Perceptual Upright: The Relative Effectiveness of Dynamic and Static Images Under Different Gravity States

2011 ◽  
Vol 24 (1) ◽  
pp. 53-64 ◽  
Author(s):  
Michael Jenkin ◽  
James Zacher ◽  
Richard Dyde ◽  
Laurence Harris ◽  
Heather Jenkin
Keyword(s):  
Character Recognition ◽  
Visual Cues ◽  
Parabolic Flight ◽  
Ground Plane ◽  
Relative Effectiveness ◽  
Video Clip ◽  
Visual Background ◽  
Microgravity Conditions ◽  
Static Images ◽  
Orientation Cues

AbstractThe perceived direction of up depends on both gravity and visual cues to orientation. Static visual cues to orientation have been shown to be less effective in influencing the perception of upright (PU) under microgravity conditions than they are on earth (Dyde et al., 2009). Here we introduce dynamic orientation cues into the visual background to ascertain whether they might increase the effectiveness of visual cues in defining the PU under different gravity conditions. Brief periods of microgravity and hypergravity were created using parabolic flight. Observers viewed a polarized, natural scene presented at various orientations on a laptop viewed through a hood which occluded all other visual cues. The visual background was either an animated video clip in which actors moved along the visual ground plane or an individual static frame taken from the same clip. We measured the perceptual upright using the oriented character recognition test (OCHART). Dynamic visual cues significantly enhance the effectiveness of vision in determining the perceptual upright under normal gravity conditions. Strong trends were found for dynamic visual cues to produce an increase in the visual effect under both microgravity and hypergravity conditions.

scholarly journals Long-duration head down bed rest as an analog of microgravity: Effects on the static perception of upright

2021 ◽  
pp. 1-16
Author(s):  
Laurence R. Harris ◽  
Michael Jenkin ◽  
Rainer Herpers
Keyword(s):  
Character Recognition ◽  
Visual Cues ◽  
Time Course ◽  
Critical Time ◽  
Bed Rest ◽  
Long Duration ◽  
Visual Vertical ◽  
Microgravity Conditions ◽  
Line Test

BACKGROUND: Humans demonstrate many physiological changes in microgravity for which long-duration head down bed rest (HDBR) is a reliable analog. However, information on how HDBR affects sensory processing is lacking. OBJECTIVE: We previously showed (25) that microgravity alters the weighting applied to visual cues in determining the perceptual upright (PU), an effect that lasts long after return. Does long-duration HDBR have comparable effects? METHODS: We assessed static spatial orientation using the luminous line test (subjective visual vertical, SVV) and the oriented character recognition test (PU) before, during and after 21 days of 6° HDBR in 10 participants. Methods were essentially identical as previously used in orbit (25). RESULTS: Overall, HDBR had no effect on the reliance on visual relative to body cues in determining the PU. However, when considering the three critical time points (pre-bed rest, end of bed rest, and 14 days post-bed rest) there was a significant decrease in reliance on visual relative to body cues, as found in microgravity. The ratio had an average time constant of 7.28 days and returned to pre-bed-rest levels within 14 days. The SVV was unaffected. CONCLUSIONS: We conclude that bed rest can be a useful analog for the study of the perception of static self-orientation during long-term exposure to microgravity. More detailed work on the precise time course of our effects is needed in both bed rest and microgravity conditions.

scholarly journals The Weighting of Cues to Upright Following Stroke With and Without a History of Pushing

2018 ◽  
Vol 45 (4) ◽  
pp. 405-414 ◽  
Author(s):  
Lindsey E. Fraser ◽  
Avril Mansfield ◽  
Laurence R. Harris ◽  
Daniel M. Merino ◽  
Svetlana Knorr ◽  
...  
Keyword(s):  
Character Recognition ◽  
Visual Cues ◽  
Internal Representation ◽  
The Body ◽  
Perceptual Bias ◽  
Vector Model ◽  
Control Group ◽  
Visual Background ◽  
History Of ◽  
Main Factors

AbstractObjective:Perceived upright depends on three main factors: vision, graviception, and the internal representation of the long axis of the body. We assessed the relative contributions of these factors in individuals with sub-acute and chronic stroke and controls using a novel tool; the Oriented Character Recognition Test (OCHART). We also considered whether individuals who displayed active pushing or had a history of pushing behaviours had different weightings than those with no signs of pushing.Method:Three participants experienced a stroke <3 months before the experiment: one with active pushing. In total, 14 participants experienced a stroke >6 months prior: eight with a history of pushing. In total, 12 participants served as healthy aged-matched controls. Visual and graviceptive cues were dissociated by orienting the visual background left, right, or upright relative to the body, or by orienting the body left, right, or upright relative to gravity. A three-vector model was used to quantify the weightings of vision, graviception, and the body to the perceptual upright.Results:The control group showed weightings of 13% vision, 25% graviception, and 62% body. Some individuals with stroke showed a similar pattern; others, particularly those with recent stroke, showed different patterns, for example, being unaffected by one of the three factors. The participant with active pushing behaviour displayed an ipsilesional perceptual bias (>30°) and was not affected by visual cues to upright.Conclusion:The results of OCHART may be used to quantify the weightings of multisensory inputs in individuals post-stroke and may help characterize perceptual sources of pushing behaviours.

Can itch-related visual stimuli provoke an itch response?

2012 ◽  
Vol 25 (0) ◽  
pp. 173
Author(s):  
Donna M. Lloyd ◽  
Elizabeth Hall ◽  
Samantha Hall ◽  
Francis McGlone
Keyword(s):  
Visual Cues ◽  
Mirror Neuron System ◽  
Mirror Neuron ◽  
Preliminary Evidence ◽  
Skin Contact ◽  
Skin Response ◽  
Static Images ◽  
Skin Conditions ◽  
The Impact ◽  
Picture Type

Itching is a common subjective sensation experienced on the skin and is associated with the desire and impulse to scratch. We tested whether visual cues could generate feelings of itch and provoke a scratch response in healthy volunteers. A secondary aim was to assess whether certain pictures were more effective in evoking sensations of itch. Thirty participants viewed static images that could either be itch-related (i.e., viewing ants or skin conditions) or neutral (viewing butterflies or healthy skin). These were further separated by picture type: ‘skin contact’ (i.e., ants crawling on the skin or a butterfly sitting on the hand); ‘skin response’ (i.e., scratching an insect bite or washing the hands) or ‘no skin’ (simply viewing midges or birds flying). The results indicate that the sensation of itch was successfully generated using itch-related pictures in terms of significantly higher self-reports of itch in answer to the questions ‘how itchy do you feel?’ and ‘how itchy do you think the person in the picture feels?’ compared to viewing neutral pictures (). In addition, participants scratched themselves significantly more when viewing itch-related pictures compared to neutral (). The picture type also had an effect upon these measures with more scratching behaviour recorded when viewing pictures depicting others scratching (). This study demonstrates the impact of visual cues on the sensation of itch and the scratch response and may provide preliminary evidence linking contagious itching to the mirror neuron system and the effectiveness of itch-inducing stimuli as a way to probe social communication.

scholarly journals Nanopore sequencing at Mars, Europa, and microgravity conditions

2020 ◽  
Vol 6 (1) ◽  
Author(s):  
Christopher E. Carr ◽  
Noelle C. Bryan ◽  
Kendall N. Saboda ◽  
Srinivasa A. Bhattaru ◽  
Gary Ruvkun ◽  
...  
Keyword(s):  
Parabolic Flight ◽  
Space Station ◽  
Space Vehicles ◽  
Nanopore Sequencing ◽  
Icy Moons ◽  
Microbial Monitoring ◽  
Oxford Nanopore ◽  
Microgravity Conditions ◽  
Low Mass ◽  
Consistent Performance

Abstract Nanopore sequencing, as represented by Oxford Nanopore Technologies’ MinION, is a promising technology for in situ life detection and for microbial monitoring including in support of human space exploration, due to its small size, low mass (~100 g) and low power (~1 W). Now ubiquitous on Earth and previously demonstrated on the International Space Station (ISS), nanopore sequencing involves translocation of DNA through a biological nanopore on timescales of milliseconds per base. Nanopore sequencing is now being done in both controlled lab settings as well as in diverse environments that include ground, air, and space vehicles. Future space missions may also utilize nanopore sequencing in reduced gravity environments, such as in the search for life on Mars (Earth-relative gravito-inertial acceleration (GIA) g = 0.378), or at icy moons such as Europa (g = 0.134) or Enceladus (g = 0.012). We confirm the ability to sequence at Mars as well as near Europa or Lunar (g = 0.166) and lower g levels, demonstrate the functionality of updated chemistry and sequencing protocols under parabolic flight, and reveal consistent performance across g level, during dynamic accelerations, and despite vibrations with significant power at translocation-relevant frequencies. Our work strengthens the use case for nanopore sequencing in dynamic environments on Earth and in space, including as part of the search for nucleic-acid based life beyond Earth.

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.

The relative role of visual and non-visual cues in determining the perceived direction of “up”: Experiments in parabolic flight

2005 ◽  
Vol 56 (9-12) ◽  
pp. 1025-1032 ◽  
Author(s):  
H.L. Jenkin ◽  
R.T. Dyde ◽  
J.E. Zacher ◽  
D.C. Zikovitz ◽  
M.R. Jenkin ◽  
...  
Keyword(s):  
Visual Cues ◽  
Parabolic Flight ◽  
Relative Role

Altered Gravity Highlights Central Pattern Generator Mechanisms

2008 ◽  
Vol 100 (5) ◽  
pp. 2819-2824 ◽  
Author(s):  
Olivier White ◽  
Yannick Bleyenheuft ◽  
Renaud Ronsse ◽  
Allan M. Smith ◽  
Jean-Louis Thonnard ◽  
...  
Keyword(s):  
Neural Networks ◽  
Resonant Frequency ◽  
Parabolic Flight ◽  
Central Pattern Generators ◽  
Arm Movement ◽  
Rhythmic Movements ◽  
Earth Environment ◽  
Major Interest ◽  
Microgravity Conditions ◽  
Pattern Generators

In many nonprimate species, rhythmic patterns of activity such as locomotion or respiration are generated by neural networks at the spinal level. These neural networks are called central pattern generators (CPGs). Under normal gravitational conditions, the energy efficiency and the robustness of human rhythmic movements are due to the ability of CPGs to drive the system at a pace close to its resonant frequency. This property can be compared with oscillators running at resonant frequency, for which the energy is optimally exchanged with the environment. However, the ability of the CPG to adapt the frequency of rhythmic movements to new gravitational conditions has never been studied. We show here that the frequency of a rhythmic movement of the upper limb is systematically influenced by the different gravitational conditions created in parabolic flight. The period of the arm movement is shortened with increasing gravity levels. In weightlessness, however, the period is more dependent on instructions given to the participants, suggesting a decreased influence of resonant frequency. Our results are in agreement with a computational model of a CPG coupled to a simple pendulum under the control of gravity. We demonstrate that the innate modulation of rhythmic movements by CPGs is highly flexible across gravitational contexts. This further supports the involvement of CPG mechanisms in the achievement of efficient rhythmic arm movements. Our contribution is of major interest for the study of human rhythmic activities, both in a normal Earth environment and during microgravity conditions in space.

scholarly journals Nanopore Sequencing at Mars, Europa and Microgravity Conditions

2020 ◽  
Author(s):  
Christopher E. Carr ◽  
Noelle C. Bryan ◽  
Kendall N. Saboda ◽  
Srinivasa A. Bhattaru ◽  
Gary Ruvkun ◽  
...  
Keyword(s):  
Parabolic Flight ◽  
Space Station ◽  
Space Vehicles ◽  
Nanopore Sequencing ◽  
Icy Moons ◽  
Microbial Monitoring ◽  
Oxford Nanopore ◽  
Microgravity Conditions ◽  
Low Mass ◽  
Consistent Performance

AbstractNanopore sequencing, as represented by Oxford Nanopore Technologies’ MinION, is a promising technology for in situ life detection and for microbial monitoring including in support of human space exploration, due to its small size, low mass (∼100 g) and low power (∼1W). Now ubiquitous on Earth and previously demonstrated on the International Space Station (ISS), nanopore sequencing involves translocation of DNA through a biological nanopore on timescales of milliseconds per base. Nanopore sequencing is now being done in both controlled lab settings as well as in diverse environments that include ground, air and space vehicles. Future space missions may also utilize nanopore sequencing in reduced gravity environments, such as in the search for life on Mars (Earth-relative gravito-inertial acceleration (GIA) g = 0.378), or at icy moons such as Europa (g = 0.134) or Enceladus (g = 0.012). We confirm the ability to sequence at Mars as well as near Europa or Lunar (g = 0.166) and lower g levels, demonstrate the functionality of updated chemistry and sequencing protocols under parabolic flight, and reveal consistent performance across g level, during dynamic accelerations, and despite vibrations with significant power at translocation-relevant frequencies. Our work strengthens the use case for nanopore sequencing in dynamic environments on Earth and in space, including as part of the search for nucleic-acid based life beyond Earth.

scholarly journals Age-Related Changes in Human Posture Control: Sensory Organization Tests

1990 ◽  
Vol 1 (1) ◽  
pp. 73-85 ◽  
Author(s):  
R.J. Peterka ◽  
F.O. Black
Keyword(s):  
Visual Cues ◽  
Human Subjects ◽  
Body Sway ◽  
Support Surface ◽  
Eyes Closed ◽  
Sensory Organization ◽  
Age Related ◽  
Eyes Open ◽  
Orientation Cues ◽  
Anterior Posterior

Postural control was measured in 214 human subjects ranging in age from 7 to 81 y. Sensory organization tests measured the magnitude of anterior-posterior body sway during six 21 s trials in which visual and somatosensory orientation cues were normal, altered (by rotating the visual surround and support surface in proportion to the subject’s sway), or vision eliminated (eyes closed). No age-related increase in postoral sway was found for subjects standing on a fixed support surface with eyes open or closed. However, age-related increases in sway were found for conditions involving altered visual or somatosensory cues. Subjects older tban about 55 y showed the largest sway increases. Subjects younger than about 15 y were also sensitive to alteration of sensory cues. On average, the older subjects were more affected by altered visual cues, whereas younger subjects had more difficulty with altered somatosensory cues.

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