Dynamical patterns of human postural responses to emotional stimuli

Erotic scenes and images of mutilated bodies are emotional stimuli that have repeatedly shown to evoke specific neurophysiological responses associated with enhanced attention and perceptual processing. Remarkably however, only a handful of studies have investigated human motor reactions to emotional activation as a direct index of physical approximation or withdrawal. Given the inconclusive results of these studies, the approach-avoidance distinction, one of the most salient concepts in human motivational research, remains a broadly exploited hypothesis that has never been empirically demonstrated. Here, we investigate postural responses elicited by discrete emotional stimuli in healthy young adults. We discover that both positive and negative affective pictures induce a significant posterior deviation from postural baseline equilibrium. Further, we find that neutral pictures also evoke posterior deviation, although with a less pronounced amplitude. Exploring the dynamical evolution of postural responses to emotional pictures at high temporal resolution, we uncover a characteristic profile that remains stable for stimuli from all three affective categories. In contrast, the postural response amplitude is modulated by the emotional content of the stimulus. Our observations do not support the interpretation of postural responses to affective picture-viewing as approach-avoidance behavior. Instead, our findings indicate the involvement of a previously unrecognized motor component of the physiological mechanism underlying human orienting responses

Emotional reactivity monitoring using electrodermal activity analysis in individuals with suicidal behaviors

Suicide, considered as one of the leading causes of death, has not been given enough attention in order to reduce it\u27s rate. The problem addressed in this paper is the analysis of the relation between an extra stimulus and physiological data\u27s responses. In order to record the physiological data set from multiple subjects over many weeks, we used an acoustic startle during a Paced Auditory Serial Addition Task (PASAT) test that spontaneously leads subjects to real emotional reactivity, without any deliberate laboratory setting. Crucially, we show that, by inducing anxiety during the test, changes appear in Electrodermal activity, Electrocardiogram, Heart Rate and Respiration Rate. A wide range of physiological features from various analysis domains, including modeling, time/frequency analysis, an algorithm and etc., is proposed in order to find the best emotional reactivity feature to correlate them with emotional states which can be considered as a suicide factor. More specifically, this paper is focused on the EDA data analysis. Experimental results highlight that all cited techniques perform well and we achieved a high resolution of tonic and phasic components which allow us to measure the latency, onsets and amplitudes of EDA responses to a stimulus. This paper follows the association of recommendations for advancement of health care instruments

Genetic associations of nonsynonymous exonic variants with psychophysiological endophenotypes

We mapped ∼85,000 rare nonsynonymous exonic single nucleotide polymorphisms ( SNPs ) to 17 psychophysiological endophenotypes in 4,905 individuals, including antisaccade eye movements, resting EEG , P 300 amplitude, electrodermal activity, affect‐modulated startle eye blink. Nonsynonymous SNPs are predicted to directly change or disrupt proteins encoded by genes and are expected to have significant biological consequences. Most such variants are rare, and new technologies can efficiently assay them on a large scale. We assayed 247,870 mostly rare SNPs on an Illumina exome array. Approximately 85,000 of the SNPs were polymorphic, rare ( MAF  < .05), and nonsynonymous. Single variant association tests identified a SNP in the PARD 3 gene associated with theta resting EEG power. The sequence kernel association test, a gene‐based test, identified a gene PNPLA 7 associated with pleasant difference startle, the difference in startle magnitude between pleasant and neutral images. No other single nonsynonymous variant, or gene‐based group of variants, was strongly associated with any endophenotype.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/109617/1/psyp12349.pd

Development of a novel startle response task in Duchenne muscular dystrophy

Duchenne muscular dystrophy (DMD), an X-linked childhood-onset muscular dystrophy caused by loss of the protein dystrophin, can be associated with neurodevelopmental, emotional and behavioural problems. A DMD mouse model also displays a neuropsychiatric phenotype, including increased startle responses to threat which normalise when dystrophin is restored in the brain. We hypothesised that startle responses may also be increased in humans with DMD, which would have potential translational therapeutic implications. To investigate this, we first designed a novel discrimination fear-conditioning task and tested it in six healthy volunteers, followed by male DMD (n = 11) and Control (n = 9) participants aged 7–12 years. The aims of this methodological task development study were to: i) confirm the task efficacy; ii) optimise data processing procedures; iii) determine the most appropriate outcome measures. In the task, two neutral visual stimuli were presented: one ‘safe’ cue presented alone; one ‘threat’ cue paired with a threat stimulus (aversive noise) to enable conditioning of physiological startle responses (skin conductance response, SCR, and heart rate). Outcomes were the unconditioned physiological startle responses to the initial threat, and retention of conditioned responses in the absence of the threat stimulus. We present the protocol development and optimisation of data processing methods based on empirical data. We found that the task was effective in producing significantly higher physiological startle SCR in reinforced ‘threat’ trials compared to ‘safe’ trials (P &lt; .001). Different data extraction methods were compared and optimised, and the optimal sampling window was derived empirically. SCR amplitude was the most effective physiological outcome measure when compared to SCR area and change in heart rate, with the best profile on data processing, the least variance, successful conditioned response retention (P = .01) and reliability assessment in test-retest analysis (rho = .86). The definition of this novel outcome will allow us to study this response in a DMD population

Pupil dilation as an implicit measure of appetitive Pavlovian learning

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

The application of human factors in wake vortex encounter flight simulations for the reduction of flight upset risk and startle response

The current top safety risk concern for commercial air travel in Europe is known as “Flight Upset”. This term, also known as “Loss of Control in Flight”, entails the flight crew suddenly finding themselves in an unexpected, complex, and even confusing situation that if not resolved quickly can lead to a major accident. Accidents such as AF447 and the two B737 Max accidents fall into this category. An undesirable aspect of such events is known as the “startle response”, wherein one or both flight crew, finding themselves in dire and dangerous conditions, may experience ‘startle’, which temporarily affects their cognitive functioning. This may only last half a minute, but its effect can have a severe impact on the survivability of such events. A Horizon 2020 research project called SAFEMODE, which aims to integrate Human Factors techniques into a unified framework for designers in aviation and maritime domains, is exploring the use of state-of-the-art flight simulation facilities to measure pilot performance in severe wake turbulence events, which can induce the startle effect. This is part of a broader use case within SAFEMODE to validate the design of a new Wake Vortex Air Traffic Alert for the Cruise phase of flight. A tactical short-term alert to the Flight Crew, ahead of the wake encounter, is seen as beneficial to reduce the startle effect and support the appropriate management of these conflicts. The envisaged risk-alerting logic relies on a ground-based predictor, connected to the Air Traffic Control system, displaying an alert to the En-route Air Traffic Controllers, who can then provide a cautionary advisory to the Flight Crew so they can take appropriate actions.The cockpit flight simulations involve type-rated flight crews in realistic and representative cruise flight conditions, using a Type VI Boeing 737-800 full flight motion-based simulator (also used for Upset Prevention and Recovery training programs). During the simulation runs, pilots are exposed to simulated wake vortex encounters, corresponding to a strong wake-induced upset (between 30 and 40 degrees of bank), with or without prior ATC wake caution, and varying the initial direction of roll between left and right to limit the simulation training effect.Human Factors measurements include workload, situation awareness, trust, acceptability-based user feedback, as well as psychophysiological measures such as eye-tracking and Electro-Dermal Activity (EDA). In particular, eye-tracking is expected to support the refined determination of the sequence of actions before and after detection, and the reaction of flight crews to the en-route ATC Wake alert.A cockpit flight simulation, via combining the analyses of psychophysiological measures, flight parameters, expert observations and subjective pilot feedback, enables evaluation of Flight Crews performance in preparing for, managing or avoiding wake encounter upsets with the new ATC wake alerts, showing the net safety benefits. Early results indicate that the simulations can indeed induce startle effect, and that repeated exposure enables flight crew to overcome it and manage the situation in a more measured and controlled fashion

A wearable system for stress detection through physiological data analysis

In the last years the impact of stress on the society has been increased, resulting in 77% of people that regularly experiences physical symptoms caused by stress with a negative impact on their personal and professional life, especially in aging working population. This paper aims to demonstrate the feasibility of detection and monitoring of stress, inducted by mental stress tests, through the analysis of physiological data collected by wearable sensors. In fact, the physiological features extracted from heart rate variability and galvanic skin response showed significant differences between stressed and not stressed people. Starting from the physiological data, the work provides also a cluster analysis based on Principal Components (PCs) able to showed a visual discrimination of stressed and relaxed groups. The developed system would support active ageing, monitoring and managing the level of stress in ageing workers and allowing them to reduce the burden of stress related to the workload on the basis of personalized interventions