Is a knife the same as a plunger? Comparing the attentional effects of weapons and non-threatening unusual objects in dynamic scenes.

Observers' memory for a person's appearance can be compromised by the presence of a weapon, a phenomenon known as the weapon-focus effect (WFE). According to the unusual-item hypothesis, attention shifts from the perpetrator to the weapon because a weapon is an unusual object in many contexts. To test this assumption, we monitored participants' eye movements while they watched a mock-crime video. The video was presented with sound and featured a female perpetrator holding either a weapon, a non-threatening unusual object, or a neutral object. Contrary to the predictions of current theories, there were no significant differences in total viewing times for the three objects. For the perpetrator, total viewing time was reduced when she held the non-threatening unusual object, but not when she held the weapon. However, weapon presence led to an attentional shift from the perpetrator's face toward her body. Detailed time-course analyses revealed that the effects of object type were more pronounced during early scene viewing. Thus, our results do not support the idea of extended attentional shifts from the perpetrator toward the unusual objects, but instead suggest more complex attentional effects. Contrary to previous research, memory for the perpetrator's appearance was not affected by object type. Thus, there was no WFE. An additional online experiment using the same videos and methodology produced a WFE, but this effect disappeared when the videos were presented without sound.

Secondary capture: Salience information persistently drives attentional selection.

It is well known that attention is captured by salient objects or events. The notion that attention is attracted by salience information present in the visual field is also at the heart of many influential models of attention. These models typically posit a hierarchy of saliency, suggesting that attention progresses from the most to the least salient item in the visual field. However, despite the significance of this claim in various models, research on eye movements challenges the idea that search strictly follows this saliency hierarchy. Instead, eye-tracking studies have suggested that saliency information has a transient impact, only influencing the initial saccade toward the most salient object, and only if executed swiftly after display onset. While these findings on overt eye movements are important, they do not address covert attentional processes occurring before a saccade is initiated. In the current series of experiments, we explored whether there was evidence for secondary capture-whether attention could be captured by another salient item after the initial capture episode. To explore this, we utilized displays with multiple distractors of varying levels of saliency. Our primary question was whether two distractors with different saliency levels would disrupt search more than a single, highly salient distractor. Across three experiments, clear evidence emerged indicating that two distractors interfered more with search than a single salient distractor. This observation suggests that following initial capture, secondary capture by the next most salient distractor occurred. These findings collectively support the idea that covert attention traverses the saliency hierarchy. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Column setting and text justification influence return-sweep eye movement behavior during Chinese multi-line reading.

People regularly read multi-line texts in different formats and publishers, internationally, must decide how to present text to make reading most effective and efficient. Relatively few studies have examined multi-line reading, and fewer still Chinese multi-line reading. Here, we examined whether texts presented in single or double columns, and either left-justified or fully-justified affect Chinese reading. Text format had minimal influence on overall reading time; however, it significantly impacted return-sweeps (large saccades moving the eyes from the end of one line of text to the beginning of the next). Return-sweeps were launched and landed further away from margins and involved more corrective saccades in single- than double-column format. For left- compared to fully-justified format, return-sweeps were launched and landed closer to margins. More corrective saccades also occurred. Our results showed more efficient return-sweep behavior for fully- than left-justified text. Moreover, there were clear trade-off effects such that formats requiring increased numbers of shorter return-sweeps produced more accurate targeting and reduced numbers of corrective fixations, whereas formats requiring reduced numbers of longer return-sweeps caused less accurate targeting and an increased rate of corrective fixations. Overall, our results demonstrate that text formats substantially affect return-sweep eye movement behavior during Chinese reading without affecting efficiency and effectiveness, that is, the overall time it takes to read and understand the text.

Why are some individuals better at using negative attentional templates to suppress distractors? Exploration of interindividual differences in cognitive control efficiency.

Negative templates are based on foreknowledge of distractor features and can lead to more efficient visual search at the group level. However, large individual differences exist in the size of benefits induced by negative cues. The cognitive factors underlying these interindividual differences remain unknown. Previous research has suggested higher engagement of proactive control for negative templates compared to positive templates. We thus hypothesized that interindividual differences in proactive control efficiency may explain the large variability in negative cue benefits. A large data set made up of data from two previously published studies was reanalyzed (N = 139), with eye movements recorded in 36 participants. Individual proactive control efficiency was measured through reaction time (RT) variability. Participants with higher proactive control efficiency exhibited larger benefits after negative cues across two critical measures: Individuals with higher proactive control showed larger RT benefits following negative compared to neutral cues; similarly, individuals with higher proactive control exhibited lower first saccades to cued distractor items. No such relationship was observed for positive cues. Our results confirmed the existence of large interindividual differences in the benefits induced by negative attentional templates. Critically, we show that proactive control drives these interindividual differences in negative template use. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Tablet-Based Cognitive and Eye Movement Measures as Accessible Tools for Schizophrenia Assessment: Multisite Usability Study.

BACKGROUND: Schizophrenia is a complex mental disorder characterized by significant cognitive and neurobiological alterations. Impairments in cognitive function and eye movement have been known to be promising biomarkers for schizophrenia. However, cognitive assessment methods require specialized expertise. To date, data on simplified measurement tools for assessing both cognitive function and eye movement in patients with schizophrenia are lacking. OBJECTIVE: This study aims to assess the efficacy of a novel tablet-based platform combining cognitive and eye movement measures for classifying schizophrenia. METHODS: Forty-four patients with schizophrenia, 67 healthy controls, and 41 patients with other psychiatric diagnoses participated in this study from 10 sites across Japan. A free-viewing eye movement task and 2 cognitive assessment tools (Codebreaker task from the THINC-integrated tool and the CognitiveFunctionTest app) were used for conducting assessments in a 12.9-inch iPad Pro. We performed comparative group and logistic regression analyses for evaluating the diagnostic efficacy of the 3 measures of interest. RESULTS: Cognitive and eye movement measures differed significantly between patients with schizophrenia and healthy controls (all 3 measures; P<.001). The Codebreaker task showed the highest classification effectiveness in distinguishing schizophrenia with an area under the receiver operating characteristic curve of 0.90. Combining cognitive and eye movement measures further improved accuracy with a maximum area under the receiver operating characteristic curve of 0.94. Cognitive measures were more effective in differentiating patients with schizophrenia from healthy controls, whereas eye movement measures better differentiated schizophrenia from other psychiatric conditions. CONCLUSIONS: This multisite study demonstrates the feasibility and effectiveness of a tablet-based app for assessing cognitive functioning and eye movements in patients with schizophrenia. Our results suggest the potential of tablet-based assessments of cognitive function and eye movement as simple and accessible evaluation tools, which may be useful for future clinical implementation.

A chinrest-based approach to measure eye movements and experimental task engagement in macaques with minimal restraint.

BACKGROUND: The use of Rhesus macaques in vision research is crucial due to their visual system's similarity to humans. While invasive techniques have been the norm, there has been a shift towards non-invasive methods, such as facemasks and head molds, to enhance animal welfare and address ethical concerns. NEW METHOD: We present a non-invasive, 3D-printed chinrest with infrared sensors, adapted from canine research, allowing for accurate eye movement measurements and voluntary animal participation in experiments. RESULTS: The chinrest method showed a 16% and 28% increase in average trial numbers for Monkey 1 and Monkey 2, respectively, compared to the traditional headpost method. The engagement was high, with monkeys performing over 500 trials per session and initiating a new trial after an average intertrial interval of approximately 1 second. The hit rate improved by about 10% for Monkey 1 in the chinrest condition, and the fixation precision, measured by the standard deviation of gaze positions, was significantly better in the chinrest condition, with Monkey 1 showing a reduction in fixation imprecision from 0.26° to 0.17° in the X-axis. COMPARISON WITH EXISTING METHODS: The chinrest approach showed significant improvements in trial engagement and reduction in aborted trials due to fixation breaks, indicating less stress and potentially improved data quality compared to previous non-invasive methods. CONCLUSIONS: The chinrest method offers a significant advancement in primate cognitive testing by allowing for precise data collection while addressing animal welfare concerns, possibly leading to better scientific outcomes and a paradigm shift in primate research methodologies.

Reading proficiency predicts spatial eye-movement control in the first and second language.

Research on first language (L1) reading has long since established the link between the proficiency of the reader and their efficiency in oculomotor control. More proficient readers make longer saccades and land closer to the word's center, which is a word's optimal viewing position, and make fewer refixations. Eye-tracking studies of second language (L2) reading have so far provided little evidence in this regard. This study analyzes spatial oculomotor measures in the Multilingual Eye-movement Corpus, which contains data on English text reading and its component skills from 543 participants representing 12 different L1s. Our analyses establish a strong role of proficiency in English, both for L1 and L2 readers of English. While most effects replicated ones observed in L1 reading, we also found that more proficient readers of English were less accurate in targeting optimal viewing positions. We link this finding to Fitts' law of motor control for aimed movements. This article discusses the theoretical implications of the novel findings for reading research. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Eyes meet, hands greet: The art of timing in social interactions.

Shaking hands is a fundamental form of social interaction. The current study used high-definition cameras during a university graduation ceremony to examine the temporal sequencing of eye contact and shaking hands. Analyses revealed that mutual gaze always preceded shaking hands. A follow up investigation manipulated gaze when shaking hands, and found that participants take significantly longer to accept a handshake when an outstretched hand precedes eye contact. These findings demonstrate that the timing between a person's gaze and their offer to shake hands is critical to how their action is interpreted.

Scale for Ocular Motor Disorders in Ataxia (SODA) in Patients with Multiple System Atrophy.

A clinical scale fully dedicated to evaluating ocular motor abnormalities is required for now. We investigated the utility of a recently developed Scale for Ocular motor Disorders in Ataxia (SODA) in patients with multiple system atrophy (MSA). We prospectively assessed SODA in consecutive patients with MSA between August 2021 and August 2023 at the Korea University Medical Center. The results of the clinical exam-based SODA were compared with those measured using video-oculography (VOG-guided SODA). We also compared the findings with other established clinical scales targeting patients with MSA, including the Unified Multiple System Atrophy Rating Scale (UMSARS) I-II, Movement Disorder Society-Unified Parkinson's Disease Rating Scale motor part (UPDRS-III), Scale for Assessment of Rating of Ataxia (SARA), Composite Autonomic Symptom Score-31 (COMPASS-31), and Composite Autonomic Severity Score (CASS). Twenty patients were enrolled in our study (17 with cerebellar-type MSA and three with Parkinson-type MSA). Scores ranged from 1 to 14 (median [interquartile range (IQR)] = 8 [5-10]). Among the subscales, saccades had a median score of 2.5 (IQR = 1-3), followed by ocular pursuit (1 [0-1]), nystagmus (1 [0-2]), saccadic intrusions (1 [0-1]), vestibulo-ocular reflex (VOR) (0.5 [0-1]), ocular alignment (0 [0-1]), and VOR cancellation (1 [0-1]). The clinical-exam-based SODA (p = 0.020) and VOG-guided SODA (p = 0.034) positively correlated with disease duration. No correlation was found between clinical exam-based SODA and other scales. Skew deviation, gaze-evoked nystagmus, VOR cancellation, and smooth pursuit had the highest precision among the items. Ocular misalignment and spontaneous and positional nystagmus were frequently false positive and were poorly detected with clinical exam-based SODA. Six patients with repeated evaluation exhibited higher scores, along with deterioration documented on other clinical scales. The SODA can reliably predict neurodegeneration as an additional clinical surrogate in MSA.

Impact of strabismus and binocular dysfunctions in the developmental eye movement test and test of visual perception skills: A multicentric and retrospective study

Purpose: To compare the performance in the Developmental Eye Movement test (DEM) and the Test of Visual Perceptual Skills (TVPS) between three groups: individuals with strabismus and amblyopia, patients with binocular and accommodative dysfunctions, and subjects with normal binocular and accommodative function. Methods: A multicentric, retrospective study including 110 children aged 6–14 years old was conducted to investigate the potential impact of strabismus, amblyopia, and different binocular conditions in DEM results (adjusted time in vertical and horizontal parts) and TVPS (percentiles in the seven sub-skills). Results: No significant differences were found in the different subtests of the vertical and horizontal DEM and all the sub-skills in the TVPS between the three groups of the study. We found high variability of performance in the DEM test between participants with strabismus and amblyopia compared with binocular and accommodative problems. Conclusion: DEM and TVPS scores have not been found to be influenced by the presence of strabismus with or without amblyopia, nor by binocular and accommodative dysfunctions. A slightly correlation tendency with horizontal DEM and degree of exotropia deviation was observed. (AU)

Vertical dynamic visual acuity is significantly lower than horizontal dynamic visual acuity.

Dynamic visual acuity (DVA) is crucial for the perception of moving objects. While traditional DVA assessment tools predominantly focus on horizontal movements, the evaluation of vertical DVA remains unstandardized. Consequently, the disparities between vertical and horizontal DVAs are yet to be thoroughly investigated. Therefore, we designed a system capable of conducting multidirectional DVA tests and eye movement measurements. During the experiments, the participants identified the gap direction of the Landolt-C ring moving either horizontally or vertically. The speed of movement decelerated from its maximum as a high-speed infrared camera captured the pupil movements of the left eye at 500 fps. We conducted tests on 15 healthy university students (aged [Formula: see text] years) and measured vertical and horizontal DVAs five times each. DVA was deduced from the Landolt-C ring speed with accurate gap direction responses, and eye movement was assessed based on the total gaze movement distance. The results revealed superior DVA and eye movement in the horizontal direction compared with the vertical direction ([Formula: see text]). This highlights the anisotropic characteristics of DVA and eye movement. The proposed system has the potential for multidirectional dynamic vision evaluation and training in clinical scenarios.

Are eye movements and EEG on the same page?: A coregistration study on parafoveal preview and lexical frequency.

Readers extract visual and linguistic information not only from fixated words but also upcoming parafoveal words to introduce new input efficiently into the language processing pipeline. The lexical frequency of upcoming words and similarity with subsequent foveal information both influence the amount of time people spend once they fixate the word foveally. However, it is unclear from eye movements alone the extent to which parafoveal word processing, and the integration of that word with foveally obtained information, continues after saccade plans have been initiated. To investigate the underlying neural processes involved in word recognition after saccade planning, we coregistered electroencephalogram (EEG) and eye movements during a gaze-contingent display change paradigm. We orthogonally manipulated the frequency of the parafoveal and foveal words and measured fixation related potentials (FRPs) upon foveal fixation. Eye movements showed primarily an effect of preview frequency, suggesting that saccade planning is based on the familiarity of the parafoveal input. FRPs, on the other hand, demonstrated a disruption in downstream processing when parafoveal and foveal input differed, but only when the parafoveal word was high frequency. These findings demonstrate that lexical processing continues after the eyes have moved away from a word and that eye movements and FRPs provide distinct but complementary accounts about oculomotor behavior and neural processing that cannot be obtained from either method in isolation. Furthermore, these findings put constraints on models of reading by suggesting that lexical processes that occur before an eye movement program is initiated are qualitatively different from those that occur afterward. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Do the eyes have it? A comparison of eye-movement and attentional-probe-based approaches to indexing attentional control within the antisaccade paradigm.

Individual differences in the ability to control visual attention, often termed "attentional control," have been of particular interest to cognitive researchers. This has led to the development of numerous tasks intended to measure attentional control, including the antisaccade task. While attentional performance on the antisaccade task is typically indexed through the recording of eye movements, increasingly researchers are reporting the use of probe-based methods of indexing attentional performance on the task. Critically, no research has yet determined the convergence of measures yielded by each of these assessment methods, nor compared the reliability of these measures. The purpose of the present study was to examine whether antisaccade cost measures yielded by a probe-based adaptation of the task converge with antisaccade cost measures yielded by an eye movement task in the sample of individuals, and whether these alternative approaches have comparable levels of psychometric reliability. Ninety-three individuals completed an eye movement task and a probe-based task at two assessment times, and an index of antisaccade cost was computed from each task at each assessment time. Analyses revealed that the antisaccade cost index yielded by each task demonstrated high internal reliability (eye-movement, rSB = .92; probe-based, rSB = .80-.84) and high test-retest reliability (eye-movement, rSB = .82; probe-based, rSB = .72), but modest measurement convergence (r = .21-.35). Findings suggest that probe-based and eye-movement based antisaccade tasks measure shared variance in attentional control, although their measures do not converge strongly enough to be considered equivalent measures of attentional control.

How robust are wearable eye trackers to slow and fast head and body movements?

How well can modern wearable eye trackers cope with head and body movement? To investigate this question, we asked four participants to stand still, walk, skip, and jump while fixating a static physical target in space. We did this for six different eye trackers. All the eye trackers were capable of recording gaze during the most dynamic episodes (skipping and jumping). The accuracy became worse as movement got wilder. During skipping and jumping, the biggest error was 5.8∘. However, most errors were smaller than 3∘. We discuss the implications of decreased accuracy in the context of different research scenarios.

Effective differentiation between depressed patients and controls using discriminative eye movement features.

BACKGROUND: Depression is a common debilitating mental disorder caused by various factors. Identifying and diagnosing depression are challenging because the clinical evaluation of depression is mainly subjective, lacking objective and quantitative indicators. The present study investigated the value and significance of eye movement measurements in distinguishing depressed patients from controls. METHODS: Ninety-five depressed patients and sixty-nine healthy controls performed three eye movement tests, including fixation stability, free-viewing, and anti-saccade tests, and eleven eye movement indexes were obtained from these tests. The independent t-test was adopted for group comparisons, and multiple logistic regression analysis was employed to identify diagnostic biomarkers. Support vector machine (SVM), quadratic discriminant analysis (QDA), and Bayesian (BYS) algorithms were applied to build the classification models. RESULTS: Depressed patients exhibited eye movement anomalies, characterized by increased saccade amplitude in the fixation stability test; diminished saccade velocity in the anti-saccade test; and reduced saccade amplitude, shorter scan path length, lower saccade velocity, decreased dynamic range of pupil size, and lower pupil size ratio in the free-viewing test. Four features mentioned above entered the logistic regression equation. The classification accuracies of SVM, QDA, and BYS models reached 86.0%, 81.1%, and 83.5%, respectively. CONCLUSIONS: Depressed patients exhibited abnormalities across multiple tests of eye movements, assisting in differentiating depressed patients from healthy controls in a cost-effective and non-invasive manner.

Visual gaze patterns in trainee endoscopists - a novel assessment tool.

BACKGROUND: Colonoscopy proficiency is significantly influenced by skills achieved during training. Although assessment scores exist, they do not evaluate the impact of visual search strategies and their use is time and labour intensive. Eye-tracking has shown significant differences in visual gaze patterns (VGPs) between expert endoscopists with varying polyp detection rates, so may provide a means of automated assessment and guidance for trainees. This study aimed to assess the feasibility of eye-tracking as a novel assessment method for trainee endoscopists. METHODS: Eye-tracking glasses were used to record 26 colonoscopies from 12 endoscopy trainees who were assessed with directly observed procedural scores (DOPS), devised by the Joint Advisory Group (JAG) on GI endoscopy, and a visual analogue score of overall competence. A 'total weighted procedure score' (TWPS) was calculated from 1 to 20. Primary outcomes of fixation duration (FixD) and fixation frequency (FixF) were analysed according to areas of interest (AOIs) with the bowel surface and lumen represented by three concentric rings. Correlation was assessed using Pearson's coefficient. Significance was set at p<.050. RESULTS: Trainees displayed a significant positive correlation between TWPS and FixD (R = 0.943, p<.0001) and FixF (R = 0.936, p<.0001) in the anatomical bowel mucosa peripheries. Conversely, they had significant negative correlations between TWPS and the anatomical bowel lumen (FixD: R= -0.546, p=.004; FixF: R= -0.568, p=.002). CONCLUSIONS: Higher objective performance scores were associated with VGPs focussing on bowel mucosa. This is consistent with prior analysis showing peripheral VGPs correspond with higher polyp detection rates. Analysis of VGPs, therefore, has potential for training and assessment in colonoscopy.

Why do children struggle on analogical reasoning tasks? Considering the role of problem format by measuring visual attention.

Given the importance of analogical reasoning to bootstrapping children's understanding of the world, why is this ability so challenging for children? Two common sources of error have been implicated: 1) children's inability to prioritize relational information during initial problem solving; 2) children's inability to disengage from salient distractors. Here, we use eye tracking to examine children and adults' looking patterns when solving scene analogies, finding that children and adults attended differently to distractors, and that this attention predicted performance. These results provide the most direct evidence to date that feature based distraction is an important way children and adults differ during early analogical reasoning. In contrast to recent work using propositional analogies, we find no differences in children and adults' prioritization of relational information during problem solving, and while there are some differences in general attentional strategies across age groups, neither prioritization of relational information nor attentional strategy predict successful problem solving. Together, our results suggest that analogy problem format should be taken into account when considering developmental factors in children's analogical reasoning.

Sensory processing sensitivity predicts performance in an emotional antisaccade paradigm.

Sensory Processing Sensitivity (SPS) is a common, heritable, and evolutionarily conserved trait, describing inter-individual differences in responsiveness and a more cautious approach to novel stimuli. It is associated with increased activation of brain regions involved in awareness, integration of sensory information, and empathy during processing of emotional faces. Furthermore, SPS is related to better performance in a visual detection task. Even though SPS is conceptualized to be closely related to traits characterized by pausing before acting, no study to date has assessed the relation between SPS and inhibitory control in a behavioral inhibition task. The present study fills this gap by investigating how SPS influences individual performance on two different antisaccade paradigms including emotional face stimuli. In addition, we assessed self-reported mood, anxiety, and depressiveness. Results showed that SPS was related to faster processing speed on the emotional, but not the classic antisaccade paradigm. Moreover, SPS predicted inhibitory control speed above mood and depressiveness. Our results provide evidence that higher SPS participants show superior inhibitory abilities, especially during the processing of emotional stimuli. This is in line with earlier findings showing better performance in a visual detection task as well as increased brain activation during emotional face processing.

Gaze-angle dependency of pupil-size measurements in head-mounted eye tracking.

Pupillometry - the study of temporal changes in pupil diameter as a function of external light stimuli or cognitive processing - requires the accurate and gaze-angle independent measurement of pupil dilation. Expected response amplitudes often are only a few percent relative to a pre-stimulus baseline, thus demanding for sub-millimeter accuracy. Video-based approaches to pupil-size measurement aim at inferring pupil dilation from eye images alone. Eyeball rotation in relation to the recording camera as well as optical effects due to refraction at corneal interfaces can, however, induce so-called pupil foreshortening errors (PFE), i.e. systematic gaze-angle dependent changes of apparent pupil size that are on a par with typical response amplitudes. While PFE and options for its correction have been discussed for remote eye trackers, for head-mounted eye trackers such an assessment is still lacking. In this work, we therefore gauge the extent of PFE in three measurement techniques, all based on eye images recorded with a single near-eye camera. We present both real world experimental data as well as results obtained on synthetically generated eye images. We discuss PFE effects at three different levels of data aggregation: the sample, subject, and population level. In particular, we show that a recently proposed refraction-aware approach employing a mathematical 3D eye model is successful in providing pupil-size measurements which are gaze-angle independent at the population level.

Peritraumatic dissociation revisited: associations with autonomic activation, facial movements, staring, and intrusion formation.

Background: Peritraumatic dissociation is purported to emerge together with attenuated autonomic arousal, immobility, and staring. However, empirical evidence is scarce and heterogeneous. Moreover, it is still a matter of debate whether these responses predict intrusion formation. Objective: The present trauma-analogue study examined associations between peritraumatic dissociation, autonomic activation, facial movements, staring, and intrusion formation. Method: Seventy-one healthy women watched a highly aversive film, while autonomic activation (heart rate, respiratory sinus arrhythmia, skin conductance level), facial movements (temporal variations in corrugator electromyography), and staring (fixation duration, tracklength) were assessed. Afterwards, participants rated the intensity of dissociation during film viewing and reported intrusions and associated distress in a smartphone application for 24 hours. Results: Peritraumatic dissociation was linked to higher autonomic arousal (higher heart rate and, on a trend-level, lower respiratory sinus arrhythmia), increased facial movements, and staring (lower tracklength). Peritraumatic dissociation, higher autonomic arousal (higher heart rate and lower respiratory sinus arrhythmia), staring (higher fixation duration), and, on a trend-level, more facial movements were linked to higher intrusion load (number x distress of intrusions) and together explained 59% of variance. Skin conductance level was neither linked to peritraumatic dissociation nor intrusion load. Conclusions: Our results suggest that, at low-dissociation-levels observed in trauma-analogue studies, peritraumatic dissociation may occur together with heightened autonomic arousal and facial movements, indexing increased negative affect. Staring might, irrespectively of dissociation-levels, serve as objective marker for dissociation. Together, peritraumatic dissociation and its psychophysiological correlates might set the stage for later intrusion formation.

Antecedentes: Se supone que la disociación peritraumática surge junto con la activación autonómica atenuada, la inmovilidad y la mirada fija. Sin embargo, la evidencia empírica es escasa y heterogénea. Además, sigue siendo objeto de debate si estas respuestas predicen la formación de intrusiones.Objetivo: El presente estudio análogo al trauma examinó las asociaciones entre la disociación peritraumática, la activación autonómica, los movimientos faciales, la mirada fija y la formación de intrusiones.Método: Setenta y una mujeres sanas vieron una película altamente aversiva mientras se evaluaba la activación autonómica (frecuencia cardíaca, arritmia sinusal respiratoria, nivel de conductancia de la piel), los movimientos faciales (variaciones temporales en la electromiografía del corrugador) y la mirada fija (duración de la fijación, longitud del seguimiento). Posteriormente, las participantes calificaron la intensidad de la disociación durante la visualización de la película e informaron sobre las intrusiones y la angustia asociada en una aplicación para teléfonos inteligentes durante 24 horas.Resultados: La disociación peritraumática se relacionó con una mayor activación autonómica (mayor frecuencia cardíaca y, a nivel de tendencia, menor arritmia sinusal respiratoria), mayores movimientos faciales y mirada fija (menor duración del seguimiento). La disociación peritraumática, la mayor activación autonómica (mayor frecuencia cardíaca y menor arritmia sinusal respiratoria), la mirada fija (mayor duración de la fijación) y, en un nivel de tendencia, más movimientos faciales estaban vinculados a una mayor carga de intrusiones (número x angustia de intrusiones) y juntos explicaban el 59% de la varianza. El nivel de conductancia de la piel no se relacionó con la disociación peritraumática ni con la carga de intrusión.Conclusiones: Nuestros resultados sugieren que, a niveles bajos de disociación observados en estudios de trauma análogos, la disociación peritraumática puede ocurrir junto con una mayor activación autonómica y movimientos faciales, lo que indica un aumento del afecto negativo. La mirada fija, independientemente de los niveles de disociación, podría servir como marcador objetivo de disociación. En conjunto, la disociación peritraumática y sus correlatos psicofisiológicos podrían sentar las bases para la formación posterior de intrusiones.