Psychophysics Research Articles

Psychometric properties of the Social Anxiety Scale (SAS) using psychophysical and categorical scaling

This study evaluated the psychometric properties of a newly developed instrument, the Social Anxiety Scale (SAS) within a non-clinical Swedish adult population (n: 384), in which psychophysical (SAS-cMax) and categorical (SAS-C) scaling methods were compared. Unlike many common rating scales, the SAS items were designed to align with the perceived intensity of symptom severity. With a reduced number of items, both scaling methods (SAS11-cMax and SAS13-C) demonstrated robust conceptual validity, with a three-factor model encompassing “fear of interaction in groups and with strangers”, “fear of speaking in front of others and being in the center of attention”, and “fear of performing tasks while being observed”. In addition, the SAS showed an excellent internal consistency (SAS11-cMax, α = 0.93 and SAS13-C, α = 0.93), as well as good to satisfactory convergent and discriminant validity. ROC-analyses revealed an excellent accurcay of both scaling methods to distinguish between high and low social anxiety levels. A score of 25.3 cM (“moderate social anxiety”) yielded the most optimal sensitivity (0.80) and specificity (0.80) of the SAS11-cMax. A score of 18.5 points yielded the most optimal sensitivity (0.85) and specificity (0.87) of the SAS13-C. Overall, its concluded that the SAS exhibits sound psychometric properties regardless of scaling method. Further validation with other social anxiety scales and within a clinical population, is needed to establish its effectiveness as a screening tool for social anxiety.

Assessing individual sensitivity to the Thermal Grill Illusion: A two-dimensional adaptive psychophysical approach

In the Thermal Grill Illusion (TGI), the spatial alternation of non-noxious warm and cool temperatures elicits burning sensations that resemble the presence of noxious stimuli. Previous research has largely relied on the use of specific temperature values (i.e., 20 °C and 40 °C) to study this phenomenon in both healthy individuals and patient populations. However, this methodology fails to account for inter-individual differences in thermal sensitivity, limiting the precision with which TGI responses can be evaluated across diverse populations. To address this gap, we created a Two-Dimensional Thermal Grill Calibration (2D-TGC) protocol, enabling an efficient and precise estimation of the combinations of warm and cool temperatures needed to elicit burning sensations tailored to each individual. By applying the 2D-TGC protocol in 43 healthy participants, we demonstrated that the TGI can be thresholded using an adaptive psychophysical method, and that multiple combinations of warm and cool temperatures can elicit this phenomenon. More specifically, the protocol facilitated the identification of temperature combinations that elicit TGI with varying levels of probability, intensity, and perceived quality ranging from freezing cold to burning hot. Finally, our results indicate that TGI responsivity can be quantified as a continuous variable, moving beyond the conventional classification of individuals as responders vs. non-responders based on arbitrary temperature values in the innocuous temperature range. The 2D-TGC offers a comprehensive approach to investigate the TGI across populations with altered thermal sensitivity, and can be integrated with other methods (e.g., neuroimaging) to elucidate the mechanisms responsible for perceptual illusions in the thermo-nociceptive system. PerspectiveThis study reveals that the Thermal Grill Illusion can be accurately measured using psychophysical methods. The innovative Two-Dimensional Thermal Grill Calibration protocol allows for personalized temperature assessments, enhancing our understanding of thermal sensitivity variations and perceptual illusions in the thermo-nociceptive system across different populations.

The influence of body posture on facial expression perception in Autism

Facial expression perception is influenced by body posture, with perception biased toward the body emotion. Previous research has suggested that the magnitude of this biasing influence of body posture is driven by individual differences in the precision of facial expression representations underlying discrimination abilities, where lower precision leads to a greater influence of body posture. It is unclear however whether similar mechanisms might drive the influence of contextual cues in Autism, which is often characterised by reduced facial expression discrimination abilities. Here, we addressed this question by using online psychophysical methods to determine the precision of isolated face and body expression representations of anger and disgust, and the influence of body on facial expression perception, in autistic and non-autistic adults. Both groups showed a strong influence of body context on facial expression perception, but this influence was larger in the autistic group, mirroring their lower overall precision of facial expression representations relative to non-autistic individuals. Crucially, the magnitude of the biasing influence of body posture in both groups was related to the precision of individuals’ facial expression representations. The results suggest that similar principles govern the integration of facial expression and body posture information in both autistic and non-autistic individuals.

A preliminary exploration of quantitative models for evaluating binocular visual perception impairments among patients diagnosed with stroke.

The objective of this study is to formulate and implement graded biological models pertaining to binocular visual perception function with the use of computer algorithms. We aim to quantitatively assess the location, severity, and degree of impairment in binocular visual perception among patients who have suffered stroke, thereby providing valuable insights into the repercussions of cerebral tissue damage on the visual system. To overcome the shortcomings of previous instruments used to assess binocular function in terms of stereoscopic effects and the challenges posed by physiological and psychological interference during examinations, this study optimized its approach by integrating polarized stereovision technology with computer graphic modeling techniques. This study employed computer models to assess binocular visual perception function in stroke patients. Computer models refer to psychophysical testing methods used to measure binocular visual perception function, including various assessment tasks such as recognizing inverted letters and assessing stereopsis during high-speed movements. The cross-into-circle test was used as a means to quantify perceptual eye position. Subsequently, the collected data was analyzed to assess the magnitude of impairment in binocular visual perception. The results of the study revealed a spectrum of binocular visual perception impairment among patients diagnosed with stroke, demonstrating discernible variations in the recognition of inverted letters and stereopsis across different movement speeds. Importantly, perceptual eye position measurements offered valuable insights into ocular misalignment. The computational models effectively quantified both the spatial distribution and severity of these identified impairments. Damage to brain tissue resulting from a stroke can give rise to notable impairments in binocular visual perception function. Graded biological models, formulated through computer algorithms, provide a systematic framework for the comprehensive evaluation and quantification of these impairments. The comprehension of the nature and extent of visual impairments observed in patients with stroke establishes a basis for the development of personalized visual perception learning methodologies. Based on such tailored approaches, we aim to facilitate the recovery of impaired visual function, thereby contributing to the broader objective of neural system rehabilitation.

Hand’s Vibration Perception Thresholds—A Systematic Review

The term vibration perception threshold (VPT) refers to the minimum amplitude required for a vibration to be consciously perceived. Knowledge of VPTs can be used to aid in the diagnosis of various pathologies, or to support design decisions during human-machine interface development. However, several factors affect VPT measurements (e.g., contactor size and pressure), thus, comparing VPT results from multiple studies should not be done without considering both the similarities and differences between said studies. This paper presents a systematic review on VPT results obtained across multiple studies, taking into consideration the different factors affecting the values reported in the literature. We intended to answer the following question: “What are the Vibration Perception Thresholds assessed on the glabrous skin of the hands and fingers of healthy humans?” To the best of our knowledge, this is the first attempt at conducting a systematic review focused specifically on numerical VPT results. Starting from 936 records, VPT results from 37 studies were organized according to various factors (gender, age, probe size, contact pressure, psychophysical method, room temperature, skin temperature, and hand location). This data was organized into a table, the Organization Table that is available for readers. This review can help future researchers and developers working on or working with the topic of human perception of vibrations by examining the factors that affect VPTs and discussing strategies to address them. We offer recommendations for future research and insights on how design engineers can utilize VPTs in the development of new haptic devices.

Terrestrial hearing in bearded seals (Erignathus barbatus)

As the Arctic becomes more accessible to human activities—and thus to anthropogenic noise sources—it becomes increasingly important to understand the auditory sensitivity of sound-reliant marine mammals, such as bearded seals (Erignathus barbatus). To address knowledge gaps, the in-air hearing of one adult bearded seal was measured outdoors in ambient noise conditions using psychophysical methods. 50% detection thresholds were measured for 10 frequencies (0.04–51.2 kHz) that extended across the subject’s hearing range. For low to mid frequencies (0.04–12.8 kHz), thresholds were limited, or masked, by ambient noise. Thresholds obtained at higher frequencies (25.6–51.2 kHz) were sufficiently elevated above background noise to provide absolute measures of hearing sensitivity. These data reveal that the in-air, high-frequency roll off for bearded seals is in alignment with available data for related species despite more than 12 million years of evolutionary isolation. Furthermore, the masked data collected at low and mid frequencies enable an unconventional approach for estimating critical ratios, a key parameter in masking models. These findings highlight auditory similarities within the northern clade of phocid seals and improve our ability to predict potential noise effects for these species in a rapidly changing soundscape.

Visual Performance of People With Albinism Assessed With Generalizable and Adaptive AIM and FInD Methods.

People with albinism (PwA) are known to have visual impairments; however, little is known about whether these functions are disrupted across earlier and later stages of the visual pathway. We investigated distinct perceptual functions and fixation stability within each observer and compared the data with age- (±5years) and sex-matched controls. Twenty-one self-reported PwA and twenty-one controls were recruited. Angular-indication measurement (AIM) and foraging-interactive-D-prime (FInD) psychophysical methods were deployed to measure OS, OD, and OU near visual acuity, spatial contrast sensitivity function (CSF), temporal contrast sensitivity (tCS; 0.5 c/°; horizontal grating: 0, 1, 2, 4, and 8Hz), OU glare acuity, threshold-versus-contrast (2c/° vertical grating), long, medium, and short wavelength cone-isolated color detection, color discrimination, stereoacuity across spatial frequencies (1c/°, 2c/°, 4c/°, 8c/°), horizontal, circular, radial pattern and motion coherence, and equivalent-noise motion detection. Thresholds were determined by AIM and FInD and compared using N-ANOVAs, t-tests, planned multi-comparisons, correlations, and unsupervised, agglomerative hierarchical cluster analysis for each group. We found significant differences between groups for most visual functions except for simple and complex form-coherence (two way-ANOVAs, P > 0.05) and complex motion coherence. Correlations between outcomes revealed more significant correlations for PwA and differences in the specific correlates between groups. Unsupervised hierarchical clustering revealed different functional clusters between groups. AIM and FInD successfully interrogated visual deficits in PwA. Overall, PwA showed impaired performance in achromatic, chromatic, temporal, and binocular functions, and had higher intrinsic noise levels. Midlevel vision was comparable between groups. Unsupervised cluster analysis and correlation between outcomes revealed a difference in functional outcome clusters between groups. The results may help to increase the efficiency of screening and identify target deficits for rehabilitation.

A perspective review on the role of engine sound in speed perception and control: state of the art and methodological suggestions.

In this review we focus on the role of in-car sound, specifically the artificial engine sounds, on drivers' speed perception and control, a topic that has received little attention so far. Previous studies indicate that removing or reducing engine sound leads drivers to underestimate speed and, consequently, to drive faster. Furthermore, evidence suggests that specific sound frequencies could play a role in this process, highlighting the importance of in-car sound features. First, we show that the amount of research in the field is scarce and rather outdated, and that this is largely due to the fact that industrial research is subject to very few publications. Then, we examine benefits and limitations of different research paradigms used and we propose a protocol to investigate systematically the phenomenon. In particular, we argue for the benefits of a wider use of psychophysical methods in speed perception, a field that has been typically explored by means of driving simulation. Finally, we highlight some methodological and statistical limitations that might impact the interpretation of the evidence considered. Our methodological considerations could be particularly useful for researchers aiming to investigate the impact of sound on speed perception and control, as well as for those involved in the design of in-car sounds. These are particularly relevant for the design of electric vehicles, which represent a challenge but also the ideal testing ground to advance the knowledge in the field.

Reading comfort in relation to monitor and ambient luminance levels: A study using continuous rating scale and paired comparison methodology

In this work, it is investigated how reading comfort is influenced by monitor and ambient luminance levels, when employing high-luminance monitors. High-luminance monitors can be used to get more light on the eye and elicit non-image-forming effects. However, this might lead to reduced reading comfort. Two psychophysical methods, a continuous rating scale and paired comparison, were employed to investigate reading comfort in relation to the luminance of the monitor and the ambient environment. The results of 18 observers for the continuous rating scale experiment (aged 20 y to 30 y) and 20 observers for the paired comparison experiment (aged 20 y to 37 y) indicate that reading comfort is significantly influenced by both monitor and ambient luminance levels The paired comparison methodology provided more distinctive capabilities and thus offered a deeper insight. In contrast to prior work suggesting a linear relation between monitor luminance and preferred ambient luminance, the current results indicate that the reading comfort level reaches a tipping or saturation point. A monitor luminance level of 260 cd m−2 combined with an ambient luminance level of 68 cd m−2 provided the highest reading comfort. This reading comfort could not be matched when employing a higher monitor luminance level of 700 cd m−2.

A Special Equation between Visual Lightness and the Luxurious Impression of Interior Architecture through the New Classic

This research examines the application of the new classic contemporary style in interior architecture, focusing on achieving luxury and visual lightness. The study highlights the historical evolution of the new classic style and its relevance to modern interior design, emphasizing its suitability for contemporary settings. It addresses challenges such as higher costs, modern lifestyle constraints, and technological limitations. The research also seeks to dispel the misconception that the new classic style is inflexible and heavily reliant on aesthetic richness alone. To explore these themes, various methods were employed, including data collection and evaluation, observation, quantitative analysis, and psychophysical methods. These approaches allowed for a comprehensive analysis of the new classic style's adaptability across different building types, spaces, and cultural contexts. The study also examined the psychological and emotional impacts of this style on occupants. The research resulted in a practical designed for interior designers and enthusiasts, offering guidelines for effectively incorporating the new classic style in contemporary designs. This aims to help balance luxury with visual lightness in various settings, particularly in modern tourist destinations and the hotel industry, providing a detailed approach for applying this style in diverse interior spaces

Comparison of horizontal plane auditory spatial discrimination abilities and testing methods in patients with symmetrical sensorineural hearing loss

Objective: To evaluate auditory spatial discrimination capabilities in patients with mild to moderately severe symmetrical sensorineural hearing loss (SNHL) and to compare the impact of different psychophysical testing methods on Minimum Audible Angle (MAA) and test duration. Methods: A total of 105 symmetrical SNHL patients aged from 18 to 60 years old were enrolled from April to July 2023, including 56 males and 49 females. They were divided into three groups based on PTA: mild, moderate, and moderately severe hearing loss, with 35 individuals in each group. Additionally, a control group of 35 individuals with normal hearing was tested, including 18 males and 17 females. Participants underwent four distinct psychophysical discrimination tests: the block up-down, 1-up/1-down, 1-up/2-down, and 1-up/3-down procedures. We recorded the MAA and test duration for each. We employed repeated measures of ANOVA to compare the MAA and test duration across different methods and groups, and Pearson's correlation to assess the relationship between MAA and degree of hearing loss. Results: MAA of sound localization in patients with symmetrical SNHL was significantly positively correlated with the degree of hearing loss (r=0.59, P<0.01). Significant deterioration in MAA was observed as hearing loss progressed to the moderate level (PTA≥35 dBHL, P<0.01). The testing methods significantly influenced MAA and testing duration (F=24.02, P<0.01; F=75.56, P<0.01) and the 1-up/1-down method was the quickest, averaging only (0.69±0.32) mins. Conclusions: The horizontal plane auditory spatial discrimination abilities in patients with symmetrical SNHL is impaired progressively with increasing hearing loss, notably beyond moderate hearing loss levels. Different psychophysical methods influence both MAA and test duration, the quicker 1-up/1-down method is recommended for assessing MAA in symmetrical SNHL patients.

Intranasal Trigeminal Function in Aging Adults.

Intranasal trigeminal function is important in detecting environmental stimuli. The impact of age-associated chemosensory dysfunction upon taste and olfaction is well described, but an understanding of trigeminal loss (chemesthesis) is lacking. The goal of this study was to characterize trigeminal function in a cohort of older adults and explore potential impacts. Twenty-eight participants over 50 years of age were recruited from the community as part of an aging cohort study. This nested cohort completed chemosensory questionnaires, patient-reported outcome measures (PROMs), and psychophysical testing for taste (taste strips), olfaction (Sniffin' Sticks), and trigeminal function (eucalyptol lateralization). Data were analyzed for associations between trigeminal function, olfactory, and taste psychophysical performance, patient-reported metrics, and demographic risk factors. Patient-reported trigeminal impairment is less severe than other chemosensory loss, with mean visual analog scores (VAS, rated 0-100 from least to most severe) for smell (32.9 ± 34.2), taste (20.6 ± 28.4), and trigeminal sensation (9.5 ± 12.8). Despite low VAS scores, psychophysical trigeminal dysfunction was present in 10 (35.7%) subjects. Psychophysical olfactory and taste dysfunction were present in 16 (57.1%) and eight (28.6%) participants respectively. Hypercholesterolemia was associated with psychophysical trigeminal dysfunction (mean lateralization performance in hypercholesterolemia 57.7% ± 17.1 vs. 74.1% ± 10.4, p = .008). Intranasal trigeminal impairment is present in nearly one-third of aging adults when assessed by psychophysical methods but is under-recognized. Hyperlipidemia may be associated with trigeminal impairment. Future inquiries should better characterize these findings in larger and prospective cohorts.

Comparative Quantification of Fungiform Papillae Density and Taste Perception in Anemic and Healthy Controls: A Case-Control Study.

Background Taste perception is crucial for dietary choices, nutrition, and overall health. The human tongue, particularly the fungiform papillae, plays a significant role in taste sensation, especially for sweet and umami flavors. Anemia, a common condition characterized by low hemoglobin levels, can affect sensory perception, including taste. Recent research has begun to explore the relationship between fungiform papillae density and taste perception in individuals with anemia. Objective This study aimed to investigate the comparative quantification of fungiform papillae density and its correlation with taste perception in anemic and healthy individuals, with the goal of understanding the underlying mechanisms linking anemia to taste disturbances. Methods A total of 100 adults (50 anemic and 50 healthy controls) aged 18-65 participated in the study. Demographic data, dietary habits, and medical history were collected. Taste perception was assessed using a taste strip test and psychophysical scaling methods, including magnitude estimation and the method of constant stimuli. Fungiform papillae density was quantified using high-resolution images of the tongue. Statistical analyses, including t-tests and correlation analyses, were conducted to compare the groups and explore relationships between hemoglobin levels, papillae density, and taste perception. Results The study found that anemic individuals had a slightly lower mean fungiform papillae density (49 papillae per square centimeter) compared to healthy controls (57 papillae per square centimeter). In the taste strip test, anemic participants showed reduced accuracy in taste perception, particularly for bitter flavors. However, psychophysical scaling results, as measured by magnitude estimation, revealed no statistically significant difference in subjective taste intensity between the anemic and healthy control groups (p=0.8666). Conclusion The study suggests that while anemic individuals may exhibit reduced fungiform papillae density and altered taste perception, particularly for bitter flavors, the overall subjective perception of taste intensity does not significantly differ from that of healthy controls. These findings contribute to the understanding of taste disturbances in anemia and may inform future diagnostic and therapeutic approaches for managing taste disorders in affected individuals.

Weaker number sense accounts for impaired numerosity perception in dyscalculia: Behavioral and computational evidence.

Impaired numerosity perception in developmental dyscalculia (low "number acuity") has been interpreted as evidence of reduced representational precision in the neurocognitive system supporting non-symbolic number sense. However, recent studies suggest that poor numerosity judgments might stem from stronger interference from non-numerical visual information, in line with alternative accounts that highlight impairments in executive functions and visuospatial abilities in the etiology of dyscalculia. To resolve this debate, we used a psychophysical method designed to disentangle the contribution of numerical and non-numerical features to explicit numerosity judgments in a dot comparison task and we assessed the relative saliency of numerosity in a spontaneous categorization task. Children with dyscalculia were compared to control children with average mathematical skills matched for age, IQ, and visuospatial memory. In the comparison task, the lower accuracy of dyscalculics compared to controls was linked to weaker encoding of numerosity, but not to the strength of non-numerical biases. Similarly, in the spontaneous categorization task, children with dyscalculia showed a weaker number-based categorization compared to the control group, with no evidence of a stronger influence of non-numerical information on category choice. Simulations with a neurocomputational model of numerosity perception showed that the reduction of representational resources affected the progressive refinement of number acuity, with little effect on non-numerical bias in numerosity judgments. Together, these results suggest that impaired numerosity perception in dyscalculia cannot be explained by increased interference from non-numerical visual cues, thereby supporting the hypothesis of a core number sense deficit. RESEARCH HIGHLIGHTS: A strongly debated issue is whether impaired numerosity perception in dyscalculia stems from a deficit in number sense or from poor executive and visuospatial functions. Dyscalculic children show reduced precision in visual numerosity judgments and weaker number-based spontaneous categorization, but no increasing reliance on continuous visual properties. Simulations with deep neural networks demonstrate that reduced neural/computational resources affect the developmental trajectory of number acuity and account for impaired numerosity judgments. Our findings show that weaker number acuity in developmental dyscalculia is not necessarily related to increased interference from non-numerical visual cues.

Neural network based cognitive approaches from face perception with human performance benchmark

Artificial neural network models are able to achieve great performance at numerous computationally challenging tasks like face recognition. It is of significant importance to explore the difference between neural network models and human brains in terms of computational mechanism. This issue has become an experimental focus for some researchers in recent studies, and it is believed that using human behavior to understand neural network models can address this issue. This paper compares the neural network model performance with human performance on a classic yet important task: judging the ethnicity of a given face. This study uses Caucasian and East Asian faces to train 4 neural networks including AlexNet, VGG11, VGG13, and VGG16. Then, the ethnicity judgments of the neural networks are compared with human data using classical psychophysical methods by fitting psychometric curves. The results suggest that VGG11, followed by VGG16, shows a similar response pattern as humans, while simpler AlexNet and more complex VGG13 do not resemble human performance. Thus, this paper explores a new paradigm to compare neural networks and human brains.

Attention facilitates initiation of perceptual decision making: a combined psychophysical and electroencephalography study

Humans can selectively process information and make decisions by directing their attention to desired locations in their daily lives. Numerous studies have shown that attention increases the rate of correct responses and shortens reaction time, and it has been hypothesized that this phenomenon is caused by an increase in sensitivity of the sensory signals to which attention is directed. The present study employed psychophysical methods and electroencephalography (EEG) to test the hypothesis that attention accelerates the onset of information accumulation. Participants were asked to discriminate the motion direction of one of two random dot kinematograms presented on the left and right sides of the visual field, one of which was cued by an arrow in 80% of the trials. The drift–diffusion model was applied to the percentage of correct responses and reaction times in the attended and unattended fields of view. Attention primarily increased sensory sensitivity and shortened the time unrelated to decision making. Next, we measured centroparietal positivity (CPP), an EEG measure associated with decision making, and found that CPP latency was shorter in attended trials than in unattended trials. These results suggest that attention not only increases sensory sensitivity but also accelerates the initiation of decision making.

Therapeutic effects of rehabilitation technologies in patients with functional asthenia

Abstract. Post-traumatic stress disorder is widespread in the young patient population and tends to increase. Studying the therapeutic effects of a complex of rehabilitation technologies in patients with post-traumatic stress disorder is an urgent scientific and practical task. Purpose of the study: to determine the therapeutic effects of a complex of rehabilitation technologies in patients with post-traumatic stress disorder. Material and methods. 71 patients aged 33 (20–49) years with post-traumatic stress disorder (ICD–X code F43.1) were studied. The patients were prescribed a set of physical exercises, a course of audiovisual polysensory relaxation, transcranial magnetic stimulation, chromotherapy, hydrobalneotherapy, climatotherapy, therapeutic nutrition and psychotherapy. The total duration of the course is 20 days. Clinical, instrumental, psychophysical, and integral methods of assessing the condition of patients were used. Results. A significant improvement in clinical and psychological status, an increase in adaptive potential, the level of physical health, a significant increase in physical performance, and an improvement in autonomic regulation were revealed. Conclusion. The complex of restorative technologies of medical and psychological rehabilitation produces pronounced actoprotective and psychocorrective therapeutic effects in patients with post-traumatic stress disorder.

Continuous psychophysics shows millisecond-scale visual processing delays are faithfully preserved in movement dynamics.

Image differences between the eyes can cause interocular discrepancies in the speed of visual processing. Millisecond-scale differences in visual processing speed can cause dramatic misperceptions of the depth and three-dimensional direction of moving objects. Here, we develop a monocular and binocular continuous target-tracking psychophysics paradigm that can quantify such tiny differences in visual processing speed. Human observers continuously tracked a target undergoing Brownian motion with a range of luminance levels in each eye. Suitable analyses recover the time course of the visuomotor response in each condition, the dependence of visual processing speed on luminance level, and the temporal evolution of processing differences between the eyes. Importantly, using a direct within-observer comparison, we show that continuous target-tracking and traditional forced-choice psychophysical methods provide estimates of interocular delays that agree on average to within a fraction of a millisecond. Thus, visual processing delays are preserved in the movement dynamics of the hand. Finally, we show analytically, and partially confirm experimentally, that differences between the temporal impulse response functions in the two eyes predict how lateral target motion causes misperceptions of motion in depth and associated tracking responses. Because continuous target tracking can accurately recover millisecond-scale differences in visual processing speed and has multiple advantages over traditional psychophysics, it should facilitate the study of temporal processing in the future.

Distinct patterns of monocular advantage for facial emotions in social anxiety

Individuals with social anxiety often exhibit atypical processing of facial expressions. Previous research in social anxiety has primarily emphasized cognitive bias associated with face processing and the corresponding abnormalities in cortico-limbic circuitry, yet whether social anxiety influences early perceptual processing of emotional faces remains largely unknown. We used a psychophysical method to investigate the monocular advantage for face perception (i.e., face stimuli are better recognized when presented to the same eye compared to different eyes), an effect that is indicative of early, subcortical processing of face stimuli. We compared the monocular advantage for different emotional expressions (neutral, angry and sad) in three groups (N = 24 per group): individuals clinically diagnosed with social anxiety disorder (SAD), individuals with high social anxiety in subclinical populations (SSA), and a healthy control (HC) group of individuals matched for age and gender. Compared to SSA and HC groups, we found that individuals with SAD exhibited a greater monocular advantage when processing neutral and sad faces. While the magnitudes of monocular advantages were similar across three groups when processing angry faces, individuals with SAD performed better in this condition when the faces were presented to different eye. The former findings suggest that social anxiety leads to an enhanced role of subcortical structures in processing nonthreatening expressions. The latter findings, on the other hand, likely reflect an enhanced cortical processing of threatening expressions in SAD group. These distinct patterns of monocular advantage indicate that social anxiety altered representation of emotional faces at various stages of information processing, starting at an early stage of the visual system.

Alcohol Use Disorder and Chronic Pain: An Overlooked Epidemic.

Alcohol use disorder (AUD) and chronic pain disorders are pervasive, multifaceted medical conditions that often co-occur. However, their comorbidity is often overlooked, despite its prevalence and clinical relevance. Individuals with AUD are more likely to experience chronic pain than the general population. Conversely, individuals with chronic pain commonly alleviate their pain with alcohol, which may escalate into AUD. This narrative review discusses the intricate relationship between AUD and chronic pain. Based on the literature available, the authors present a theoretical model explaining the reciprocal relationship between AUD and chronic pain across alcohol intoxication and withdrawal. They propose that the use of alcohol for analgesia rapidly gives way to acute tolerance, triggering the need for higher levels of alcohol consumption. Attempts at abstinence lead to alcohol withdrawal syndrome and hyperalgesia, increasing the risk of relapse. Chronic neurobiological changes lead to preoccupation with pain and cravings for alcohol, further entrenching both conditions. To stimulate research in this area, the authors review methodologies to improve the assessment of pain in AUD studies, including self-report and psychophysical methods. Further, they discuss pharmacotherapies and psychotherapies that may target both conditions, potentially improving both AUD and chronic pain outcomes simultaneously. Finally, the authors emphasize the need to manage both conditions concurrently, and encourage both the scientific community and clinicians to ensure that these intertwined conditions are not overlooked given their clinical significance.