18 research outputs found
Examining the ability to track multiple moving targets as a function of postural stability: a comparison between team sports players and sedentary individuals
Background: The ability to track multiple objects plays a key role in team ball sports
actions. However, there is a lack of research focused on identifying multiple object
tracking (MOT) performance under rapid, dynamic and ecologically valid
conditions. Therefore, we aimed to assess the effects of manipulating postural
stability on MOT performance.
Methods: Nineteen team sports players (soccer, basketball, handball) and sixteen
sedentary individuals performed the MOT task under three levels of postural stability
(high, medium, and low). For the MOT task, participants had to track three out of
eight balls for 10 s, and the object speed was adjusted following a staircase procedure.
For postural stability manipulation, participants performed three identical protocols
(randomized order) of the MOT task while standing on an unstable platform, using
the training module of the Biodex Balance System SD at levels 12 (high-stability),
eight (medium-stability), and four (low-stability).
Results: We found that the ability to track moving targets is dependent on the
balance stability conditions (F2,66 = 8.7, p < 0.001, ηÂČ = 0.09), with the disturbance of
postural stability having a negative effect on MOT performance. Moreover, when
compared to sedentary individuals, team sports players showed better MOT scores
for the high-stability and the medium-stability conditions (corrected p-value = 0.008,
Cohenâs d = 0.96 and corrected p-value = 0.009, Cohenâs d = 0.94; respectively)
whereas no differences were observed for the more unstable conditions (lowstability)
between-groups.
Conclusions: The ability to track moving targets is sensitive to the level of postural
stability, with the disturbance of balance having a negative effect on MOT
performance. Our results suggest that expertise in team sports training is transferred
to non-specific sport domains, as shown by the better performance exhibited by team
sports players in comparison to sedentary individuals. This study provides novel
insights into the link between individualâs ability to track multiple moving objects
and postural control in team sports players and sedentary individuals
Effects of water drinking on corneal biomechanics: The association with intraocular pressure changes
Purpose: We aimed to assess the impact of drinking water (500 and 1000 mL) on corneal biomechanics
and determine the level of association between changes in intraocular pressure and variations in the
different biomechanical properties of the cornea. Methods: A total of 39 healthy young adults ingested
either 1000 mL (n = 21) or 500 mL (n = 18) of tap water in 5 min. The CorVis ST system was used to assess
corneal biomechanics at baseline and at 15, 30, and 45 min after water ingestion. Results: Water drinking
induced statistically significant changes in the deformation amplitude (P < 0.001, ηÂČ = 0.166), highest
concavity time (P = 0.012, ηÂČ = 0.093), peak distance (P < 0.001, ηÂČ = 0.171), time and velocity of the first
applanation (P < 0.001, ηÂČ = 0.288 and P = 0.016, ηÂČ = 0.087, respectively), and time and velocity of the second
applanation (P = 0.030, ηÂČ = 0.074 and P = 0.001, ηÂČ = 0.132, respectively), being independent of the amount
of water ingested (P > 0.05 in all cases). There were significant associations between changes in intraocular
pressure and some parameters of corneal biomechanics. Conclusion: Small variations in wholeâbody
hydration status alter different biomechanical properties of the cornea, with these changes being associated
with intraocular pressure levels. These findings indicate that wholeâbody hydration status can be considered
for the diagnosis and management of different ocular conditions
The shortâterm effects of wearing swimming goggles on corneal biomechanics
Funding for open access charge: Universidad de Granada/CBUA. The authors have no financial or proprietary interest in a product, method or material described herein. The article has not been presented in a meeting.Purpose This study aimed to assess the impact
of wearing swimming goggles (SG) on corneal
biomechanics.
Methods Corneal deformation response, central
corneal thickness (CCT), intraocular pressure (IOP)
and biomechanically corrected intraocular pressure
(bIOP) were measured with the Corvis system (Oculus
OptikgerÀte GmbH, Wetzlar, Germany) in thirtyone
healthy young adults while wearing a drilled
SG. All measurements were obtained before, at 30 s,
2 min, 3.5 min and 5 min of wearing SG, just after
SG removal and after 2 min of SG removal.
Results The corneal biomechanics is sensitive to
SG wear, observing lower corneal deformability
during SG use. Specifically, wearing SG caused an
increase in the time and length of the first applanation
and radius curvature at the highest concavity,
as well as a decrease and in the velocity of the first
applanation and time and deformation amplitude
of the second applanation (p < 0.001 in all cases).
After SG removal, corneal biomechanical parameters
showed a rebound-effect, obtaining a higher corneal
deformability in comparison with baseline reading
(p-corrected < 0.05 in all cases). Additionally, IOP and bIOP significantly increased while wearing SG
(p < 0.001 in both cases), whereas CCT remained stable
(p = 0.850).
Conclusions Wearing SG modifies the biomechanical
properties of the cornea, with reduced corneal
deformability during SG wear. The outcomes of this
study should be taken into consideration when making
clinical decisions in subjects at high risk of developing
corneal ectasias or glaucoma, as well as in the
post-surgical management of these ocular conditions.Universidad de Granada/CBU
'Greenwashing': amistades peligrosas. PredisposiciĂłn directiva a involucrarse con 'greenwashers' ante diferentes niveles de certeza
El "greenwashing" es una estrategia de comunicación simbólica que consiste en divulgar información medioambiental positiva de la empresa, tratando de obviar los aspectos negativos. Usando un experimento con 125 directivos de empresas españolas, en este trabajo se analiza como la percepción del "greenwashing" afecta a mantener relaciones comerciales con un "greenwashers", existiendo discrepancias cuando los resultados económicos de la relación comercial son conocidos. Los resultados muestran que los directivos tienden a penalizar los comportamientos de "greenwasing", pero que esta predisposición negativa es menor cuando se conoce la obtención de ganancias en la relación con el "greenwasher"
Changes in accommodation and behavioural performance with a contact lens for myopia management: A comparison between a dual-focus and a single-vision soft contact lens
Introduction: Dual-focus
soft contact lenses for myopia management have demonstrated
to be an effective strategy to reduce myopia progression. However, this
optical design has been shown to alter visual quality and accommodative function.
The aim of this study was to examine the accommodative and behavioural performance
during the execution of a psychomotor vigilance task (PVT) while wearing
dual-focus
and single-vision
soft contact lenses.
Methods: The steady-state
accommodative response was recorded with the
WAM-5500
binocular open-field
autorefractor during the execution of a 10-min
PVT at 50 cm either with the dual-focus
(MiSight 1-day)
or single-vision
(Proclear
1-day)
soft contact lenses, using a sample of 23 healthy young adults. Each experimental
session was performed on two different days in a counterbalanced order.
Results: A greater lag of accommodation, variability of accommodation and reaction
time was found while wearing dual-focus
in comparison with single-vision
soft contact lenses (mean differences during the 10-min
PVT were 0.58 ± 0.81 D,
p < 0.001; 0.31 ± 0.17 D, p < 0.001 and 15.22 ± 20.93 ms, p = 0.002, respectively). Also,
a time-on-
task
effect was found for the variability of accommodation and reaction
time (p = 0.001 and p < 0.001, respectively), observing higher values over time.
However, the lag of accommodation did not change significantly as a function of
time-on-
task
(p = 0.33).
Conclusion: Dual-focus
soft contact lens wear influences the steady-state
accommodative
response and behavioural performance during the execution of a visual
vigilance task in the short-term.
Eye care practitioners should be aware of these effects
when prescribing these lenses for myopia management, and provide specific
recommendations according to the individual visual needs
Effect of manipulating the vergence/accommodation and image size mismatches of the ±2D flipper test on the frequency and precision of accommodative facility
Purpose: The ±2.00 D accommodative facility test presents several limitations, in-
cluding the lack of objective information and inherent characteristics such as ver-
gence/accommodative conflict, change in apparent size of the image, subjective
criteria for judging blur and motor reaction time. By using free-space viewing con-
ditions and an open-field autorefractor to monitor the refractive state, we exam-
ined the impact of manipulating these factors on the qualitative and quantitative
assessment of accommodative facility.
Methods: Twenty-five healthy young adults (24.5 ± 4.5 years) took part in this
study. Participants performed three accommodative facility tests (adapted flipper,
4D free-space viewing and 2.5D free-space viewing) under both monocular and
binocular conditions in random order. A binocular open-field autorefractor was
used to assess the accommodative response continuously, and these data were
used to characterise accommodative facility quantitatively and qualitatively.
Results: There were statistically significant differences between the three testing
methods both quantitatively (p < 0.001) and qualitatively (p = 0.02). For the same
accommodative demand, a lower number of cycles was obtained for the adapted
flipper condition in comparison with the 4D free-space viewing test (corrected
p-value < 0.001, Cohen's d = 0.78). However, this comparison did not reach statisti-
cal significance for qualitative measures of accommodative facility (corrected p-
value = 0.82, Cohen's d 0.05).
Conclusions: These data provide evidence that the qualitative assessment of ac-
commodative facility is not influenced by the inherent limitations of the ±2.00 D
flipper test. The use of qualitative outcomes by incorporating an open-field au-
torefractor allows examiners to increase the validity of the accommodative facility
test in both clinical and research settings
Intraocular pressure responses to a virtual reality shooting simulation in active-duty members of the Spanish Army: The influence of task complexity
Ocular physiology is sensitive to cognitively demanding tasks. However, it is unknown whether the intraocular
pressure is also affected by the cognitive demands of military operations. The main objective was to determine
the impact of a virtual reality shooting simulation with two levels of complexity on intraocular pressure levels in
military personnel. Eighteen active-duty members of the Spanish Army and eighteen civilians performed two 4
min simulated shooting tasks with two levels of complexity using a virtual reality. In the âeasyâ task participants
performed a simulated shoot when the stimulus (military with a rifle) appeared, while in the âdifficultâ task the
stimulus randomly was a military with a rifle or with his hands on the air and participants were instructed to
respond only when the military with a rifle appeared. Intraocular pressure was measured with a rebound
tonometer before and immediately after each task. Complementarily, perceived levels of mental load and
shooting performance (reaction time) were assessed. Intraocular pressure was greater after completing the more
complex task in both military personnel (p-value < 0.01, CohenÂŽs d = 1.19) and civilians (p-value < 0.01, CohenÂŽs
d = 1.16). Also, perceived levels of task load and reaction time were higher in the difficult compared to the easy
shooting tasks (both p < 0.001). The rise in intraocular pressure is positively associated with the cognitive
demands of simulated military operations. The potential application of this finding is the development of
objective tools based on intraocular pressure for the evaluation of the mental state in real-world contexts,
permitting to improve soldiersÂŽsafety and performance.CEMIX (Centro Mixto UGR-MADOC, Army of Spain) 5/4/20 TR-COMBAT
Association of military-specific reaction time performance with physical fitness and visual skills
Background: The aim of the present study was to explore whether military-specific
reaction time (RT) test performance is affected by individualsâ physical and visual
skills.
Method: In a single testing session, the military-specific Simple and Go, No-Go RT,
aerobic power (20-m Multistage Shuttle Run test), maximal upper- and lower-body
mechanical capacities (bench press and squat against different loads), and visual
skills (multiple object tracking and dynamic visual acuity) of 30 young men (15
active-duty military personnel and 15 sport science students) were evaluated.
Results: The main findings revealed that the Simple RT and Go, No-Go RT presented
(1) with aerobic power non-significant small correlations in military personnel
(r = â0.39 and â0.35, respectively) and non-significant negligible correlations in
sport science students (r = â0.10 and 0.06, respectively), (2) inconsistent and
generally non-significant correlations with the maximal mechanical capacities of the
upper- and lower-body muscles (r range = â0.10, 0.67 and â0.27, 0.48, respectively),
(3) non-significant correlations with visual skills (r magnitude â„ 0.58) with the only
exception of the Go, No-Go RT that was significantly correlated to all visual variables
in the group of students (i.e., students who achieved better results during visual tests
had shorter RT; r magnitude â„ 0.58), and (4) none of the physical and visual variables
significantly predicted the Simple RT or Go, No-Go RT.
Conclusion: Altogether, these results indicate that military-specific RT performance
is generally independent of physical and visual skills in both military personnel and
active university students.CEMIX (Centro Mixto UGR-MADOC, Army of Spain) 5/4/20 TR-COMBATEMinistry of Education, Science & Technological Development, Serbia 451-03-9/2021-14/20015
Analysis of oculo - visual parameters as biomarkers of physical and/or mental effort
The human eyes are outgrowths of the brain and thus part of the central nervous system (Wilson
& OâDonnell, 1988). For this reason, the homeostatic disturbances as consequence of physically
or mentally demanding tasks are reflected on different ocular parameters with important
implications on the performance of different activities (e.g. sport games, driving), as well as in
terms of ocular health (e.g. glaucoma). Due to the fact that the ocular system is tightly linked to
the nervous systemÂŽs activation state, a small number of indices based on the ocular physiology
have been used to detect fatigue in several contexts (e.g. military operations, surgical procedures).
This field of research has direct applications in sport performance as well as in the management
and prevention of ocular diseases, and also has the potential impact to improve operator`s
performance and patient safety in risky situations. Therefore, it is reasonable to explore the effect
of physical and/or mental demands on the oculo-visual system, using objective visual indices
sensitive to central nervous system alterations.
The main objectives of the present Doctoral Thesis were to analyze the effects of physical and/or
mental effort on the oculo-visual system, and to examine the utility of different ocular
physiological indices as neuroergonomic tools for detecting cognitive and physical load and/or
fatigue.Tesis Univ. Granada. Departamento de Ăptic
How does greenwashing influence managers' decision-making? An experimental approach under stakeholder view
Greenwashing is a communication practice that consists of the deliberate and voluntary disclosure of environmentally misleading (or even false) information by a firm and which the public understands to be deceptive. Although prior literature analyzes greenwashing effects from the greenwasher perspective, the underlying perceptions of managers in the decision-making process related to maintaining (or contracting a new) a commercial partner, client, supplier, or other stakeholder who is a greenwasher, remain underexplored. This work empirically examines how greenwashing could influence managersâ decision making and whether a moderation effect of attitude toward environmental management exists in this relationship. In doing so, this work relies on experimental design