Increasing Altitude and the Optokinetic Cervical Reflex

2021 ◽  
Vol 92 (5) ◽  
pp. 319-325
Author(s):  
Matthew A. Stewart ◽  
Sravan Pingali ◽  
David G. Newman
Keyword(s):  
High Altitude ◽  
Opposite Direction ◽  
Spatial Orientation ◽  
Visual Cues ◽  
Head Tilt ◽  
Flight Simulator ◽  
Visual Environment ◽  
Bank Angle ◽  
Environment Changes ◽  
Post Hoc

INTRODUCTION: When an aircraft banks pilots will reflexively tilt their heads in the opposite direction, known as the optokinetic cervical reflex (OKCR). This is elicited by the appearance of the horizon and is an attempt to keep the moving horizon stable on the pilots retina to help maintain spatial orientation. The appearance of the horizon and the visual environment changes at higher altitudes and there is little research studying the effects of this. Our hypothesis was that increasing altitude would alter the visual cues present and decrease the OKCR.METHODS: There were 16 subjects who flew two flights in a flight simulator while their head tilt, aircraft altitude, and angle of aircraft bank were recorded. The flights were at an altitude of under 1500 ft above ground and above 15,000 ft above ground.RESULTS: Aircraft bank caused head tilt in the opposite direction at both altitudes. A two-way ANOVA with Bonferroni post hoc tests showed that 86% of aircraft bank angles from 0 to 90 in either direction had a head tilt that was statistically significantly smaller at high altitude.DISCUSSION: This study shows that there appears to be a difference between the OKCR at low and high altitude. Pilots at higher altitude seem to exhibit a smaller head tilt for the same aircraft bank angle. More research is required to fully understand why there is a decrease in the OKCR at high altitude, as well as the actual consequences of the decreased reflex on pilot orientation.Stewart MA, Pingali S, Newman DG. Increasing altitude and the optokinetic cervical reflex. Aerosp Med Hum Perform. 2021; 92(5):319325.

scholarly journals Camouflage, communication and thermoregulation: lessons from colour changing organisms

2008 ◽  
Vol 364 (1516) ◽  
pp. 463-470 ◽  
Author(s):  
Devi Stuart-Fox ◽  
Adnan Moussalli
Keyword(s):  
Visual Perception ◽  
Visual Processing ◽  
Comparative Studies ◽  
Visual Cues ◽  
Colour Change ◽  
Visual Environment ◽  
Multiple Predators ◽  
Physiological Colour Change ◽  
Colour Patterns ◽  
Insight Into

Organisms capable of rapid physiological colour change have become model taxa in the study of camouflage because they are able to respond dynamically to the changes in their visual environment. Here, we briefly review the ways in which studies of colour changing organisms have contributed to our understanding of camouflage and highlight some unique opportunities they present. First, from a proximate perspective, comparison of visual cues triggering camouflage responses and the visual perception mechanisms involved can provide insight into general visual processing rules. Second, colour changing animals can potentially tailor their camouflage response not only to different backgrounds but also to multiple predators with different visual capabilities. We present new data showing that such facultative crypsis may be widespread in at least one group, the dwarf chameleons. From an ultimate perspective, we argue that colour changing organisms are ideally suited to experimental and comparative studies of evolutionary interactions between the three primary functions of animal colour patterns: camouflage; communication; and thermoregulation.

The Implications of Image Collimation for Flight Simulator Training

1998 ◽  
Vol 42 (20) ◽  
pp. 1383-1387 ◽  
Author(s):  
Byron J. Pierce ◽  
George A. Geri
Keyword(s):  
Visual Cues ◽  
Laboratory Data ◽  
Simulator Training ◽  
Flight Simulator ◽  
Real Image ◽  
Temporal Aspects ◽  
Accurate Perception ◽  
Image Displays ◽  
Real Imagery ◽  
Perceived Velocity

There is some question as to whether non-collimated (i.e., real) imagery viewed at one meter or less provides sufficiently realistic visual cues to support out-the-window flight simulator training. As a first step toward answering this question, we have obtained perceived size and velocity estimates using both simple stimuli in a controlled laboratory setting and full simulator imagery in an apparatus consisting of optically combined collimated and real-image displays. In the size study it was found that real imagery appeared 15-30% smaller than collimated imagery. In the velocity studies, the laboratory data showed that the perceived velocity of real imagery was less than that of collimated imagery. No perceived velocity effects were found with the simulator imagery. Results support the position that for training tasks requiring accurate perception of spatial and temporal aspects of the simulated visual environment, misperceptions of size, but not velocity, need to be considered when real-image displays are used.

scholarly journals Validating an Academic Group Tutorial Discussion Speaking Test

2016 ◽  
Vol 6 (4) ◽  
pp. 12 ◽  
Author(s):  
Peter Crosthwaite ◽  
Simon Boynton ◽  
Sam Cole
Keyword(s):  
Language Proficiency ◽  
Visual Cues ◽  
Intraclass Correlation ◽  
Active Listening ◽  
Speaking Test ◽  
Group Settings ◽  
Threats To Validity ◽  
Freshmen Students ◽  
Post Hoc ◽  
Academic Group

<p>This study attempts to validate an academic group tutorial discussion speaking test for undergraduate freshmen students taking initial EAP training at a university in Hong Kong in terms of task, rater and criterion validity. Three quantitative measures (Cronbach’s Alpha, Intraclass Correlation Coefficient, and Exploratory Factor Analysis) are used to assess validity of rater scores for the test using a rubric with considerations for assessment of academic stance presentation, inter-candidate interaction, and individual language proficiency. These results are triangulated with post-hoc interview data from the raters regarding the difficulties they face assessing individual proficiency and group interaction over time. The results suggest that current provisions of the rubric in dealing with the assessment of interaction in group settings (namely visual cues such as “active listening” as well as provisions for interruptions in the form of “domination”) are problematic, and that raters are unable to separate the grading of academic stance from the grading of language concerns. We also note affective and cognitive difficulties involved with assessing extended periods of interactional discourse including student talking time (or lack of it), the group dynamic, and raters” personal beliefs and practice as threats to validity that the statistical measurements were unable to capture. A new sample rubric and further suggestions for improving the validity of group tutorial assessments are provided.</p>

scholarly journals Spatial Orientation In Sportsmen

2016 ◽  
Vol 12 (24) ◽  
pp. 88
Author(s):  
Stanislava Stoyanova ◽  
Nikolay Ivantchev ◽  
Kremka Petrova
Keyword(s):  
Gender Differences ◽  
Cognitive Processes ◽  
Spatial Orientation ◽  
Test System ◽  
Test Methods ◽  
Visual Environment ◽  
Sports Training

Cognitive processes are important for successful practicing of sport. 69 national and regional competitors in different kinds of sports were studied by means of 2D Visualisation, the subtest “Comparing surfaces” of AHA and GESTA - computerized test methods from Vienna Test System measuring spatial orientation, precision of estimation of the size of the surfaces, and perception of more or few details in visual environment respectively. There were not any significant gender differences in athletes’ spatial orientation. Longer period of sports training was related to better spatial orientation.

scholarly journals Different Visual Weighting due to Fast or Slow Vestibular Deafferentation: Before and after Schwannoma Surgery

2019 ◽  
Vol 2019 ◽  
pp. 1-11 ◽  
Author(s):  
Fredrik Tjernström ◽  
Per-Anders Fransson ◽  
Babar Kahlon ◽  
Mikael Karlberg ◽  
Sven Lindberg ◽  
...  
Keyword(s):  
Postural Control ◽  
Spatial Orientation ◽  
Visual Cues ◽  
Time Course ◽  
Vestibular Function ◽  
Sensory Systems ◽  
Vestibular Loss ◽  
Group 3 ◽  
Group 2 ◽  
Group 1

Background. Feedback postural control depends upon information from somatosensation, vision, and the vestibular system that are weighted depending on their relative importance within the central nervous system. Following loss of any sensory component, the weighting changes, e.g., when suffering a vestibular loss, the most common notion is that patients become more dependent on visual cues for maintaining postural control. Dizziness and disequilibrium are common after surgery in schwannoma patients, which could be due to interpretation of the remaining sensory systems involved in feedback-dependent postural control and spatial orientation. Objective. To compare visual dependency in spatial orientation and postural control in patients suffering from unilateral vestibular loss within different time frames. Methods. Patients scheduled for schwannoma surgery: group 1 (n=27) with no vestibular function prior to surgery (lost through years), group 2 (n=12) with remaining vestibular function at the time of surgery (fast deafferentation), and group 3 (n=18) with remaining function that was lost through gentamicin installations in the middle ear (slow deafferentation). All patients performed vibratory posturography and rod and frame investigation before surgery and 6 months after surgery. Results. Postural control improved after surgery in patients that suffered a slow deafferentation (groups 1 and 3) (p<0.001). Patients that suffered fast loss of remaining vestibular function (group 2) became less visual field dependent after surgery (p≤0.035) and were less able to maintain stability compared with group 1 (p=0.010) and group 3 (p=0.010). Conclusions. The nature and time course of vestibular deafferentation influence the weighting of remaining sensory systems in order to maintain postural control and spatial orientation.

scholarly journals Leans Illusion in Hexapod Simulator Facilitates Erroneous Responses to Artificial Horizon in Airline Pilots

2020 ◽  
pp. 001872082097524
Author(s):  
Annemarie van den Hoed ◽  
Annemarie Landman ◽  
Dirk Van Baelen ◽  
Olaf Stroosma ◽  
M. M. (René) van Paassen ◽  
...  
Keyword(s):  
Opposite Direction ◽  
Learning Effect ◽  
Baseline Condition ◽  
Control Input ◽  
Bank Angle ◽  
Airline Pilots ◽  
Spatial Disorientation ◽  
Interpretation Errors ◽  
And Control

Objective We tested whether a procedure in a hexapod simulator can cause incorrect assumptions of the bank angle (i.e., the “leans”) in airline pilots as well as incorrect interpretations of the attitude indicator (AI). Background The effect of the leans on interpretation errors has previously been demonstrated in nonpilots. In-flight, incorrect assumptions can arise due to misleading roll cues (spatial disorientation). Method Pilots ( n = 18) performed 36 runs, in which they were asked to roll to wings level using only the AI. They received roll cues before the AI was shown, which matched with the AI bank angle direction in most runs, but which were toward the opposite direction in a leans-opposite condition (four runs). In a baseline condition (four runs), they received no roll cues. To test whether pilots responded to the AI, the AI sometimes showed wings level following roll cues in a leans-level condition (four runs). Results Overall, pilots made significantly more errors in the leans-opposite (19.4%) compared to the baseline (6.9%) or leans-level condition (0.0%). There was a pronounced learning effect in the leans-opposite condition, as 38.9% of pilots made an error in the first exposure to this condition. Experience (i.e., flight hours) had no significant effects. Conclusion The leans procedure was effective in inducing AI misinterpretations and control input errors in pilots. Application The procedure can be used in spatial disorientation demonstrations. The results underline the importance of unambiguous displays that should be able to quickly correct incorrect assumptions due to spatial disorientation.

Exploring the effect of eye gaze cues on novel L2 morphosyntactic pattern learning

2020 ◽  
pp. 026765831989682
Author(s):  
Dato Abashidze ◽  
Kim McDonough ◽  
Yang Gao
Keyword(s):  
Visual Cues ◽  
Eye Gaze ◽  
Generalization Test ◽  
Pattern Learning ◽  
The Gaze ◽  
Movement Data ◽  
Visual Events ◽  
Static Images ◽  
Post Hoc ◽  
Gaze Cues

Recent research that explored how input exposure and learner characteristics influence novel L2 morphosyntactic pattern learning has exposed participants to either text or static images rather than dynamic visual events. Furthermore, it is not known whether incorporating eye gaze cues into dynamic visual events enhances dual pattern learning. Therefore, this exploratory eye-tracking study examined whether eye gaze cues during dynamic visual events facilitate novel L2 pattern learning. University students ( n = 72) were exposed to 36 training videos with two dual novel morphosyntactic patterns in pseudo-Georgian: completed events ( bich-ma kocn-ul gogoit, ‘boy kissed girl’) and ongoing actions ( bich-su kocn-ar gogoit, ‘boy is kissing girl’). They then carried out an immediate test with 24 items using the same vocabulary words, followed by a generalization test with 24 items created from new vocabulary words. Results indicated that learners who received the eye gaze cues scored significantly higher on the immediate test and relied on the verb cues more than on the noun cues. A post-hoc analysis of eye-movement data indicated that the gaze cues elicited longer looks to the correct images. Findings are discussed in relation to visual cues and novel morphosyntactic pattern learning.

scholarly journals Loudness judgements are not necessarily affected by visual cues to sound source distance

2017 ◽  
Author(s):  
sol libesman ◽  
Thomas Whitford ◽  
Damien Mannion
Keyword(s):  
Sound Source ◽  
Visual Cues ◽  
Apparent Distance ◽  
Sound Level ◽  
Acoustic Energy ◽  
Visual Environment ◽  
Potential Contribution ◽  
Subjective Loudness ◽  
Source Distance ◽  
Source Level

The level of the auditory signals at the ear depends both on the capacity of the sound source to produce acoustic energy and on the distance of the source from the listener. Loudness constancy requires that our perception of sound level, loudness, corresponds to the source level by remaining invariant to the confounding effects of distance. Here, we assessed the evidence for a potential contribution of vision, via the disambiguation of sound source distance, to loudness constancy. We presented participants with a visual environment, on a computer monitor, which contained a visible loudspeaker at a particular distance and was accompanied by the auditory delivery, via headphones, of an anechoic sound of a particular aural level. We measured the point of subjective loudness equality for sounds associated with loudspeakers at different visually-depicted distances. We report strong evidence that such loudness judgements were closely aligned with the aural level, rather than being affected by the apparent distance of the sound source conveyed visually. Similar results were obtained across variations in sound and environment characteristics. We conclude that the loudness of anechoic sounds are not necessarily affected by indications of the sound source distance as established via vision.

scholarly journals Show Me More! The Influence of Visibility on Sustainable Food Choices

Foods ◽  
2019 ◽  
Vol 8 (6) ◽  
pp. 186 ◽  
Author(s):  
Nicky Coucke ◽  
Iris Vermeir ◽  
Hendrik Slabbinck ◽  
Anneleen Van Kerckhove
Keyword(s):  
Visual Cues ◽  
Meat Products ◽  
Purchase Behavior ◽  
Post Intervention ◽  
Sustainable Food ◽  
Policy Makers ◽  
Poultry Products ◽  
Display Area ◽  
Store Environment ◽  
Post Hoc

Visual cues are omnipresent in an in-store environment and can enhance the visibility of a product. By using these visual cues, policy makers can design a choice environment to nudge consumers towards more sustainable consumer behavior. In this study, we use a combined nudge of display area size and quantity of displayed products to nudge consumers towards more sustainable meat choices. We performed a field experiment of four weeks in a butchery, located in a supermarket. The size of the display area and quantity of displayed poultry products, serving as the nudging intervention, were increased, whereas these were decreased for less sustainable meat products. In order to evaluate the effectiveness of our nudging intervention, we also collected data from a control store and performed a pre-and post-intervention measurement. We kept records of the sales data of the sold meat (amount of weight & revenue). When conducting a three-way ANOVA and post hoc contrast tests, we found that the sales of poultry increased during the nudging intervention, but did not decrease for less sustainable meat products. When removing the nudge again, the sales of poultry decreased again significantly in the experimental store. Changing the size of display area and the amount of products displayed in this display area created a shift in the consumers’ purchase behavior of meat.

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