scholarly journals Difference threshold for stimulus length under simultaneous and nonsimultaneous viewing conditions

1967 ◽  
Vol 2 (5) ◽  
pp. 201-207 ◽  
Author(s):  
Hiroshi Ono
Keyword(s):  
Difference Threshold ◽  
Stimulus Length

Relationships Between Subjective Ratings and Objective Measures of Performance in Speechreading Sentences

1997 ◽  
Vol 40 (4) ◽  
pp. 900-911 ◽  
Author(s):  
Marilyn E. Demorest ◽  
Lynne E. Bernstein
Keyword(s):  
Hearing Impairment ◽  
Performance Evaluations ◽  
Objective Measures ◽  
Large Individual ◽  
Subjective Ratings ◽  
Objective Performance ◽  
Phonetic Distance ◽  
Stimulus Length ◽  
Measures Of Performance ◽  
Confidence Scale

Ninety-six participants with normal hearing and 63 with severe-to-profound hearing impairment viewed 100 CID Sentences (Davis & Silverman, 1970) and 100 B-E Sentences (Bernstein & Eberhardt, 1986b). Objective measures included words correct, phonemes correct, and visual-phonetic distance between the stimulus and response. Subjective ratings were made on a 7-point confidence scale. Magnitude of validity coefficients ranged from .34 to .76 across materials, measures, and groups. Participants with hearing impairment had higher levels of objective performance, higher subjective ratings, and higher validity coefficients, although there were large individual differences. Regression analyses revealed that subjective ratings are predictable from stimulus length, response length, and objective performance. The ability of speechreaders to make valid performance evaluations was interpreted in terms of contemporary word recognition models.

Ambient temperature does not affect the tactile sensitivity of mystacial vibrissae in harbour seals.

1998 ◽  
Vol 201 (22) ◽  
pp. 3023-3029 ◽  
Author(s):  
G Dehnhardt ◽  
B Mauck ◽  
H Hyvärinen
Keyword(s):  
Ambient Temperature ◽  
Thermal Emission ◽  
Normal Skin ◽  
Cold Season ◽  
Cooling Power ◽  
Difference Threshold ◽  
Tactile Sensitivity ◽  
Camera System ◽  
Width Difference ◽  
Harbour Seals

Vibrissae provide pinnipeds with tactile information primarily in the aquatic environment, which is characterized by its high thermal conductivity and large potential cooling power. Since studies of thermal effects on human tactile sensitivity have revealed that cooling below normal skin temperature impairs sensitivity, the present study investigates the tactile sensitivity of the vibrissal system of harbour seals at varying ambient temperatures. Using plates bearing gratings of alternating grooves and ridges, the texture difference thresholds of two adult seals were determined under water. We took advantage of the natural difference in ambient temperature between summer and winter. Mean water temperature was 1. 2 degreesC during the winter and 22 degreesC during the summer. During the cold season, the thermal status of both seals was examined using an infrared-sensitive camera system. The texture difference threshold of both seals remained the same (0.18 mm groove width difference) under both test conditions. The thermographic examination revealed that the skin areas of the head where the mystacial and supraorbital vibrissae are located show a substantially higher degree of thermal emission than do adjacent skin areas. This suggests that, in the vibrissal follicles of harbour seals, no vasoconstriction occurs during cold acclimation, so that the appropriate operating temperature for the mechanoreceptors is maintained.

Comparison of High Temperature Mechanical Behaviour and Microstructure of the New Gamma–TiAl8Ta with Gamma-TiAl8Nb Alloy

2010 ◽  
Vol 72 ◽  
pp. 40-45
Author(s):  
Giuliano Angella ◽  
Valentino Lupinc ◽  
Maurizio Maldini ◽  
Giovanni Onofrio
Keyword(s):  
High Temperature ◽  
Mechanical Behaviour ◽  
Low Cycle Fatigue ◽  
Fatigue Properties ◽  
Stress Intensity Factor Range ◽  
Fatigue Crack Propagation Rate ◽  
Difference Threshold ◽  
Temperature Range ◽  
R Ratio ◽  
Significant Difference

The high temperature creep and fatigue properties of two  -TiAl base intermetallic alloys, for gas turbine components, have been investigated within the Integrated European project IMPRESS. The alloys contain 8% at. of Ta or Nb, respectively. The microstructure of both alloys was cross convoluted lamellar rather than the well known conventional lamellar, typical of the usual -TiAl. The microstructure of the Ta containing alloy was homogeneous in all the analyzed batches whilst that of the Nb alloy appeared significantly spread out from specimen to specimen. The creep properties of the alloys were investigated in the temperature range 700-850°C with applied stresses in order to have times to rupture up to about 3,000 h. The creep behaviour presented no steady state regimes, but only minima of the creep rates between significant decelerating and accelerating regimes. The minimum creep rates of the Ta alloy resulted to be significantly slower than the Niobium alloy at the same creep conditions. In low cycle fatigue at 650 and 700°C the Ta  -TiAl showed longer lives than the Nb alloy, whilst the fatigue crack propagation rate in the same temperature range did not show any significant difference. Threshold values of stress intensity factor range were accurately measured at different R ratio. The microstructures of the two alloys were analysed by scanning microscopy in order to rationalise the different mechanical behaviour.

scholarly journals Temporal difference thresholds and repetitive stimulation: Can click trains improve temporal sensitivity?

2021 ◽  
Author(s):  
Emily A. Williams ◽  
Ruth Ogden ◽  
Andrew James Stewart ◽  
Luke Anthony Jones
Keyword(s):  
Internal Clock ◽  
Theory Model ◽  
Repetitive Stimulation ◽  
Difference Threshold ◽  
Temporal Difference ◽  
Temporal Bisection ◽  
Null Result ◽  
Verbal Estimation ◽  
Difference Thresholds ◽  
Main Component

Trains of auditory clicks increase subsequent judgements of stimulus duration by approximately 10%. Scalar timing theory suggests this is due to a 10% increase in pacemaker rate, a main component of the internal clock. The effect has been demonstrated in many timing tasks, including verbal estimation, temporal generalisation, and temporal bisection. However, the effect of click trains has yet to be examined on temporal sensitivity, commonly measured by temporal difference thresholds. We sought to investigate this both experimentally; where we found no significant increase in temporal sensitivity, and computationally; by modelling the temporal difference threshold task according to scalar timing theory. Our experimental null result presented three possibilities which we investigated by simulating a 10% increase in pacemaker rate in a newly-created scalar timing theory model of thresholds. We found that a 10% increase in pacemaker rate led to a significant improvement in temporal sensitivity in only 8.66% of 10,000 simulations. When a 74% increase in pacemaker rate was modelled to simulate the filled-duration illusion, temporal sensitivity was significantly improved in 55.36% of simulations. Therefore, scalar timing theory does predict improved temporal sensitivity for a faster pacemaker, but the effect of click trains (a supposed 10% increase) appears to be too small to be reliably found in the temporal difference threshold task.

scholarly journals IMPLICATION OF ALTERNATIVE MINIMAL CLINICALLY IMPORTANT DIFFERENCE THRESHOLD ESTIMATION METHODS ON TECHNOLOGY ASSESSMENT

2016 ◽  
Vol 32 (6) ◽  
pp. 371-375 ◽  
Author(s):  
Diana Brixner ◽  
Eli O. Meltzer ◽  
Kellie Morland ◽  
Cathryn A. Carroll ◽  
Ullrich Munzel ◽  
...  
Keyword(s):  
Technology Assessment ◽  
Minimal Clinically Important Difference ◽  
Nasal Symptom ◽  
Healthcare Research ◽  
Estimation Methods ◽  
Difference Threshold ◽  
Threshold Estimation ◽  
Clinically Important Difference ◽  
The Difference ◽  
The Impact

Objectives: Various minimal clinically important difference (MCID) threshold estimation techniques have been applied to seasonal allergic rhinitis (SAR). The objectives of this study are to (i) assess the difference in magnitude of alternative SAR MCID threshold estimates and (ii) evaluate the impact of alternative MCID estimates on health technology assessment (HTA).Methods: Data describing change from baseline of the reflective Total Nasal Symptom Score (rTNSS) for four intranasal SAR treatments were obtained from United States Food and Drug Administration-approved prescribing information. Treatment effects were then compared with anchor-based MCID thresholds derived by Barnes et al. and thresholds obtained from an Agency for Healthcare Research and Quality (AHRQ) panel.Results: The change in rTNSS score from baseline, represented as the average of the twice-daily recorded scores of the rTNSS, was -2.1 (p < .001) for azelastine hydrochloride 0.10%, 1.35 (p = .014) for ciclesonide, and -1.47 (p < .001) for fluticasone furoate. The change in the rTNSS score from baseline, represented by sum of the AM and PM score, was -2.7 for MP-AzeFlu (p < .001). The rTNSS change from baseline for each product was compared with anchor-based MCID threshold and the AHRQ panel estimates. Comparison of the observed treatment effect to the anchor-based and AHRQ panel MCID thresholds results in different conclusions, with clinically important differences being inferred when anchor-based estimates serve as the reference point.Conclusion: The AHRQ panel MCID threshold for the rTNSS was twelve times larger than the anchor-based estimates resulting in conflicting recommendations on whether different SAR treatments provide clinically meaningful benefit.

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