scholarly journals The time course of binocular rivalry during the phases of the menstrual cycle

2016 ◽  
Vol 16 (15) ◽  
pp. 22 ◽  
Author(s):  
Jocelyn L. Sy ◽  
Andrew J. Tomarken ◽  
Vaama Patel ◽  
Randolph Blake
Keyword(s):  
Menstrual Cycle ◽  
Binocular Rivalry ◽  
Time Course

scholarly journals The time course of binocular rivalry reveals a fundamental role of noise

2006 ◽  
Vol 6 (11) ◽  
pp. 8-8 ◽  
Author(s):  
J. W. Brascamp ◽  
R. van Ee ◽  
A. J. Noest ◽  
R. H. A. H. Jacobs ◽  
A. V. van den Berg
Keyword(s):  
Binocular Rivalry ◽  
Time Course

Visual sensitivity across the menstrual cycle

2004 ◽  
Vol 21 (4) ◽  
pp. 513-531 ◽  
Author(s):  
ALVIN EISNER ◽  
SARA N. BURKE ◽  
MAUREEN D. TOOMEY
Keyword(s):  
Oral Contraceptive ◽  
Menstrual Cycle ◽  
Time Course ◽  
Light Adaptation ◽  
Contraceptive Use ◽  
Visual Sensitivity ◽  
Visual Adaptation ◽  
Hormonal Change ◽  
Menstrual Cycles ◽  
Sensitivity Change

This study was designed to evaluate the hypothesis that hormonal change can affect lower level light-adaptation processes, which are likely to be retinally based. Foveal visual sensitivities were measured across several menstrual cycles of four women not using hormonally acting medication and across several menstrual cycles of three women using a triphasic oral contraceptive. One woman, diagnosed with premenstrual syndrome (PMS), was a subject for both groups. Sensitivities were measured for a series of test wavelengths for 580-nm backgrounds of 2.0 and 4.0 log td. Of the six individuals tested, one had clear evidence of visual-adaptation changes occurring in phase with the menstrual cycle. Prior to using the oral contraceptive, this individual (the PMS subject) experienced changes of short-wavelength-sensitive (SWS)-cone-mediated sensitivities of up to about 1.4 log unit on the 4.0 log td background. Her SWS-cone-mediated sensitivities tended to be highest near ovulation and lowest premenstrually. Threshold-versus-illuminance (TVI) curves confirmed that the rate of sensitivity decrease with increasing background illuminance (i.e. the TVI slope) was greater premenstrually. The degree of background-induced desensitization within her middle-wavelength-sensitive (MWS)/long-wavelength-sensitive (LWS) cone pathways also appeared to vary cyclically, but the magnitude of the variation was smaller and the time course appeared to be different. When this subject began oral contraceptive use, the patterns of sensitivity change were all altered. None of the other five subjects experienced changes of SWS-cone-mediated vision that were cyclic and significantly adaptation-state dependent. However, there was evidence for a limited degree of cyclic adaptation change within the MWS/LWS cone pathways of at least one additional subject. We conclude that hormonal change can—for some unknown proportion of women—be linked to alterations of retinal function. However, the alterations are not the same for all visual pathways, and there are pronounced individual differences. The data also demonstrate that individuals' visual adaptation capabilities can vary substantially over periods of weeks.

scholarly journals Mathematical Modeling and Simulation Provides Evidence for New Strategies of Ovarian Stimulation

2021 ◽  
Vol 12 ◽  
Author(s):  
Sophie Fischer ◽  
Rainald Ehrig ◽  
Stefan Schäfer ◽  
Enrico Tronci ◽  
Toni Mancini ◽  
...  
Keyword(s):  
Mathematical Modeling ◽  
Menstrual Cycle ◽  
Ovarian Stimulation ◽  
Time Course ◽  
Scientific Evidence ◽  
Coupled Model ◽  
Continuous Growth ◽  
Time Points ◽  
Follicular Waves ◽  
Normal Menstrual Cycle

New approaches to ovarian stimulation protocols, such as luteal start, random start or double stimulation, allow for flexibility in ovarian stimulation at different phases of the menstrual cycle. It has been proposed that the success of these methods is based on the continuous growth of multiple cohorts (“waves”) of follicles throughout the menstrual cycle which leads to the availability of ovarian follicles for ovarian controlled stimulation at several time points. Though several preliminary studies have been published, their scientific evidence has not been considered as being strong enough to integrate these results into routine clinical practice. This work aims at adding further scientific evidence about the efficiency of variable-start protocols and underpinning the theory of follicular waves by using mathematical modeling and numerical simulations. For this purpose, we have modified and coupled two previously published models, one describing the time course of hormones and one describing competitive follicular growth in a normal menstrual cycle. The coupled model is used to test ovarian stimulation protocols in silico. Simulation results show the occurrence of follicles in a wave-like manner during a normal menstrual cycle and qualitatively predict the outcome of ovarian stimulation initiated at different time points of the menstrual cycle.

scholarly journals Evidence for neural rhythms embedded within binocular rivalry

2019 ◽  
Vol 116 (30) ◽  
pp. 14811-14812 ◽  
Author(s):  
Oakyoon Cha ◽  
Randolph Blake
Keyword(s):  
Binocular Rivalry ◽  
Time Course ◽  
Time Series Data ◽  
Brain Activity ◽  
Series Data ◽  
Neural Oscillations ◽  
Large Dataset ◽  
Perceptual Judgments ◽  
Multistable Perception ◽  
Periodic Fluctuations

Evidence for perceptual periodicity emerges from studies showing periodic fluctuations in visual perception and decision making that are accompanied by neural oscillations in brain activity. We have uncovered signs of periodicity in the time course of binocular rivalry, a widely studied form of multistable perception. This was done by analyzing time series data contained in an unusually large dataset of rivalry state durations associated with states of exclusive monocular dominance and states of mixed perception during transitions between exclusive dominance. Identifiable within the varying durations of dynamic mixed perception are rhythmic clusters of durations whose incidence falls within the frequency band associated with oscillations in neural activity accompanying periodicity in perceptual judgments. Endogenous neural oscillations appear to be especially impactful when perception is unusually confounding.

Women at altitude: ventilatory acclimatization at 4,300 m

2001 ◽  
Vol 91 (4) ◽  
pp. 1791-1799 ◽  
Author(s):  
Stephen R. Muza ◽  
Paul B. Rock ◽  
Charles S. Fulco ◽  
Stacy Zamudio ◽  
Barry Braun ◽  
...  
Keyword(s):  
Menstrual Cycle ◽  
Time Course ◽  
Ventilatory Response ◽  
Alveolar Ventilation ◽  
Cycle Phase ◽  
Hypoxic Ventilatory Response ◽  
Menstrual Cycle Phase ◽  
Response Parameter ◽  
Effective Ventilation ◽  
End Tidal

Women living at low altitudes or acclimatized to high altitudes have greater effective ventilation in the luteal (L) compared with follicular (F) menstrual cycle phase and compared with men. We hypothesized that ventilatory acclimatization to high altitude would occur more quickly and to a greater degree in 1) women in their L compared with women in their F menstrual cycle phase, and 2) in women compared with men. Studies were conducted on 22 eumenorrheic, unacclimatized, sea-level (SL) residents. Indexes of ventilatory acclimatization [resting ventilatory parameters, hypoxic ventilatory response, hypercapnic ventilatory response (HCVR)] were measured in 14 women in the F phase and in 8 other women in the L phase of their menstrual cycle, both at SL and again during a 12-day residence at 4,300 m. At SL only, ventilatory studies were also completed in both menstrual cycle phases in 12 subjects (i.e., within-subject comparison). In these subjects, SL alveolar ventilation (expressed as end-tidal Pco 2) was greater in the L vs. F phase. Yet the comparison between L- and F-phase groups found similar levels of resting end-tidal Pco 2, hypoxic ventilatory response parameter A, HCVR slope, and HCVR parameter B, both at SL and 4,300 m. Moreover, these indexes of ventilatory acclimatization were not significantly different from those previously measured in men. Thus female lowlanders rapidly ascending to 4,300 m in either the L or F menstrual cycle phase have similar levels of alveolar ventilation and a time course for ventilatory acclimatization that is nearly identical to that reported in male lowlanders.

scholarly journals Revisiting individual differences in the time course of binocular rivalry

2018 ◽  
Vol 18 (7) ◽  
pp. 3 ◽  
Author(s):  
Jan W. Brascamp ◽  
Mark W. Becker ◽  
David Z. Hambrick
Keyword(s):  
Individual Differences ◽  
Binocular Rivalry ◽  
Time Course

Perimenstrual symptoms: time course of symptom intensity in relation to endocrinologically defined segments of the menstrual cycle.

1989 ◽  
Vol 51 (2) ◽  
pp. 173-194 ◽  
Author(s):  
D Schechter ◽  
G A Bachmann ◽  
J Vaitukaitis ◽  
D Phillips ◽  
D Saperstein
Keyword(s):  
Menstrual Cycle ◽  
Time Course ◽  
Symptom Intensity

Change in time course of posthyperventilation hyperpnea during menstrual cycle

1988 ◽  
Vol 64 (6) ◽  
pp. 2631-2635 ◽  
Author(s):  
N. Takano
Keyword(s):  
Menstrual Cycle ◽  
Time Course ◽  
Ventilatory Response ◽  
Minute Ventilation ◽  
Inverse Correlation ◽  
Decay Process ◽  
Slow Recovery ◽  
Voluntary Hyperventilation ◽  
End Tidal ◽  
The Brain

Ventilatory response after 1 min of voluntary hyperventilation (HV) was studied in 10 healthy women. Before, during, and after HV, end-tidal PCO2 (PETCO2) was maintained at a given level between resting and 60 Torr. After cessation of HV, hyperpnea was seen in 179 out of a total of 195 runs but in the remaining 16 runs in 3 subjects hypopnea occurred, both ventilatory changes being followed by slow recovery to the pre-HV level. The time constant (tau) of the decay process of post-HV hyperpnea was calculated and compared between the follicular (F) and luteal (L) phases of menstruation. For post-HV hypopnea, tau was assumed to be zero. There was an inverse correlation between tau and PETCO2 during the test, the relation being similar in F and L. With a phase change from F to L, tau value at resting PETCO2 increased from 17.7 to 23.7 s. Resting PETCO2 decreased from 40.8 to 37.7 Torr, and minute ventilation (VE) increased by 10%. The increased tau in L was ascribable to the decrease in resting PETCO2 but not to the increased ventilatory activity during the pre-HV period (corresponding to the resting VE) that was probably produced by ventilatory stimulation with progesterone in L. From these results, it is inferred that the ventilatory influence of progesterone might not be exerted on the brain stem, which has been implicated as a locus of the afterdischarge mechanism.

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