One of the most basic reaction time experiments employed by psychologists is the comparison of latencies to responses for single and redundant targets. The general effect is that participants are capable of responding faster, that is having shorter response latencies when redundant stimuli, as opposed to an individual stimulus, are presented. Interestingly, several models attempting to predict this effect, including the well known race model, have not been entirely successful. The following study evaluated redundancy gain and violations of the race model, in three experimental models: visual only, auditory only, and a visual-auditory bimodal paradigm. The results showed redundancy gain in all three paradigms, but they were only significant violations of the race model for the visual-auditory condition. Additionally, correlations between the different paradigms were explored with respect to redundancy gain and violations of the race model on an individual participant basis.

Thesis (Ph. D.)--University of California, San Diego, 2009. / Title from first page of PDF file (viewed July 7, 2009). Available via ProQuest Digital Dissertations. Vita. Includes bibliographical references.

This Master Thesis involves the analysis and evaluation of military students psychomotor processes. This was carried out using the analyzer DPA – 1. This device is used for measuring dynamic parameters of independent or coordinated arm and leg movements by reacting to the target with a variety of geometric, colour or time parameters appearing on the screen. The DPA – 1 device enables scientists to analyse psychomotor reaction and dynamic and kinematical characteristics. The goal of the research was to identify the peculiarities of psychomotor reaction performing movements with the right and left arms. The participants of the research were 40 students (n=40) of the Lithuanian Military academy. Their age was 22.03 ± 0.54 years, body mass – 76.04 ± 9.13 kg, height – 180.29 ± 7.99 cm. Their right arm was dominant. To achieve this goal the following tasks had to be completed: 1. To determine the differences in psychomotor reaction by performing the moves with the dominant and non-dominant arms. 2. To determine the difference between movement speed and accuracy by performing the movement with the right and the left arms. 3. To determine the connection between the parameters of psychomotor reaction of the right and the left arms. The hypothesis: We think that movements performed with the dominant arm have better psychomotor qualities. The research methods: 1. Analysis of the scientific literature resources 2. Testing 3. Mathematical statistics Conclusions 1. There were no... [to full text]

Chronic lateral instability of the ankle (CLI), defined as frequent sprains and recurrent giving way, difficulty in walking and running on uneven surface, is often connected with pain and swollen ankles. It occurs in 10 to 20 percent after acute ankle injuries. Mechanical instability of the talocrural and subtalar joint, peroneal weakness and impaired proprioception has been suggested as etiological factors. Aim. To investigate the natural course in conservatively treated patients with CLI. To assess the mechanical stability in patients with CLI by measuring the three dimensional motions in the talus, the fibula and the calcaneus in relation to the tibia during different testing procedures pre- and postoperatively. To determine if CLI is associated with proprioceptive deficiency. Patients and Methods. This Thesis includes 127 ankles in 78 patients (30 women, 48 men) with CLI. Thirty-seven patients were followed up 20 years after their first contact with the orthopaedic department because of CLI. Forty-six ankles were evaluated radiographically and the result was compared with a gender- and age - matched control-material. The neuromuscular response to a sudden angular displacement of the ankles was studied in 15 ankles in 13 patients using EMG. Thirty-six patients entered a prospective study using roentgen stereophotogrammetric analysis (RSA) in which the ankles were tested at manual adduction, adduction with predetermined torque, with and without external support and at drawer tests (40 N and 160N). Twenty-seven patients were followed five years postoperatively. Result. After 20 years 22 patients, conservatively treated still suffered from instability of the ankle and ten had recurrent giving way symptoms even on plane surface. Six ankles in the patient group and four in the control group displayed osteoarthritic changes Prolonged ipsilateral reaction time (m. per. long, and m. tib. ant.) was found in patients with CLI indicating proprioceptive insufficiency. Increased talar adduction and a tendency toward increased total translation of the talar center was found in ankles with CLI. Concomitant fibular rotations and translations were found but with no conclusive deviation in the ankles with symptoms. The talo-calcaneal adduction reached the same level in the patient and control groups regardless of symptoms. External support (ankle brace) increased the talar stability. The use of predetermined torque and constrained testing procedure did not add information compared with the manual test Twenty-five patients graded the result as excellent or good five years after lateral ligament reconstruction. Talar stability (decreased adduction and translation) was increased two years postoperatively and was improved or remained the same at five years without comprising the range of motion. Conclusion. In more than half the cases symptoms of CLI did not resolve spontaneously. Minor degenerative changes was found after twenty years, but not to a greater extent than in a control group. CLI was associated with proprioceptive insufficiency and talocrural but not subtalar instability. Increased ankle stability can be obtained by the use of an ankle brace and by an anatomical ligament reconstruction. / <p>Diss. (sammanfattning) Umeå : Umeå universitet, 1994</p> / digitalisering@umu

A real-time system is a system such that the correctness of operations depends not only on the logical results, but also on the time at which these results are available. A fundamental problem in designing real-time systems is to analyze response time of operations, which is defined as the time elapsed from the moment when the operation is requested to the moment when the operation is completed. Response time analysis is challenging due to the complex dynamics among operations. A common technique is to study response time under worst-case scenario. However, using worst-case response time may lead to the conservative real-time system designs. To improve the real-time system design, we analyze the non-worst-case response time of operations and apply these results in the design process. The main contribution of this thesis includes mathematical modeling of real-time systems, calculation of non-worst-case response time, and improved real-time system design. We perform analysis and design on three common types of real-time systems as the real-time computing system, real-time communication network, and real-time energy management. For the real-time computing systems, our non-worst-response time analysis leads a necessary and sufficient online schedulability test and a measure of robustness of real-time systems. For the real-time communication network, our non-worst-response time analysis improves the performance for the model predictive control design based on the real-time communication network. For the real-time energy management, we use the non-worst-case response time to check whether the micro-grid can operate independently from the main grid.

Moment-to-moment fluctuation in performance (i.e. across-trial inconsistency) was examined in 2-choice reaction time data in three separate samples of participants: healthy controls ranging in age from 6 to 81 years, and both children and adolescents with Attention Deficit /Hyperactivity Disorder (ADHD). A methodological approach was employed that allowed for the examination of inconsistency while controlling for the effects of practice, fatigue, and group differences in mean level of performance. Among healthy controls, a U-shaped curve defined the relationship between age and inconsistency with optimal performance found in those aged approximately 20 years old. In children (aged 6-12 years old) those with ADHD were significantly more inconsistent than controls, and inconsistency was related to ratings of symptoms of ADHD both at home and school. Group differences were also observed in adolescents (aged 12- 17 years old) with ADHD, however, in general, differences were observed only in those participants who also had reading difficulties (RD). Inconsistency was also examined separately in each end of the reaction time distribution. Evidence for a specific effect selectively affecting the slow portion of the distribution was found across all three samples. However, in addition, there was also evidence for effects that were general to both the fast and slow portions of the distribution (in the normal population in those age 6 to 20 years), as well as evidence for an effect selectively affecting the fast portion of the distribution (in adolescents with and without ADHD). The findings indicate that in addition to traditional outcomes of interest (e.g. mean level of performance), moment-to-moment fluctuation in cognitive performance is an important phenomenon which should be taken into account in future research in developmental psychology and psychopathology.

For nearly two decades researchers have been interested in identifying what specifically is learned when individuals learn a sequence (e.g., sequence of stimuli, sequence of motor movements, etc.). Despite extensive research in the area, considerable controversy remains surrounding the locus of learning. There are three main theories concerning the nature of spatial sequence learning: sequence learning is purely perceptual, sequence learning includes a motor component and sequence learning is based on stimulus-response (S-R) rules. The present studies sought to disentangle these theories by demonstrating that sequence learning has both a perceptual and motor component and that altering S-R rules alone disrupts sequence learning. Experiment 1 results fully supported this S-R rule theory of sequence learning. Experiment 2 results provided only partial support for this theory, though the data were also inconsistent with both of the other accounts.

The effects of caffeine (250 mg) and placebo on healthy controls were studied in a double-blind, cross over study on 24 healthy subjects who performed a working memory n-back task. Reaction time and accuracy levels were tested using the n-back working memory measure in cognitive neuroscience. An experimental study tested on the 1, 2 and 3-back tasks under the placebo/coffee condition. Based on the empirical results obtained in this thesis it can be concluded that changes produced by caffeine ingestion support the hypothesis that caffeine acts as a stimulant. However, it cannot be proven that the stimulant translates into enhanced motor processes with an improvement in performance.

Thesis (M.S.)--State University of New York at Binghamton, Department of Psychology, 2007. / Includes bibliographical references.

Diss. (sammanfattning) Stockholm : Karol. inst., 2002. / Härtill 4 uppsatser.