PubMed Health⌕ Search

Biomedical subjects

T O Kvålseth

Publications and source records attributed to T O Kvålseth.

17 recordsLinked to original sources
PubMed2001

On weighted exponential entropies.

As an alternative to Shannon's classical entropy measure of information, an exponential entropy function was proposed by Pal and Pal in 1989 and 1991. To generalize Pal's entropy further, this author introduced two different families of exponential entropies that are one-parameter generalizations of Pal's entropy. The purpose of the present paper is to define weighted entropies corresponding to those one-parameter generalizations. Some properties and examples of such weighted exponential entropies are discussed.

Entropy↗
PubMed1996

Square-root formula for choice reaction time.

The power law of choice reaction time, first proposed by Kvãlseth (1980), is further discussed. It is shown that the so called Hick-Hyman law is a special case of the power law. It is suggested that a particular square-root case provides a most concise and adequate formula for predicting reaction time when the number of equiprobable stimulus-response pairs ranges from 1 to 10. A potential theoretical explanation is briefly discussed.

Choice Behavior↗
PubMed1993

The paternity of the power law of human motor control.

It is pointed out that, contrary to a recent paternity claim, the power law of human motor control was first discovered by this author more than ten years ago. The classical Fitts' law is shown to be a special case of the power law.

Adult↗
PubMed1979

Statistical models of the demand for emergency medical services in an urban area.

First- and second-order statistical regression models are presented for the Emergency Medical Services (EMS) demand in an urban area as it relates to various socioeconomic, demographic, and other characteristics of the area. Individual models are formulated for different types of medical emergencies with the city of Atlanta, GA, serving as the data base. These models are generally shown to provide excellent fits to the empirical data.

Emergency Medical Services↗
PubMed1977

Effects of marijuana on human reaction time and motor control.

In this research were analyzed the effects of marijuana on human reaction time and on performance for motor responses involving both linear and rotary serial arm movements aimed at a target. A total of six experienced marijuana users served as subjects and three drug conditions (dose levels) were used, i.e., 0, 6.5, and 19.5-26.0 mg delta9-THC. The results showed that (a) (simple and complex) reaction time was not significantly affected by marijuana or by the interaction between drug conditions and the amount of information transmitted during the task, (b) linear movement time was significantly reduced after smoking marijuana, while rotary movement time was not significantly affected, (c) interaction between drug conditions and task complexity was insignificant in the case of both linear and rotary movements, and (d) error rates for the two types of motor movements increased significantly and especially for linear movements as the dose level increased.

Adult↗
PubMed1976

Distribution of movement time in a target-aiming task.

Various characteristics of the distribution of movement time were analyzed for a task involving serial and rotary arm movements aimed at a target. For experimental data generated from five Ss, (a) the distribution tended to be unimodal and more peaked than a normal distribution, (b) the skewness of the distribution was predominantly positive and (c) the standard deviation, in addition to the mean, of movement time was significantly affected by the complexity of the task as measured by Fitts' index of difficulty, while the skewness and the kurtosis were not. For the average results for the Ss, a first-order linear model with the standard deviation of movement time as the dependent variable and Fitts' index as the independent one explained 67% of the variation in standard deviation as compared to 98% of the variation in mean movement time accounted for by the Fitts' index.

Adult↗
PubMed1975

Note on Fitts' law for manipulative temporal motor responses with path constraints.

This paper presents a first-order version of an earlier model by Kvålseth (1973) of manipulative motor responses involving serial hand movements with different types of movement-path constraints. This model represents a generalization of Fitts' law. Comparisons are also made between experimental movement times obtained and predetermined and motion-time systems predictions.

Humans↗