Perceptions Of Effectiveness Research Articles

“Angry at the Wrong Thing:” Queering Ketamine Assisted Psychotherapy for Clients Experiencing Body Image and Eating Distress

ABSTRACT Unlike classic serotonergic psychedelics, whose psychoactive shifts are recognized as having therapeutic value, ketamine’s perceptual effects are often overshadowed by its rapid antidepressant properties. However, within a ketamine assisted psychotherapeutic (KAP) context, ketamine’s distinct anxiolytic and dissociative features can cocreate a safe setting for client-directed psycho-spiritual exploration, including around body image and feeding disturbances. Eating disorders affect approximately 9% of Americans, and present a significant concern for LGBTQ2SIA+ community. This paper outlines a KAP framework, for further study, that is foundationally queer and grounded in postcolonial and intersectional feminist theories. This paper introduces societal body dysphoria, as a tool for clinicians to recontextualize how unrealistic ideals, identified as a societal distortion rooted in white supremacy, are individually internalized and collectively enforced through self-policing, with the belief that adherence will yield access to power and resources. Within this framework, a case report presents an example of how KAP can facilitate the deconstruction of societal constructs and alleviate distress.

UNVEILING THE SOCIO-CULTURAL IMPACT OF RELIGIOUS TOURISM AT BOUDHANATH STUPA IN KATHMANDU, NEPAL

This study explores the socio-cultural and economic impacts of religious tourism at Boudhanath Stupa, Kathmandu, Nepal, examining their influence on the quality of life and cultural integrity of the local community. It aims to gauge community perceptions and assess the sustainability of tourism practices at this heritage site. Employing a positivist paradigm and a deductive approach, this research used quantitative methods to analyze the socio-cultural, economic, and perceptual effects of religious tourism. Utilizing Cronbach's Alpha, descriptive and Analytical statistical techniques, the study analyzed local community perceptions, providing insights into sustainable tourism practices relevant to religious tourism. Community perceptions, attitudes, and beliefs significantly impact the dynamics and outcomes of religious tourism at Boudhanath Stupa. These findings underscore the complex impacts of religious tourism, including cultural, social, economic, and perceptual dimensions, highlighting the importance of these factors in the planning, management, and promotion of religious tourism at the site.

Pupillometry indexes ocular dominance plasticity

Short-term monocular deprivation in normally sighted adult humans produces a transient shift of ocular dominance, boosting the deprived eye. This effect has been documented with both perceptual tests and through physiological recordings, but no previous study simultaneously measured physiological responses and the perceptual effects of deprivation. Here we propose an integrated experimental paradigm that combines binocular rivalry with pupillometry, to introduce an objective physiological index of ocular dominance plasticity, acquired concurrently with perceptual testing. Ten participants reported the perceptual dynamics of binocular rivalry, while we measured pupil diameter. Stimuli were a white and a black disk, each presented monocularly. Rivalry dynamics and pupil-size traces were compared before and after 2 h of monocular deprivation, achieved by applying a translucent patch over the dominant eye. Consistent with prior research, we observed that monocular deprivation boosts the deprived-eye signal and consequently increases ocular dominance. In line with previous studies, we also observed subtle but systematic modulations of pupil size that tracked alternations between exclusive dominance phases of the black or white disk. Following monocular deprivation, the amplitude of these pupil-size modulations increased, which is consistent with the post-deprivation boost of the deprived eye and the increase of ocular dominance. This provides evidence that deprivation impacts the effective strength of monocular visual stimuli, coherently affecting perceptual reports and the automatic and unconscious regulation of pupil diameter. Our results show that a combined paradigm of binocular rivalry and pupillometry gives new insights into the physiological mechanisms underlying deprivation effects.

“Composite formations” as a Stylistic Device (Based on the Material of D. I. Rubina’s Novel “Maniac Gurevich”)

This article is devoted to the analysis of “composite formations” in the text of D. I. Rubina’s novel “Maniac Gurevich”. “Composite formations” are units that are formally similar to compound names or compound words. However, their structure, semantics and functions are different. They cannot be considered compound words due to their difference from the latter in the internal form of the word, as well as a wide range of linguistic units that become components of such “composites”. In addition to nouns, their components can be adjectives, participles, verbs, adverbs, etc. “Composite formations” are characterized by multicomponence, this is characteristic of those units, the lexical and grammatical content of which are nouns and verbs. The main function of such formations is a stylistic device. In the text of the novel, they help to create a non-linear narrative, to make it the very sequence of pictures from the life of the hero, which the author of the work considers to be the main feature of the composition of the novel. Such constructions are able to convey a situation or event through the prism of the hero’s perception of the actions of objects, their signs, all this merges into a synthesis of sensations and memories in the mind of the character and creates a special perceptual effect for the reader. It is difficult to determine their linguistic status, when analyzing such formations. The problem arises whether the concept of a word is applicable to them, what are the semantic and grammatical characteristics of this linguistic unit.

Perceptual Effects of Walnut Volatiles on the Codling Moth.

The volatile organic compounds (VOCs) of plant hosts allow insect localization through olfactory recognition. In this study, the oviposition behavior of the codling moth was investigated and the VOCs from different walnut organs were extracted and analyzed to systematically study their composition and content differences. The electrophysiological and behavioral responses of the codling moth to walnut VOCs were measured using gas chromatography-electroantennographic detection (GC-EAD) and a four-arm olfactometer to screen the key active contents. The field investigation results indicated that 90.3% of the eggs spawned by the first generation of adult codling moths were adjacent to the walnut fruits. Walnut VOCs are mainly composed of terpenes, aromatics, and alkanes. Twelve VOCs can produce electroantennogenic (EAG) responses in the codling moths. Both adult males and females exhibit concentration dependence, with notable disparities in their EAG response levels. In the olfactory behavioral bioassay, linalool, eucalyptol, and high doses of geranyl acetate showed repellent effects on the codling moths, while myrcene, β-ocimene, nonanal, methyl salicylate, α-farnesene, and heptaldehyde showed the opposite. The relative levels of heptaldehyde, geranyl acetate, nonanal, and methyl salicylate were high in the fruits, which is intimately related to the localization of the walnut fruit by females. These VOCs can influence the oviposition behavior of codling moths but their application in the control of this pest needs to be confirmed and improved through further field experiments.

Concurrent response and action effect representations across the somatomotor cortices during novel task preparation

Instructions allow us to fulfill novel and complex tasks on the first try. This skill has been linked to preparatory brain signals that encode upcoming demands in advance, facilitating novel performance. To deepen insight into these processes, we explored whether instructions pre-activated task-relevant motoric and perceptual neural states. Critically, we addressed whether these representations anticipated activity patterns guiding overt sensorimotor processing, which could reflect that internally simulating novel tasks facilitates the preparation. To do so, we collected functional magnetic resonance imaging data while female and male participants encoded and implemented novel stimulus-response associations. Participants also completed localizer tasks designed to isolate the neural representations of the mappings-relevant motor responses, perceptual consequences, and stimulus categories. Using canonical template tracking, we identified whether and where these sensorimotor representations were pre-activated. We found that response-related templates were encoded in advance in regions linked with action control, entailing not only the instructed responses but also their somatosensory consequences. This result was particularly robust in primary motor and somatosensory cortices. While, following our predictions, we found a systematic decrease in the irrelevant stimulus templates’ representational strength compared to the relevant ones, this difference was due to below-zero estimates linked to the irrelevant category activity patterns. Overall, our findings reflect that instruction processing relies on the sensorimotor cortices to anticipate motoric and kinesthetic representations of prospective action plans, suggesting the engagement of motor imagery during novel task preparation. More generally, they stress that the somatomotor system could participate with higher-level frontoparietal regions during anticipatory task control.

The Not-So-Slight Perceptual Consequences of Slight Hearing Loss in School-Age Children: A Scoping Review.

This study aimed to conduct a scoping review of research exploring the effects of slight hearing loss on auditory and speech perception in children. A comprehensive search conducted in August 2023 identified a total of 402 potential articles sourced from eight prominent bibliographic databases. These articles were subjected to rigorous evaluation for inclusion criteria, specifically focusing on their reporting of speech or auditory perception using psychoacoustic tasks. The selected studies exclusively examined school-age children, encompassing those between 5 and 18 years of age. Following rigorous evaluation, 10 articles meeting these criteria were selected for inclusion in the review. The analysis of included articles consistently shows that even slight hearing loss in school-age children significantly affects their speech and auditory perception. Notably, most of the included articles highlighted a common trend, demonstrating that perceptual deficits originating due to slight hearing loss in children are particularly observable under challenging experimental conditions and/or in cognitively demanding listening tasks. Recent evidence further underscores that the negative impacts of slight hearing loss in school-age children cannot be solely predicted by their pure-tone thresholds alone. However, there is limited evidence concerning the effect of slight hearing loss on the segregation of competing speech, which may be a better representation of listening in the classroom. This scoping review discusses the perceptual consequences of slight hearing loss in school-age children and provides insights into an array of methodological issues associated with studying perceptual skills in school-age children with slight hearing losses, offering guidance for future research endeavors.

Neural oscillations guiding action during effects imagery

Goal-directed acting requires the integration of sensory information but can also be performed without direct sensory input. Examples of this can be found in sports and can be conceptualized by feedforward processes. There is, however, still a lack of understanding of the temporal neural dynamics and neuroanatomical structures involved in such processes. In the current study, we used EEG beamforming methods and examined 37 healthy participants in two well-controlled experiments varying the necessity of anticipatory processes during goal-directed action. We found that alpha and beta activity in the medial and posterior cingulate cortex enabled feedforward predictions about the position of an object based on the latest sensorimotor state. On this basis, theta band activity seems more related to sensorimotor representations, while beta band activity would be more involved in setting up the structure of the neural representations themselves. Alpha band activity in sensory cortices reflects an intensified gating of the anticipated perceptual consequences of the to-be-executed action. Together, the findings indicate that goal-directed acting through the anticipation of the predicted state of an effector is based on accompanying processes in multiple frequency bands in midcingulate and sensory brain regions.

Transcranial Alternating Current Stimulation over Frontal Eye Fields Mimics Attentional Modulation of Visual Processing.

Attentional control over sensory processing has been linked to neural alpha oscillations and related inhibition of cerebral cortex. Despite the wide consensus on the functional relevance of alpha oscillations for attention, precise neural mechanisms of how alpha oscillations shape perception and how this top-down modulation is implemented in cortical networks remain unclear. Here, we tested the hypothesis that alpha oscillations in frontal eye fields (FEFs) are causally involved in the top-down regulation of visual processing in humans (male and female). We applied sham-controlled, intermittent transcranial alternating current stimulation (tACS) over bilateral FEF at either 10 Hz (alpha) or 40 Hz (gamma) to manipulate attentional preparation in a visual discrimination task. Under each stimulation condition, we measured psychometric functions for contrast perception and introduced a novel linear mixed modeling approach for statistical control of neurosensory side effects of the electric stimulation. tACS at alpha frequency reduced the slope of the psychometric function, resulting in improved subthreshold and impaired superthreshold contrast perception. Side effects on the psychometric functions were complex and showed large interindividual variability. Controlling for the impact of side effects on the psychometric parameters by using covariates in the linear mixed model analysis reduced this variability and strengthened the perceptual effect. We propose that alpha tACS over FEF mimicked a state of endogenous attention by strengthening a fronto-occipitoparietal network in the alpha band. We speculate that this network modulation enhanced phasic gating in occipitoparietal cortex leading to increased variability of single-trial psychometric thresholds, measurable as a reduction of psychometric slope.

The perceptual effect of forms used on walls and furnishings in cafés

PurposeThis study researched the effects on the perceptual evaluations of participants for the physical environmental factors of cafés using curvilinear, rectilinear, and mixed forms to provide for the spatial states of belonging, to increase the pleasures, and to extend the periods of remaining in the space.Design/methodology/approachThis study used virtual reality (VR) technology to model the cafés designed by using curvilinear, rectilinear and mixed forms as an experimental environment. After experiencing the virtual images of the experimental spaces, participants filled out a “spatial perception” questionnaire. Perceptual evaluations of 415 participants regarding the environmental factors of cafés designed using curvilinear, linear and mixed forms were analyzed in a computer environment.FindingsAccording to the analysis of the questionnaire data, the cafés using mixed forms were perceived as more positive for the factors of appeal (inviting, restful, warm and sincere), planning (well-planned) and space freedom (roomy, uncluttered, uncrowded, large, wide and free space) compared with the cafés using curvilinear and rectilinear forms. Furthermore, the cafés using curvilinear forms were perceived as more positive for all elements compared with the cafés using rectilinear forms. However, there was a more negative approach in the perceptual evaluations of participants connected to increases in level of education.Originality/valueThe research results clearly demonstrated that the different interior and furniture forms frequently encountered in cafés cause significant effects on users’ perceptual evaluations.

Perceptual consequences of online group speech treatment for individuals with Parkinson's disease: A pilot study case series.

We examined perceptual changes in the domains of ease of understanding, naturalness, and speech severity, as well as changes in self-perceptions of voice disability, following an online group speech treatment program for people with Parkinson's disease (PD) conducted during the COVID-19 pandemic. Seven speakers with hypokinetic dysarthria associated with PD participated in a university and community-based online group speech program for 10 weeks. Speech recordings occurred remotely 1 week before and 1 week after the online program. Thirty naïve listeners rated ease of understanding, naturalness, and speech severity based on the speech recordings. Speakers' self-perceptions of voice disability were also obtained at both time points. Individual analysis of the speech data showed that for most speakers with dysarthria, ease of understanding and perceptions of severity were rated the same or better pre- to post-treatment. Naturalness, however, was only perceived to be the same or better post-treatment in three out of seven speakers. Over half of the speakers reported improvements in their self-perception of voice disability. This pilot study highlighted the individual variability among speakers with dysarthria and the potential of online group speech treatment to maintain and/or improve speech function in this population.

Comparing perception of L1 and L2 English by human listeners and machines: Effect of interlocutor adaptationsa).

Speakers tailor their speech to different types of interlocutors. For example, speech directed to voice technology has different acoustic-phonetic characteristics than speech directed to a human. The present study investigates the perceptual consequences of human- and device-directed registers in English. We compare two groups of speakers: participants whose first language is English (L1) and bilingual L1 Mandarin-L2 English talkers. Participants produced short sentences in several conditions: an initial production and a repeat production after a human or device guise indicated either understanding or misunderstanding. In experiment 1, a separate group of L1 English listeners heard these sentences and transcribed the target words. In experiment 2, the same productions were transcribed by an automatic speech recognition (ASR) system. Results show that transcription accuracy was highest for L1 talkers for both human and ASR transcribers. Furthermore, there were no overall differences in transcription accuracy between human- and device-directed speech. Finally, while human listeners showed an intelligibility benefit for coda repair productions, the ASR transcriber did not benefit from these enhancements. Findings are discussed in terms of models of register adaptation, phonetic variation, and human-computer interaction.

Reviving Bistable Perception in Patients With Depression by Decreasing the Overestimation of Prior Precision.

Slower perceptual alternations, a notable perceptual effect observed in psychiatric disorders, can be alleviated by antidepressant therapies that affect serotonin levels in the brain. While these phenomena have been well documented, the underlying neurocognitive mechanisms remain to be elucidated. Our study bridges this gap by employing a computational cognitive approach within a Bayesian predictive coding framework to explore these mechanisms in depression. We fitted a prediction error (PE) model to behavioral data from a binocular rivalry task, uncovering that significantly higher initial prior precision and lower PE led to a slower switch rate in patients with depression. Furthermore, serotonin-targeting antidepressant treatments significantly decreased the prior precision and increased PE, both of which were predictive of improvements in the perceptual alternation rate of depression patients. These findings indicated that the substantially slower perception switch rate in patients with depression was caused by the greater reliance on top-down priors and that serotonin treatment's efficacy was in its recalibration of these priors and enhancement of PE. Our study not only elucidates the cognitive underpinnings of depression, but also suggests computational modeling as a potent tool for integrating cognitive science with clinical psychology, advancing our understanding and treatment of cognitive impairments in depression.

Grasping tiny objects.

In grasping studies, maximum grip aperture (MGA) is commonly used as an indicator of the object size representation within the visuomotor system. However, a number of additional factors, such as movement safety, comfort, and efficiency, might affect the scaling of MGA with object size and potentially mask perceptual effects on actions. While unimanual grasping has been investigated for a wide range of object sizes, so far very small objects (<5mm) have not been included. Investigating grasping of these tiny objects is particularly interesting because it allows us to evaluate the three most prominent explanatory accounts of grasping (the perception-action model, the digits-in-space hypothesis, and the biomechanical account) by comparing the predictions that they make for these small objects. In the first experiment, participants ( ) grasped and manually estimated the height of square cuboids with heights from 0.5 to 5mm. In the second experiment, a different sample of participants ( ) performed the same tasks with square cuboids with heights from 5 to 20mm. We determined MGAs, manual estimation apertures (MEA), and the corresponding just-noticeable differences (JND). In both experiments, MEAs scaled with object height and adhered to Weber's law. MGAs for grasping scaled with object height in the second experiment but not consistently in the first experiment. JNDs for grasping never scaled with object height. We argue that the digits-in-space hypothesis provides the most plausible account of the data. Furthermore, the findings highlight that the reliability of MGA as an indicator of object size is strongly task-dependent.

Effects of perceptual redundancy, conceptual redundancy and self-relatedness on categorical responses.

A redundancy gain occurs when perceptually identical stimuli are presented together, resulting in quicker categorization of these paired stimuli than lone stimuli. Similar effects have been reported for paired stimuli within the same conceptual category, particularly if the category is self-related. We recruited 528 individuals across three related studies to investigate whether, during perceptual and conceptual redundancy, such self-bias effects on foreground stimuli are modulated by natural versus urban backgrounds. Here, we highlight our observations pertaining to perceptual and conceptual redundancy effects of the foreground stimuli. In our first experiment, response options were randomised per trial. Results showed reaction time gains for perceptually identical stimuli, but this advantage was not modulated by self/other categorization. However, slower reaction times were observed for conceptually-related stimulus pairs and were influenced by self/other categorization. The second experiment replicated the methods of earlier studies of redundancy and observed comparable results to Experiment 1: a perceptual redundancy gain unmodulated by self/other categorization, yet for conceptual redundancy, no gain/cost but effects of self/other categorization. In the third experiment, self/other categories were substituted with arbitrary A/B categories: Once more, there was a perceptual redundancy gain and no conceptual redundancy gain. Notably, A/B categorisation produced effects equivalent to self/other categorisation. Overall, these findings challenge previous research on the facilitated early processing of conceptually-related stimuli and suggest that self-relatedness may not exert a unique effect on stimulus processing beyond attentional and response preferences during categorization. Our study motivates further research to understand conceptual categorization and redundancy gain effects.

Multimodal prosody: gestures and speech in the perception of prominence in Spanish

Multimodal communication cannot be properly understood without analyzing the natural interweaving of speech and gestures as it typically occurs in everyday spoken language, thus moving beyond studies that elicit gestures in the laboratory, most of which are also conducted for English. Therefore, this study addresses the effect of both visual and acoustic cues in the perception of prominence in Castilian Spanish using spontaneous speech from a TV talent-show. Four between-subjects experiments in each modality—audio-only and audiovisual—were conducted online, each including a different combination of manipulated cues: Exp1 (flat F0), Exp2 (flat intensity), and Exp3 (flat F0 + flat intensity), while all cues remained intact in the control experiment Exp0. Additionally, the capability of the different gesture phases to convey prominence was analyzed in their interaction with the acoustic cues. The results showed that, when prominence was perceived in manipulated stimuli, the effect of the visual information depended on the acoustic cues available in the signal and was also reduced when compared to non-manipulated stimuli, pointing to a strong integration of both modalities in prominence perception. In non-manipulated stimuli, all acoustic cues—except for spectral balance—played a role in the perception of prominence; however, when the visual information was added, it reduced the perceptual effect of the acoustic cues, and the main role played by duration was combined with that of the stroke phase of gestures.

BiPMAP: a toolbox for predicting perceived motion artifacts on modern displays.

Viewers of digital displays often experience motion artifacts (e.g., flicker, judder, edge banding, motion blur, color breakup, depth distortion) when presented with dynamic scenes. We developed an interactive software tool for display designers that predicts how a viewer perceives motion artifacts for a variety of stimulus, display, and viewing parameters: the Binocular Perceived Motion Artifact Predictor (BiPMAP). The tool enables the user to specify numerous stimulus, display, and viewing parameters. It implements a model of human spatiotemporal contrast sensitivity in order to determine which artifacts will be seen by a viewer and which will not. The tool visualizes the perceptual effects of discrete space-time sampling on the display by presenting side by side the expected perception when the stimulus is continuous compared to when the same stimulus is presented with the spatial and temporal parameters of a prototype display.

THE ROLE OF SPIRITUAL AND FORMAL EFFECTS IN THE PERCEPTION OF EMOTIONAL STATES CONSTITUTING A WORK OF ART

: The emotional states that constitute a work of art are formed through the effects of a series of rules and regularities that explain the organization of various systems and also form the foundation of a field of study. Emotions, formal pleasures, and spiritual approaches are among the phenomena that develop a theory defining the general definition of art, delineating its boundaries, and identifying the qualities that allow us to label something as a "work of art." Additionally, art is related with the aesthetics of nature and human subjective realities. The emotional sentiments, characterized as reality for the artist and manifested through seeing and understanding, are dependent on the subjects to be addressed in art. Art, an inherent human capability, is essentially a representation of existence. The tangible qualities of natural objects, considered reality for the artist, assist in perceiving and grasping these emotional feelings in art. Furthermore, individually arising emotional states give rise to aesthetic judgment based on both objective and subjective evaluations. The essential qualities inherent in the essence of the artwork are the foundation of artistic existence. The form that aids in the emergence of artistic presence appears as the perceptible reality of any object through our senses. For the artist, the material characteristics in nature bring forth perceptions. Artistic works produced for aesthetic purposes help bring forth the existing emotional states.&#x0D; The artist reflects their artistic expression through a perspective developed from their perception of the dynamics of art, attempting to create artistic forms based on the interaction between everyday objects and the senses. Objects that transport perceived forms into reality and everyday items, in interaction with the senses, aid in creating artworks as a synthesis of spiritual approaches. Cultural, sociopolitical, and economic factors influencing society are among the primary factors affecting the creation of artworks. Additionally, variables related to the artist's psychological state and societal structure play a role in this transformative process in the production of artworks. Thus, objects that inherently lack artistic meaning interact with each other in the journey of being transformed into artworks by artists.&#x0D; Our research is conducted by examining qualitative data related to the emotional states that constitute a work of art and their perceptual, spiritual, and formal effects. It is believed that this study will contribute to the field of art.

A differential impact of action–effect temporal contiguity on different measures of response inhibition in the Go\\No-Go and Stop-signal paradigms

Response inhibition refers to suppressing a prepotent motor response and is often studied and discussed as an act of cognitive control. Much less attention was given to the potential contribution of motor control processes to response inhibition. Accumulated empirical findings show that a perceptual effect temporally contiguous with a response improves motor control performance. In the current study, we followed this work by manipulating action–effect temporal contiguity to enhance motor performance and investigated its impact on response selection and inhibition. In two experiments, we integrated a Go/No-Go (GNGT; Experiment 1) and a Stop-signal (SST; Experiment 2) task with the Effect–Motivation task, previously used to capture the facilitating impact of action–effect temporal contiguity on response times (RTs). Replicating previous findings, RTs were shorter following temporally contiguous compared to Lagged action–effect in Go trials in both the GNGT (Experiment 1) and SST (Experiment 2). Notably, an Immediate action–effect improved response inhibition in the GNGT (Experiment 1) but did not modulate Stop-signal reaction time (SSRT) in the SST (Experiment 2). Unexpectedly, the error rate on Go trials was higher in the Immediate effect condition in Experiment 2. We interpret the findings to suggest that an action’s (Immediate) perceptual effect may promote response inhibition performance by enhancing selective association between the Go stimuli and the Go response and not by improving cognitive control ability. The findings also imply that an Immediate action–effect may hamper action control (e.g., by increasing general readiness to respond), at least when action control does not benefit from automatic stimulus–response association.

Attentional Tunneling in Pilots During a Visual Tracking Task With a Head Mounted Display.

We examined whether active head aiming with a Helmet Mounted Display (HMD) can draw the pilot's attention away from a primary flight task. Furthermore, we examined whether visual clutter increases this effect. Head up display symbology can result in attentional tunneling, and clutter makes it difficult to identify objects. Eighteen military pilots had to simultaneously perform an attitude control task while flying in clouds and a head aiming task in a fixed-base flight simulator. The former consisted of manual compensation for roll disturbances of the aircraft, while the latter consisted of keeping a moving visual target inside a small or large head-referenced circle. A "no head aiming" condition served as a baseline. Furthermore, all conditions were performed with or without visual clutter. Head aiming led to deterioration of the attitude control task performance and an increase of the amount of roll-reversal errors (RREs). This was even the case when head aiming required minimal effort. Head aiming accuracy was significantly lower when the roll disturbances in the attitude control task were large compared to when they were small. Visual clutter had no effect on both tasks. We suggest that active head aiming of HMD symbology can cause attentional tunneling, as expressed by an increased number of RREs and less accuracy on a simultaneously performed attitude control task. This study improves our understanding in the perceptual and cognitive effects of (military) HMDs, and has implications for operational use and possibly (re)design of HMDs.