Increased Skin Conductance Research Articles

The concealed information test with a continuously moving stimulus.

The Concealed Information Test (CIT) aims to extract concealed crime-related knowledge using physiological measures. In the present study, we propose a new variant of the CIT that contains a continuously moving stimulus. A total of 81 participants were either informed or not about the specific location of an upcoming terrorist attack. The CIT consisted of a map with a superimposed moving dot, combined with measurements of respiration and electrodermal activity. The results revealed both respiratory suppression and an increase in skin conductance when the moving dot passed the target location only in informed participants. These findings showed that this new variant of the CIT can differentiate between groups of informed and uninformed individuals and an exploratory analysis revealed it can help narrow down a search area.

The impact of threat of shock on memory for threat-irrelevant information: Evidence for a role of reduced semantic organization

Research into the effects of acute anxiety on episodic memory has produced inconsistent findings, particularly for threat-neutral information. In two experiments, we tested the hypothesis that anxiety induced by threat of shock can interfere with the use of semantic-organizational processes that benefit memory. In Experiment 1, participants viewed and freely recalled two lists of semantically unrelated neutral words, one encoded in a threatening context (threat blocks) and one encoded without threat (safe blocks). As predicted, significantly fewer words were recalled during threat than safe blocks. Moreover, free recall patterns following threat blocks showed lower levels of semantic organization as assessed using a “path length” measurement that considers the semantic distance between pairs of consecutively recalled words. Both effects unexpectedly interacted with block order, such that they primarily reflected improved recall and increased semantic organization from the first to the second block in participants who received the threat block first. Experiment 2 used semantically related word lists to reduce potential impacts of task experience on semantic organization. Free recall was again less accurate and showed longer (less organized) path lengths for threat than safe blocks, and the path length effect no longer interacted with block order. Moreover, threat-induced changes to path lengths emerged as a mediator of the relation between physiological effects of threat (increased skin conductance) and reduced subsequent memory. These data point to semantic control processes as an understudied determinant of when and how acute anxiety impacts episodic memory.

The Neurophysiological Costs of Learning in a Noisy Classroom: An Ecological Virtual Reality Study.

Many real-life situations can be extremely noisy, which makes it difficult to understand what people say. Here, we introduce a novel audiovisual virtual reality experimental platform to study the behavioral and neurophysiological consequences of background noise on processing continuous speech in highly realistic environments. We focus on a context where the ability to understand speech is particularly important: the classroom. Participants (n = 32) experienced sitting in a virtual reality classroom and were told to pay attention to a virtual teacher giving a lecture. Trials were either quiet or contained background construction noise, emitted from outside the classroom window. Two realistic types of noise were used: continuous drilling and intermittent air hammers. Alongside behavioral outcomes, we measured several neurophysiological metrics, including neural activity (EEG), eye-gaze and skin conductance (galvanic skin response). Our results confirm the detrimental effect of background noise. Construction noise, and particularly intermittent noise, was associated with reduced behavioral performance, reduced neural tracking of the teacher's speech and an increase in skin conductance, although it did not have a significant effect on alpha-band oscillations or eye-gaze patterns. These results demonstrate the neurophysiological costs of learning in noisy environments and emphasize the role of temporal dynamics in speech-in-noise perception. The finding that intermittent noise was more disruptive than continuous noise supports a "habituation" rather than "glimpsing" hypothesis of speech-in-noise processing. These results also underscore the importance of increasing the ecologically relevance of neuroscientific research and considering acoustic, temporal, and semantic features of realistic stimuli as well as the cognitive demands of real-life environments.

Disinhibition, rather than moderate-to-severe traumatic brain injury, moderates the impact of anger provocation on subjective emotional experience

Objective Altered reactivity to emotional stimuli is common after traumatic brain injury (TBI), which is suggested to reflect difficulties with emotion regulation. While disinhibition is common after moderate-to-severe TBI, limited research has investigated the link between disinhibition and emotional reactivity in this clinical group. The aim of this research, therefore, was to investigate the relationship between disinhibition and TBI to anger provocation. Method Thirty-five individuals with moderate-to-severe TBI and thirty-one controls completed an anger induction task. Participants rated their experience of emotions and subjective arousal before and after the induction. Heart rate, respiration and skin conductance were also measured. Disinhibition was measured using the Frontal Systems Behavior Scale. Results In the full sample, the mood induction led to increased skin conductance, respiration, and self-reported anger, tension, arousal and negative mood. There were no differences between those with TBI and controls. Disinhibition interacted with the impact of anger provocation on subjective, but not objective, outcomes such that those elevated in disinhibition reported increased feelings of anger and tension in response to the mood induction. Disinhibition did not interact with TBI across any subjective and objective emotional measures examined in response to mood induction. Conclusions While anger causes emotional changes for all individuals, these changes are particularly pronounced among those who are disinhibited, irrespective of whether an individual has sustained a TBI. This is an important consideration when examining emotional regulation post-TBI as the degree of disinhibition appears to alter subjective interpretations of emotional events, which could lead to emotion dysregulation.

Decoupling the role of verbal and non-verbal audience behavior on public speaking anxiety in virtual reality using behavioral and psychological measures

Public speaking is a communication ability that is expressed in social contexts. Public speaking anxiety consists of the fear of giving a speech or a presentation and the perception of being badly judged by others. Such feelings can impair the performance and physiological activation of the presenter. In this study, eighty participants, most naive in Virtual Reality experience, underwent one of four virtual reality public speaking scenarios. Four different conditions were tested in a between-group design, where the audience could express positive or negative non-verbal behavior (in terms of body gesture and facial expression), together with positive or adverse questions raised during a question-and-answer session (Q&A). The primary outcomes concerned the virtual audience behavior’s effect on perceived anxiety and physiological arousal. In general, perceived anxiety seemed to be unaffected neither by the verbal nor non-verbal behavior of the audience. Nevertheless, experimental manipulation showed a higher susceptibility to public speaking anxiety in those participants who scored higher on the Social Interaction Anxiety Scale (SIAS) than those with lower Social Interaction Anxiety Scale scores. Specifically, in the case where the verbal attitude was negative, high SIAS trait participants reported a higher level of anxiety. Participants’ physiological arousal was also affected by the proposed scenarios. Participants dealing with an approving audience and encouraging Q&A reported increased skin conductance response. The lack of correlation between reported anxiety and skin conductance response might suggest a physiological engagement in an interactive exchange with the virtual audience rather than a form of discomfort during the task.

Can I see it in the eyes? An investigation of freezing-like motion patterns in response to avoidable threat.

Freezing is one of the most extensively studied defensive behaviors in rodents. Both reduced body and gaze movements during anticipation of threat also occur in humans and have been discussed as translational indicators of freezing but their relationship remains unclear. We thus set out to elucidate body and eye movements and concomitant autonomic dynamics in anticipation of avoidable threat. Specifically, 50 participants viewed naturalistic pictures that were preceded by a colored fixation cross, signaling them whether to expect an inevitable (shock), no (safety), or a potential shock (flight) that could be avoided by a quick button press. Body sway, eye movements, the heart rate and skin conductance were recorded. We replicated previously described reductions in body sway, gaze dispersion, and the heart rate, and a skin conductance increase in flight trials. Stronger reductions in gaze but not in body sway predicted faster motor reactions on a trial-wise basis, highlighting their functional role in action preparation. We failed to find a trait-like relationship between body and gaze movements across participants, but their temporal profiles were positively related within individuals, suggesting that both metrics partly reflect the same construct. However, future research is desirable to assess these response patterns in naturalistic environments. A more ethological examination of different movement dynamics upon threat would not only warrant better comparability between rodent and human research but also help determine whether and how eye-tracking could be implemented as a proxy for fear-related movements in restricted brain imaging environments.

Similar social attention, physiological arousal, and familiarity effect in autistic and neurotypical children: A real-life recreational eye-tracking paradigm.

Social attention is reported to be crucial for the development of social skills, and, according to the social cognitive developmental theory, is fostered by social interactions. Autism is of central importance to the study of social attention, as autism is characterized by atypical social interactions and low social attention, both linked according to the social motivation theory to diminished social interest. Much evidence for positing low social interest in autism comes from eye-tracking studies, which, however, lack ecological validity. Our study documents social attention and physiological arousal, within close to real-life settings, in autistic children, as well as in their neurotypical peers, matched on gender and mental or chronological age. To explore the potential influence of partner familiarity or of the conversational topic, children gaze and electrodermal activity were recorded while they engaged in watercolor activities with, first a familiar and, next, an unfamiliar adult experimenter, who both introduced various topics. Autistic and neurotypical children exhibited comparable attention to their partners' eyes. Notably, across all groups, heightened visual attention was directed to familiar rather than unfamiliar partners. Moreover, parallel arousal patterns emerged, with all children displaying increased skin conductance responses during more engaging topics and when looking at their interactional partner's eyes. These findings underscore the task- and context-dependent nature of social attention and highlight the role of familiarity in an ecologically valid context. The absence of group differences challenges the universality of the social cognitive developmental theory and questions the scope of the social motivation theory of autism. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Social cues influence perception of others' pain.

Accurately perceiving other people's pain is important in both daily life and healthcare settings. However, judging other's pain is inherently difficult and can be biased by various social and cultural factors. Here, we examined whether perception of others' pain and pain management recommendations are socially influenced by seeing the opinions of other raters. In Experiment 1 (N = 50), participants rated pictures depicting injured hands or feet of pre-selected high, medium and low intensities. Each picture was preceded by cues indicating ratings of 10 previous participants. Cues were randomized to indicate low (SocialLOW) or high (SocialHIGH) pain judgements and were not predictive of actual normative pain intensity. In Experiment 2 (N = 209), participants viewed facial video clips of patients with chronic shoulder pain making painful movements. They estimated patients' pain intensity and provided pain management recommendations. Experiment 1 revealed that perceivers' pain estimates were significantly and substantially higher for stimuli following SocialHIGH than SocialLOW cues (Cohen's d = 1.26, p < 0.001) and paralleled by increased skin conductance responses. Experiment 2 replicated the effect of social cues on pain judgements (d = 0.58, p < 0.001). However, social cues did not influence post-study pain management recommendations, potentially due to memory limitations. Together, these studies reveal that judgements of others' pain are robustly modulated by information about others' opinions. Future research could test the prevalence and strength of such effects in clinical settings. The present study shows that even arbitrary opinions of other raters influence the perception of others' pain. This finding adds new insight into the growing evidence of social and cultural biases in pain estimation.

Personalized virtual reality exposure for panic disorder and agoraphobia: A preliminary neurophysiological study

BackgroundPersonalization is considered an important principle in virtual reality (VR) exposure therapy. We aimed to identify whether personalized VR exposure could provoke increased anxiety in patients with panic disorder and agoraphobia as it is considered the first step in successful treatment for anxiety. MethodsWe performed a double-arm, one-day preliminary study among 28 patients with panic disorder and agoraphobia. Three sessions of VR exposure, including a theater, train, and elevator scenario, were conducted in two groups. In the personalized group (n = 14), the brightness and crowd density were customized based on a pre-assessment. In the control group (n = 14), these conditions were fully randomized. Self-reported anxiety, heart rate, skin conductance, and electroencephalography were measured before, during, and after the VR sessions. ResultsIn the later VR sessions, higher self-reported anxiety levels measured by the Visual Analogue Scale were observed in the personalized exposure group. Increased heart rates during and after the VR sessions were observed in the personalized group. The changes in skin conductance peaks were not significantly different between the groups, but the increase in skin conductance was associated with the participants' perception of presence. The electroencephalogram showed widespread increases in alpha waves in the frontal and temporal areas of the brain in the personalized group than in the control group. ConclusionPersonalized VR exposure elicits stronger anxiogenic effects in patients with panic disorder and agoraphobia as suggested by self-report and neurophysiological data. Personalization of VR exposure has the potential for effective behavioral therapy.

Analysing the effect of non-acoustical parameters on physiological response due to traffic noise exposure

Traffic noise, as an environmental stressor, impacts both auditory and non-auditory human health through a combination of acoustical and non-acoustical parameters. This study investigates the effects of sex, noise sensitivity, and cross-cultural differences on physiological stress responses to traffic noise exposure. A psychophysiological listening experiment was conducted with 60 participants from the United Kingdom and India to analyze the variation in physiological responses to the noise stimuli. The findings reveal significant gender differences in psychophysiological responses, with females exhibiting higher physiological arousal and potentially experiencing greater stress levels at moderate loudness levels compared to males. Moreover, individuals with high noise sensitivity displayed heightened stress levels and physiological arousal. Additionally, British participants exhibited higher physiological arousal, as indicated by increased skin conductance response parameters, compared to the Indian group. This suggests that exposure to Indian traffic noise, characterized by louder sounds and increased honking, leads to heightened stress levels among British participants. In conclusion, these findings contribute to our understanding of the relationship between traffic noise and physiological outcomes, shedding light on the influence of non-acoustical parameters. It also underscore the potential health implications of chronic noise exposure on human health.

Neural correlates of immediate versus delayed extinction when simultaneously varying the time of the test in humans.

Anxiety disorders are effectively treated with exposure therapy based on the extinction of Pavlovian fear conditioning. Animal research indicates that both the timing of extinction and test are important factors to reduce the return of fear. However, empirical evidence in humans is incomplete and inconsistent. In this neuroimaging study, we, therefore, tested 103 young, healthy participants in a 2-factorial between-subjects design with the factors extinction group (immediate, delayed) and test group (+1day and +7days). Immediate extinction led to greater retention of fear memory at the beginning of extinction training indicated by increased skin conductance responses. A return of fear was observed in both extinction groups, with a trend toward a greater return of fear in immediate extinction. The return of fear was generally higher in groups with an early test. Neuroimaging results show successful cross-group fear acquisition and retention, as well as activation of the left nucleus accumbens during extinction training. Importantly, the delayed extinction group showed a larger bilateral nucleus accumbens activation during test. This nucleus accumbens finding is discussed in terms of salience, contingency, relief, and prediction error processing. It may imply that the delayed extinction group benefits more from the test as a new learning opportunity.

Multidimensional components of (state) mathematics anxiety: Behavioral, cognitive, emotional, and psychophysiological consequences.

The present study aimed to analyze the different components of state mathematics anxiety that students experienced while solving calculation problems by manipulating their stress levels. A computerized mathematical task was administered to 165 fifth-graders randomly assigned to three different groups: positive, negative, and control conditions, in which positive, negative, or no feedback during the task was given, respectively. Behavioral (task performance), emotional (negative feelings), cognitive (worrisome thoughts and perceived competence), and psychophysiological responses (skin conductance and vagal withdrawal) were analyzed. Behavioral responses did not differ in the positive and negative conditions, while the latter was associated with children's reportedly negative emotional states, worries, and perceived lack of competence. The stress induced in the negative condition led to an increase in skin conductance and cardiac vagal withdrawal in children. Our data suggest the importance of considering students' interpretation of mathematics-related experiences, which might affect their emotional, cognitive, and psychophysiological responses.

Do emotions evoked by music modulate visuospatial working memory capacity? A physiological study

Previous studies have shown that emotions evoked through music can have transient effects on cognitive performance. Considering the importance of working memory (WM) in the processing of new information, in this study, we investigated the impact of positive and negative emotions evoked through music on visuospatial WM performance using a within-subjects design. Moreover, we concomitantly recorded the participants’ physiological responses during listening to musical stimuli. Seventy-eight participants were allocated to counterbalanced positive, negative, and neutral emotional inductions through music (EIM) followed by an adaptive visuospatial WM task. Results revealed that participants’ visuospatial WM performance was increased after positive EIM compared with negative and neutral EIMs transiently. We also observed increased skin conductance levels during positive EIM compared with baseline and a lower heart rate throughout positive EIM than the other conditions. Overall, these findings suggest that music evoking positive emotions can boost visuospatial WM performance. This is the first study to explore cognitive performance after EIM and physiological responses to musical stimuli simultaneously, which may have important practical implications since we engage in cognitively demanding activities after listening to music that could evoke happy or sad emotions.

The causal role of affect sharing in driving vicarious fear learning.

Vicarious learning, i.e. learning through observing others rather than through one's own experiences, is an integral skill of social species. The aim of this study was to assess the causal role of affect sharing, an important aspect of empathy, in vicarious fear learning. N = 39 participants completed a vicarious Pavlovian fear conditioning paradigm. In the learning stage, they watched another person-the demonstrator-responding with distress when receiving electric shocks to a color cue (conditioned stimulus; CS+; a different color served as CS-). In the subsequent test stage, an increased skin conductance response (SCR) to the CS+ presented in the absence of the demonstrator indexed vicarious fear learning. Each participant completed this paradigm under two different hypnotic suggestions, which were administered to induce high or low affect sharing with the demonstrator in the learning stage, following a counterbalanced within-subject design. In the learning stage, high affect sharing resulted in stronger unconditioned SCR, increased eye gaze toward the demonstrator's face, and higher self-reported unpleasantness while witnessing the demonstrator's distress. In the test stage, participants showed a stronger conditioned fear response (SCR) when they had learned under high, compared to low, affect sharing. In contrast, participants' declarative memory of how many shocks the demonstrator had received with each cue was not influenced by the affect sharing manipulation. These findings demonstrate that affect sharing is involved in enhancing vicarious fear learning, and thus advance our understanding of the role of empathy, and more generally emotion, in social observational learning.

Immediate Effects of Dry Needling on Central Pain Processing and Skin Conductance in Patients with Chronic Nonspecific Neck Pain: A Randomized Controlled Trial.

Although current evidence supports the use of dry needling for improving some clinical outcomes in people with neck pain, no previous research explored the effects of dry needling on the central processing of pain and autonomic nervous system in this population. Therefore, this clinical trial aimed to compare the effects of real and sham dry needling on autonomic nervous system function, pain processing as well as clinical and psychological variables in patients with chronic nonspecific neck pain. A double-blinded randomized clinical trial including 60 patients with neck pain was conducted. Patients were randomized to the real needling (n = 30) or sham needling (n = 30) group. Skin conductance (SC), pressure pain thresholds (PPTs), temporal summation (TS), conditioned pain modulation (CPM) as well as pain intensity, related-disability, catastrophism, and kinesiophobia levels were assessed by an assessor blinded to the allocation intervention. The results did not find significant group * time interactions for most outcomes, except for the global percentage of change of SC values (mean: F = 35.90, p &lt; 0.001, ηp2 = 0.459; minimum: F = 33.99, p = 0.839, ηp2 = 0.371; maximum: F = 24.71, p &lt; 0.001, ηp2 = 0.037) and PPTs at C5-C6 joint in the same side of needling (F = 9.982; p = 0.003; = 0.147), in favor of the dry needling group. Although the proportion of subjects experiencing moderate to large self-perceived improvement after the intervention was significantly higher (X2 = 8.297; p = 0.004) within the dry needling group (n = 18, 60%) than in the sham needling group (n = 7, 23.3%), both groups experienced similar improvements in clinical and psychological variables. Our results suggested that dry needling applied to patients with chronic nonspecific neck pain produced an immediate decrease in mechanical hyperalgesia at local sites and produced an increase in skin conductance as compared with sham needling. No changes in central pain processing were observed. A single session of sham or real dry needling was similarly effective for decreasing related disability, pain intensity, catastrophism, and kinesiophobia levels. Further studies are needed to better understand the clinical implications of autonomic nervous system activation on central sensitization and pain processing in the long-term after the application of dry needling.

Guided reactivation of personal phobic memories prior to exposure exercises prevents the renewal of fear responses in subjects with claustrophobic fears

Background and objectivesBasic research suggest behavioral strategies for interferencing the reconsolidation of fear memories to be a promising approach in reducing clinical fears. However, first clinical studies revealed mixed results highlighting the need to identify boundary conditions. We experimentally tested the specific hypothesis that post-retrieval threat exposure prevents context renewal usually observed in protocols without fear memory reactivation. MethodsIn a preliminary investigation forty-three individuals with claustrophobic fears reactivated the individual phobic memory or not during a guided emotional imagery task and then performed standardized threat exposure to provide new information for updating the original memory. During retests seven and 28 days later, the context was different from that during treatment in half of the subjects. ResultsIn those who were guided, the fear memory was successfully reactivated as indexed by increased skin conductance level (SCL) during the imagery of personal scenes relative to neutral scenes. During retests the subjects of the memory non-activation group showed a return of reported fear after context change that, however, was not observed after post-retrieval exposure. In line, autonomic arousal (SCL) decreased over time in the memory reactivation group only if the context changed during retest. LimitationsLimited sample size and the inclusion of an analog sample reduce the generalizability of the results. ConclusionsThe reactivation of fear memory prior to treatment through guided imagery of past personal phobic situations prevented contextual renewal of phobic fears which was observed in those subjects without reactivation of memory.

Depressive rumination and heart rate variability: A pilot study on the effect of biofeedback on rumination and its physiological concomitants.

ObjectiveRecent studies suggest that lower resting heart rate variability (HRV) is associated with elevated vulnerability to depressive rumination. In this study, we tested whether increases in HRV after HRV-biofeedback training are accompanied by reductions in rumination levels.Materials and methodsSixteen patients suffering from depression completed a 6-week HRV-biofeedback training and fourteen patients completed a control condition in which there was no intervention (waitlist). The training included five sessions per week at home using a smartphone application and an ECG belt. Depressive symptoms and autonomic function at rest and during induced rumination were assessed before and after each of the two conditions. We used a well-established rumination induction task to provoke a state of pervasive rumination while recording various physiological signals simultaneously. Changes in HRV, respiration rate, skin conductance, and pupil diameter were compared between conditions and time points.ResultsA significant correlation was found between resting HRV and rumination levels, both assessed at the first laboratory session (r = -0.43, p < 0.05). Induction of rumination led to an acceleration of heart rate and skin conductance increases. After biofeedback training, resting vagal HRV was increased (p < 0.01) and self-ratings of state anxiety (p < 0.05), rumination (p < 0.05), perceived stress (p < 0.05), and depressive symptoms (QIDS, BDI; both p < 0.05) were decreased. In the control condition, there were no changes in autonomic indices or depressive symptomatology. A significant interaction effect group x time on HRV was observed.ConclusionOur results indicate that a smartphone-based HRV-biofeedback intervention can be applied to improve cardiovagal function and to reduce depressive symptoms including self-rated rumination tendencies.

Decision-making in uncertain contexts: The role of autonomic markers in resolving indecision

Although impulsivity is associated with an increased willingness to make risky decisions, uncertainty intolerance may also contribute to maladaptive decision-making behavior, where individuals neglect to pursue potential rewards even when probabilities for success are in their favor. Several theories have sought to explain the neural systems that guide decision-making in this context, with evidence supporting a role for increased sympathetic activation. However, it remains unclear whether the sympathetic system is associated with greater apprehension in response to uncertain outcomes, or whether it serves to guide behavioral decisions in the context of this uncertainty. Furthermore, although postulated as a within-person process, most research has examined the association between decision behavior and sympathetic activation at the between-person level. We hypothesize that in the context of uncertainty between-person differences in skin conductance will be associated with longer deliberation times; whereas within-person trial-level increases in skin conductance will be associated with a tendency to reject uncertain options. Data were collected from n = 56 children aged 7–11 years, using a computerized card game in which children chose to accept or reject cards of varying point value at varying levels of probability. Skin conductance level (SCL) was recorded throughout the task. No significant between-person associations emerged. However, within-person analyses indicated that momentary deliberation time moderated the association between momentary skin-conductance and decision outcome. This moderation was such that for trials during which the individual deliberated longer (i.e., was more indecisive), a concurrent increase in skin conductance was associated with a significantly higher likelihood of rejecting the card. The within-person nature of these results suggests that skin conductance may help in resolving indecision in the context of uncertainty.

Centralized gaze as an adaptive component of defensive states in humans.

Adequate defensive responding is crucial for mental health but scientifically not well understood. Specifically, it seems difficult to dissociate defense and approach states based on autonomic response patterns. We thus explored the robustness and threat-specificity of recently described oculomotor dynamics upon threat in anticipation of either threatening or rewarding stimuli in humans. While visually exploring naturalistic images, participants (50 per experiment) expected an inevitable, no, or avoidable shock (Experiment 1) or a guaranteed, no, or achievable reward (Experiment 2) that could be averted or gained by a quick behavioural response. We observed reduced heart rate (bradycardia), increased skin conductance, pupil dilation and globally centralized gaze when shocks were inevitable but, more pronouncedly, when they were avoidable. Reward trials were not associated with globally narrowed visual exploration, but autonomic responses resembled characteristics of the threat condition. While bradycardia and concomitant sympathetic activation reflect not only threat-related but also action-preparatory states independent of valence, global centralization of gaze seems a robust phenomenon during the anticipation of avoidable threat. Thus, instead of relying on single readouts, translational research in animals and humans should consider the multi-dimensionality of states in aversive and rewarding contexts, especially when investigating ambivalent, conflicting situations.

Carrying a passenger and relaxation before driving: Classification of young drivers' physiological activation.

Drivers are often held responsible for road crashes. Previous research has shown that stressors such as carrying passengers in the vehicle can be a source of accidents for young drivers. To mitigate this problem, this study investigated whether the presence of a passenger behind the wheel can be predicted using machine learning, based on physiological signals. It also addresses the question whether relaxation before driving can positively influence the driver's state and help controlling the potential negative consequences of stressors. Sixty young participants completed a 10‐min driving simulator session, either alone or with a passenger. Before their driving session, participants spent 10 min relaxing or listening to an audiobook. Physiological signals were recorded throughout the experiment. Results show that drivers experience a higher increase in skin conductance when driving with a passenger, which can be predicted with 90%‐accuracy by a k‐nearest neighbors classifier. This might be a possible explanation for increased risk taking in this age group. Besides, the practice of relaxation can be predicted with 80% accuracy using a neural network. According to the statistical analysis, the potential beneficial effect of relaxation did not carry out on the driver's physiological state while driving, although machine learning techniques revealed that participants who exercised relaxation before driving could be recognized with 70% accuracy. Analysis of physiological characteristics after classification revealed several relevant physiological indicators associated with the presence of a passenger and relaxation.