reflects impaired goal identification or impaired goal execution, because, to date, no procedure has been developed to independently assess these two components of anti-saccade cost. The aim of the present study was to develop such an assessment task, which we term the Goal Identification Vs. Execution (GIVE) task. Fifty-one undergraduate students completed a conventional anti-saccade task, and our novel GIVE task. Our findings revealed that individual differences in anti-saccade goal identification costs and goal execution costs were uncorrelated, when assessed using the GIVE task, but both predicted unique variance in the conventional anti-saccade cost measure. These results confirm that the GIVE task is capable of independently assessing variation in the goal identification and goal execution components of the anti-saccade effect. We discuss how this newly introduced assessment procedure now can be employed to illuminate the specific basis of the increased anti-saccade cost that characterises various forms of clinical dysfunction.

Reduced Hedonic Valuation of Rewards and Unaffected Cognitive Regulation in Chronic Stress

Cognition can influence choices by modulation of decision-making processes. This cognitive regulation is defined as processing information, applying knowledge, and changing preferences to consciously modulate decisions. While cognitive regulation of emotions has been extensively studied in psychiatry, few works have detailed cognitive regulation of decision-making. Stress may influence emotional behavior, cognition, and decision-making. In addition, the brain regions responsible for decision-making are sensitive to stress-induced changes. Thus, we hypothesize that chronic stress may disrupt the ability to regulate choices. Herein, we used a functional magnetic resonance imaging task where fourteen control and fifteen chronically stressed students had to cognitively upregulate or downregulate their craving before placing a bid to obtain food. We found that stressed participants placed lower bids to get the reward and chose less frequently higher bid values for food. Nevertheless, we did not find neural and behavioral differences during cognitive regulation of craving. Our outcomes revealed that chronic stress impacts decision-making after cognitive regulation of craving by reducing the valuation of food rewards but not cognitive modulation itself. Importantly, our results need further validation with larger sample sizes.

Transcutaneous vagus nerve stimulation (tVNS) enhances conflict-triggered adjustment of cognitive control

Response conflicts play a prominent role in the flexible adaptation of behavior as they represent context-signals that indicate the necessity for the recruitment of cognitive control. Previous studies have highlighted the functional roles of the affectively aversive and arousing quality of the conflict signal in triggering the adaptation process. To further test this potential link with arousal, participants performed a response conflict task in two separate sessions with either transcutaneous vagus nerve stimulation (tVNS), which is assumed to activate the locus coeruleus-noradrenaline (LC-NE) system, or with neutral sham stimulation. In both sessions the N2 and P3 event-related potentials (ERP) were assessed. In line with previous findings, conflict interference, the N2 and P3 amplitude were reduced after conflict. Most importantly, this adaptation to conflict was enhanced under tVNS compared to sham stimulation for conflict interference and the N2 amplitude. No effect of tVNS on the P3 component was found. These findings suggest that tVNS increases behavioral and electrophysiological markers of adaptation to conflict. Results are discussed in the context of the potentially underlying LC-NE and other neuromodulatory (e.g., GABA) systems. The present findings add important pieces to the understanding of the neurophysiological mechanisms of conflict-triggered adjustment of cognitive control.

Effects of arousal on biased competition in attention and short-term memory

A recent theory proposes that arousal amplifies the competition between stimulus representations, strengthening already strong representations and weakening already weak representations in perception and memory. Here, we report a stringent test of this arousal-biased competition theory in the context of visual attention and short-term memory. We examined whether pre-trial arousal enhances the bottom-up attentional bias toward physically salient versus less salient stimuli in a multi-letter identification task. Arousal was manipulated by presenting an arousing versus a neutral picture (Experiment 1) or sound (Experiment 2) at the start of each trial. Bayesian statistics revealed strong evidence for the null hypothesis in both experiments: Arousal did not modulate the effects of physical salience on letter identification. The experiments were repeated with EEG measurements and subjective stimulus ratings, which confirmed that the stimuli successfully manipulated physiological and subjective arousal. These results pose a challenge for the arousal-biased competition theory.

Pupil dilation as an index of effort in cognitive control tasks: A review

Pupillometry research has experienced an enormous revival in the last two decades. Here we briefly review the surge of recent studies on task-evoked pupil dilation in the context of cognitive control tasks with the primary aim being to evaluate the feasibility of using pupil dilation as an index of effort exertion, rather than task demand or difficulty. Our review shows that across the three cognitive control domains of updating, switching, and inhibition, increases in task demands typically leads to increases in pupil dilation. Studies show a diverging pattern with respect to the relationship between pupil dilation and performance and we show how an effort account of pupil dilation can provide an explanation of these findings. We also discuss future directions to further corroborate this account in the context of recent theories on cognitive control and effort and their potential neurobiological substrates.

Helmets improve estimations of depth and visual angle to safe targets

Egocentric distance estimation has been shown to depend on wearing safety gear, which promotes compensatory behavior, and on target type, which regulates fight-or-flight responses. We hypothesized that the two factors interact, possibly in asymmetric fashion, and set out to uncover the limits of this interaction in a perceptual task where individuals wearing helmets or baseball caps estimated egocentric distance to non-threatening and threatening animals depicted on cards (i.e., safe and unsafe targets). We found that, compared to participants wearing caps, participants wearing helmets overshoot distance estimations and were able to distinguish not only between targets situated at two depth levels as participants wearing caps could, but also between safe targets situated at wide and narrow visual angles. Our findings help define the interaction between safety devices and target type, thereby contributing to the debate between advocates of prevention models and those who maintain that these are offset by compensatory strategies.

Pupil dilation reflects the time course of emotion recognition in human vocalizations

The processing of emotional signals usually causes an increase in pupil size, and this effect has been largely attributed to autonomic arousal prompted by the stimuli. Additionally, changes in pupil size were associated with decision making during non-emotional perceptual tasks. Therefore, in this study we investigated the relationship between pupil size fluctuations and the process of emotion recognition. Participants heard human nonverbal vocalizations (e.g., laughing, crying) and indicated the emotional state of the speakers as soon as they had identified it. The results showed that during emotion recognition, the time course of pupil response was driven by the decision-making process. In particular, peak pupil dilation betrayed the time of emotional selection. In addition, pupil response revealed properties of the decisions, such as the perceived emotional valence and the confidence in the assessment. Because pupil dilation (under isoluminance conditions) is almost exclusively promoted by norepinephrine (NE) release from the locus coeruleus (LC), the results suggest an important role of the LC-NE system during emotion processing.

Do arousal and valence have separable influences on attention across time?

Previous research has shown that emotions differentially influence attention across time, especially when the valence of the attended stimuli is congruent with the emotion of observer. Sadness produces a larger attentional blink while fear and happiness produce smaller attentional blinks. We report on four dual-task rapid serial visual presentation experiments in which participant emotion and the affective features of the first target (T1) were systematically varied to determine whether arousal and valence have unique and consistent influences on attention performance. All T1s connoted affect. Results showed that the emotional experience of negative affect with high arousal led to better second target (T2) detection than negative affect with low arousal. In conditions where positive affect was the experienced emotion, low arousal resulted in better T2 detection than high arousal. When participant arousal was held constant at a low level there were no differences in performance. When participant arousal was high, a cross-over effect was observed in which negative affect produced better performance than positive affect at early positions and negative affect produced better performance at late. The first targets in these experiments varied in arousal and valence to test for emotion congruent effects, but none were found. It was concluded that the experience of varied levels of arousal and types of valence do not have separable influences on attention across time. Rather, their influence is more consistent with emotion-specific mechanisms.

Pupil mimicry and trust - Implication for depression

Individuals suffering from depression often have difficulty trusting others. Previous research has shown a relationship between trust formation and pupil mimicry - the synchronization of pupil sizes between individuals. The current study therefore examined whether pupil mimicry is weaker in depressed individuals and an underlying factor of their low levels of trust. Forty-two patients with major depressive disorder (MDD) and 40 healthy control subjects played trust games with virtual partners. Images of these partners' eye regions were presented to participants before they had to make a monetary investment decision. Partners' pupils either dilated, constricted, or remained static over the course of 4-s interactions. During the task, participants' pupil sizes were recorded with eye-tracking equipment to assess mimicry. The results confirm that patients with MDD were somewhat less trusting than controls and used another's pupillary cues differently when deciding to trust. Specifically, whereas healthy controls trusted partners with dilating pupils more than partners with constricting pupils, patients with MDD particularly trusted partners whose pupils changed in size less, regardless of whether partners' pupils were dilating or constricting. This difference in investment behavior was unrelated to differences in pupil mimicry, which was equally apparent in both groups and fostered trust to the same extent. Whereas lower levels of trust observed in patients with MDD could not be explained by differences in pupil mimicry, our data show that pupil dilation mimicry might help people to trust. These findings provide further evidence for the important role of pupil size and pupil mimicry in interpersonal trust formation and shed light on the pathophysiology of clinically low trust in patients with MDD.

Count on arousal: introducing a new method for investigating the effects of emotional valence and arousal on visual search performance

There is a large body of research, indicating that threatening stimuli with evolutionary history are prioritised in visual processing. It has been proposed that all threatening stimuli are prioritised, irrespective of evolutionary age, but it was argued that the method used to produce the results was not suitable for investigating the phenomenon. We present a new visual search task and provide evidence that it is an appropriate tool for future research. In Experiment 1, we investigated how the influence of emotional stimuli on visual search performance varies with valence (negative, positive, and neutral) and arousal (medium and high). Negative valence found to have a greater impact. Furthermore, our results underscore the importance of controlling for arousal. Experiment 2 confirmed these findings and also revealed that negative valence decreases performance by diverting attention away from the task, but arousal can compensate for this by increasing attentional capacity. This mechanism does not seem to be affected by the evolutionary history of the stimulus. In Experiment 3, we reproduced these results using a touchscreen monitor and controlling for variance in low-level visual features. We claim that these results support the notion of preferential processing of threatening cues, regardless of evolutionary origin. However, the level of threat, i.e., how arousing the cue is, has to be taken into account to explain the findings.

The development of inhibitory saccadic trajectory deviations correlates with measures of antisaccadic inhibition

Chronological age is related positively to a participant's ability to inhibit distracting information. Inhibition can be measured using the trajectory deviation of a saccade. Saccadic curvature away from distracting visual information is controlled through top-down inhibition mediated by the frontal eye fields. In the present study, we aimed to further test the saccadic trajectory deviation paradigm's sensitivity to the development of frontal inhibitory procuresses by comparing its measure of saccadic inhibition with that of a widely used paradigm, namely, the antisaccade task. We show that the later 'inhibition' phase of the trajectory deviation function correlated strongly with the measure of antisaccadic inhibition obtained in the same individuals. As expected, the earlier 'capture' phase of the trajectory deviation function, which does not represent the involvement of frontal structures, did not correlate with antisaccadic inhibition. Further, both measures of frontal inhibition increased with chronological age.

Punishment eliminates directed forgetting: an event-related potential study

This study investigated motivational effect of reward and punishment on directed forgetting using the event-related potential technique. Participants were instructed to encode two-character words in Chinese, followed by the indicator of 'remember' or 'forget'. Then, participants were required accomplishing the judgment task of old and new words. The results suggest that (i) directed forgetting effect is significant in the punishment condition but not in the reward condition, and (ii) a positive amplitude is induced in the punishment condition but not in the reward condition. Furthermore, directed forgetting can be effectively influenced by reward motivation, whereas punishment motivation is antagonistic to active forgetting because a substantial cognitive resource attracts considerable attention. Therefore, this study supports encoding inhibition theory.

Nasal Oxytocin Treatment Biases Dogs' Visual Attention and Emotional Response toward Positive Human Facial Expressions

The neuropeptide oxytocin plays a critical role in social behavior and emotion regulation in mammals. The aim of this study was to explore how nasal oxytocin administration affects gazing behavior during emotional perception in domestic dogs. Looking patterns of dogs, as a measure of voluntary attention, were recorded during the viewing of human facial expression photographs. The pupil diameters of dogs were also measured as a physiological index of emotional arousal. In a placebo-controlled within-subjects experimental design, 43 dogs, after having received either oxytocin or placebo (saline) nasal spray treatment, were presented with pictures of unfamiliar male human faces displaying either a happy or an angry expression. We found that, depending on the facial expression, the dogs' gaze patterns were affected selectively by oxytocin treatment. After receiving oxytocin, dogs fixated less often on the eye regions of angry faces and revisited (glanced back at) more often the eye regions of smiling (happy) faces than after the placebo treatment. Furthermore, following the oxytocin treatment dogs fixated and revisited the eyes of happy faces significantly more often than the eyes of angry faces. The analysis of dogs' pupil diameters during viewing of human facial expressions indicated that oxytocin may also have a modulatory effect on dogs' emotional arousal. While subjects' pupil sizes were significantly larger when viewing angry faces than happy faces in the control (placebo treatment) condition, oxytocin treatment not only eliminated this effect but caused an opposite pupil response. Overall, these findings suggest that nasal oxytocin administration selectively changes the allocation of attention and emotional arousal in domestic dogs. Oxytocin has the potential to decrease vigilance toward threatening social stimuli and increase the salience of positive social stimuli thus making eye gaze of friendly human faces more salient for dogs. Our study provides further support for the role of the oxytocinergic system in the social perception abilities of domestic dogs. We propose that oxytocin modulates fundamental emotional processing in dogs through a mechanism that may facilitate communication between humans and dogs.

Task-irrelevant emotional faces impair response adjustments in a double-step saccade task

Cognitive control enables us to adjust behaviours according to task demands, and emotion influences the cognitive control. We examined how task-irrelevant emotional stimuli impact the ability to inhibit a prepared response and then programme another appropriate response. In the study, either a single target or two sequential targets appeared after emotional face images (positive, neutral, and negative). Subjects were required to freely viewed the emotional faces and make a saccade quickly upon target onset, but inhibit their initial saccades and redirect gaze to the second target if it appeared. We found that subjects were less successful at inhibiting their initial saccades as the inter-target delay increased. Emotional faces further reduced their inhibition ability with a longer delay, but not with a shorter delay. When subjects failed to inhibit the initial saccade, the longer delay produced longer intersaccadic interval. Especially, positive faces lengthened the intersaccadic interval with a longer delay. These results showed mere presence of emotional stimuli influences gaze redirection by impairing the ability to cancel a prepared saccade and delaying the programming of a corrective saccade. Therefore, we propose that the modulation of response adjustment exerted by emotional faces is related to the stage of initial response programming.

Wisdom in Context

Philosophers and psychological scientists have converged on the idea that wisdom involves certain aspects of thinking (e.g., intellectual humility, recognition of uncertainty and change), enabling application of knowledge to life challenges. Empirical evidence indicates that people’s ability to think wisely varies dramatically across experiential contexts that they encounter over the life span. Moreover, wise thinking varies from one situation to another, with self-focused contexts inhibiting wise thinking. Experiments can show ways to buffer thinking against bias in cases in which self-interests are unavoidable. Specifically, an ego-decentering cognitive mind-set enables wise thinking about personally meaningful issues. It appears that experiential, situational, and cultural factors are even more powerful in shaping wisdom than previously imagined. Focus on such contextual factors sheds new light on the processes underlying wise thought and its development, helps to integrate different approaches to studying wisdom, and has implications for measurement and development of wisdom-enhancing interventions.

Time-domain analysis for extracting fast-paced pupil responses

The eye pupil reacts to cognitive processes, but its analysis is challenging when luminance varies or when stimulation is fast-paced. Current approaches relying on deconvolution techniques do not account for the strong low-frequency spontaneous changes in pupil size or the large interindividual variability in the shape of the responses. Here a system identification framework is proposed in which the pupil responses to different parameters are extracted by means of an autoregressive model with exogenous inputs. In an example application of this technique, pupil size was shown to respond to the luminance and arousal scores of affective pictures presented in rapid succession. This result was significant in each subject (N = 5), but the pupil response varied between individuals both in amplitude and latency, highlighting the need for determining impulse responses subjectwise. The same method was also used to account for pupil size variations caused by respiration, illustrating the possibility to model the relation between pupil size and other continuous signals. In conclusion, this new framework for the analysis of pupil size data allows us to dissociate the response of the eye pupil from intermingled sources of influence and can be used to study the relation between pupil size and other physiological signals.

As Far as the Eye Can See: Relationship between Psychopathic Traits and Pupil Response to Affective Stimuli

Psychopathic individuals show a range of affective processing deficits, typically associated with the interpersonal/affective component of psychopathy. However, previous research has been inconsistent as to whether psychopathy, within both offender and community populations, is associated with deficient autonomic responses to the simple presentation of affective stimuli. Changes in pupil diameter occur in response to emotionally arousing stimuli and can be used as an objective indicator of physiological reactivity to emotion. This study used pupillometry to explore whether psychopathic traits within a community sample were associated with hypo-responsivity to the affective content of stimuli. Pupil activity was recorded for 102 adult (52 female) community participants in response to affective (both negative and positive affect) and affectively neutral stimuli, that included images of scenes, static facial expressions, dynamic facial expressions and sound-clips. Psychopathic traits were measured using the Triarchic Psychopathy Measure. Pupil diameter was larger in response to negative stimuli, but comparable pupil size was demonstrated across pleasant and neutral stimuli. A linear relationship between subjective arousal and pupil diameter was found in response to sound-clips, but was not evident in response to scenes. Contrary to predictions, psychopathy was unrelated to emotional modulation of pupil diameter across all stimuli. The findings were the same when participant gender was considered. This suggests that psychopathy within a community sample is not associated with autonomic hypo-responsivity to affective stimuli, and this effect is discussed in relation to later defensive/appetitive mobilisation deficits.

The neural basis of improved cognitive performance by threat of shock

Anxiety can have both detrimental and facilitatory cognitive effects. This study investigates the neural substrates of a replicated facilitatory effect of anxiety on sustained attention and response inhibition. This effect consisted of improved performance on the Sustained Attention to Response Task (a Go-NoGo task consisting of 91% Go and 9% NoGo trials) in threat (unpredictable electrical shock) vs safe (no shock) conditions. This study uses the same experimental design with fMRI and relies on an event-related analysis of BOLD signal changes. Findings reveal that threat-related cognitive facilitation (improved NoGo accuracy) is associated with greater activation of a right-lateralized frontoparietal group of regions previously implicated in sustained attention and response inhibition. Moreover, these same regions show decreased activation in the Go trials preceding NoGo errors. During NoGo trials, striatal activity is also greater in the threat vs safe condition, consistent with the notion of enhanced inhibitory processing under threat. These findings identify potential mechanisms by which threat of unpredictable shock can facilitate distinct cognitive functions. A greater understanding of the complex interaction of the anxious state and cognitive processes may have critical clinical implications.

The pupil's response to affective pictures: Role of image duration, habituation, and viewing mode

The pupil has been shown to be sensitive to the emotional content of stimuli. We examined this phenomenon by comparing fearful and neutral images carefully matched in the domains of luminance, image contrast, image color, and complexity of content. The pupil was more dilated after viewing affective pictures, and this effect was (a) shown to be independent of the presentation time of the images (from 100–3,000 ms), (b) not diminished by repeated presentations of the images, and (c) not affected by actively naming the emotion of the stimuli in comparison to passive viewing. Our results show that the emotional modulation of the pupil is present over a range of variables that typically vary from study to study (image duration, number of trials, free viewing vs. task), and encourages the use of pupillometry as a measure of emotional processing in populations where alternative techniques may not be appropriate.

Emotion moderates the association between HTR2A (rs6313) genotype and antisaccade latency

The serotonin system is heavily involved in cognitive and emotional control processes. Previous work has typically investigated this system's role in control processes separately for cognitive and emotional domains, yet it has become clear the two are linked. The present study, therefore, examined whether variation in a serotonin receptor gene (HTR2A, rs6313) moderated effects of emotion on inhibitory control. An emotional antisaccade task was used in which participants looked toward (prosaccade) or away (antisaccade) from a target presented to the left or right of a happy, angry, or neutral face. Overall, antisaccade latencies were slower for rs6313 C allele homozygotes than T allele carriers, with no effect of genotype on prosaccade latencies. Thus, C allele homozygotes showed relatively weak inhibitory control but intact reflexive control. Importantly, the emotional stimulus was either present during target presentation (overlap trials) or absent (gap trials). The gap effect (slowed latency in overlap versus gap trials) in antisaccade trials was larger with angry versus neutral faces in C allele homozygotes. This impairing effect of negative valence on inhibitory control was larger in C allele homozygotes than T allele carriers, suggesting that angry faces disrupted/competed with the control processes needed to generate an antisaccade to a greater degree in these individuals. The genotype difference in the negative valence effect on antisaccade latency was attenuated when trial N-1 was an antisaccade, indicating top-down regulation of emotional influence. This effect was reduced in C/C versus T/_ individuals, suggesting a weaker capacity to downregulate emotional processing of task-irrelevant stimuli.

Early attentional bias for negative words when competition is induced

Previous research (Zeelenberg, Wagenmakers, & Rotteveel, 2006) revealed that emotionally meaningful words were identified significantly better than neutral words, with no difference between positive and negative words. Since in that study only a single target word was displayed at a time, we hypothesized that the equivalent performances for positive and negative words were due to a lack of competition. To test this, in our Experiment 1, we replicated Zeelenberg and colleagues' finding, using emotion-laden Chinese words and the identical data-limited method, which measured the accuracy of a briefly shown target. We then introduced competition in Experiment 2 by simultaneously presenting two words during the target frame, and found evidence for an early attentional bias to negative words. In Experiment 3, we confirmed that the bias in Experiment 2 was not due to the inevitable repetition of stimuli. Taken together, these results support our hypothesis that, in the presence of competition, negative words receive attentional priority and consequently have enhanced perceptual representations.

The Impact of Emotional States on Cognitive Control Circuitry and Function

Typically in the laboratory, cognitive and emotional processes are studied separately or as a stream of fleeting emotional stimuli embedded within a cognitive task. Yet in life, thoughts and actions often occur in more lasting emotional states of arousal. The current study examines the impact of emotions on actions using a novel behavioral paradigm and functional neuroimaging to assess cognitive control under sustained states of threat (anticipation of an aversive noise) and excitement (anticipation of winning money). Thirty-eight healthy adult participants were scanned while performing an emotional go/no-go task with positive (happy faces), negative (fearful faces), and neutral (calm faces) emotional cues, under threat or excitement. Cognitive control performance was enhanced during the excited state relative to a nonarousing control condition. This enhanced performance was paralleled by heightened activity of frontoparietal and frontostriatal circuitry. In contrast, under persistent threat, cognitive control was diminished when the valence of the emotional cue conflicted with the emotional state. Successful task performance in this conflicting emotional condition was associated with increased activity in the posterior cingulate cortex, a default mode network region implicated in complex processes such as processing emotions in the context of self and monitoring performance. This region showed positive coupling with frontoparietal circuitry implicated in cognitive control, providing support for a role of the posterior cingulate cortex in mobilizing cognitive resources to improve performance. These findings suggest that emotional states of arousal differentially modulate cognitive control and point to the potential utility of this paradigm for understanding effects of situational and pathological states of arousal on behavior.

Arousal facilitates involuntary eye movements

Attention plays a critical role in action selection. However, the role of attention in eye movements is complicated as these movements can be either voluntary or involuntary, with, in some circumstances (antisaccades), these two actions competing with each other for execution. But attending to the location of an impending eye movement is only one facet of attention that may play a role in eye movement selection. In two experiments, we investigated the effect of arousal on voluntary eye movements (antisaccades) and involuntary eye movements (prosaccadic errors) in an antisaccade task. Arousal, as caused by brief loud sounds and indexed by changes in pupil diameter, had a facilitation effect on involuntary eye movements. Involuntary eye movements were both significantly more likely to be executed and significantly faster under arousal conditions (Experiments 1 and 2), and the influence of arousal had a specific time course (Experiment 2). Arousal, one form of attention, can produce significant costs for human movement selection as potent but unplanned actions are benefited more than planned ones.

Functional Equivalence of the Color Red and Enacted Avoidance Behavior?

Abstract. Research has shown that subtle stimuli and action can elicit approach and avoidance motivational states. In separate literatures, both the color red and enacting avoidance behavior have been hypothesized to evoke avoidance motivation. The purpose of the present research was to both replicate and empirically integrate prior work on red and enacted avoidance behavior. This was done by testing them together within the same paradigms in two experiments, one on anagram performance and the other on local-relative-to-global processing. Both experiments replicated prior research in each literature, with red and enacted avoidance behavior producing comparable effects across both experiments. Implications of the findings for the two literatures are discussed.

Predicting the Valence of a Scene from Observers' Eye Movements

Multimedia analysis benefits from understanding the emotional content of a scene in a variety of tasks such as video genre classification and content-based image retrieval. Recently, there has been an increasing interest in applying human bio-signals, particularly eye movements, to recognize the emotional gist of a scene such as its valence. In order to determine the emotional category of images using eye movements, the existing methods often learn a classifier using several features that are extracted from eye movements. Although it has been shown that eye movement is potentially useful for recognition of scene valence, the contribution of each feature is not well-studied. To address the issue, we study the contribution of features extracted from eye movements in the classification of images into pleasant, neutral, and unpleasant categories. We assess ten features and their fusion. The features are histogram of saccade orientation, histogram of saccade slope, histogram of saccade length, histogram of saccade duration, histogram of saccade velocity, histogram of fixation duration, fixation histogram, top-ten salient coordinates, and saliency map. We utilize machine learning approach to analyze the performance of features by learning a support vector machine and exploiting various feature fusion schemes. The experiments reveal that ‘saliency map’, ‘fixation histogram’, ‘histogram of fixation duration’, and ‘histogram of saccade slope’ are the most contributing features. The selected features signify the influence of fixation information and angular behavior of eye movements in the recognition of the valence of images.

Happiness in action: the impact of positive affect on the time of the conscious intention to act

The temporal relationship between our conscious intentions to act and the action itself has been widely investigated. Previous research consistently shows that the motor intention enters awareness a few 100 ms before movement onset. As research in other domains has shown that most behavior is affected by the emotional state people are in, it is remarkable that the role of emotional states on intention awareness has never been investigated. Here we tested the hypothesis that positive and negative affects have opposite effects on the temporal relationship between the conscious intention to act and the action itself. A mood induction procedure that combined guided imagery and music listening was employed to induce positive, negative, or neutral affective states. After each mood induction session, participants were asked to execute voluntary self-paced movements and to report when they formed the intention to act. Exposure to pleasant material, as compared to exposure to unpleasant material, enhanced positive affect and dampened negative affect. Importantly, in the positive affect condition participants reported their intention to act earlier in time with respect to action onset, as compared to when they were in the negative or in the neutral affect conditions. Conversely the reported time of the intention to act when participants experienced negative affect did not differ significantly from the neutral condition. These findings suggest that the temporal relationship between the conscious intention to act and the action itself is malleable to changes in affective states and may indicate that positive affect enhances intentional awareness.

Cortisol broadens memory of a non-stressful social interaction

RATIONALE

Stress and its associated hormonal cascade are known to enhance long-term memory consolidation. Recently we have shown that central details of a stressful situation (Trier Social Stress Test; TSST) are remembered better than central details of a similar but non-stressful control condition (friendly Trier Social Stress Test; fTSST). We reasoned that since cortisol concentrations increase during stress (TSST) but remain low during the control condition (fTSST), a pharmacological increase in cortisol during the fTSST might be able to mimic the stress effects observed previously.

OBJECTIVE

The objective of the study was to assess the impact of a pharmacologically induced cortisol increase during the non-stressful friendly TSST on long-term memory for details presented during this event.

METHODS

In a double-blind between-group design, participants (final sample: 20 men and 13 women) either received hydrocortisone (20 mg) or a placebo and were then exposed to a non-stressful social interaction (fTSST). Affect, salivary cortisol, and salivary alpha-amylase (sAA) were assessed before and after the fTSST. Recognition memory for objects presented during this situation was assessed 1 day later.

RESULTS

Positive affect and sAA increased in response to the friendly TSST in both groups. Hydrocortisone enhanced memory for peripheral objects of the situation in men but not in women. Memory for central objects was not affected by the hormone.

CONCLUSIONS

The results suggest that in a non-stressful positive social environment, cortisol induces a broadening rather than a narrowing of memory. In addition, the findings provide preliminary evidence that this effect might be more prominent in men.

Aversive emotional interference impacts behavior and prefronto-striatal activity during increasing attentional control

Earlier studies have demonstrated that emotional stimulation modulates attentional processing during goal-directed behavior and related activity of a brain network including the inferior frontal gyrus (IFG) and the caudate nucleus. However, it is not clear how emotional interference modulates behavior and brain physiology during variation in attentional control, a relevant question for everyday life situations in which both emotional stimuli and cognitive load vary. The aim of this study was to investigate the impact of negative emotions on behavior and activity in IFG and caudate nucleus during increasing levels of attentional control. Twenty two healthy subjects underwent event-related functional magnetic resonance imaging while performing a task in which neutral or fearful facial expressions were displayed before stimuli eliciting increasing levels of attentional control processing. Results indicated slower reaction time (RT) and greater right IFG activity when fearful compared with neutral facial expressions preceded the low level of attentional control. On the other hand, fearful facial expressions preceding the intermediate level of attentional control elicited faster behavioral responses and greater activity in the right and left sides of the caudate. Finally, correlation analysis indicated a relationship between behavioral correlates of attentional control after emotional interference and right IFG activity. All together, these results suggest that the impact of negative emotions on attentional processing is differentially elicited at the behavioral and physiological levels as a function of cognitive load.

Extremism reduces conflict arousal and increases values affirmation in response to meaning violations

In the social psychological threat-compensation literature, there is an apparent contradiction whereby relatively extreme beliefs both decrease markers of physiological arousal following meaning violations, and increase the values affirmation behaviors understood as a palliative responses to this arousal. We hypothesize that this is due to the differential impact of measuring extremism on behavioral inhibition and approach systems following meaning violations, whereby extremism both reduces markers of conflict arousal (BIS) and increases values affirmation (BAS) unrelated to this initial arousal. Using pupil dilation as a proxy for immediate conflict arousal, we found that the same meaning violation (anomalous playing cards) evoked greater pupil dilation, and that this pupillary reaction was diminished in participants who earlier reported extreme beliefs. We also found that reporting extreme beliefs was associated with greater affirmation of an unrelated meaning framework, where this affirmation was unrelated to physiological markers of conflict arousal.