Search results for "Differential Threshold"
showing 4 items of 14 documents
Olfaction in chemotherapy for head and neck malignancies
2015
Abstract Objective Systemic chemotherapy for different malignancies occurs alongside various side effects, including reduced sensory function. To date, little is known about the effect of chemotherapeutic agents on olfaction. The aim of this study was to provide new data about changes in sense of smell during chemotherapy among patients with advanced squamous cell carcinomas of the head and neck region. Methods In a prospective, controlled cohort study of patients undergoing up to three courses of chemotherapy (cis- or carboplatin, 5-fluorouracil and docetaxel), olfaction was evaluated prior to and directly following completing a cycle, as well as 3 weeks later with the beginning of the nex…
The veridical perception of object temperature with varying skin temperature.
1988
The effect of skin-adaptation temperature on object-temperature perception was investigated, using the method of dichiric matching, in an attempt to determine whether veridical perception of physical object temperature occurs in human subjects. Observers were presented with a test temperature on one hand and required to find a matching temperature, that is, one that produced the same sensation, on the other, differently adapted, hand. Using equality of test and matching temperatures as a criterion of veridical perception, it was found that the latter improves with ΔT, the difference between object temperature and skin-adaptation temperature. It is postulated that when ΔT is close to zero, v…
Effect of depolarizing GABAA-mediated membrane responses on excitability of Cajal-Retzius cells in the immature rat neocortex
2011
In immature neurons activation of ionotropic GABA receptors induces depolarizing membrane responses due to a high intracellular Cl− concentration ([Cl−]i). However, it is difficult to draw conclusions about the functional consequences of subthreshold GABAergic depolarizations, since GABAergic membrane shunting and additional effects on voltage-dependent ion channels or action potential threshold must be considered. To systematically investigate factors that determine the GABAergic effect on neuronal excitability we performed whole cell patch-clamp recordings from Cajal-Retzius cells in immature rat neocortex, using [Cl−]i between 10 and 50 mM. The effect of focal GABA application was quant…
Small-sample characterization of stochastic approximation staircases in forced-choice adaptive threshold estimation
2007
Despite the widespread use of up—down staircases in adaptive threshold estimation, their efficiency and usability in forced-choice experiments has been recently debated. In this study, simulation techniques were used to determine the small-sample convergence properties of stochastic approximation (SA) staircases as a function of several experimental parameters. We found that satisfying some general requirements (use of the accelerated SA algorithm, clear suprathreshold initial stimulus intensity, large initial step size) the convergence was accurate independently of the spread of the underlying psychometric function. SA staircases were also reliable for targeting percent-correct levels far …