Rating Visual Velocities: Presentation Order versus Frequency of Occurrence

Perception ◽  
1997 ◽  
Vol 26 (1_suppl) ◽  
pp. 363-363
Author(s):  
A N Sokolov ◽  
W H Ehrenstein ◽  
M A Pavlova

Given equal frequencies of occurrence of stimuli, identical velocities receive higher or lower ratings depending on whether slow or fast velocities happen to occur on the early trials of a run (Ehrenstein and Sokolov, 1996 Perception25 Supplement, 34 – 35). When stimuli vary in their frequency of occurrence, this presentation-order effect might enhance or substitute the well-known frequency effect (Parducci's range - frequency theory) on category ratings. The aim of the present study was to contrast these two effects for ratings of visual velocities. Two groups of observers had to rate five stimulus velocities (3, 4.5, 6, 7.5, and 9 deg s−1) of a single luminous dot using three categories (slow, medium, fast). Respective frequencies of occurrence for these velocities were either 4 - 4 - 8 - 14 - 20 (group 1, negative skewing for frequency) or 20 - 14 - 8 - 4 - 4 (group 2, positive skewing). The quasi-random presentation order of each set, on the contrary, corresponded to either positively skewed (group 1) or negatively skewed (group 2) frequency distributions. No significant differences in the ratings of two groups (other than a slight preference for the presentation-order effect beyond 6 deg s−1) were found, as if the presentation order and frequency effects had cancelled each other. This suggests that the presentation order of velocities is at least as powerful as their frequency of occurrence. Lack of agreement between our results and predictions of computer-simulated Haubensak's consistency model as well as of Parducci's range - frequency theory requires a model which accounts for an interaction of the two effects.

2004 ◽  
Vol 13 (2) ◽  
pp. 158-163 ◽  
Author(s):  
Jerry Punch ◽  
Brad Rakerd ◽  
Antony Joseph

This study examined test-order effects on most comfortable loudness (MCL) and uncomfortable loudness (UCL) levels for spondaic words in 2 groups of 30 normal hearing listeners each. For Group 1, MCL was measured first, followed by UCL. For Group 2, UCL was measured first, and then MCL. A retest was conducted for both groups. Results showed that MCL was significantly elevated for Group 2, but not for Group 1. There was no effect on UCL for either group. In a follow-up experiment, the magnitude of the test-order effect on MCL increased significantly when MCL measurements followed UCL measurements closely in time. These results argue for management of the ordering and temporal spacing of MCL and UCL testing in clinical loudness measurements.


Plants ◽  
2021 ◽  
Vol 10 (10) ◽  
pp. 2052
Author(s):  
Olga G. Silkova ◽  
Yulia N. Ivanova ◽  
Dina B. Loginova ◽  
Lilia A. Solovey ◽  
Elena A. Sycheva ◽  
...  

To date, few data have been accumulated on the contribution of meiotic restitution to the formation of Triticum aestivum hybrid karyotypes. In this study, based on FISH and C-banding, karyotype reorganization was observed in three groups of F5 wheat–rye hybrids 1R(1A) × R. Aberrations, including aneuploidy, telocentrics, and Robertsonian translocations, were detected in all groups. Some of the Group 1 plants and all of the Group 2 plants only had a 4R4R pair (in addition to 1R1R), which was either added or substituted for its homeolog in ABD subgenomes. In about 82% of meiocytes, 4R4R formed bivalents, which indicates its competitiveness. The rest of the Group 1 plants had 2R and 7R chromosomes in addition to 1R1R. Group 3 retained all their rye chromosomes, with a small aneuploidy on the wheat chromosomes. A feature of the meiosis in the Group 3 plants was asynchronous cell division and omission of the second division. Diploid gametes did not form because of the significant disturbances during gametogenesis. As a result, the frequency of occurrence of the formed dyads was negatively correlated (r = −0.73) with the seed sets. Thus, meiotic restitution in the 8n triticale does not contribute to fertility or increased ploidy in subsequent generations.


2017 ◽  
Vol 11 (2) ◽  
pp. 98-105
Author(s):  
Maria V. Golovataya

Objective - to estimate frequency of occurrence of critical incidents during epidural anesthesia in gynecological patients with different sensitivity of peripheral chemoreflex. Material and Methods: prospective observational blind study, 54 gynecological patients, elective surgery. The day before the surgery, the sensitivity of peripheral chemoreflex was determined by the duration of an arbitrary threshold apnea in a test with a delayed respiration. According to the duration of the test, the patients were divided into groups: high (group «1») and medium (group «2») sensitivity of peripheral chemoreflex. During the operation and in the early postoperative period, critical incidents were recorded. Results and Conclusion(s). During epidural anesthesia in gynecological patients from intraoperative critical incidents is revealed hypotension. The frequency of occurrence of hypotension was 32.1% in patients of group «1» and 15.4% in patients of group «2». High sensitivity of peripheral chemoreflex in patients during epidural anesthesia is a predictor of unstable hemodynamics, as well as the risk of postoperative nausea and vomiting.


Perception ◽  
1996 ◽  
Vol 25 (1_suppl) ◽  
pp. 42-42
Author(s):  
W H Ehrenstein ◽  
A N Sokolov

Identical stimuli receive higher category ratings when presented in a positively skewed distribution (smaller stimuli occur more often than larger) and lower ratings in a negatively-skewed distribution (larger stimuli occur more often). This frequency effect has been explained by a tendency to assign the same categories to the same stimuli (‘consistency model’ by Haubensak, 1992 Journal of Experimental Psychology: Human Perception and Performance18 303) rather than by a tendency to assign the same number of stimuli to each category. The consistency model postulates the prime importance of stimuli that occur early in a sequence, with the underlying assumption that more frequent stimuli have higher probability of occurring earlier. Thus, presentation order rather than frequency of stimuli might be decisive. We asked whether a ‘frequency’ effect would still obtain when stimuli are in fact presented with equal frequency, but in a sequence derived from positively or negatively skewed source samples. Ratings of visual velocity were obtained for a dot that started to move at 0.5 deg below fixation in leftward or rightward direction for 2, 2.5, or 3 deg. Five velocities (3.0, 4.5, 6.0, 7.5, 9.0 deg s−1) were presented 10 times each (in a balanced combination of stimulus duration and displacement) and were rated by 32 subjects using three categories (slow, medium, fast). Our results clearly support Haubensak's model: identical velocities were rated higher/lower in presentation sequences that mimicked the order effects of positive/negative skewing, respectively. Moreover, computer simulation of the Haubensak model reveals good agreement between predicted and observed results.


VASA ◽  
2020 ◽  
Vol 49 (4) ◽  
pp. 281-284
Author(s):  
Atıf Yolgosteren ◽  
Gencehan Kumtepe ◽  
Melda Payaslioglu ◽  
Cuneyt Ozakin

Summary. Background: Prosthetic vascular graft infection (PVGI) is a complication with high mortality. Cyanoacrylate (CA) is an adhesive which has been used in a number of surgical procedures. In this in-vivo study, we aimed to evaluate the relationship between PVGI and CA. Materials and methods: Thirty-two rats were equally divided into four groups. Pouch was formed on back of rats until deep fascia. In group 1, vascular graft with polyethyleneterephthalate (PET) was placed into pouch. In group 2, MRSA strain with a density of 1 ml 0.5 MacFarland was injected into pouch. In group 3, 1 cm 2 vascular graft with PET piece was placed into pouch and MRSA strain with a density of 1 ml 0.5 MacFarland was injected. In group 4, 1 cm 2 vascular graft with PET piece impregnated with N-butyl cyanoacrylate-based adhesive was placed and MRSA strain with a density of 1 ml 0.5 MacFarland was injected. All rats were scarified in 96th hour, culture samples were taken where intervention was performed and were evaluated microbiologically. Bacteria reproducing in each group were numerically evaluated based on colony-forming unit (CFU/ml) and compared by taking their average. Results: MRSA reproduction of 0 CFU/ml in group 1, of 1410 CFU/ml in group 2, of 180 200 CFU/ml in group 3 and of 625 300 CFU/ml in group 4 was present. A statistically significant difference was present between group 1 and group 4 (p < 0.01), between group 2 and group 4 (p < 0.01), between group 3 and group 4 (p < 0.05). In terms of reproduction, no statistically significant difference was found in group 1, group 2, group 3 in themselves. Conclusions: We observed that the rate of infection increased in the cyanoacyrylate group where cyanoacrylate was used. We think that surgeon should be more careful in using CA in vascular surgery.


VASA ◽  
2015 ◽  
Vol 44 (5) ◽  
pp. 381-386 ◽  
Author(s):  
Christian Uhl ◽  
Thomas Betz ◽  
Andrea Rupp ◽  
Markus Steinbauer ◽  
Ingolf Töpel

Abstract. Summary: Background: This pilot study was set up to examine the effects of a continuous postoperative wound infusion system with a local anaesthetic on perioperative pain and the consumption of analgesics. Patients and methods: We included 42 patients in this prospective observational pilot study. Patients were divided into two groups. One group was treated in accordance with the WHO standard pain management protocol and in addition to that received a continuous local wound infusion treatment (Group 1). Group 2 was treated with analgesics in accordance with the WHO standard pain management protocol, exclusively. Results: The study demonstrated a significantly reduced postoperative VAS score for stump pain in Group 1 for the first 5 days. Furthermore, the intake of opiates was significantly reduced in Group 1 (day 1, Group 1: 42.1 vs. Group 2: 73.5, p = 0.010; day 2, Group 1: 27.7 vs. Group 2: 52.5, p = 0.012; day 3, Group 1: 23.9 vs. Group 2: 53.5, p = 0.002; day 4, Group 1: 15.7 vs. Group 2: 48.3, p = 0.003; day 5, Group 1 13.3 vs. Group 2: 49.9, p = 0.001). There were no significant differences between the two groups, neither in phantom pain intensity at discharge nor postoperative complications and death. Conclusions: Continuous postoperative wound infusion with a local anaesthetic in combination with a standard pain management protocol can reduce both stump pain and opiate intake in patients who have undergone transfemoral amputation. Phantom pain was not significantly affected.


1984 ◽  
Vol 52 (03) ◽  
pp. 253-255 ◽  
Author(s):  
C Isles ◽  
G D O Lowe ◽  
B M Rankin ◽  
C D Forbes ◽  
N Lucie ◽  
...  

SummaryWe have previously shown abnormalities of haemostasis suggestive of intravascular coagulation in patients with malignant hypertension, a condition associated with retinopathy and renal fibrin deposition. To determine whether such abnormalities are specific to malignant hypertension, we have measured several haemostatic and haemorheological variables in 18 patients with malignant hypertension (Group 1), 18 matched healthy controls (Group 2), and 18 patients with non-malignant hypertension (Group 3) matched for renal pathology, blood pressure and serum creatinine with Group 1. Both Groups 1 and 3 had increased mean levels of fibrinogen, factor VIIIc, beta-thrombo- globulin, plasma viscosity and blood viscosity (corrected for haematocrit); and decreased mean levels of haematocrit, antithrombin III and platelet count. Mean levels of fast antiplasmin and alpha2-macroglobulin were elevated in Group 1 but not in Group 3. We conclude that most blood abnormalities are not specific to malignant hypertension; are also present in patients with non-malignant hypertension who have similar levels of blood pressure and renal damage; and might result from renal damage as well as promoting further renal damage by enhancing fibrin deposition. However increased levels of fibrinolytic inhibitors in malignant hypertension merit further investigation in relation to removal of renal fibrin.


Author(s):  
Han-Jun Lee ◽  
Seong Hwan Kim ◽  
Nicolas Pujol ◽  
Yong-Beom Park

AbstractThe purpose of this study is to compare perception of leg length discrepancy (LLD) and clinical results of total knee arthroplasties (TKA) in patients with or without previous ipsilateral hip arthroplasty. Between 2008 and 2015, navigation-assisted TKA was performed in 43 patients with previous hip arthroplasty after hip fracture. After 1:3 propensity score matching was performed, 108 patients of primary navigation-assisted TKA (group 1) and 36 patients with hip arthroplasty (group 2) were included. Knee Society (KS) scores, Western Ontario and McMaster Universities Index (WOMAC) scores, and patients' satisfaction including perception of LLD were evaluated. Radiographic evaluation included mechanical axis, component position, and LLD. Logistic regression analysis was performed to find the factors that affect the clinical outcomes. No significant differences in radiologic and clinical evaluations, except for KS function score, patient's satisfaction and LLD (p< 0.001), were detected between the groups. LLD and its perception were significantly higher in group 2 (1.8 ± 3.4 mm in group 1 and 9.7 ± 4.1 mm in group 2, p = 0.000). Risk factors for the low KS function score were found as LLD (odds ratio [OR]: 1.403, p = 0.008) and previous hip arthroplasty itself (OR: 15.755, p = 0.002), but much higher OR was found in previous hip arthroplasty. Although the outcomes of TKA in patients with ipsilateral hip arthroplasty are comparable to those of primary TKA, LLD was high and patient's satisfaction and functional outcomes were low in patients with previous ipsilateral hip arthroplasty. Care should be taken when considering TKA in patients with previous hip arthroplasty. This is a Level III, case control study.


JMS SKIMS ◽  
2009 ◽  
Vol 12 (1) ◽  
pp. 3-7
Author(s):  
Aejaz A Baba ◽  
Bajpai Minu

Background: We evaluated the effects of alpha-1 blocker therapy on clinical and radiological abnormalities in patients of posterior urethral valve with bladder neck hypertrophy. Materials and Methods: A total of 74 patients with posterior urethral valves were seen at our department between 2003 and 2007. Out of these 24 had radiological evidence of bladder neck hypertrophy. Those patients with bladder neck hypertrophy who were seen before June 2006 and did not receive alpha-1 blocker (prazocin) therapy after valve ablation were assigned to group 1 (n=10). Group 2 consisted of 14 age matched patients with bladder neck hypertrophy and comparable prognostic factors who received alpha-1 blocker therapy after valve ablation (n=14). Micturating cystourethrography (MCU) was done periodically and a novel method used to calculate bladder neck hypertrophy. Trends in symptoms and radiological changes were evaluated throughout follow-up. Results: Mean patient age at presentation was 3.02±2.68 years in group 1 and 3.12±3.4 years in group 2. Bladder neck hypertrophy decreased from 2.3±1.0 to 2.0±0.5 in a mean time of 52.0 (34-52) weeks in group 1 where as it decreased from 2.2±0.5 to 1.6±0.3 in a mean time of 32.0 (22-52) weeks. Symptomatically patients in group 2 who received alpha-1 blocker therapy after valve ablation were better and had quick resolution of bladder neck hypertrophy. Conclusions: Use of alpha-1 blocker therapy in patients of posterior urethral valve with bladder neck hypertrophy helps in quick resolution of bladder neck hypertrophy. J Med Sci 2009;12(1):3-7.


2015 ◽  
Vol 18 (6) ◽  
pp. 255 ◽  
Author(s):  
Hüseyin Şaşkın ◽  
Çagrı Düzyol ◽  
Kazım Serhan Özcan ◽  
Rezan Aksoy ◽  
Mustafa Idiz

<strong>Objective:</strong> To investigate the association of platelet to lymphocyte ratio to mortality and morbidity after coronary artery bypass grafting operation.<br /><strong>Methods:</strong> We evaluated records of 916 patients who underwent coronary artery bypass grafting operation between January 2009 and May 2014 retrospectively. Patients were grouped as Group 1 (n = 604) if the platelet to lymphocyte ratio was above 142 and Group 2 (n = 312) if platelet to lymphocyte ratio was below 142.<br /><strong>Results:</strong> The number of patients who developed a neurologic event during the hospital stay and in the first postoperative month was 7 (1.2%) in Group 1 and 12 (3.8%) in Group 2 for which the difference was statistically significant (P = .007). Early term mortality occurred in 3 patients (0.5%) in Group 1 and in 10 patients (3.2%) in Group 2 for which the difference was statistically highly significant (P = .001). In univariate and multivariate regression analysis, the preoperative platelet to lymphocyte ratio was determined as an independent risk factor for occurrence of atrial fibrillation in the early postoperative period, reoperation for sternum dehiscence, occurrence of a neurologic event, prolonged stay in the hospital and mortality.<br /><strong>Conclusion:</strong> In this study, elevated levels of platelet to lymphocyte ratio were associated with mortality and morbidity after coronary artery bypass grafting operation.


Sign in / Sign up

Export Citation Format

Share Document