Publications by authors named "Hakan Fischer"

89 Publications

Effects of aging on emotion recognition from dynamic multimodal expressions and vocalizations.

Sci Rep 2021 Jan 29;11(1):2647. Epub 2021 Jan 29.

Department of Psychology, Stockholm University, Stockholm, Sweden.

Age-related differences in emotion recognition have predominantly been investigated using static pictures of facial expressions, and positive emotions beyond happiness have rarely been included. The current study instead used dynamic facial and vocal stimuli, and included a wider than usual range of positive emotions. In Task 1, younger and older adults were tested for their abilities to recognize 12 emotions from brief video recordings presented in visual, auditory, and multimodal blocks. Task 2 assessed recognition of 18 emotions conveyed by non-linguistic vocalizations (e.g., laughter, sobs, and sighs). Results from both tasks showed that younger adults had significantly higher overall recognition rates than older adults. In Task 1, significant group differences (younger > older) were only observed for the auditory block (across all emotions), and for expressions of anger, irritation, and relief (across all presentation blocks). In Task 2, significant group differences were observed for 6 out of 9 positive, and 8 out of 9 negative emotions. Overall, results indicate that recognition of both positive and negative emotions show age-related differences. This suggests that the age-related positivity effect in emotion recognition may become less evident when dynamic emotional stimuli are used and happiness is not the only positive emotion under study.
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http://dx.doi.org/10.1038/s41598-021-82135-1DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7846600PMC
January 2021

A combined fMRI and EMG study of emotional contagion following partial sleep deprivation in young and older humans.

Sci Rep 2020 10 21;10(1):17944. Epub 2020 Oct 21.

Stress Research Institute, Department of Psychology, Stockholm University, Stockholm, Sweden.

Sleep deprivation is proposed to inhibit top-down-control in emotion processing, but it is unclear whether sleep deprivation affects emotional mimicry and contagion. Here, we aimed to investigate effects of partial sleep deprivation on emotional contagion and mimicry in young and older humans. Participants underwent partial sleep deprivation (3 h sleep opportunity at the end of night), crossed-over with a full sleep condition in a balanced order, followed by a functional magnetic resonance imaging and electromyography (EMG) experiment with viewing of emotional and neutral faces and ratings of emotional responses. The final sample for main analyses was n = 69 (n = 36 aged 20-30 years, n = 33 aged 65-75 years). Partial sleep deprivation caused decreased activation in fusiform gyri for angry faces and decreased ratings of happiness for all stimuli, but no significant effect on the amygdala. Older participants reported more anger compared to younger participants, but no age differences were seen in brain responses to emotional faces or sensitivity to partial sleep deprivation. No effect of the sleep manipulation was seen on EMG. In conclusion, emotional contagion, but not mimicry, was affected by sleep deprivation. Our results are consistent with the previously reported increased negativity bias after insufficient sleep.The Stockholm sleepy brain study: effects of sleep deprivation on cognitive and emotional processing in young and old. https://clinicaltrials.gov/ct2/show/NCT02000076 .
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http://dx.doi.org/10.1038/s41598-020-74489-9DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7578048PMC
October 2020

Cortical thickness and resting-state cardiac function across the lifespan: A cross-sectional pooled mega-analysis.

Psychophysiology 2020 Oct 10. Epub 2020 Oct 10.

Norwegian Centre for Mental Disorders Research (NORMENT), Institute of Clinical Medicine, University of Oslo, Oslo, Norway.

Understanding the association between autonomic nervous system [ANS] function and brain morphology across the lifespan provides important insights into neurovisceral mechanisms underlying health and disease. Resting-state ANS activity, indexed by measures of heart rate [HR] and its variability [HRV] has been associated with brain morphology, particularly cortical thickness [CT]. While findings have been mixed regarding the anatomical distribution and direction of the associations, these inconsistencies may be due to sex and age differences in HR/HRV and CT. Previous studies have been limited by small sample sizes, which impede the assessment of sex differences and aging effects on the association between ANS function and CT. To overcome these limitations, 20 groups worldwide contributed data collected under similar protocols of CT assessment and HR/HRV recording to be pooled in a mega-analysis (N = 1,218 (50.5% female), mean age 36.7 years (range: 12-87)). Findings suggest a decline in HRV as well as CT with increasing age. CT, particularly in the orbitofrontal cortex, explained additional variance in HRV, beyond the effects of aging. This pattern of results may suggest that the decline in HRV with increasing age is related to a decline in orbitofrontal CT. These effects were independent of sex and specific to HRV; with no significant association between CT and HR. Greater CT across the adult lifespan may be vital for the maintenance of healthy cardiac regulation via the ANS-or greater cardiac vagal activity as indirectly reflected in HRV may slow brain atrophy. Findings reveal an important association between CT and cardiac parasympathetic activity with implications for healthy aging and longevity that should be studied further in longitudinal research.
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http://dx.doi.org/10.1111/psyp.13688DOI Listing
October 2020

Psychotically driven aggression is associated with greater mentalizing challenges in psychotic spectrum disorders.

BMC Psychiatry 2020 09 29;20(1):470. Epub 2020 Sep 29.

Child and Adolescent Psychiatry, Stockholm Health Care Services, Region Stockholm, Stockholm, 118 61, Sweden.

Background: Some aggressive acts committed by individuals with psychotic spectrum disorders (PSD) are understandable in the context of interpersonal conflict or goal attainment, yet others are unpredictable, arising from delusions or hallucinations (psychotically driven aggressive acts, PDA). It is unknown if there are underlying differences in cognitive or perceptive social cognition in relation to aggression motivation in PSD.

Method: We compared differences in social cognition performance between 49 individuals with PSD who had committed PDA with those exhibiting other types of aggression (n = 31) (non-PDA) and to community controls (n = 81) on the Swedish version of Double Movie for the Assessment of Social Cognition - Multiple Choice (DMASC-MC). Participants with PSD had more than 3 months of clinical stability and substance use abstention and stable antipsychotic medication doses. General intellectual ability was assessed with the information and matrix reasoning subtests of the Wechsler Intelligence Scales.

Results: The PSD group with a history of PDA exhibited lower total and perceptive social cognition scores on the DMASC-MC than the non-PDA group and controls. In addition, they also showed lower cognitive scores compared to typical controls. Lower total scores were associated with lower scores on Wechsler intelligence subtests information and matrix reasoning. Taking this into account, the PDA group still had lower social cognition scores. There were no associations of antipsychotic medication dosages, positive or negative symptoms with social cognition scores. Higher antipsychotic dosage at the time of DMASC-MC testing and social cognition scores predicted a past history of PDA.

Conclusions: We conclude that impaired social cognition, particularly perceptive social cognition, is associated with PDA in individuals with PSD.
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http://dx.doi.org/10.1186/s12888-020-02868-7DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7526168PMC
September 2020

Gray Matter Volume Correlates of Sleepiness: A Voxel-Based Morphometry Study in Younger and Older Adults.

Nat Sci Sleep 2020 21;12:289-298. Epub 2020 May 21.

Centre for Psychiatry Research, Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden.

Background: Subjectively experienced sleepiness is a problem in society, possibly linked with gray matter (GM) volume. Given a different sleep pattern, aging may affect such associations, possibly due to shrinking brain volume.

Purpose: The purpose of the present study was to investigate the association between subjectively rated sleepiness and GM volume in thalamus, insula, hippocampus, and orbitofrontal cortex of young and older adults, after a normal night's sleep.

Methods: Eighty-four healthy individuals participated (46 aged 20-30 years, and 38 aged 65-75 years). Morphological brain data were collected in a 3T magnetic resonance imaging (MRI) scanner. Sleepiness was rated multiple times during the imaging sessions.

Results: In older, relative to younger, adults, clusters within bilateral mid-anterior insular cortex and right thalamus were negatively associated with sleepiness. Adjustment for the immediately preceding total sleep time eliminated the significant associations.

Conclusion: Self-rated momentary sleepiness in a monotonous situation appears to be negatively associated with GM volume in clusters within both thalamus and insula in older individuals, and total sleep time seems to play a role in this association. Possibly, this suggests that larger GM volume in these clusters may be protective against sleepiness in older individuals. This notion needs confirmation in further studies.
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http://dx.doi.org/10.2147/NSS.S240493DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7247733PMC
May 2020

Improvement in indices of cellular protection after psychological treatment for social anxiety disorder.

Transl Psychiatry 2019 12 19;9(1):340. Epub 2019 Dec 19.

Department of Psychology, Uppsala University, Uppsala, Sweden.

Telomere attrition is a hallmark of cellular aging and shorter telomeres have been reported in mood and anxiety disorders. Telomere shortening is counteracted by the enzyme telomerase and cellular protection is also provided by the antioxidant enzyme glutathione peroxidase (GPx). Here, telomerase, GPx, and telomeres were investigated in 46 social anxiety disorder (SAD) patients in a within-subject design with repeated measures before and after cognitive behavioral therapy. Treatment outcome was assessed by the Liebowitz Social Anxiety Scale (self-report), administered three times before treatment to control for time and regression artifacts, and posttreatment. Venipunctures were performed twice before treatment, separated by 9 weeks, and once posttreatment. Telomerase activity and telomere length were measured in peripheral blood mononuclear cells and GPx activity in plasma. All patients contributed with complete data. Results showed that social anxiety symptom severity was significantly reduced from pretreatment to posttreatment (Cohen's d = 1.46). There were no significant alterations in telomeres or cellular protection markers before treatment onset. Telomere length and telomerase activity did not change significantly after treatment, but an increase in telomerase over treatment was associated with reduced social anxiety. Also, lower pretreatment telomerase activity predicted subsequent symptom improvement. GPx activity increased significantly during treatment, and increases were significantly associated with symptom improvement. The relationships between symptom improvement and putative protective enzymes remained significant also after controlling for body mass index, sex, duration of SAD, smoking, concurrent psychotropic medication, and the proportion of lymphocytes to monocytes. Thus, indices of cellular protection may be involved in the therapeutic mechanisms of psychological treatment for anxiety.
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http://dx.doi.org/10.1038/s41398-019-0668-2DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6920472PMC
December 2019

Impaired facial emotion perception of briefly presented double masked stimuli in violent offenders with schizophrenia spectrum disorders.

Schizophr Res Cogn 2020 Mar 24;19:100163. Epub 2019 Oct 24.

Department of Clinical Neuroscience, Karolinska Institute, 171 77 Stockholm, Sweden.

Social interactions require decoding of subtle rapidly changing emotional cues in others to facilitate socially appropriate behaviour. It is possible that impairments in the ability to detect and decode these signals may increase the risk for aggression. Therefore, we examined violent offenders with schizophrenia spectrum disorders (SSD) and compared these with healthy controls on a computerized paradigm of briefly presented double masked faces exhibiting 7 basic emotions. Our hypotheses were that impaired semantic understanding of emotion words and low cognitive ability would yield lowest emotion recognition. SSD exhibited lower accuracy of emotion perception than controls (46.1% compared with 64.5%,  = 0.026), even when considering the unbiased hit rate (22.4% compared with 43%, Z = 2.62,  < 0.01). Raw data showed uncommon but significant misclassifications of fear as sad, disgust as sad, sad as happy and angry as surprise. Once guessing and presentation frequencies were considered, only overall accuracy differed between SSD and healthy controls. There were significant correlations between cognitive ability, antipsychotic dose, speed and emotion accuracy in the SSD group. In conclusion, that there were no specific emotion biases in the SSD group compared to healthy controls, but particular individuals may have greater impairments in facial emotion perception, being influenced by intellectual ability, psychomotor speed and medication dosages, rather than specifically emotion word understanding. This implies that both state and trait factors influence emotion perception in the aggressive SSD group and may reveal one source of potential misunderstanding of social situations which may lead to boundary violations and aggression.
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http://dx.doi.org/10.1016/j.scog.2019.100163DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6890976PMC
March 2020

The effects of face attractiveness on face memory depend on both age of perceiver and age of face.

Cogn Emot 2020 08 20;34(5):875-889. Epub 2019 Nov 20.

Department of Psychology, University of Florida, Gainesville, FL, USA.

Face attractiveness can influence memory for previously seen faces. This effect has been shown to differ for young and older perceivers. Two parallel studies examined the moderation of both the age of the face and the age of the perceiver on the relationship between facial attractiveness and face memory. Study 1 comprised 29 young and 31 older participants; Study 2 comprised 25 young and 24 older participants. In both studies, participants completed an incidental face encoding and a surprise old/new recognition test with young and older faces that varied in face attractiveness. Face attractiveness affected memory for young but not older faces. In addition, young but not older perceivers showed a linear effect of facial attractiveness on memory for young faces, while both young and older perceivers showed a quadratic effect on memory for young faces. These findings extend previous work by demonstrating that the effect of facial attractiveness on face memory is a function of both the age of the perceiver and the age of the face. Factors that could account for such moderations of face and perceiver age on the associations between face attractiveness and face memory are discussed (e.g. age differences in social goals and face similarity/distinctiveness).
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http://dx.doi.org/10.1080/02699931.2019.1694491DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7237279PMC
August 2020

Age-differential relationships among dopamine D1 binding potential, fusiform BOLD signal, and face-recognition performance.

Neuroimage 2020 02 5;206:116232. Epub 2019 Oct 5.

Aging Research Center, Karolinska Institute, Stockholm, Sweden.

Facial recognition ability declines in adult aging, but the neural basis for this decline remains unknown. Cortical areas involved in face recognition exhibit lower dopamine (DA) receptor availability and lower blood-oxygen-level-dependent (BOLD) signal during task performance with advancing adult age. We hypothesized that changes in the relationship between these two neural systems are related to age differences in face-recognition ability. To test this hypothesis, we leveraged positron emission tomography (PET) and functional magnetic resonance imaging (fMRI) to measure D1 receptor binding potential (BP) and BOLD signal during face-recognition performance. Twenty younger and 20 older participants performed a face-recognition task during fMRI scanning. Face recognition accuracy was lower in older than in younger adults, as were D1 BP and BOLD signal across the brain. Using linear regression, significant relationships between DA and BOLD were found in both age-groups in face-processing regions. Interestingly, although the relationship was positive in younger adults, it was negative in older adults (i.e., as D1 BP decreased, BOLD signal increased). Ratios of BOLD:D1 BP were calculated and relationships to face-recognition performance were tested. Multiple linear regression revealed a significant Group × BOLD:D1 BP Ratio interaction. These results suggest that, in the healthy system, synchrony between neurotransmitter (DA) and hemodynamic (BOLD) systems optimizes the level of BOLD activation evoked for a given DA input (i.e., the gain parameter of the DA input-neural activation function), facilitating task performance. In the aged system, however, desynchronization between these brain systems would reduce the gain parameter of this function, adversely impacting task performance and contributing to reduced face recognition in older adults.
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http://dx.doi.org/10.1016/j.neuroimage.2019.116232DOI Listing
February 2020

Viewing Pictures Triggers Rapid Morphological Enlargement in the Human Visual Cortex.

Cereb Cortex 2020 03;30(3):851-857

Department of Psychology, Stockholm University, SE-10691 Stockholm, Sweden.

Measuring brain morphology with non-invasive structural magnetic resonance imaging is common practice, and can be used to investigate neuroplasticity. Brain morphology changes have been reported over the course of weeks, days, and hours in both animals and humans. If such short-term changes occur even faster, rapid morphological changes while being scanned could have important implications. In a randomized within-subject study on 47 healthy individuals, two high-resolution T1-weighted anatomical images were acquired (á 263 s) per individual. The images were acquired during passive viewing of pictures or a fixation cross. Two common pipelines for analyzing brain images were used: voxel-based morphometry on gray matter (GM) volume and surface-based cortical thickness. We found that the measures of both GM volume and cortical thickness showed increases in the visual cortex while viewing pictures relative to a fixation cross. The increase was distributed across the two hemispheres and significant at a corrected level. Thus, brain morphology enlargements were detected in less than 263 s. Neuroplasticity is a far more dynamic process than previously shown, suggesting that individuals' current mental state affects indices of brain morphology. This needs to be taken into account in future morphology studies and in everyday clinical practice.
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http://dx.doi.org/10.1093/cercor/bhz131DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7132946PMC
March 2020

Age-related differences in evaluation of social attributes from computer-generated faces of varying intensity.

Psychol Aging 2019 Aug 3;34(5):686-697. Epub 2019 Jun 3.

Department of Psychology, Stockholm University.

In everyday life throughout the life span, people frequently evaluate faces to obtain information crucial for social interactions. We investigated age-related differences in judgments of a wide range of social attributes based on facial appearance. Seventy-one younger and 60 older participants rated 196 computer-generated faces that systematically varied in facial features such as shape and reflectance to convey different intensity levels of seven social attributes (i.e., attractiveness, competence, dominance, extraversion, likeability, threat, and trustworthiness). Older compared to younger participants consistently gave higher attractiveness ratings to faces representing both high and low levels of attractiveness. Older participants were also less sensitive to the likeability of faces and tended to evaluate faces representing low likeability as more likable. The age groups did, however, not differ substantially in their evaluations of the other social attributes. Results are in line with previous research showing that aging is associated with preference toward positive and away from negative information and extend this positivity effect to social perception of faces. (PsycINFO Database Record (c) 2019 APA, all rights reserved).
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http://dx.doi.org/10.1037/pag0000364DOI Listing
August 2019

Background odors affect behavior in a dot-probe task with emotionally expressive faces.

Physiol Behav 2019 10 17;210:112540. Epub 2019 May 17.

Stockholm University, Sweden.

Odors affect perception of social cues in visual environments. Although often underestimated, people use their sense of smell to guide approach or avoidance behavior in social contexts. However, underlying psychological mechanisms are not well known. Prior work suggested olfactory effects are due to increased attention or arousal, or depend on the congruency between olfactory and visual cues. Our aim was to assess how odors influence attentional processes using a dot-probe task with odor-congruent and odor-incongruent facial expressions (happy, disgusted and neutral expressions paired with pleasant odor, unpleasant odor and no-odor). In a preregistered analysis plan, we hypothesized either faster reaction times attributed to arousal from odors in general, or to faces that were emotionally congruent with the odors. We also hypothesized time-on-task effects specific to the odor compared to the control condition. Using Bayesian linear models, we found strong evidence that the faces were rated as more arousing and emotional in odor contexts. However, the dot-probe task did in fact not provide an effective cue to selective visual attention, and odors did not modulate overall attention to the faces. However, we found a time-on-task effect such that in the unpleasant odor condition, response times decreased over time, whereas in the no-odor and pleasant condition there was a slight increase in response times. We conclude that time-on-task effects is an interesting venue for odor-visual interaction research, and such effects might explain inconsistent findings in the prior research literature.
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http://dx.doi.org/10.1016/j.physbeh.2019.05.001DOI Listing
October 2019

Sleep restriction caused impaired emotional regulation without detectable brain activation changes-a functional magnetic resonance imaging study.

R Soc Open Sci 2019 Mar 27;6(3):181704. Epub 2019 Mar 27.

Department of Clinical Neuroscience, Karolinska Institutet, Nobels väg 9, Stockholm 171 77, Sweden.

Sleep restriction has been proposed to cause impaired emotional processing and emotional regulation by inhibiting top-down control from prefrontal cortex to amygdala. Intentional emotional regulation after sleep restriction has, however, never been studied using brain imaging. We aimed here to investigate the effect of partial sleep restriction on emotional regulation through cognitive reappraisal. Forty-seven young (age 20-30) and 33 older (age 65-75) participants (38/23 with complete data and successful sleep intervention) performed a cognitive reappraisal task during fMRI after a night of normal sleep and after restricted sleep (3 h). Emotional downregulation was associated with significantly increased activity in the dorsolateral prefrontal cortex ( < 0.05) and lateral orbital cortex ( < 0.05) in young, but not in older subjects. Sleep restriction was associated with a decrease in self-reported regulation success to negative stimuli ( < 0.01) and a trend towards perceiving all stimuli as less negative ( = 0.07) in young participants. No effects of sleep restriction on brain activity nor connectivity were found in either age group. In conclusion, our data do not support the idea of a prefrontal-amygdala disconnect after sleep restriction, and neural mechanisms underlying behavioural effects on emotional regulation after insufficient sleep require further investigation.
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http://dx.doi.org/10.1098/rsos.181704DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6458356PMC
March 2019

Positivity Effect and Working Memory Performance Remains Intact in Older Adults After Sleep Deprivation.

Front Psychol 2019 22;10:605. Epub 2019 Mar 22.

Stress Research Institute, Stockholm University, Stockholm, Sweden.

Older adults perform better in tasks which include positive stimuli, referred to as the positivity effect. However, recent research suggests that the positivity effect could be attenuated when additional challenges such as stress or cognitive demands are introduced. Moreover, it is well established that older adults are relatively resilient to many of the adverse effects of sleep deprivation. Our aim was to investigate if the positivity effect in older adults is affected by one night of total sleep deprivation using an emotional working memory task. A healthy sample of 48 older adults (60-72 years) was either sleep deprived for one night ( = 24) or had a normal night's sleep ( = 24). They performed an emotional working memory -back ( = 1 and 3) task containing positive, negative and neutral pictures. Performance in terms of accuracy and reaction times was best for positive stimuli and worst for negative stimuli. This positivity effect was not altered by sleep deprivation. Results also showed that, despite significantly increased sleepiness, there was no effect of sleep deprivation on working memory performance. A working memory load × valence interaction on the reaction times revealed that the beneficial effect of positive stimuli was only present in the 1-back condition. While the positivity effect and general working memory abilities in older adults are intact after one night of sleep deprivation, increased cognitive demand attenuates the positivity effect on working memory speed.
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http://dx.doi.org/10.3389/fpsyg.2019.00605DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6440387PMC
March 2019

Oxytocin alters patterns of brain activity and amygdalar connectivity by age during dynamic facial emotion identification.

Neurobiol Aging 2019 06 29;78:42-51. Epub 2019 Jan 29.

Department of Psychology, University of Florida, Gainesville, FL, USA; Department of Clinical and Health Psychology, Center for Cognitive Aging and Memory, University of Florida, Gainesville, FL, USA; Department of Aging and Geriatric Research, Institute on Aging, University of Florida, Gainesville, FL, USA.

Aging is associated with increased difficulty in facial emotion identification, possibly due to age-related network change. The neuropeptide oxytocin (OT) facilitates emotion identification, but this is understudied in aging. To determine the effects of OT on dynamic facial emotion identification across adulthood, 46 young and 48 older participants self-administered intranasal OT or a placebo in a randomized, double-blind procedure. Older participants were slower and less accurate in identifying emotions. Although there was no behavioral treatment effect, partial least squares analysis supported treatment effects on brain patterns during emotion identification that varied by age and emotion. For young participants, OT altered the processing of sadness and happiness, whereas for older participants, OT only affected the processing of sadness (15.3% covariance, p = 0.004). Furthermore, seed partial least squares analysis showed that older participants in the OT group recruited a large-scale amygdalar network that was positively correlated for anger, fear, and happiness, whereas older participants in the placebo group recruited a smaller, negatively correlated network (7% covariance, p = 0.002). Advancing the literature, these findings show that OT alters brain activity and amygdalar connectivity by age and emotion.
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http://dx.doi.org/10.1016/j.neurobiolaging.2019.01.016DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6545147PMC
June 2019

Mood impairment is stronger in young than in older adults after sleep deprivation.

J Sleep Res 2019 08 25;28(4):e12801. Epub 2018 Dec 25.

Stress Research Institute, Stockholm University, Stockholm, Sweden.

Sleep deprivation commonly impairs affective regulation and causes worse mood. However, the majority of previous research concerns young adults. Because susceptibility to sleep deprivation and emotion regulation change distinctively across adult age, we tested here the hypothesis that the effect of sleep deprivation on mood is stronger in young than in older adults. In an experimental design, young (18-30 years) and older adults (60-72 years) participated in either a sleep control (young, n = 63; older, n = 47) or a total sleep deprivation condition (young, n = 61; older, n = 47). Sleepiness, mood and common symptoms of sleep deprivation were measured using established questionnaires and ratings. Sleep-deprived participants felt more sleepy, stressed and cold, and reported lower vigour and positive affect, regardless of age. All the other outcome measures (negative affect, depression, confusion, tension, anger, fatigue, total mood disturbance, hunger, cognitive attenuation, irritability) showed a weaker response to sleep deprivation in the older group, as indicated by age*sleep deprivation interactions (ps < 0.05). The results show that older adults are emotionally less affected by sleep deprivation than young adults. This tolerance was mainly related to an attenuated increase in negative mood. This could possibly be related to the well-known positivity effect, which suggests that older adults prioritize regulating their emotions to optimize well-being. The results also highlight that caution is warranted when generalizing results from sleep deprivation studies across the adult lifespan.
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http://dx.doi.org/10.1111/jsr.12801DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7379256PMC
August 2019

Exploring emotional expression recognition in aging adults using the Moving Window Technique.

PLoS One 2018 18;13(10):e0205341. Epub 2018 Oct 18.

Department of Psychology, Stockholm University, Stockholm, Sweden.

Adult aging is associated with difficulties in recognizing negative facial expressions such as fear and anger. However, happiness and disgust recognition is generally found to be less affected. Eye-tracking studies indicate that the diagnostic features of fearful and angry faces are situated in the upper regions of the face (the eyes), and for happy and disgusted faces in the lower regions (nose and mouth). These studies also indicate age-differences in visual scanning behavior, suggesting a role for attention in emotion recognition deficits in older adults. However, because facial features can be processed extrafoveally, and expression recognition occurs rapidly, eye-tracking has been questioned as a measure of attention during emotion recognition. In this study, the Moving Window Technique (MWT) was used as an alternative to the conventional eye-tracking technology. By restricting the visual field to a moveable window, this technique provides a more direct measure of attention. We found a strong bias to explore the mouth across both age groups. Relative to young adults, older adults focused less on the left eye, and marginally more on the mouth and nose. Despite these different exploration patterns, older adults were most impaired in recognition accuracy for disgusted expressions. Correlation analysis revealed that among older adults, more mouth exploration was associated with faster recognition of both disgusted and happy expressions. As a whole, these findings suggest that in aging there are both attentional differences and perceptual deficits contributing to less accurate emotion recognition.
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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0205341PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6193651PMC
March 2019

Amygdala reactivity and connectivity during social and non-social aversive stimulation in social anxiety disorder.

Psychiatry Res Neuroimaging 2018 10 22;280:56-61. Epub 2018 Aug 22.

Department of Psychology, Uppsala University, Uppsala, Sweden.

Social anxiety disorder (SAD) is characterized by exaggerated amygdala reactivity in response to symptom provocation, but it is unclear if such hyper-reactivity is elicited by disorder-specific challenges only or characterizes reactions to aversive stimuli in general. Here, using functional magnetic resonance imaging in 14 patients with SAD, as compared to 12 healthy controls, we found that amygdala hyper-reactivity is confined to disorder-relevant social stimulation. SAD patients displayed increased amygdala reactivity to fearful as compared to neutral facial pictures, but not in response to generally aversive but mainly non-social stimulation when compared to neutral pictorial stimuli taken from the International Affective Picture System. The increased amygdala reactivity was not mediated by an altered prefrontal inhibition among SAD patients as compared to controls, suggesting increased bottom-up processes rather than attenuated top-down control. In conclusion, the enhanced amygdala reactivity in SAD seems specific to socially relevant stimuli rather than aversive stimuli in general.
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http://dx.doi.org/10.1016/j.pscychresns.2018.08.012DOI Listing
October 2018

Mixed support for a causal link between single dose intranasal oxytocin and spiritual experiences: opposing effects depending on individual proclivities for absorption.

Soc Cogn Affect Neurosci 2018 09;13(9):921-932

Stockholm University, Department of Psychology.

Intranasal oxytocin (OT) has previously been found to increase spirituality, an effect moderated by OT-related genotypes. This pre-registered study sought to conceptually replicate and extend those findings. Using a single dose of intranasal OT vs placebo (PL), we investigated experimental treatment effects, and moderation by OT-related genotypes on spirituality, mystical experiences, and the sensed presence of a sentient being. A more exploratory aim was to test for interactions between treatment and the personality disposition absorption on these spirituality-related outcomes. A priming plus sensory deprivation procedure that has facilitated spiritual experiences in previous studies was used. The sample (N = 116) contained both sexes and was drawn from a relatively secular context. Results failed to conceptually replicate both the main effects of treatment and the treatment by genotype interactions on spirituality. Similarly, there were no such effects on mystical experiences or sensed presence. However, the data suggested an interaction between treatment and absorption. Relative to PL, OT seemed to enhance spiritual experiences in participants scoring low in absorption and dampen spirituality in participants scoring high in absorption.
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http://dx.doi.org/10.1093/scan/nsy068DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6137319PMC
September 2018

Effect of sleep deprivation on emotional working memory.

J Sleep Res 2019 02 8;28(1):e12744. Epub 2018 Aug 8.

Stress Research Institute, Stockholm University, Stockholm, Sweden.

The emotional dysregulation and impaired working memory found after sleep loss can have severe implications for our daily functioning. Considering the intertwined relationship between emotion and cognition in stimuli processing, there could be further implications of sleep deprivation in high-complex emotional situations. Although studied separately, this interaction between emotion and cognitive processes has been neglected in sleep research. The aim of the present study was to investigate the effect of 1 night of sleep deprivation on emotional working memory. Sixty-one healthy participants (mean age: 23.4 years) were either sleep deprived for 1 night (n = 30) or had a normal night's sleep (n = 31). They performed an N-back task with two levels of working memory load (1-back and 3-back) using positive, neutral and negative picture scenes. Sleep deprivation, compared with full night sleep, impaired emotional working memory accuracy, but not reaction times. The sleep-deprived participants, but not the controls, responded faster to positive than to negative and neutral pictures. The effect of sleep deprivation was similar for both high and low working memory loads. The results showed that although detrimental in terms of accuracy, sleep deprivation did not impair working memory speed. In fact, our findings indicate that positive stimuli may facilitate working memory processing speed after sleep deprivation.
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http://dx.doi.org/10.1111/jsr.12744DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7379257PMC
February 2019

Background Odors Modulate N170 ERP Component and Perception of Emotional Facial Stimuli.

Front Psychol 2018 26;9:1000. Epub 2018 Jun 26.

Department of Psychology, Stockholm University, Stockholm, Sweden.

Successful social interaction relies on the accurate decoding of other peoples' emotional signals, and their contextual integration. However, little is known about how contextual odors may lead to modulation of cortical processing in response to facial expressions. We investigated how unpleasant and pleasant contextual background odors affected emotion perception and cortical event-related potential (ERP) responses to pictures of faces expressing happy, neutral and disgusted facial expressions. Faces were, regardless of expression, rated more positively in the pleasant odor condition and more negatively in the unpleasant odor condition. Faces were overall rated as more emotionally arousing in the presence of an odor, irrespective of its valence. Contextual odors also interacted with facial expressions, such that happy faces were rated as especially non-arousing in the unpleasant odor condition. The early, face-sensitive N170 ERP component also displayed an interaction effect. Here, disgusted faces were affected by the odor context such that the N170 revealed a relatively larger negativity in the context of a pleasant odor compared with an unpleasant odor. There were no odor effects on the responses to faces in other measured ERP components (P1, VPP, P2, and LPP). These results suggest that odors bias socioemotional perception early stages of the visual processing stream. However, effects may vary across emotional expressions and measurements.
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http://dx.doi.org/10.3389/fpsyg.2018.01000DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6029154PMC
June 2018

Does sleep deprivation increase the vulnerability to acute psychosocial stress in young and older adults?

Psychoneuroendocrinology 2018 10 4;96:155-165. Epub 2018 Jun 4.

Stress Research Institute, Stockholm University, Sweden; Department of Clinical Neuroscience, Karolinska Institute, Sweden.

Sleep loss and psychosocial stress often co-occur in today's society, but there is limited knowledge on the combined effects. Therefore, this experimental study investigated whether one night of sleep deprivation affects the response to a psychosocial challenge. A second aim was to examine if older adults, who may be less affected by both sleep deprivation and stress, react differently than young adults. 124 young (18-30 years) and 94 older (60-72 years) healthy adults participated in one of four conditions: i. normal night sleep & Placebo-Trier Social Stress Test (TSST), ii. normal night sleep & Trier Social Stress Test, iii. sleep deprivation & Placebo-TSST, iv. sleep deprivation & TSST. Subjective stress ratings, heart rate variability (HRV), salivary alpha amylase (sAA) and cortisol were measured throughout the protocol. At the baseline pre-stress measurement, salivary cortisol and subjective stress values were higher in sleep deprived than in rested participants. However, the reactivity to and recovery from the TSST was not significantly different after sleep deprivation for any of the outcome measures. Older adults showed higher subjective stress, higher sAA and lower HRV at baseline, indicating increased basal autonomic activity. Cortisol trajectories and HRV slightly differed in older adults compared with younger adults (regardless of the TSST). Moreover, age did not moderate the effect of sleep deprivation. Taken together, the results show increased stress levels after sleep deprivation, but do not confirm the assumption that one night of sleep deprivation increases the responsivity to an acute psychosocial challenge.
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http://dx.doi.org/10.1016/j.psyneuen.2018.06.003DOI Listing
October 2018

Brain activation due to postoperative pain from the right hand measured with regional cerebral blood flow using positron emission tomography.

Scand J Pain 2010 Jul 1;1(3):115-119. Epub 2010 Jul 1.

Hospital Pharmacy and Uppsala PET Centre, University of Uppsala, SE 751 85 Uppsala, Sweden.

Background Brain activation resulting from acute postoperative pain has to our knowledge not previously been studied using positron emission tomography, except from one case study. The aim of this study was to monitor activation in brain sensory pathways during acute pain after surgery of the hand. A secondary aim was to compare brain activation in clinical postoperative pain to that previously reported, by the same research group, for a model of experimental pain from the same body area. Increase in regional cerebral blood flow (rCBF) is presumed to indicate neuronal activation and decrease in blood flow decreased neuronal firing. An increase in blood flow in a brain region may represent stimulatory activity as well as inhibitory. Methods Brain activity was measured during clinical postoperative pain and a pain free state in six patients with positron emission tomography (PET) as changes in regional cerebral blood flow (rCBF). rCBF during pain from surgery of the right thumb base was compared with a pain free state achieved by regional anaesthesia of the painful area. Results In postoperative pain, patients had a significantly higher CBF in the contralateral/primary and secondary somatosensory cortices as well as in the contralateral motor cortex compared to the pain free stat during local regional anaesthesia. Relatively lower rCBF during the pain state was observed in clusters in the contralateral tertiary sensory cortex, ipsilateral and contralateral secondary visual cortex, prelimbic cortex, ipsilateral prefrontal as well as anterior cingulate cortex and contralateral secondary somatosensory cortex. The increased rCBF in primary and somatosensory cortices probably correspond to pain localizing processing. We also compared the findings in cerebral activation patterns of the postoperative pain state as described above, with the results from a previously published study by the same research group, using an experimental pain model when pain was inflicted with application of mustard oil in the same location, the thumb base region of the right hand. Since no formal statistical analysis was carried out between the two studies, the data are not very strong, but the differences reported were obvious when comparing the two situations. The comparison gave the following outcome: Digit activation occurred in identical sensory brain areas, i.e. primary and secondary somatosensory cortices, as compared to the changes in this study, supporting that pain localization processes use similar sensory pathways in a nociceptive acute experimental pain model, and in clinical acute postoperative nociceptive pain. Dissimilarities were observed between the models in activation of brain areas coding of the emotional pain qualities, indicating some differences between the experimental and "real" acute nociceptive pain. Conclusion We have reported a distinct cerebral activation pattern produced by acute postoperative pain following hand surgery. The findings were compared to data obtained in a previously published report of the cerebral activation pattern from an acute experimental pain model in volunteers. We found similarities as well as some differences in the activation pattern between the two situations.
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http://dx.doi.org/10.1016/j.sjpain.2010.05.036DOI Listing
July 2010

Emotion recognition associated with polymorphism in oxytocinergic pathway gene ARNT2.

Soc Cogn Affect Neurosci 2018 02;13(2):173-181

Department of Pharmacology, Institute of Neuroscience and Physiology at the Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden.

The ability to correctly understand the emotional expression of another person is essential for social relationships and appears to be a partly inherited trait. The neuropeptides oxytocin and vasopressin have been shown to influence this ability as well as face processing in humans. Here, recognition of the emotional content of faces and voices, separately and combined, was investigated in 492 subjects, genotyped for 25 single nucleotide polymorphisms (SNPs) in eight genes encoding proteins important for oxytocin and vasopressin neurotransmission. The SNP rs4778599 in the gene encoding aryl hydrocarbon receptor nuclear translocator 2 (ARNT2), a transcription factor that participates in the development of hypothalamic oxytocin and vasopressin neurons, showed an association that survived correction for multiple testing with emotion recognition of audio-visual stimuli in women (n = 309). This study demonstrates evidence for an association that further expands previous findings of oxytocin and vasopressin involvement in emotion recognition.
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http://dx.doi.org/10.1093/scan/nsx141DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5827350PMC
February 2018

Effects of late-night short-sleep on in-home polysomnography: relation to adult age and sex.

J Sleep Res 2018 08 30;27(4):e12626. Epub 2017 Oct 30.

Department of Clinical Neuroscience, Karolinska Institute, Stockholm, Sweden.

Bedtime is frequently delayed by many factors in life, and a homeostatic response to the delay may compensate partly for increased time awake and shortened sleep. Because sleep becomes shorter with age and women complain of disturbed sleep more often than men, age and sex differences in the homeostatic response to a delayed bedtime may modify the homeostatic response. The purpose of the present study was to investigate the effect of late-night short-sleep (3 h with awakening at about 07:00 hours) on in-home recorded sleep in men and women in two age groups (20-30 and 65-75 years). Results (N = 59) showed that late-night short-sleep was associated with an increase in percentage of N3 sleep and a decrease in percentage of rapid eye movement sleep, as well as decreases in several measures of sleep discontinuity and rapid eye movement density. Men showed a smaller decrease in percentage of rapid eye movement sleep than women in response to late-night short-sleep, as did older individuals of both sexes compared with younger. Older men showed a weaker percentage of N3 sleep in response to late-night short-sleep than younger men. In general, men showed a greater percentage of rapid eye movement sleep and a lower percentage of N3 sleep than women, and older individuals showed a lower percentage of N3 sleep than younger. In particular, older men showed very low levels of percentage of N3 sleep. We conclude that older males show less of a homeostatic response to late-night short-sleep. This may be an indication of impaired capacity for recovery in older men. Future studies should investigate if this pattern can be linked to gender-associated differences in morbidity and mortality.
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http://dx.doi.org/10.1111/jsr.12626DOI Listing
August 2018

Influence of DARPP-32 genetic variation on BOLD activation to happy faces.

Soc Cogn Affect Neurosci 2017 10;12(10):1658-1667

Department of Psychology, Stockholm University, Stockholm, Sweden.

Dopaminergic pathways play a crucial role in reward processing, and advanced age can modulate its efficiency. DARPP-32 controls dopaminergic function and is a chemical nexus of reward processing. In 61 younger (20-30 years) and older adults (54% ♀) (65-74 years), we examined how blood-oxygen-level dependent (BOLD) activation to emotional faces, vary over genotypes at three single nucleotide polymorphism (SNPs), coding for DARPP-32 (rs879606; rs907094; 3764352). We also assessed age-magnification of DARPP-32 effects on BOLD activation. We found that major homozygote G, T or A genotypes, with higher cortical expression of DARPP-32, higher dopamine receptor efficacy, and greater bias toward positive cues, had increased functional connectivity in cortical-subcortical circuits in response to happy faces, engaging the dorsal prefrontal cortex (DLPFC), fusiform gyrus (FG) and the midbrain (MB). Local BOLD response to happy faces in FG, and MB was age-dependent, so that older carriers of the major G, T or A alleles showed lesser activation than minor genotypes. These genetic variants of DARPP-32 did not modulate BOLD response to angry faces, or engagement of the inferior occipital gyrus, to happy or angry faces. Taken together our results lend support for a potential role of DARPP-32 genetic variants in neural response to potential reward triggering cues.
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http://dx.doi.org/10.1093/scan/nsx089DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5647797PMC
October 2017

Multimodal Emotion Recognition Is Resilient to Insufficient Sleep: Results From Cross-Sectional and Experimental Studies.

Sleep 2017 11;40(11)

Department of Clinical Neuroscience, Karolinska Institutet, Sweden.

Objectives: Insufficient sleep has been associated with impaired recognition of facial emotions. However, previous studies have found inconsistent results, potentially stemming from the type of static picture task used. We therefore examined whether insufficient sleep was associated with decreased emotion recognition ability in two separate studies using a dynamic multimodal task.

Methods: Study 1 used a cross-sectional design consisting of 291 participants with questionnaire measures assessing sleep duration and self-reported sleep quality for the previous night. Study 2 used an experimental design involving 181 participants where individuals were quasi-randomized into either a sleep-deprivation (N = 90) or a sleep-control (N = 91) condition. All participants from both studies were tested on the same forced-choice multimodal test of emotion recognition to assess the accuracy of emotion categorization.

Results: Sleep duration, self-reported sleep quality (study 1), and sleep deprivation (study 2) did not predict overall emotion recognition accuracy or speed. Similarly, the responses to each of the twelve emotions tested showed no evidence of impaired recognition ability, apart from one positive association suggesting that greater self-reported sleep quality could predict more accurate recognition of disgust (study 1).

Conclusions: The studies presented here involve considerably larger samples than previous studies and the results support the null hypotheses. Therefore, we suggest that the ability to accurately categorize the emotions of others is not associated with short-term sleep duration or sleep quality and is resilient to acute periods of insufficient sleep.
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http://dx.doi.org/10.1093/sleep/zsx145DOI Listing
November 2017

The effect of sleep restriction on empathy for pain: An fMRI study in younger and older adults.

Sci Rep 2017 09 25;7(1):12236. Epub 2017 Sep 25.

Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden.

Age and sleep both affect emotional functioning. Since sleep patterns change over the lifespan, we investigated the effects of short sleep and age on empathic responses. In a randomized cross-over experimental design, healthy young and older volunteers (n = 47 aged 20-30 years and n = 39 aged 65-75 years) underwent functional magnetic resonance imaging (fMRI) after normal sleep or night sleep restricted to 3 hours. During fMRI, participants viewed pictures of needles pricking a hand (pain) or Q-tips touching a hand (control), a well-established paradigm to investigate empathy for pain. There was no main effect of sleep restriction on empathy. However, age and sleep interacted so that sleep restriction caused increased unpleasantness in older but not in young participants. Irrespective of sleep condition, older participants showed increased activity in angular gyrus, superior temporal sulcus and temporo-parietal junction compared to young. Speculatively, this could indicate that the older individuals adopted a more cognitive approach in response to others' pain. Our findings suggest that caution in generalizability across age groups is needed in further studies of sleep on social cognition and emotion.
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http://dx.doi.org/10.1038/s41598-017-12098-9DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5612991PMC
September 2017

Intrinsic brain connectivity after partial sleep deprivation in young and older adults: results from the Stockholm Sleepy Brain study.

Sci Rep 2017 08 25;7(1):9422. Epub 2017 Aug 25.

Stockholm University, Stress Research Institute, Stockholm, Sweden.

Sleep deprivation has been reported to affect intrinsic brain connectivity, notably reducing connectivity in the default mode network. Studies to date have however shown inconsistent effects, in many cases lacked monitoring of wakefulness, and largely included young participants. We investigated effects of sleep deprivation on intrinsic brain connectivity in young and older participants. Participants aged 20-30 (final n = 30) and 65-75 (final n = 23) years underwent partial sleep deprivation (3 h sleep) in a cross-over design, with two 8-minutes eyes-open resting state functional magnetic resonance imaging (fMRI) runs in each session, monitored by eye-tracking. We assessed intrinsic brain connectivity using independent components analysis (ICA) as well as seed-region analyses of functional connectivity, and also analysed global signal variability, regional homogeneity, and the amplitude of low-frequency fluctuations. Sleep deprivation caused increased global signal variability. Changes in investigated resting state networks and in regional homogeneity were not statistically significant. Younger participants had higher connectivity in most examined networks, as well as higher regional homogeneity in areas including anterior and posterior cingulate cortex. In conclusion, we found that sleep deprivation caused increased global signal variability, and we speculate that this may be caused by wake-state instability.
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http://dx.doi.org/10.1038/s41598-017-09744-7DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5573389PMC
August 2017

Do Valenced Odors and Trait Body Odor Disgust Affect Evaluation of Emotion in Dynamic Faces?

Perception 2017 Dec 14;46(12):1412-1426. Epub 2017 Jul 14.

Stockholm University, Stockholm, Sweden; Swedish Collegium for Advanced Study, Uppsala, Sweden.

Disgust is a core emotion evolved to detect and avoid the ingestion of poisonous food as well as the contact with pathogens and other harmful agents. Previous research has shown that multisensory presentation of olfactory and visual information may strengthen the processing of disgust-relevant information. However, it is not known whether these findings extend to dynamic facial stimuli that changes from neutral to emotionally expressive, or if individual differences in trait body odor disgust may influence the processing of disgust-related information. In this preregistered study, we tested whether a classification of dynamic facial expressions as happy or disgusted, and an emotional evaluation of these facial expressions, would be affected by individual differences in body odor disgust sensitivity, and by exposure to a sweat-like, negatively valenced odor (valeric acid), as compared with a soap-like, positively valenced odor (lilac essence) or a no-odor control. Using Bayesian hypothesis testing, we found evidence that odors do not affect recognition of emotion in dynamic faces even when body odor disgust sensitivity was used as moderator. However, an exploratory analysis suggested that an unpleasant odor context may cause faster RTs for faces, independent of their emotional expression. Our results further our understanding of the scope and limits of odor effects on facial perception affect and suggest further studies should focus on reproducibility, specifying experimental circumstances where odor effects on facial expressions may be present versus absent.
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http://dx.doi.org/10.1177/0301006617720831DOI Listing
December 2017