What our eyes tell us about feelings: Tracking pupillary responses during emotion regulation processes

An influence of menopausal symptoms on mental health, emotion perception, and quality of life: a multi-faceted approach

PURPOSE

The menopausal transition brings with it many physical, cognitive, and affective changes in a woman's life, impacting quality of life. Whereas prior work has examined impact on general mental health and cognitive function, research on basic affective processing during menopause remains scarce.

METHODS

Using a median-split procedure, this pre-registered study examined the impact of stronger (N = 46 women) vs. milder (N = 47 women) menopausal symptoms using a behavioural task of subjective emotion perception (embody) and a passive eye tracking viewing task of emotional faces in addition to self-report questionnaires. After 3 months, participants completed the questionnaires again to examine whether objective measures of emotion perception (eye tracking) might predict mental health at follow-up.

RESULTS

As anticipated, women with stronger vs. milder menopausal symptoms reported increased symptoms of anxiety, depression, stress, emotion regulation difficulties, and lower quality of life during both time points. While no evidence was found in the behavioural task, eye tracking data indicated blunted emotion perception in women with high menopausal symptoms, while women with low symptoms spent more time looking at happy faces relative to fearful or surprised faces. Although eye tracking or hormonal data did not predict mental health at follow-up, a higher estradiol/FSH ratio indicated a higher quality of life.

CONCLUSIONS

This study documented an impact of the menopausal transition and strength of menopausal symptoms in particular on objective emotion perception as well as mental health and quality of life in women suffering from stronger vs. milder menopausal symptoms. Clinical implications are discussed.

Communication Under Sharply Degraded Auditory Input and the "2-Sentence" Problem

OBJECTIVES

Despite performing well in standard clinical assessments of speech perception, many cochlear implant (CI) users report experiencing significant difficulties when listening in real-world environments. We hypothesize that this disconnect may be related, in part, to the limited ecological validity of tests that are currently used clinically and in research laboratories. The challenges that arise from degraded auditory information provided by a CI, combined with the listener's finite cognitive resources, may lead to difficulties when processing speech material that is more demanding than the single words or single sentences that are used in clinical tests.

DESIGN

Here, we investigate whether speech identification performance and processing effort (indexed by pupil dilation measures) are affected when CI users or normal-hearing control subjects are asked to repeat two sentences presented sequentially instead of just one sentence.

RESULTS

Response accuracy was minimally affected in normal-hearing listeners, but CI users showed a wide range of outcomes, from no change to decrements of up to 45 percentage points. The amount of decrement was not predictable from the CI users' performance in standard clinical tests. Pupillometry measures tracked closely with task difficulty in both the CI group and the normal-hearing group, even though the latter had speech perception scores near ceiling levels for all conditions.

CONCLUSIONS

Speech identification performance is significantly degraded in many (but not all) CI users in response to input that is only slightly more challenging than standard clinical tests; specifically, when two sentences are presented sequentially before requesting a response, instead of presenting just a single sentence at a time. This potential "2-sentence problem" represents one of the simplest possible scenarios that go beyond presentation of the single words or sentences used in most clinical tests of speech perception, and it raises the possibility that even good performers in single-sentence tests may be seriously impaired by other ecologically relevant manipulations. The present findings also raise the possibility that a clinical version of a 2-sentence test may provide actionable information for counseling and rehabilitating CI users, and for people who interact with them closely.

Neuropsychobiology of fear-induced bradycardia in humans: progress and pitfalls

In the last century, the paradigm of fear conditioning has greatly evolved in a variety of scientific fields. The techniques, protocols, and analysis methods now most used have undergone a progressive development, theoretical and technological, improving the quality of scientific productions. Fear-induced bradycardia is among these techniques and represents the temporary deceleration of heart beats in response to negative outcomes. However, it has often been used as a secondary measure to assess defensive responding to threat, along other more popular techniques. In this review, we aim at paving the road for its employment as an additional tool in fear conditioning experiments in humans. After an overview of the studies carried out throughout the last century, we describe more recent evidence up to the most contemporary research insights. Lastly, we provide some guidelines concerning the best practices to adopt in human fear conditioning studies which aim to investigate fear-induced bradycardia.

Emotional response in babies' pupil contagion

In this study, it was investigated whether an emotional response would occur in pupil contagion by using skin conductance response (SCR) in 5- and 6-month-old infants. In the experiment, emotional responses to pupil diameter change (dilating/constricting) between the face and eyes regions were compared by using pupil diameter response and SCR. The results showed that pupil diameter responses to pupil diameter changes did not differ between face and eyes regions. The emotional response indicated by the SCR significantly increased when participants looked at dilating pupils of face stimuli compared with when participants looked at constricted pupils of face stimuli. In addition, we found a significant correlation between SCR and pupil dilation in the face. This means that pupil diameter expansion significantly increases emotional response in pupil dilation of the face region.

Erotic cue exposure increases physiological arousal, biases choices toward immediate rewards, and attenuates model-based reinforcement learning

Computational psychiatry focuses on identifying core cognitive processes that appear altered across distinct psychiatric disorders. Temporal discounting of future rewards and model-based control during reinforcement learning have proven as two promising candidates. Despite its trait-like stability, temporal discounting may be at least partly under contextual control. Highly arousing cues were shown to increase discounting, although evidence to date remains somewhat mixed. Whether model-based reinforcement learning is similarly affected by arousing cues remains unclear. Here, we tested cue-reactivity effects (erotic pictures) on subsequent temporal discounting and model-based reinforcement learning in a within-subjects design in n = 39 healthy heterosexual male participants. Self-reported and physiological arousal (cardiac activity and pupil dilation) were assessed before and during cue exposure. Arousal was increased during exposure of erotic versus neutral cues both on the subjective and autonomic level. Erotic cue exposure increased discounting as reflected by more impatient choices. Hierarchical drift diffusion modeling (DDM) linked increased discounting to a shift in the starting point bias of evidence accumulation toward immediate options. Model-based control during reinforcement learning was reduced following erotic cues according to model-agnostic analysis. Notably, DDM linked this effect to attenuated forgetting rates of unchosen options, leaving the model-based control parameter unchanged. Our findings replicate previous work on cue-reactivity effects in temporal discounting and for the first time show similar effects in model-based reinforcement learning in a heterosexual male sample. This highlights how environmental cues can impact core human decision processes and reveal that comprehensive modeling approaches can yield novel insights in reward-based decision processes.

Attentional, emotional, and behavioral response toward spiders, scorpions, crabs, and snakes provides no evidence for generalized fear between spiders and scorpions

Spiders are among the animals evoking the highest fear and disgust and such a complex response might have been formed throughout human evolution. Ironically, most spiders do not present a serious threat, so the evolutionary explanation remains questionable. We suggest that other chelicerates, such as scorpions, have been potentially important in the formation and fixation of the spider-like category. In this eye-tracking study, we focused on the attentional, behavioral, and emotional response to images of spiders, scorpions, snakes, and crabs used as task-irrelevant distractors. Results show that spider-fearful subjects were selectively distracted by images of spiders and crabs. Interestingly, these stimuli were not rated as eliciting high fear contrary to the other animals. We hypothesize that spider-fearful participants might have mistaken crabs for spiders based on their shared physical characteristics. In contrast, subjects with no fear of spiders were the most distracted by snakes and scorpions which supports the view that scorpions as well as snakes are prioritized evolutionary relevant stimuli. We also found that the reaction time increased systematically with increasing subjective fear of spiders only when using spiders (and crabs to some extent) but not snakes and scorpions as distractors. The maximal pupil response covered not only the attentional and cognitive response but was also tightly correlated with the fear ratings of the picture stimuli. However, participants' fear of spiders did not affect individual reactions to scorpions measured by the maximal pupil response. We conclude that scorpions are evolutionary fear-relevant stimuli, however, the generalization between scorpions and spiders was not supported in spider-fearful participants. This result might be important for a better understanding of the evolution of spider phobia.

The impact of physical exercise on the consolidation of fear extinction memories

Based on the mechanisms of fear extinction, exposure therapy is the most common treatment for anxiety disorders. However, extinguished fear responses can reemerge even after successful treatment. Novel interventions enhancing exposure therapy efficacy are therefore critically needed. Physical exercise improves learning and memory and was also shown to enhance extinction processes. This study tested whether physical exercise following fear extinction training improves the consolidation of extinction memories. Sixty healthy men underwent a differential fearconditioning paradigm with fear acquisition training on day 1 and fear extinction training followed by an exercise or resting control intervention on day 2. On day 3, retrieval and reinstatement were tested including two additional but perceptually similar stimuli to explore the generalization of exercise effects. Exercise significantly increased heart rate, salivary alpha amylase, and cortisol, indicating successful exercise manipulation. Contrary to our expectations, exercise did not enhance but rather impaired extinction memory retrieval on the next day, evidenced by significantly stronger differential skin conductance responses (SCRs) and pupil dilation (PD). Importantly, although conditioned fear responses were successfully acquired, they did not fully extinguish, explaining why exercise might have boosted the consolidation of the original fear memory trace instead. Additionally, stronger differential SCRs and PD toward the novel stimuli suggest that the memory enhancing effects of exercise also generalized to perceptually similar stimuli. Together, these findings indicate that physical exercise can facilitate both the long-term retrievability and generalization of extinction memories, but presumably only when extinction was successful in the first place.

The open toolbox for behavioral research

In this work, we describe a new open-source MATLAB toolbox for the control of behavioral experiments. The toolbox caters to very different types of experiments in different species, and with different underlying hardware. Typical examples are operant chambers in animals, with or without neurophysiology, behavioral experiments in human subjects, and neurophysiological recordings in humans such as EEG and fMRI. In addition, the toolbox supports communication via Ethernet to either control and monitor one or several experimental setups remotely or to implement distributed paradigms across different computers. This flexibility is possible, since the toolbox supports a wide range of hardware, some of which is custom developments. An example is a fast network-based digital-IO device for the communication with experimental hardware such as feeders or triggers in neurophysiological setups. We also included functions for online video analysis allowing paradigms to be contingent on responses to a screen, the head movement of a bird in an operant chamber, or the physical location of an animal in an open arena. While the toolbox is well tested and many components of it have been in use for many years, we do not see it as a finished product but rather a continuing development with a focus on easy extendibility and customization.

Evaluating Physician Emotion Regulation in Serious Illness Conversations Using Multimodal Assessment

CONTEXT

Emotion regulation by the physician can influence the effectiveness of serious illness conversations. The feasibility of multimodal assessment of emotion regulation during these conversations is unknown.

OBJECTIVES

To develop and assess an experimental framework for evaluating physician emotion regulation during serious illness conversations.

METHODS

We developed and then assessed a multimodal assessment framework for physician emotion regulation using a cross-sectional, pilot study on physicians trained in the Serious Illness Conversation Guide (SICG) in a simulated, telehealth encounter. Development of the assessment framework included a literature review and subject matter expert consultations. Our predefined feasibility endpoints included: an enrollment rate of ≥60% of approached physicians, >90% completion rate of survey items, and <20% missing data from wearable heart rate sensors. To describe physician emotion regulation, we performed a thematic analysis of the conversation, its documentation, and physician interviews.

RESULTS

Out of 12 physicians approached, 11 (92%) SICG-trained physicians enrolled in the study: five medical oncology and six palliative care physicians. All 11 completed the survey (100% completion rate). Two sensors (chest band, wrist sensor) had <20% missing data during study tasks. The forearm sensor had >20% missing data. The thematic analysis found that physicians': 1) overarching goal was to move beyond prognosis to reasonable hope; 2) tactically focused on establishing a trusting, supportive relationship; and 3) possessed incomplete awareness of their emotion regulation strategies.

CONCLUSION

Our novel, multimodal assessment of physician emotion regulation was feasible in a simulated SICG encounter. Physicians exhibited an incomplete understanding of their emotion regulation strategies.

Transcranial magnetic stimulation and transcranial direct current stimulation affect explicit but not implicit emotion regulation: a meta-analysis

Emotion regulation (ER) refers to the process through which people influence the occurrence, experience, and expression of emotions. It can be established in an explicit (voluntary) or implicit (automatic) way, both of which are essential for mental and physical well-being. Recent evidence has highlighted the potential of transcranial magnetic stimulation (TMS) and transcranial direct current stimulation (tDCS) targeting the prefrontal cortex (PFC) to modulate ER. However, previous studies have only evaluated the effects of TMS and tDCS on explicit ER, leaving implicit ER relatively unexplored. In this review and meta-analysis, we systematically evaluated the effects of TMS and tDCS over the PFC on the two forms of ER, using both subjective and physiological response as outcome indicators. Twenty-seven studies were included in our study. Both subjective (Hedges' g = - 0.20) and physiological (Hedges' g = - 0.65) results indicated a significant effect of TMS and tDCS targeting PFC on down-regulation of explicit ER, but not implicit ER (Hedges' g = - 0.04). Moreover, moderation analysis indicated that the effect of TMS and tDCS on the down-regulating of subjective experience was moderated by several factors, including stimulation method, target area, target hemisphere, and stimulation timing. Specifically, our results showed that applying TMS or targeting the right PFC, particularly the right ventrolateral prefrontal cortex, or using offline TMS and tDCS produced a larger stimulation effect on ER. In summary, these findings suggest that TMS and tDCS has a positive effect on explicit, but not implicit ER. The distinct TMS and tDCS effect on the two forms of ER help deepen our understanding of TMS and tDCS use and provide valuable insights for the development of tailored TMS and tDCS protocols for explicit and implicit regulation.

The role of ventrolateral prefrontal cortex on voluntary emotion regulation of social pain

The right ventrolateral prefrontal cortex (rVLPFC) is highly engaged in emotion regulation of social pain. However, there is still lack of both inhibition and excitement evidence to prove the causal relationship between this brain region and voluntary emotion regulation. This study used high-frequency (10 Hz) and low-frequency (1 Hz) repetitive transcranial magnetic stimulation (rTMS) to separately activate or inhibit the rVLPFC in two groups of participants. We recorded participants' emotion ratings as well as their social attitude and prosocial behaviors following emotion regulation. Also, we used eye tracker to record the changes of pupil diameter to measure emotional feelings objectively. A total of 108 healthy participants were randomly assigned to the activated, inhibitory or sham rTMS groups. They were required to accomplish three sequential tasks: the emotion regulation (cognitive reappraisal) task, the favorability rating task, and the donation task. Results show that the rVLPFC-inhibitory group reported more negative emotions and showed larger pupil diameter while the rVLPFC-activated group showed less negative emotions and reduced pupil diameter during emotion regulation (both compared with the sham rTMS group). In addition, the activated group gave more positive social evaluation to peers and donated more money to a public welfare activity than the rVLPFC-inhibitory group, among which the change of social attitude was mediated by regulated emotion. Taken together, these findings reveal that the rVLPFC plays a causal role in voluntary emotion regulation of social pain and can be a potential brain target in treating deficits of emotion regulation in psychiatric disorders.

Parents regulate arousal while sharing experiences with their child: a study of pupil diameter change responses

Introduction

Parents provide their children with their first exposures to reciprocal shared experiences, and parental modeling of socio-emotional behaviors and regulatory responses largely influences their child's behavioral and neurological development. Some parental reactions are conscious, while others are non-volitional. This project aimed to explore parent-child pupil dilation change responses during shared interactions, specifically, whether parents' neuro-regulatory responses when sharing experiences with their child are different than responses of children interacting with their parents or children and adult peers sharing with each other.

Methods

To test this, four distinct interacting groups were recruited: (1) Parents sharing with their child; (2) Children sharing with their parent; (3) Children sharing with peers; and (4) Adults sharing with peers. All dyads engaged in a computerized shared imagery task, which facilitates communication and mental imagery during a shared experience. During the task, pupil diameter change was recorded as a measure of regulatory response.

Results

Findings highlight that parents sharing with their child have lower pupil diameter change than children sharing with their parents (p < 0.01), children sharing with peers (p < 0.01), and adults sharing with peers (p < 0.05), While no differences were seen between children sharing with parents, children sharing with peers or adults sharing with peers.

Discussion

Findings deepen the understanding of the neuroscience of parenting, by suggesting that parents, even of older children and adolescents, tend to regulate their arousal when interacting with their child, a response that proves to be unique compared to other dyad types for sharing experiences. Considering this dynamic, findings may direct future parent-led intervention methods to improve the child's socio-emotional development.

Pupillary motility responses to affectively salient stimuli in individuals with depression or elevated risk of depression: A systematic review and meta-analysis

Elaborative affective processing is observed in depression, and pupillary reactivity, a continuous, sensitive, and reliable indicator of physiological arousal and neurocognitive processing, is increasingly utilized in studies of depression-related characteristics. As a first attempt to quantitively summarize existing evidence on depression-related pupillary reactivity alterations, this review and meta-analysis evaluated the direction, magnitude, and specificity of pupillary indices of affective processing towards positively, negatively, and neutrally-valenced stimuli among individuals diagnosed with depression or with elevated risk of depression. Studies on pupillary responses to affective stimuli in the target groups were identified in PsycINFO and PubMed databases. Twenty-two articles met inclusion criteria for the qualitative review and 16 for the quantitative review. Three-level frequentist and Bayesian models were applied to summarize pooled effects from baseline-controlled stimuli-induced average changes in pupillary responses. In general, compared to non-depressed individuals, individuals with depression or elevated risk of depression exhibited higher pupillary reactivity (d =0.15) towards negatively-valenced stimuli during affective processing. Pupillary motility towards negatively-valenced stimuli may be a promising trait-like marker for depression vulnerability.

Rapid effects of acute stress on cognitive emotion regulation

Acute stress has been shown to either enhance or impair emotion regulation (ER) performances. Besides sex, strategy use and stimulus intensity, another moderating factor appears to be timing of the ER task relative to stress exposure. Whereas somewhat delayed increases in the stress hormone cortisol have been shown to improve ER performances, rapid sympathetic nervous system (SNS) actions might oppose such effects via cognitive regulatory impairments. Here, we thus investigated rapid effects of acute stress on two ER strategies: reappraisal and distraction. N = 80 healthy participants (40 men & 40 women) were exposed to the Socially Evaluated Cold-Pressor Test or a control condition immediately prior to an ER paradigm which required them to deliberately downregulate emotional responses towards high intensity negative pictures. Subjective ratings and pupil dilation served as ER outcomes measures. Increases in salivary cortisol and cardiovascular activity (index of SNS activation) verified successful induction of acute stress. Unexpectedly, stress reduced subjective emotional arousal when distracting from negative pictures in men indicating regulatory improvements. However, this beneficial effect was particularly pronounced in the second half of the ER paradigm and fully mediated by already rising cortisol levels. In contrast, cardiovascular responses to stress were linked to decreased subjective regulatory performances of reappraisal and distraction in women. However, no detrimental effects of stress on ER occurred at the group level. Yet, our findings provide initial evidence for rapid, opposing effects of the two stress systems on the cognitive control of negative emotions that are critically moderated by sex.

Emotion Detection Based on Pupil Variation

Emotion detection is a fundamental component in the field of Affective Computing. Proper recognition of emotions can be useful in improving the interaction between humans and machines, for instance, with regard to designing effective user interfaces. This study aims to understand the relationship between emotion and pupil dilation. The Tobii Pro X3-120 eye tracker was used to collect pupillary responses from 30 participants exposed to content designed to evoke specific emotions. Six different video scenarios were selected and presented to participants, whose pupillary responses were measured while watching the material. In total, 16 data features (8 features per eye) were extracted from the pupillary response distribution during content exposure. Through logistical regression, a maximum of 76% classification accuracy was obtained through the measurement of pupillary response in predicting emotions classified as fear, anger, or surprise. Further research is required to precisely calculate pupil size variations in relation to emotionally evocative input in affective computing applications.

The effect of visual attention process and thinking styles on environmental aesthetic preference: An eye-tracking study

People often form different aesthetic preferences for natural and built environments, which affects their behavioral intention; however, it remains unknown whether this difference in aesthetic preference is due to differences in thinking styles. However, whether tourists' aesthetic preferences differ when using different visual attention processes has not been studied further. This study used eye-tracking and self-reporting to investigate these questions. The results show that natural environment images are more favored visually because they can evoke in tourists larger pupil diameters and longer scan paths, but we found no significant difference in fixation duration and fixation counts. We also found that the scanning path of tourists who predominantly rely on intuitive thinking is modulated by the bottom-up attention process, while the scanning path of tourists who prefer rational thinking is modulated by the top-down attention process. In the bottom-up process, tourists who prefer rational thinking exhibit more positive aesthetic preferences and emotional arousal. In summary, the present study verified that aesthetic preference is more likely to be influenced by both thinking style and visual attention processing. The results of the present work provide preliminary evidence that the aesthetic preference of the environment is not only related to visual attention but also affected by the individual visual attention process and thinking style.

Brightness Perception in World-Centered Coordinates Assessed by Pupillometry

Subjective brightness perception reportedly differs among the peripheral visual fields owing to lower- and higher-order cognition. However, there is still a lack of information associated with subjective brightness perception in the world-centered coordinates, not in the visual fields. In this study, we aimed to investigate the anisotropy of subjective brightness perception in the world-centered coordinates based on pupillary responses to the stimuli in five locations by manipulating the world-centered coordinates through active (requiring head movement) and passive scenes (without head movement) in a virtual reality environment. Specifically, this study aimed to elucidate if there is an ecological advantage in the five different locations in the world-centered coordinates. The pupillary responses to glare and halo stimuli indicated that the brightness perception differed among the five locations in the world-centered coordinates. Furthermore, we found that the pupillary response to stimuli at the top location might be influenced by ecological factors (such as from the bright sky and the sun's existence). Thus, we have contributed to the understanding of the extraretinal information influence on subjective brightness perception in the world-centered coordinates, demonstrating that the pupillary response is independent of head movement.

Does past/current pain change pain experience? Comparing self-reports and pupillary responses

Introduction

For decades, a substantial body of research has confirmed the subjective nature of pain. Subjectivity seems to be integrated into the concept of pain but is often confined to self-reported pain. Although it seems likely that past and current pain experiences would interact and influence subjective pain reports, the influence of these factors has not been investigated in the context of physiological pain. The current study focused on exploring the influence of past/current pain on self-reporting and pupillary responses to pain.

Methods

Overall, 47 participants were divided into two groups, a 4°C-10°C group (experiencing major pain first) and a 10°C-4°C group (experiencing minor pain first), and performed cold pressor tasks (CPT) twice for 30 s each. During the two rounds of CPT, participants reported their pain intensity, and their pupillary responses were measured. Subsequently, they reappraised their pain ratings in the first CPT session.

Results

Self-reported pain showed a significant difference (4°C-10°C: p = 0.045; 10°C-4°C: p < 0.001) in the rating of cold pain stimuli in both groups, and this gap was higher in the 10°C-4°C group than in the 4°C-10°C group. In terms of pupillary response, the 4°C-10°C group exhibited a significant difference in pupil diameter, whereas this was marginally significant in the 10°C-4°C group (4°C-10°C: p < 0.001; 10°C-4°C: p = 0.062). There were no significant changes in self-reported pain after reappraisal in either group.

Discussion

The findings of the current study confirmed that subjective and physiological responses to pain can be altered by previous experiences of pain.

Affective states and regulation of learning during socio-emotional interactions in secondary school collaborative groups

BACKGROUND

Group affective states for learning are constantly formed through socio-emotional interactions. However, it remains unclear how the affective states vary during collaboration and how they occur with regulation of learning. Appropriate methods are needed to track both group affective states and these interaction processes.

AIMS

The present study identifies different socio-emotional interaction episodes during groups' collaborative learning and examines how group affective states fluctuate with regulation of learning during these episodes.

SAMPLE

The participants were 54 secondary school students working in groups across four science learning sessions.

METHODS

Multichannel process data (video, electrodermal activity [EDA]) were collected in an authentic classroom. Groups' affective states were measured with emotional valence captured from video data, and activation captured as sympathetic arousal from EDA data. Regulation of learning was observed from the videotaped interactions.

RESULTS

The study disclosed four clusters of socio-emotional interaction episodes (positive, negative, occasional regulation, frequent regulation), which differed in terms of fluctuation of affective states and activated regulation of learning. These clustered episodes confirm how affective states are constantly reset by socio-emotional interactions and regulation of learning. The results also show that states requiring regulation do not automatically lead to its activation.

CONCLUSIONS

By advancing existing understanding of how group level socio-emotional processes contribute to regulation of learning, the study has implications for educational design and psychological practice. Methodologically, it contributes to collaborative learning research by employing multiple data channels (including biophysiological measures) to explore the various dimensions of socio-emotional processes in groups.

Anisotropy in the peripheral visual field based on pupil response to the glare illusion

Visual-field (VF) anisotropy has been investigated in terms of spatial resolution of attention, spatial frequency, and semantic processing. Brightness perception has also been reported to vary between VFs. However, the influence of VF anisotropy on brightness perception using pupillometry has not been investigated. The present study measured participants' pupil size during glare illusion, in which converging luminance gradients evoke brightness enhancement and a glowing impression on the central white area of the stimulus, and halo stimuli, in which the same physical brightness of the glare illusion is used with a diverging luminance pattern. The results revealed greater stimulus-evoked pupillary dilation and glare-related dilated pupil reduction in the upper VF (UVF) compared with other VFs and halo-related pupillary changes, respectively. The stimulus-evoked pupillary dilation was affected by poor contrast sensitivity. However, owing to the superior cognitive bias formed by statistical regularity in natural scene processing of the glare illusion in the UVF, we found reduced pupillary dilation compared with the response to halo stimuli and the response from other VFs. These findings offer valuable insight into a method to reduce the potential glare effect of any VF anisotropy induced by the glare effect experienced in daily vision. An important practical implication of our study may be in informing the design of applications aimed at improving nighttime driving behavior. We also believe that our study makes a significant contribution to the literature because it offers valuable insights on VF anisotropy using evidence from pupillometry and the glare illusion.

Trial-wise exposure to visual emotional cues increases physiological arousal but not temporal discounting

Humans and many animals devalue future rewards as a function of time (temporal discounting). Increased discounting has been linked to various psychiatric conditions, including substance-use-disorders, behavioral addictions, and obesity. Despite its high intra-individual stability, temporal discounting is partly under contextual control. One prominent manipulation that has been linked to increases in discounting is the exposure to highly arousing appetitive cues. However, results from trial-wise cue exposure studies appear highly mixed, and changes in physiological arousal were not adequately controlled. Here we tested the effects of appetitive (erotic), aversive, and neutral visual cues on temporal discounting in 35 healthy male participants. The contribution of single-trial physiological arousal was assessed using comprehensive monitoring of autonomic activity (pupil size, heart rate, electrodermal activity). Physiological arousal was elevated following aversive and in particular erotic cues. In contrast to our pre-registered hypothesis, steepness of temporal discounting was not significantly affected by emotional cues of either valence. Aversive cues tended to increase decision noise. Computational modeling revealed that trial-wise arousal only accounted for minor variance over and above aversive and erotic condition effects, arguing against a general effect of physiological arousal on temporal discounting.

Acute stress influences strategy preference when dealing with high intensity emotions in men

Stress has been shown to initiate a shift from flexible to rigid, less demanding cognitive processes. Reappraisal and distraction are two emotion regulation strategies varying in their cognitive demands. Previous studies indicate that stress improves regulatory performances of high arousal stimuli. We thus investigated whether acute stress alters the preference for reappraisal or distraction when downregulating emotions of different intensities and further explored its influence on regulatory outcomes. Eighty males were either socially stressed (n=40) or exposed to a control condition (n=40) prior to an emotion regulation choice paradigm. Stress increased the probability to prefer distraction for downregulating high intensity emotions. Stressed (vs. control) participants reported to be generally more successful in regulating high intensity emotions, which was positively associated with cortisol but not alpha-amylase increases. Our findings provide initial evidence that stress fosters a preference for less demanding regulatory options, suggesting favorable strategy choices in response to acute stressors. DATA AVAILABILITY: The data that support the findings of this study are available at the Open Science Framework (OSF) under https://osf.io/b9ae3/.

Adults with cochlear implants can use prosody to determine the clausal structure of spoken sentences

Speech prosody, including pitch contour, word stress, pauses, and vowel lengthening, can aid the detection of the clausal structure of a multi-clause sentence and this, in turn, can help listeners determine the meaning. However, for cochlear implant (CI) users, the reduced acoustic richness of the signal raises the question of whether CI users may have difficulty using sentence prosody to detect syntactic clause boundaries within sentences or whether this ability is rescued by the redundancy of the prosodic features that normally co-occur at clause boundaries. Twenty-two CI users, ranging in age from 19 to 77 years old, recalled three types of sentences: sentences in which the prosodic pattern was appropriate to the location of a clause boundary within the sentence (congruent prosody), sentences with reduced prosodic information, or sentences in which the location of the clause boundary and the prosodic marking of a clause boundary were placed in conflict. The results showed the presence of congruent prosody to be associated with superior sentence recall and a reduced processing effort as indexed by the pupil dilation. The individual differences in a standard test of word recognition (consonant-nucleus-consonant score) were related to the recall accuracy as well as the processing effort. The outcomes are discussed in terms of the redundancy of the prosodic features, which normally accompany a clause boundary and processing effort.

Artificial Eyes with Emotion and Light Responsive Pupils for Realistic Humanoid Robots

This study employs a novel 3D engineered robotic eye system with dielectric elastomer actuator (DEA) pupils and a 3D sculpted and colourised gelatin iris membrane to replicate the appearance and materiality of the human eye. A camera system for facial expression analysis (FEA) was installed in the left eye, and a photo-resistor for measuring light frequencies in the right. Unlike previous prototypes, this configuration permits the robotic eyes to respond to both light and emotion proximal to a human eye. A series of experiments were undertaken using a pupil tracking headset to monitor test subjects when observing positive and negative video stimuli. A second test measured pupil dilation ranges to high and low light frequencies using a high-powered artificial light. This data was converted into a series of algorithms for servomotor triangulation to control the photosensitive and emotive pupil dilation sequences. The robotic eyes were evaluated against the pupillometric data and video feeds of the human eyes to determine operational accuracy. Finally, the dilating robotic eye system was installed in a realistic humanoid robot (RHR) and comparatively evaluated in a human-robot interaction (HRI) experiment. The results of this study show that the robotic eyes can emulate the average pupil reflex of the human eye under typical light conditions and to positive and negative emotive stimuli. However, the results of the HRI experiment indicate that replicating natural eye contact behaviour was more significant than emulating pupil dilation.

Pupillary response reflects attentional modulation to sound after emotional arousal

There have been various studies on the effects of emotional visual processing on subsequent non-emotional auditory stimuli. A previous study with EEG has shown that responses to deviant sounds presented after presenting negative pictures collected more attentional resources than those for neutral pictures. To investigate such a compelling between emotional and cognitive processing, this study aimed to examined pupillary responses to an auditory stimulus after a positive, negative, or neutral emotional state was elicited by an emotional image. An emotional image was followed by a beep sound that was either repetitive or unexpected, and the pupillary dilation was measured. As a result, we found that the early component of the pupillary response to the beep sound was larger for negative and positive emotional states than the neutral emotional state, whereas the late component was larger for the positive emotional state than the negative and neutral emotional states. In addition, the peak latency of the pupillary response was earlier for negative than neutral or positive images. Further, to compensate for the disadvantage of low-temporal resolution of the pupillary data, the pupillary responses were deconvoluted and used in the analysis. The deconvolution analysis of pupillary responses confirmed that the responses to beep sound were more likely to be modulated by the emotional state rather than being influenced by the short presentation interval between the images and sounds. These findings suggested that pupil size index modulations in the compelling situation between emotional and cognitive processing.

Effort beats effectiveness in emotion regulation choice: Differences between suppression and distancing in subjective and physiological measures

Emotion regulation (ER) can be implemented by different strategies which differ in their capacity to alter emotional responding. What all strategies have in common is that cognitive control must be exercised in order to implement them. The aim of the present preregistered study was to investigate whether the two ER strategies, expressive suppression and distancing, require different amounts of cognitive effort and whether effort is associated with personality traits. Effort was assessed subjectively via ratings and objectively via pupillometry and heart period. In two studies, N = 110 and N = 52 healthy adults conducted an ER paradigm. Participants used suppression and distancing during inspection of positive and negative pictures. They also had the choice to reapply either of the strategies at the end of the paradigm. Although distancing was more effective in downregulation of subjective arousal (Study 1: p < .001, η p 2  = .20; Study 2: p < .001, η p 2  = .207), about two thirds reapplied suppression, because it was perceived as less effortful. Effort was rated significantly lower for suppression compared to distancing (Study 1: p = .042, η p 2  = .04; Study 2: p = .002, η p 2  = .13). However, differences in effort were not reflected in pupillary data or heart period. Broad and narrow personality traits were neither associated with the preferred strategy nor with subjective or physiological effort measures. Findings suggest that people tend to use the ER strategy that is perceived as less effortful, even though it might not be the most effective strategy.

Pupil dilation predicts individual self-regulation success across domains

Multiple theories have proposed that increasing central arousal through the brain's locus coeruleus-norepinephrine system may facilitate cognitive control and memory. However, the role of the arousal system in emotion regulation is less well understood. Pupil diameter is a proxy to infer upon the central arousal state. We employed an emotion regulation paradigm with a combination of design features that allowed us to dissociate regulation from emotional arousal in the pupil diameter time course of 34 healthy adults. Pupil diameter increase during regulation predicted individual differences in emotion regulation success beyond task difficulty. Moreover, the extent of this individual regulatory arousal boost predicted performance in another self-control task, dietary health challenges. Participants who harnessed more regulation-associated arousal during emotion regulation were also more successful in choosing healthier foods. These results suggest that a common arousal-based facilitation mechanism may support an individual's self-control across domains.

Investigating the relationship between users' eye movements and perceived product attributes in design concept evaluation

Eye movements as the indicators of human information processing have been studied in many domains. However, it is not clear how users' eye movements differ among specific product attribute, while visual impression of a product plays a crucial part in distinguishing product designs. Therefore, this paper attempts to establish guidance for exploring eye tracking applications in design concept validations through two case studies. The first case study investigated the product attributes based on the theory of cognitive-affective emotions. The second investigated the product attributes for apparent functionality and affective quality. The eye movements of 105 participants were analyzed when they evaluated the products images. The results indicated that product attributes perceived in evaluation tasks can be predicted from eye movements. Moreover, compared to the new users, experienced users had a longer mean fixation duration and tended to form their impressions of the product from multiple components.

Expressive suppression versus cognitive reappraisal: Effects on self-report and peripheral psychophysiology

Effectiveness of various emotion regulation (ER) strategies have received much attention in recent research. Among the most studied ER strategies are cognitive reappraisal and expressive suppression. However, the evidence of their effectiveness is controversial and depends on the measures used. The aim of the present study was to compare the effectiveness of cognitive reappraisal and expressive suppression strategies of ER via different measures such as self-report, facial expressions (zygomaticus major and corrugator supercilii electromyography), and physiological assessment (skin conductance response and heart rate deceleration). Participants were presented with intensely unpleasant or neutral pictures and performed ER tasks. We expected that the implementation of ER strategies would reduce negative emotions, and cognitive reappraisal would produce greater reduction in negative emotions compared to expressive suppression. Self-report data showed that reappraisal had a greater effect on the reduction of negative emotions compared to suppression. There was no difference between reappraisal and suppression assessed with skin conductance response and electromyography. Curiously, heart rate deceleration increased while participants tried to suppress their emotional expressions, which could reflect efforts exerted in the attempt to suppress. The ER strategies reduced negative emotions during the presentation of unpleasant pictures partially in skin conductance response and heart rate deceleration. Overall, reappraisal is more effective in changing subjective experience, whereas the physiological reactions do not differ substantially between the two ER strategies explored. We therefore recommend that the assessment of ER strategies in the laboratory should accommodate more than one type of measures to come to more reliable conclusions.

Emotion regulation by attentional deployment moderates bilinguals' language-dependent emotion differences

Unbalanced bilinguals react differently to emotional stimuli in their first (L1) and second (L2) language. However, the size and direction of the emotion difference varies across emotions and tasks, so that its causes are controversial. Therefore, we investigated if the attentional resources bilinguals allocate to emotion processing moderate their language-dependent emotions. In two experiments, we crossed language and emotion regulation. Study 1 compared effects of distraction and concentration on bilingual emotion-word valence ratings. Study 2 induced positive emotion-focused rumination (or not) prior to a simulated, video-based online-dating activity. It measured emotional attraction to dating candidates speaking the participant's L1 or L2 in pupillary, eye-fixation and self-report responses. The studies found reduced L2 emotions when emotion processing was distracted or when its level was low to start with. Yet, if bilinguals concentrated or had ruminated on their emotions, their self-reported and physiological emotionality was comparable or even stronger in L2, relative to L1. The findings suggest that bilinguals' language-dependent emotions vary with differential language-processing automaticity. We propose that the observed emotion-regulation moderation generates further testable predictions about where and when language choice is relevant for bilinguals' emotions.

The Principle of Least Effort and Comprehension of Spoken Sentences by Younger and Older Adults

There is considerable evidence that listeners' understanding of a spoken sentence need not always follow from a full analysis of the words and syntax of the utterance. Rather, listeners may instead conduct a superficial analysis, sampling some words and using presumed plausibility to arrive at an understanding of the sentence meaning. Because this latter strategy occurs more often for sentences with complex syntax that place a heavier processing burden on the listener than sentences with simpler syntax, shallow processing may represent a resource conserving strategy reflected in reduced processing effort. This factor may be even more important for older adults who as a group are known to have more limited working memory resources. In the present experiment, 40 older adults (M age = 75.5 years) and 20 younger adults (M age = 20.7) were tested for comprehension of plausible and implausible sentences with a simpler subject-relative embedded clause structure or a more complex object-relative embedded clause structure. Dilation of the pupil of the eye was recorded as an index of processing effort. Results confirmed greater comprehension accuracy for plausible than implausible sentences, and for sentences with simpler than more complex syntax, with both effects amplified for the older adults. Analysis of peak pupil dilations for implausible sentences revealed a complex three-way interaction between age, syntactic complexity, and plausibility. Results are discussed in terms of models of sentence comprehension, and pupillometry as an index of intentional task engagement.

Cortisol promotes the cognitive regulation of high intensive emotions independent of timing

Failures to cognitively downregulate negative emotions are a crucial risk factor for mental disorders. Previous studies provide evidence for a stress-induced improvement of cognitive emotion regulation possibly mediated via glucocorticoid actions. Cortisol can initialize immediate non-genomic as well as delayed genomic effects on cognitive control functioning, but its distinct effects on emotion regulation processes remain to be shown. Here, we sought to characterize time-dependent effects of oral cortisol administration on cognitive emotion regulation outcomes. We expected cortisol to improve emotion regulation success. Possible interactions with the delay between cortisol treatment and emotion regulation, strategy use and intensity of the emotional stimuli were examined. Eighty-five healthy men received either 10 mg hydrocortisone or a placebo in a double-blind, randomized design 30 or 90 min prior to an emotion regulation paradigm, in which they were asked to downregulate their emotional responses towards low and high intensive negative pictures via reappraisal or distraction. Affective ratings and pupil dilation served as outcome measures. Reduced arousal, enhanced valence ratings as well as increases in pupil dilations indexing the cognitive regulatory effort indicated successful downregulation of negative emotions evoked by high intensive but not low intensive negative pictures. Cortisol significantly reduced arousal ratings when downregulating high intensive negative emotions via distraction and (at a trend level) via reappraisal, independent of timing, demonstrating a beneficial effect of cortisol on subjective regulatory outcomes. Taken together, this study provides initial evidence suggesting that cortisol promotes the cognitive control of high intensive negative emotions both, 30 and 90 min after treatment.

Delayed effects of acute stress on cognitive emotion regulation

Acute stress has been shown to modulate cognitive emotion regulation. Besides interactions with strategy use or sex, another critical modulating factor appears to be stress timing. Exposure to acute stress initiates immediate and delayed glucocorticoid effects on cognitive control functions. Previous studies indicated a delayed increase in prefrontal activity after stress and cortisol elevations, which might also improve the ability to cognitively regulate emotions when the acute stress state has subsided. In this study, we investigated the delayed impact of acute stress on the two emotion regulation strategies reappraisal and distraction. Eighty-one healthy males and free-cycling females were exposed to the Trier Social Stress Test or a control condition 90 min before they were tested in an emotion regulation paradigm, which required them to up- and downregulate their emotional responses towards negative pictures. Affective ratings served to measure emotion regulation success, whereas pupil dilation was included to additionally assess the cognitive effort required to deliberately regulate emotions. Stress affected neither arousal, valence or success ratings nor pupil dilation. However, cortisol increases were significantly associated with reduced arousal and enhanced valence ratings when regulating negative emotions via distraction. Exploratory mediation analyses revealed an indirect effect of stress on arousal and valence ratings for distraction that was mediated by cortisol increase. Our findings thereby provide further evidence that cortisol is positively related to emotion regulation success, which might be driven by a glucocorticoid-mediated mechanism facilitating attentional shifting.

Reappraising fear: is up-regulation more efficient than down-regulation?

Catastrophizing thoughts may contribute to the development of anxiety, but functional emotion regulation may help to improve treatment. No study so far directly compared up- and down-regulation of fear by cognitive reappraisal. Here, healthy individuals took part in a cued fear experiment, in which multiple pictures of faces were paired twice with an unpleasant scream or presented as safety stimuli. Participants (N = 47) were asked (within-subjects) to down-regulate, to up-regulate and to maintain their natural emotional response. Valence and arousal ratings indicated successful up- and down-regulation of the emotional experience, while heart rate and pupil dilation increased during up-regulation, but showed no reduction in down-regulation. State and trait anxiety correlated with evaluations of safety but not threat stimuli, which supports the role of deficient safety learning in anxiety. Reappraisal did not modulate this effect. In conclusion, this study reveals evidence for up-regulation effects in fear, which might be even more efficient than down-regulation on a physiological level and highlights the importance of catastrophizing thoughts for the maintenance of fear and anxiety.

Pupil dilation reflects the authenticity of received nonverbal vocalizations

The ability to infer the authenticity of other’s emotional expressions is a social cognitive process taking place in all human interactions. Although the neurocognitive correlates of authenticity recognition have been probed, its potential recruitment of the peripheral autonomic nervous system is not known. In this work, we asked participants to rate the authenticity of authentic and acted laughs and cries, while simultaneously recording their pupil size, taken as proxy of cognitive effort and arousal. We report, for the first time, that acted laughs elicited higher pupil dilation than authentic ones and, reversely, authentic cries elicited higher pupil dilation than acted ones. We tentatively suggest the lack of authenticity in others’ laughs elicits increased pupil dilation through demanding higher cognitive effort; and that, reversely, authenticity in cries increases pupil dilation, through eliciting higher emotional arousal. We also show authentic vocalizations and laughs (i.e. main effects of authenticity and emotion) to be perceived as more authentic, arousing and contagious than acted vocalizations and cries, respectively. In conclusion, we show new evidence that the recognition of emotional authenticity can be manifested at the level of the autonomic nervous system in humans. Notwithstanding, given its novelty, further independent research is warranted to ascertain its psychological meaning.

Improving emotion regulation of social exclusion in depression-prone individuals: a tDCS study targeting right VLPFC

BACKGROUND

Growing evidence has indicated that right ventrolateral prefrontal cortex (RVLPFC) is critical in down-regulating emotional responses to social exclusion, and that depression is accompanied by social emotional dysregulation associated with reduced lateral prefrontal engagement. This study used anodal transcranial direct current stimulation (tDCS) to examine whether stimulating RVLPFC could improve emotional down-regulation of social exclusion in individuals with high depressive mood (DM).

METHODS

A total of 96 high and 94 low DM individuals received active or sham tDCS while viewing social exclusion or individual negative pictures under no-reappraisal (passive viewing) and reappraisal conditions. Participants rate their negative emotional experience following the presentation of each image. Pupil diameter and visual fixation duration were also recorded during the task.

RESULTS

It was found that tDCS-activated RVLPFC induced a stronger regulation effect on social exclusion than individual negative emotions. The effect of tDCS on regulation of social exclusion was more pronounced in low v. high DM individuals.

CONCLUSIONS

These findings demonstrate the specific role of RVLPFC on social emotion regulation, which has implications for refining target areas for the treatment of social emotion dysregulation in depression. However the findings do not suggest that high DM individuals benefit from a single-tDCS session on the emotion regulation of social exclusion. Thus we suggest to use multiple tDCS sessions or transcranial magnetic stimulation to further explore the therapeutic proposal in the future.

Acute stress improves the effectivity of cognitive emotion regulation in men

Emotion regulation is crucial for coping with stressors but in turn can also be influenced by stress. Initial studies provided mixed evidence showing either beneficial or impairing stress effects on cognitive emotion regulation depending on stress timing, sex or the regulatory strategy. Here, we investigated the impact of acute stress on different emotion regulation strategies in men and women. N = 118 healthy participants were subjected to the Trier Social Stress Test or a control condition after which they completed an emotion regulation paradigm, requiring them to regulate their emotions in response to negative pictures using reappraisal or distraction. Cortisol levels were repeatedly measured to quantify changes in HPA axis activity. Affective ratings and pupil dilation served to measure emotion regulation success and the cognitive effort to regulate emotions. Stress reduced arousal and increased valence and success ratings for reappraisal in men, whereas no significant stress effects were found in women. Moreover, stressed men displayed a significant expansion of pupil diameter during reappraisal suggesting enhanced cognitive regulatory engagement, which ultimately may have led to better emotion regulation outcomes. Cortisol secretion positively correlated with subjective reappraisal success in men, suggesting a glucocorticoid-driven mechanism that may promote emotion regulatory performance in the aftermath of stress.

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.

Mind the social feedback: effects of tDCS applied to the left DLPFC on psychophysiological responses during the anticipation and reception of social evaluations

The left dorsolateral prefrontal cortex (lDLPFC) is implicated in anticipatory (i.e. during anticipation of emotional stimuli) and online (i.e. during confrontation with emotional stimuli) emotion regulatory processes. However, research that investigates the causal role of the lDLPFC in these processes is lacking. In this study, 74 participants received active or sham transcranial direct current stimulation (tDCS) over the lDLPFC. Participants were told strangers evaluated them. These (rigged) social evaluations were presented, and in 50% of the trials, participants could anticipate the valence (positive or negative) of the upcoming social feedback. Pupil dilation (a marker of cognitive resource allocation), and skin conductance responses (a marker of arousal) were measured. The results indicate that active (compared to sham) tDCS reduced arousal during the confrontation with anticipated feedback, but only marginally during the confrontation with unanticipated feedback. When participants were given the opportunity to anticipate the social feedback, tDCS reduced arousal, irrespective of whether one was anticipating or being confronted with the anticipated feedback. Moreover, tDCS reduced cognitive resource allocation during anticipation, which was associated with resource allocation increases during the subsequent confrontation. Altogether, results suggest that the lDLPFC is causally implicated in the interplay between anticipatory and online emotion regulatory processes.

Psychophysiological Effects of Downregulating Negative Emotions: Insights From a Meta-Analysis of Healthy Adults

Assessing psychophysiological responses of emotion regulation is a cost-efficient way to quantify emotion regulation and to complement subjective report that may be biased. Previous studies have revealed inconsistent results complicating a sound interpretation of these findings. In the present study, we summarized the existing literature through a systematic search of articles. Meta-analyses were used to evaluate effect sizes of instructed downregulation strategies on common autonomic (electrodermal, respiratory, cardiovascular, and pupillometric) and electromyographic (corrugator activity, emotion-modulated startle) measures. Moderator analyses were conducted, with moderators including study design, emotion induction, control instruction and trial duration. We identified k = 78 studies each contributing multiple sub-samples and performed 23 meta-analyses for combinations of emotion regulation strategy and psychophysiological measure. Overall, results showed that effects of reappraisal and suppression on autonomic measures were highly inconsistent across studies with rather small mean effect sizes. Electromyography (startle and corrugator activity) showed medium effect sizes that were consistent across studies. Our findings highlight the diversity as well as the low level of standardization and comparability of research in this area. Significant moderation of effects by study design, trial duration, and control condition emphasizes the need for better standardization of methods. In addition, the small mean effect sizes resulting from our analyses on autonomic measures should be interpreted with caution. Findings corroborate the importance of multi-channel approaches.

Asymmetrical characteristics of emotional responses to pictures and sounds: Evidence from pupillometry

In daily life, our emotions are often elicited by a multimodal environment, mainly visual and auditory stimuli. Therefore, it is crucial to investigate the symmetrical characteristics of emotional responses to pictures and sounds. In this study, we aimed to elucidate the relationship of attentional states to emotional unimodal stimuli (pictures or sounds) and emotional responses by measuring the pupil diameter, which reflects the emotional arousal associated with increased sympathetic activity. Our hypothesis was that the emotional responses to both the image and sound stimuli are symmetrical: emotion might be suppressed when attentional resources are allocated to another stimulus of the same modality as the emotional stimulus—such as a dot presented at the same time as an emotional image, and a beep sound presented at the same time as an emotional sound. In our two experiments, data for 24 participants were analyzed for a pupillary response. In experiment 1, we investigated the relationship of the attentional state with emotional visual stimuli (International Affective Picture System) and emotional responses by using pupillometry. We set four task conditions to modulate the attentional state (emotional task, no task, visual detection task, and auditory detection task). We observed that the velocity of pupillary dilation was faster during the presentation of emotionally arousing pictures compared to that of neutral ones, regardless of the valence of the pictures. Importantly, this effect was not dependent on the task condition. In experiment 2, we investigated the relationship of the attentional state with emotional auditory sounds (International Affective Digitized Sounds) and emotional responses. We observed a trend towards a significant interaction between the stimulus and the task conditions with regard to the velocity of pupillary dilation. In the emotional and auditory detection tasks, the velocity of pupillary dilation was faster with positive and neutral sounds than negative sounds. However, there were no significant differences between the no task and visual detection task conditions. Taken together, the current data reveal that different pupillary responses were elicited to emotional visual and auditory stimuli, at least in the point that there is no attentional effect to emotional responses to visual stimuli, despite both experiments being sufficiently controlled to be of symmetrical experimental design.

Effects of stimulus size, eccentricity, luminance, and attention on pupillary light response examined by concentric stimulus

Previous studies show that the amplitude of pupillary light response (PLR) depends on the corneal flux density (CFD), which is the product of stimulus area by luminance. However, the contribution of CFD has been investigated only when the stimulus was centered on the fovea, whereas perceived luminance to pupillary response would reduce with stimulus eccentricity. Additionally, it has been shown recently that attentional state modulates pupillary response. In this study, we aimed to clarify the complete mechanisms of PLR by manipulating the stimulus size, eccentricity, luminance, and the participants' attentional states. We focused on four indices to examine PLR, that is, pupillary latency (PL), maximum constriction velocity (MCV), maximum constriction (MC), and mean pupil change (MPC). Results showed that PL was a function of CFD, whereas MCV, MC, and MPC were functions of both CFD and stimulus eccentricity. Furthermore, the magnitude of effect due to stimulus eccentricity for MCV and MC was different from that for MPC. These results provided new evidence that the different processing systems in PLR existed.

Anticipatory Baseline Pupil Diameter Is Sensitive to Differences in Hearing Thresholds

Task-evoked changes in pupil dilation have long been used as a physiological index of cognitive effort. Unlike this response, that is measured during or after an experimental trial, the baseline pupil dilation (BPD) is a measure taken prior to an experimental trial. As such, it is considered to reflect an individual’s arousal level in anticipation of an experimental trial. We report data for 68 participants, ages 18 to 89, whose hearing acuity ranged from normal hearing to a moderate hearing loss, tested over a series 160 trials on an auditory sentence comprehension task. Results showed that BPDs progressively declined over the course of the experimental trials, with participants with poorer pure tone detection thresholds showing a steeper rate of decline than those with better thresholds. Data showed this slope difference to be due to participants with poorer hearing having larger BPDs than those with better hearing at the start of the experiment, but with their BPDs approaching that of the better hearing participants by the end of the 160 trials. A finding of increasing response accuracy over trials was seen as inconsistent with a fatigue or reduced task engagement account of the diminishing BPDs. Rather, the present results imply BPD as reflecting a heightened arousal level in poorer-hearing participants in anticipation of a task that demands accurate speech perception, a concern that dissipates over trials with task success. These data taken with others suggest that the baseline pupillary response may not reflect a single construct.

Positive and detached reappraisal in older adulthood: A temporal examination of gaze patterns

Objectives: Cognitive reappraisal is an emotion regulation strategy that involves the adaptive restructuring of one's thoughts surrounding an emotionally evocative stimulus. Previous studies have produced mixed results on how distinct reappraisal and attentional processes are, but few studies have teased apart specific reappraisal methods. This is of particular interest in aging as older adults' regulation success may vary by reappraisal type. The current study examined whether detached and positive reappraisal are associated with distinct temporal patterns of attention in a sample of older adults. Method: 29 older adult participants viewed negative IAPS images and were instructed to implement both positive and detached reappraisal while eye movements were monitored. Participants also reported on their mood before and after viewing the images. Results: Participants fixated on negative areas early on and looked at them less over time, however their attention was oriented specifically towards the most negative region during reappraisal. They also re-fixated on the negative areas of the images during the last second of viewing during detached reappraisal, and reported feeling best while using this strategy. Conclusion: These findings provide information about the temporal nature of visual attention while utilizing distinct cognitive reappraisal strategies. Results highlight the importance of further teasing apart differences between detached and positive reappraisal as regulatory success and attentional shifts differ between these reappraisal types in older adulthood.

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.

Pupil dilation as an implicit measure of appetitive Pavlovian learning

Appetitive Pavlovian conditioning is a learning mechanism of fundamental biological and pathophysiological significance. Nonetheless, its exploration in humans remains sparse, which is partly attributed to the lack of an established psychophysiological parameter that aptly represents conditioned responding. This study evaluated pupil diameter and other ocular response measures (gaze dwelling time, blink duration and count) as indices of conditioning. Additionally, a learning model was used to infer participants' learning progress on the basis of their pupil dilation. Twenty-nine healthy volunteers completed an appetitive differential delay conditioning paradigm with a primary reward, while the ocular response measures along with other psychophysiological (heart rate, electrodermal activity, postauricular and eyeblink reflex) and behavioral (ratings, contingency awareness) parameters were obtained to examine the relation among different measures. A significantly stronger increase in pupil diameter, longer gaze duration and shorter eyeblink duration was observed in response to the reward-predicting cue compared to the control cue. The Pearce-Hall attention model best predicted the trial-by-trial pupil diameter. This conditioned response was corroborated by a pronounced heart rate deceleration to the reward-predicting cue, while no conditioning effect was observed in the electrodermal activity or startle responses. There was no discernible correlation between the psychophysiological response measures. These results highlight the potential value of ocular response measures as sensitive indices for representing appetitive conditioning.