Remote Emotion Recognition Using Continuous-Wave Bio-Radar System.

The Bio-Radar is herein presented as a non-contact radar system able to capture vital signs remotely without requiring any physical contact with the subject. In this work, the ability to use the proposed system for emotion recognition is verified by comparing its performance on identifying fear, happiness and a neutral condition, with certified measuring equipment. For this purpose, machine learning algorithms were applied to the respiratory and cardiac signals captured simultaneously by the radar and the referenced contact-based system. Following a multiclass identification strategy, one could conclude that both systems present a comparable performance, where the radar might even outperform under specific conditions. Emotion recognition is possible using a radar system, with an accuracy equal to 99.7% and an F1-score of 99.9%. Thus, we demonstrated that it is perfectly possible to use the Bio-Radar system for this purpose, which is able to be operated remotely, avoiding the subject awareness of being monitored and thus providing more authentic reactions.

Think positive! Resolving human motion ambiguity in the presence of disease threat.

Recently, approach-avoidance tendencies and visual perception biases have been increasingly studied using bistable point-light walkers (PLWs). Prior studies have found a facing-the-viewer bias when one is primed with general threat stimuli (e.g. angry faces), explained by the "error management theory", as failing to detect a threat as approaching is riskier than the opposite. Importantly, no study has explored how disease threat - linked to the behavioural immune system - might affect this bias. This study aimed to explore whether disease-signalling cues can alter how we perceive the motion direction of ambiguous PLWs. Throughout 3 experiments, participants indicated the motion direction of a bistable PLW previously primed with a control or disease-signalling stimuli - that is, face with a surgical mask (Experiment 1), sickness sound (Experiment 2), or face with a disease cue (Experiment 3). Results showed that sickness cues do not significantly modulate the perception of approach-avoidance behaviours. However, a pattern emerged in Experiments 2 and 3, suggesting that sickness stimuli led to more facing away percepts. Unlike other types of threat, this implies that disease-related threat stimuli might trigger a distinct perceptual bias, indicating a preference to avoid a possible infection source. Nonetheless, this finding warrants future investigations.

The impact of COVID-19 concerns on perceiving others' faces.

Unlike most infectious diseases, COVID-19 is characterised by an absence of facial disease-signalling cues. Yet, it is still unclear whether it has influenced face perception. Understanding this may help clarify if and how our motivation toward social interactions is conditional on situational pathogen threats. The present study investigated if priming disease concerns about COVID-19 would change people's perception of neutral faces on perceived disease, social discomfort and arousal elicited by such faces; this condition was compared with other infectious/non-infectious diseases and a non-disease priming condition. One-hundred sixty-six participants recruited nationally performed the online task. When compared with the non-disease condition, participants primed for COVID-19 perceived faces as sicker and tended to view them as eliciting more social discomfort; no difference occurred in arousal. No other difference was found between conditions. These findings suggest that the pandemic context can shape how we perceive others' apparent sickness. Overall, these might reflect adaptations intertwined with the behavioural immune system's defence mechanisms.

Emotional self-body odors do not influence the access to visual awareness by emotional faces.

A growing body of research suggests that emotional chemosignals in others' body odor (BO), particularly those sampled during fearful states, enhance emotional face perception in conscious and preconscious stages. For instance, emotional faces access visual awareness faster when presented with others' fear BOs. However, the effect of these emotional signals in self-BO, that is, one's own BO, is still neglected in the literature. In the present work, we sought to determine whether emotional self-BOs modify the access to visual awareness of emotional faces. Thirty-eight women underwent a breaking-Continuous Flash Suppression task in which they were asked to detect fearful, happy, and neutral faces, as quickly and accurately as possible, while being exposed to their fear, happiness, and neutral self-BOs. Self-BOs were previously collected and later delivered via an olfactometer, using an event-related design. Results showed a main effect of emotional faces, with happy faces being detected significantly faster than fearful and neutral faces. However, our hypothesis that fear self-BOs would lead to faster emotional face detection was not confirmed, as no effect of emotional self-BOs was found-this was confirmed with Bayesian analysis. Although caution is warranted when interpreting these results, our findings suggest that emotional face perception is not modulated by emotional self-BOs, contrasting with the literature on others' BOs. Further research is needed to understand the role of self-BOs in visual processing and emotion perception.

Emotional interference and attentional control in schizophrenia-spectrum disorders: The special case of neutral faces.

BACKGROUND AND OBJECTIVES: Schizophrenia-spectrum disorders (SSD) are characterized by impaired emotion processing and attention. SSD patients are more sensitive to the presence of emotional distractors. But despite growing interest on the emotion-attention interplay, emotional interference in SSD is far from fully understood. Moreover, research to date has not established the link between emotional interference and attentional control in SSD. This study thus aimed to investigate the effects of facial expression and attentional control in SSD, by manipulating perceptual load. METHODS: Twenty-two SSD patients and 22 healthy controls performed a target-letter discrimination task with task-irrelevant angry, happy, and neutral faces. Target-letter was presented among homogenous (low load) or heterogenous (high load) distractor-letters. Accuracy and RT were analysed using (generalized) linear mixed-effect models. RESULTS: Accuracy was significantly lower in SSD patients than controls, regardless of perceptual load and facial expression. Concerning RT, SSD patients were significantly slower than controls in the presence of neutral faces, but only at high load. No group differences were observed for angry and happy faces. LIMITATIONS: Heterogeneity of SSD, small sample size, lack of clinical control group, medication. CONCLUSIONS: One possible explanation is that neutral faces captured exogenous attention to a greater extent in SSD, thus challenging attentional control in perceptually demanding conditions. This may reflect abnormal processing of neutral faces in SSD. If replicated, these findings will help to understand the interplay between exogenous attention, attentional control, and emotion processing in SSD, which may unravel the mechanism underlying socioemotional dysfunction in SSD.

Identifying knowledge gaps in understanding the effects of selective serotonin reuptake inhibitors (SSRIs) on fish behaviour.

Selective serotonin reuptake inhibitors (SSRIs) are a class of antidepressants increasingly prescribed to treat patients with clinical depression. As a result of the significant negative impact of the COVID-19 pandemic on the population's mental health, its consumption is expected to increase even more. The high consumption of these substances leads to their environmental dissemination, with evidence of their ability to compromise molecular, biochemical, physiological, and behavioural endpoints in non-target organisms. This study aimed to provide a critical review of the current knowledge regarding the effects of SSRI antidepressants on fish ecologically relevant behaviours and personality-dependent traits. A literature review shows limited data concerning the impact of fish personality on their responses to contaminants and how such responses could be influenced by SSRIs. This lack of information may be attributable to a lack of widely adopted standardized protocols for evaluating behavioural responses in fish. The existing studies examining the effects of SSRIs across various biological levels overlook the intra-specific variations in behaviour and physiology associated with different personality patterns or coping styles. Consequently, some effects may remain undetected, such as variations in coping styles and the capacity to handle environmental stressors. This oversight could potentially result in long-term effects with ecological implications. Data support the need for more studies to understand the impact of SSRIs on personality-dependent traits and how they may impair fitness-related behaviours. Given the considerable cross-species similarity in the personality dimensions, the collected data may allow new insights into the correlation between personality and animal fitness.

The angry versus happy recognition advantage: the role of emotional and physical properties.

Facial emotional expressions are pivotal for social communication. Their fast and accurate recognition is crucial to promote adaptive responses to social demands, for the development of functional relationships, and for well-being. However, the literature has been inconsistent in showing differentiated recognition patterns for positive vs. negative facial expressions (e.g., happy and angry expressions, respectively), likely due to affective and perceptual factors. Accordingly, the present study explored differences in recognition performance between angry and happy faces, while specifically assessing the role of emotional intensity and global/regional low-level visual features. 98 participants categorized angry and happy faces morphed between neutral and emotional across 9 levels of expression intensity (10-90%). We observed a significantly higher recognition efficiency (higher accuracy and shorter response latencies) for angry compared to happy faces in lower levels of expression intensity, suggesting that our cognitive resources are biased to prioritize the recognition of potentially harmful stimuli, especially when briefly presented at an ambiguous stage of expression. Conversely, an advantage for happy faces was observed from the midpoint of expression intensity, regarding response speed. However, when compensating for the contribution of regional low-level properties of distinct facial key regions, the effect of emotion was maintained only for response accuracy. Altogether, these results shed new light on the processing of facial emotional stimuli, emphasizing the need to consider emotional intensity and regional low-level image properties in emotion recognition analysis.

Autism traits dimensionality and multivariate relationship with alexithymia and anxiety in the general population.

BACKGROUND: Autism is characterized by social and non-social alterations observed beyond the clinical diagnosis. Research analyzing the expression of autism traits in the general population helps to unravel the relationship between autism dimensions and other associated variables, such as alexithymia and anxiety. The Autism-Spectrum Quotient (AQ) was developed to assess autism traits in the general population; however, inconsistent results regarding its dimensionality have emerged. AIMS: This study aimed to extend evidence about the AQ measurement model, and explore the multivariate relationship between autism traits, alexithymia, and trait anxiety. METHODS: 292 adults of the general population were recruited. An Exploratory Factor Analysis and Confirmatory Factor Analysis were performed to assess the factorial structure of AQ. A path analysis was carried out to explore the relationship between autism traits, alexithymia, and trait anxiety. RESULTS: The results supported a three-factor model of AQ. The path analysis model showed evidence of a significant role of alexithymia as a mediator of the relationship between autism traits and anxiety. CONCLUSIONS AND IMPLICATIONS: The present study provides empirical support for a three-factor model of AQ in the general population. The association between autism traits, alexithymia, and anxiety dimensions highlights the multidimensional nature of these variables and the need to account for their distinct impact on autism-related variables.

Perceived Vulnerability to Disease Questionnaire: psychometric validation with a Portuguese sample.

BACKGROUND: Individual differences in one's perceived vulnerability to infectious diseases are implicated in psychological distress, social and behavioral disease avoidance phenomena. The Perceived Vulnerability to Disease Questionnaire (PVD) is the most extensively used measure when it comes to assessing subjective vulnerability to infectious diseases. However, this measure is not yet accessible to the Portuguese population. The present study aimed to adapt and validate the PVD with 136 Portuguese participants. METHODS: Factorial, convergent and discriminant validity (of both the scale and between each factor), and reliability analysis were assessed. RESULTS: A modified bifactorial model, comprised of Perceived Infectability and Germ Aversion factors, was obtained, with acceptable goodness-of-fit indices, adequate convergent and discriminant validity, and good internal consistencies. CONCLUSIONS: Overall, the 10-items European-Portuguese PVD appears to be a reliable and valid measure of one's perceived vulnerability to disease, with potential relevance for application in both research and clinical practice pertaining to disease-avoidance processes.

Multidimensional assessment of anxiety through the State-Trait Inventory for Cognitive and Somatic Anxiety (STICSA): From dimensionality to response prediction across emotional contexts.

The assessment of mal-adaptive anxiety is crucial, considering the associated personal, economic, and societal burden. The State-Trait Inventory for Cognitive and Somatic Anxiety (STICSA) is a self-report instrument developed to provide multidimensional anxiety assessment in four dimensions: trait-cognitive, trait-somatic, state-cognitive and state-somatic. This research aimed to extend STICSA's psychometric studies through the assessment of its dimensionality, reliability, measurement invariance and nomological validity in the Portuguese population. Additionally, the predictive validity of STICSA-Trait was also evaluated, through the analysis of the relationship between self-reported trait anxiety and both the subjective and the psychophysiological response across distinct emotional situations. Similarly to previous studies, results supported both a four-factor and two separated bi-factor structures. Measurement invariance across sex groups was also supported, and good nomological validity was observed. Moreover, STICSA trait-cognitive dimension was associated with differences in self-reported arousal between groups of high/low anxiety, whereas STICSA trait-somatic dimension was related to differences in both the subjective and psychophysiological response. Together, these results support STICSA as a useful instrument for a broader anxiety assessment, crucial for an informed diagnosis and practice.

Sensory Processing in the Autism Spectrum: The Role of Attention to Detail and Somatic Trait Anxiety in the Olfactory Perception of the General Population.

Autism Spectrum Disorders, as well as autism traits (AT), have been associated with altered sensory processing. However, the role of AT in olfactory processing is still unclear. We analyzed the impact of AT and trait anxiety (TANX), relevant in the context of autism and olfactory perception, in the olfactory abilities of a nonclinical adult sample. Participants (N = 116) completed the Autism-Spectrum Quotient (AQ), the State-Trait Inventory for Cognitive and Somatic Anxiety (STICSA) and the Sniffin' Sticks Extended Test to measure AT, TANX and olfactory abilities, respectively. A hierarchical multiple regression analysis suggested that women and higher scores on the Attention to Detail subscale of AQ were associated with better odor discrimination, and higher somatic TANX was related to poorer odor discrimination.

Multimodal Emotion Evaluation: A Physiological Model for Cost-Effective Emotion Classification.

Emotional responses are associated with distinct body alterations and are crucial to foster adaptive responses, well-being, and survival. Emotion identification may improve peoples' emotion regulation strategies and interaction with multiple life contexts. Several studies have investigated emotion classification systems, but most of them are based on the analysis of only one, a few, or isolated physiological signals. Understanding how informative the individual signals are and how their combination works would allow to develop more cost-effective, informative, and objective systems for emotion detection, processing, and interpretation. In the present work, electrocardiogram, electromyogram, and electrodermal activity were processed in order to find a physiological model of emotions. Both a unimodal and a multimodal approach were used to analyze what signal, or combination of signals, may better describe an emotional response, using a sample of 55 healthy subjects. The method was divided in: (1) signal preprocessing; (2) feature extraction; (3) classification using random forest and neural networks. Results suggest that the electrocardiogram (ECG) signal is the most effective for emotion classification. Yet, the combination of all signals provides the best emotion identification performance, with all signals providing crucial information for the system. This physiological model of emotions has important research and clinical implications, by providing valuable information about the value and weight of physiological signals for emotional classification, which can critically drive effective evaluation, monitoring and intervention, regarding emotional processing and regulation, considering multiple contexts.

Giving meaning to the social world in autism spectrum disorders: Olfaction as a missing piece of the puzzle?

Altered social cognition is a core feature of Autism Spectrum Disorders (ASD). These impairments have been explained as the consequence of compromised social motivational mechanisms that limit social interest and activate a cascade of social deficits. Following this rational, we argue that approaches capable of surpassing ASD usual restraints (e.g., deficits in verbal abilities), and able to assign social meaning, could be more effective at responding to these difficulties. In this framework, we propose that olfaction, as well as cross-modal integration strategies involving both visual and olfactory domains, may have such potential. In fact, most of socioemotional processing deficits in ASD have been shown in an uni-modal perspective, mainly with visual stimuli. However, the social environment involves other modalities and is typically multisensorial. Given the potential of olfaction as a gateway for socioemotional information in ASD, we argue in favor of studying olfactory perception, as well as visuo-olfactory integration, given the potential of these approaches to drive effective interventions and give the access to a meaningful social world in ASD.

"Threat-unrelated" properties: An ill-defined concept. A reply to "The danger of interpreting detection differences between image categories" (Gayet, Stein, & Peelen, 2019).

In our previous work (Gomes, Soares, Silva, & Silva, 2018), we evidenced that snakes (vs. birds), an archetypal threat-related stimulus, have an advantage in accessing visual awareness during continuous flash suppression. This advantage was observed when the images were filtered in low spatial frequency (LSF) but not in high spatial frequency and interpreted as supporting the role of a subcortical pathway (superior colliculus-pulvinar) to the amygdala in threat detection, thought to be sensitive to LSF but not to high spatial frequency information. Recently Gayet, Stein, and Peelen (2019), using stimuli without differences in the threat they represented (bicycles and cars) but with an analogous perimeter-area ratio as snakes and birds (respectively), evidenced that bicycles had a faster access to visual awareness than cars. As in our study, this advantage relied on LSF information. The authors argued that the images' perimeter-area ratio (a characteristic intrinsically related with stimuli shape referred to by the authors as threat-unrelated properties), but not the threat itself, may have driven the detection advantage observed in our study and the association with the action of the subcortical pathway to the amygdala. We propose that the results obtained by Gayet et al. do not undermine ours and discuss the relevance of higher perimeter-area ratios (such as images with elongated shapes; e.g., snakes) as a threat-related property required for a fast-initial snake processing. We argue that stimuli shape is a prime feature for the fast-initial threat processing, relevant to grab early visual attention, an effect that might explain the obtained results. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

The scent of the other women: Body odor-induced behavioral and physiological effects on face categorization.

In body odor research, the interaction of female donors and receivers is scarcely investigated. With the aim to investigate effects of female body odor in a competitive context, we tested 51 women divided into two groups (i.e., a competitive and a non-competitive group, based on verbal instructions). Between groups, we explored whether female body odor exposure (vs. masker odor) modulates emotion categorization (via RT variance and distribution) and physiological reactions (via instantaneous heart rate) in a task with dynamic male and female faces as either angry or happy. Women in the competitive group reported to feel more competitive and performed more accurately. They gathered more emotional information to categorize dynamic faces and when additionally exposed to female body odor, they showed a resistance to cardiac deceleration. Lapses of attention (via RT distribution) occurred irrespective of body odor exposure. Our results support the idea that female body odors, presented in a competitive context, contrast cardiac deceleration and, by tendency, modulate emotion categorization. Data are discussed in the context of chemosignaling and social interactions among women.

Ethnic influences on the perceptual properties of human chemosignals.

Individuals of African and Caucasian descent show different chemical signatures in their body odors (BO). Does such biological difference have a perceptual correlate? We tested BO donors and raters of Afro-Portuguese (AP) and Caucasian (C) descent to investigate whether olfactory ratings reveal an ethnic bias and whether olfactory ethnic discrimination is possible. C (vs. AP) women rated the C BO as more pleasant, even when controlling for intensity. The C BO labelled as AP was rated as more intense by C raters. Although discriminability of ethnicity and sex is at chance, a nominal advantage for AP vs. C BO emerges.

Exogenous attention and memory for faces following contextual behavioral immune system activation.

The behavioral immune system (BIS) is characterized by affective, cognitive and behavioral processes that work in an articulated manner to prevent the occurrence of infections. Attention and memory evolved to enhance the organism's chances of survival and have been proposed to play an important role in the BIS. The present study investigated the effects of attention and memory for neutral faces after a contextual activation of the BIS. Participants were primed, by the use of film clips, either with infectious disease concerns or non-infectious disease concerns. They performed an exogenous attentional task involving the discrimination of target letters, with face stimuli presented as distractors, which was then followed by a surprise recognition task for the faces. The results showed that participants in the infectious disease condition were more accurate in the attentional task than participants in the control condition. No significant difference between groups was found in the response times during the attention task nor in memory performance. Overall, these results suggest that the BIS might be associated with a hypervigilant state towards cues in general and that BIS activation through this type of priming may not be sufficient to clearly activate mnemonic mechanisms.

Anxiety Body Odors as Context for Dynamic Faces: Categorization and Psychophysiological Biases.

Body odors (BOs) can convey social information. In particular, their effects are maximal when their presence is paired with meaningful social contexts. Static faces have been widely used as social stimuli. However, they miss a key feature of our phenomenological experience, characterized by multisensory dynamic stimulations. Here, we investigate how BO sampled from individuals experiencing a transitory anxiety state, (a) induce a stress response and (b) bias the recognition of dynamic facial expressions, compared with BO of relaxed individuals. Participants ( n=46) categorized the emotion of a face, morphing from a neutral expression to either an angry or happy expression, during exposure to either BO condition. In addition, their cardiac activity was measured. Exposure to anxiety BO increased the accuracy of dynamic facial recognition and reduced cardiac parasympathetic activity. These results suggest that in social situations that simulate part of the multisensory and dynamic features of real-life social contexts, anxiety BOs will induce a stress response in recipients, modulating both arousal and cognitive-emotional skills but facilitating emotional facial processing.