Eyelid Movements: Behavioral Studies of Blinking in Humans Under Different Stimulus Conditions

2003 ◽  
Vol 89 (5) ◽  
pp. 2784-2796 ◽  
Author(s):  
Frans VanderWerf ◽  
Peter Brassinga ◽  
Dik Reits ◽  
Majid Aramideh ◽  
Bram Ongerboer de Visser
Keyword(s):  
Human Subjects ◽  
Total Duration ◽  
Eye Position ◽  
Healthy Human ◽  
Phase Duration ◽  
Upper Eyelid ◽  
Search Coil ◽  
Behavioral Studies ◽  
Zero Position ◽  
Phase Amplitude

The kinematics and neurophysiological aspects of eyelid movements were examined during spontaneous, voluntary, air puff, and electrically induced blinking in healthy human subjects, using the direct magnetic search coil technique simultaneously with electromyographic recording of the orbicularis oculi muscles (OO-EMG). For OO-EMG recordings, surface electrodes were attached to the lower eyelids. To measure the vertical lid displacement, a search coil with a diameter of 3 mm was placed 1 mm from the rim on the upper eyelid on a marked position. Blink registrations were performed from the zero position and from 28 randomly chosen positions. Blinks elicited by electrical stimulation of the supraorbital nerve had shortest duration and were least variable. In contrast, spontaneous blinks had longer duration and greater variability. Blinks induced by air puff had a slightly longer duration and similar variability as electrically induced blinks. There was a correlation between the maximal down phase amplitude and the integrated OO-EMG. Blink duration and maximal down phase amplitude were affected by eye position. Eyes positioned 30° above horizontal displayed the shortest down phase duration and the largest maximal down phase amplitude and velocity. At 30° below horizontal, blinks had the longest total duration, the longest down phase duration, and the lowest maximal down phase amplitude and velocity. The simultaneously recorded integrated OO-EMG was largest in the 30° downward position. In four subjects, the average blinking data showed a linear relation between eye position and OO-EMG, maximal down phase amplitude, and maximal downward velocity.

Dissociated Hysteresis of Static Ocular Counterroll in Humans

2006 ◽  
Vol 95 (4) ◽  
pp. 2222-2232 ◽  
Author(s):  
A. Palla ◽  
C. J. Bockisch ◽  
O. Bergamin ◽  
D. Straumann
Keyword(s):  
Second Harmonic ◽  
Human Subjects ◽  
Body Position ◽  
Three Dimensional ◽  
Upright Position ◽  
Whole Body ◽  
Eye Position ◽  
Healthy Human ◽  
Ocular Counterroll ◽  
Head Roll

In stationary head roll positions, the eyes are cyclodivergent. We asked whether this phenomenon can be explained by a static hysteresis that differs between the eyes contra- (CE) and ipsilateral (IE) to head roll. Using a motorized turntable, healthy human subjects ( n = 8) were continuously rotated about the earth-horizontal naso-occipital axis. Starting from the upright position, a total of three full rotations at a constant velocity (2°/s) were completed (acceleration = 0.05°/s2, velocity plateau reached after 40 s). Subjects directed their gaze on a flashing laser dot straight ahead (switched on 20 ms every 2 s). Binocular three-dimensional eye movements were recorded with dual search coils that were modified (wires exiting inferiorly) to minimize torsional artifacts by the eyelids. A sinusoidal function with a first and second harmonic was fitted to torsional eye position as a function of torsional whole body position at constant turntable velocity. The amplitude and phase of the first harmonic differed significantly between the two eyes (paired t-test: P < 0.05): on average, counterroll amplitude of IE was larger [CE: 6.6 ± 1.6° (SD); IE: 8.1 ± 1.7°), whereas CE showed more position lag relative to the turntable (CE: 12.5 ± 10.7°; IE: 5.1 ± 8.7°). We conclude that cyclodivergence observed during static ocular counterroll is mainly a result of hysteresis that depends on whether eyes are contra- or ipsilateral to head roll. Static hysteresis also explains the phenomenon of residual torsion, i.e., an incomplete torsional return of the eyes when the first 360° whole body rotation was completed and subjects were back in upright position (extorsion of CE: 2.0 ± 0.10°; intorsion of IE: 1.4 ± 0.10°). A computer model that includes asymmetric backlash for each eye can explain dissociated torsional hysteresis during quasi-static binocular counterroll. We hypothesize that ocular torsional hysteresis is introduced at the level of the otolith pathways because the direction-dependent torsional position lag of the eyes is related to the head roll position and not the eye position.

Minimizing Carry-Over Effects After Treatment Failure and Maximizing Therapeutic Outcome

2014 ◽  
Vol 222 (3) ◽  
pp. 171-178 ◽  
Author(s):  
Mareile Hofmann ◽  
Nathalie Wrobel ◽  
Simon Kessner ◽  
Ulrike Bingel
Keyword(s):  
Treatment Failure ◽  
Human Subjects ◽  
Subsequent Treatment ◽  
Clinical Samples ◽  
Administration Route ◽  
Healthy Human ◽  
Negative Experiences ◽  
Analgesic Treatment ◽  
Balanced Design ◽  
Carry Over

According to experimental and clinical evidence, the experiences of previous treatments are carried over to different therapeutic approaches and impair the outcome of subsequent treatments. In this behavioral pilot study we used a change in administration route to investigate whether the effect of prior treatment experience on a subsequent treatment depends on the similarity of both treatments. We experimentally induced positive or negative experiences with a topical analgesic treatment in two groups of healthy human subjects. Subsequently, we compared responses to a second, unrelated and systemic analgesic treatment between both the positive and negative group. We found that there was no difference in the analgesic response to the second treatment between the two groups. Our data indicate that a change in administration route might reduce the influence of treatment history and therefore be a way to reduce negative carry-over effects after treatment failure. Future studies will have to validate these findings in a fully balanced design including larger, clinical samples.

Detection of Soluble Fibrin Monomer Complexes in Blood by Means of Protamine Sulphate Test

1968 ◽  
Vol 20 (01/02) ◽  
pp. 044-049 ◽  
Author(s):  
B Lipiński ◽  
K Worowski
Keyword(s):  
Human Subjects ◽  
Coronary Thrombosis ◽  
Mean Value ◽  
Healthy Human ◽  
Protamine Sulphate ◽  
Soluble Fibrin ◽  
Fibrin Monomer ◽  
Dog Plasma ◽  
The Mean ◽  
Precipitable Protein

SummaryIn the present paper described is a simple test for detecting soluble fibrin monomer complexes (SFMC) in blood. The test consists in mixing 1% protamine sulphate with diluted oxalated plasma or serum and reading the optical density at 6190 Å. In experiments with dog plasma, enriched with soluble fibrin complexes, it was shown that OD read in PS test is proportional to the amount of fibrin recovered from the precipitate. It was found that SFMC level in plasma increases in rabbits infused intravenously with thrombin and decreases after injection of plasmin with streptokinase. In both cases PS precipitable protein in serum is elevated indicating enhanced fibrinolysis. In healthy human subjects the mean value of OD readings in plasma and sera were found to be 0.30 and 0.11, while in patients with coronary thrombosis they are 0.64 and 0.05 respectively. The origin of SFMC in circulation under physiological and pathological conditions is discussed.

Chronic stress decreases circulating endocannabinoid 2-arachidonoylglycerol in healthy human subjects

2015 ◽  
Author(s):  
Buqing Yi ◽  
Igor Nichiporuk ◽  
Matthias Feuerecker ◽  
Gustav Schelling ◽  
Alexander Chouker
Keyword(s):  
Chronic Stress ◽  
Human Subjects ◽  
Healthy Human ◽  
Healthy Human Subjects

scholarly journals Critical Examination of the Parametric Approaches to Analysis of the Non-Verbal Human Behavior: A Case Study in Facial Pre-Touch Interaction

2020 ◽  
Vol 10 (11) ◽  
pp. 3817
Author(s):  
Soheil Keshmiri ◽  
Masahiro Shiomi ◽  
Kodai Shatani ◽  
Takashi Minato ◽  
Hiroshi Ishiguro
Keyword(s):  
Normal Distribution ◽  
Human Subjects ◽  
Critical Examination ◽  
Reliable Estimate ◽  
Support Vector ◽  
Face Area ◽  
Behavioral Studies ◽  
Touch Interaction ◽  
Ordinary Regression ◽  
Simplifying Assumptions

A prevailing assumption in many behavioral studies is the underlying normal distribution of the data under investigation. In this regard, although it appears plausible to presume a certain degree of similarity among individuals, this presumption does not necessarily warrant such simplifying assumptions as average or normally distributed human behavioral responses. In the present study, we examine the extent of such assumptions by considering the case of human–human touch interaction in which individuals signal their face area pre-touch distance boundaries. We then use these pre-touch distances along with their respective azimuth and elevation angles around the face area and perform three types of regression-based analyses to estimate a generalized facial pre-touch distance boundary. First, we use a Gaussian processes regression to evaluate whether assumption of normal distribution in participants’ reactions warrants a reliable estimate of this boundary. Second, we apply a support vector regression (SVR) to determine whether estimating this space by minimizing the orthogonal distance between participants’ pre-touch data and its corresponding pre-touch boundary can yield a better result. Third, we use ordinary regression to validate the utility of a non-parametric regressor with a simple regularization criterion in estimating such a pre-touch space. In addition, we compare these models with the scenarios in which a fixed boundary distance (i.e., a spherical boundary) is adopted. We show that within the context of facial pre-touch interaction, normal distribution does not capture the variability that is exhibited by human subjects during such non-verbal interaction. We also provide evidence that such interactions can be more adequately estimated by considering the individuals’ variable behavior and preferences through such estimation strategies as ordinary regression that solely relies on the distribution of their observed behavior which may not necessarily follow a parametric distribution.

scholarly journals Acacia Gum Is Well Tolerated While Increasing Satiety and Lowering Peak Blood Glucose Response in Healthy Human Subjects

Nutrients ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 618
Author(s):  
Riley Larson ◽  
Courtney Nelson ◽  
Renee Korczak ◽  
Holly Willis ◽  
Jennifer Erickson ◽  
...  
Keyword(s):  
Blood Glucose ◽  
Human Subjects ◽  
Area Under The Curve ◽  
Soluble Fiber ◽  
Healthy Human ◽  
Glucose Response ◽  
Blood Glucose Response ◽  
Acacia Gum ◽  
Fiber Treatment ◽  
Healthy Human Subjects

Acacia gum (AG) is a non-viscous soluble fiber that is easily incorporated into beverages and foods. To determine its physiological effects in healthy human subjects, we fed 0, 20, and 40 g of acacia gum in orange juice along with a bagel and cream cheese after a 12 h fast and compared satiety, glycemic response, gastrointestinal tolerance, and food intake among treatments. Subjects (n = 48) reported less hunger and greater fullness at 15 min (p = 0.019 and 0.003, respectively) and 240 min (p = 0.036 and 0.05, respectively) after breakfast with the 40 g fiber treatment. They also reported being more satisfied at 15 min (p = 0.011) and less hungry with the 40 g fiber treatment at 30 min (p = 0.012). Subjects reported more bloating, flatulence, and GI rumbling on the 40 g fiber treatment compared to control, although values for GI tolerance were all low with AG treatment. No significant differences were found in area under the curve (AUC) or change from baseline for blood glucose response, although actual blood glucose with 20 g fiber at 30 min was significantly less than control. Individuals varied greatly in their postprandial glucose response to all treatments. AG improves satiety response and may lower peak glucose response at certain timepoints, and it is well tolerated in healthy human subjects. AG can be added to beverages and foods in doses that can help meet fiber recommendations.

Heart rate variability and baroreflex sensitivity are reduced in chronically undernourished, but otherwise healthy, human subjects

2003 ◽  
Vol 104 (3) ◽  
pp. 295-302 ◽  
Author(s):  
Mario VAZ ◽  
A.V. BHARATHI ◽  
S. SUCHARITA ◽  
D. NAZARETH
Keyword(s):  
Heart Rate ◽  
Heart Rate Variability ◽  
High Frequency ◽  
Baroreflex Sensitivity ◽  
Human Subjects ◽  
Normal Weight ◽  
Autonomic Nerve ◽  
Total Power ◽  
Healthy Human ◽  
Frequency Power

Alterations in autonomic nerve activity in subjects in a chronically undernourished state have been proposed, but have been inadequately documented. The present study evaluated heart rate and systolic blood pressure variability in the frequency domain in two underweight groups, one of which was undernourished and recruited from the lower socio-economic strata [underweight, undernourished (UW/UN); n = 15], while the other was from a high class of socio-economic background [underweight, well nourished (UW/WN); n = 17], as well as in normal-weight controls [normal weight, well nourished (NW/WN); n = 27]. Baroreflex sensitivity, which is a determinant of heart rate variability, was also assessed. The data indicate that total power (0–0.4Hz), low-frequency power (0.04–0.15Hz) and high-frequency power (0.15–0.4Hz) of RR interval variability were significantly lower in the UW/UN subjects (P<0.05) than in the NW/WN controls when expressed in absolute units, but not when the low- and high-frequency components were normalized for total power. Baroreflex sensitivity was similarly lower in the UW/UN group (P<0.05). Heart rate variability parameters in the UW/WN group were generally between those of the UW/UN and NW/WN groups, but were not statistically different from either. The mechanisms that contribute to the observed differences between undernourished and normal-weight groups, and the implications of these differences, remain to be elucidated.

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