The entire thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file; a non-technical public abstract appears in the public.pdf file. Title from PDF of title page (University of Missouri--Columbia, viewed on November 13, 2009). Thesis advisor: Dr. Jeffrey Rouder. Includes bibliographical references.

Apraxia of speech (AOS) is a motor speech disorder that poses significant obstacles to a person's ability to communicate and take part in everyday life. Agreement exists between current theories of AOS that the impairment affects the speech motor planning stage, where linguistic representations are transformed into speech movements, but they disagree on the specific nature of the breakdown at this processing level. A more detailed understanding of this impairment is essential for developing targeted, effective treatment approaches and for identifying the appropriate candidates for these treatments. The study of AOS is complicated by the fact that this disorder rarely occurs in isolation but is commonly accompanied by various degrees of aphasia (a language impairment) and/or dysarthria (a neuromuscular impairment of speech motor control). In addition, the behavioral similarities of AOS and its closest clinical neighbor, aphasia with phonemic paraphasias, undermine the usefulness of traditional methods, such as perceptual error analysis, in the study of both disorders. The purpose of this dissertation was to test three competing hypotheses about the specific nature of the speech motor planning impairment in AOS in a systematic sequence of three reaction time experiments. This research was formulated in the context of a well-established theoretical framework of speech production and it combines psycholinguistic reaction time paradigms with a cognitive neuropsychological approach. The results of the three experiments provide evidence that one component of the speech motor planning impairment in AOS involves difficulty with selecting the intended motor program for articulation. Furthermore, this difficulty appears to be intensified by simultaneously activated alternative speech motor programs that compete with the target program for selection. These findings may prove useful as a theoretically-motivated basis for improving diagnostic tools and treatment protocols for people with AOS and aphasia, thus enhancing clinical decision-making. Such translational and clinical research aimed at developing sensitive and specific diagnostic tools and improving treatment approaches is the ultimate long-term objective of this research program.

The main purpose of this study was to investigate a theory of information storage and retrieval of a simple motor task as an explanation of the repetition effect (RE) in a 2-choice reaction time task. Subsidiary problems involved 1) examining the effect of inter-trial interval (ITI) on RE, 2) examining the effect of probability (P) of occurrence of an S-R pair on the RE and, 3) examining the interacting effects of ITI and P on the RE. The experimental task was a 2-choice reaction time (RT) task where the subject had to respond as quickly as possible by depressing a response key following the onset of a stimulus light. Two types of tasks were used: 1) self-paced, in which the ITI was approximately 380 msec. and, 2) discrete, in which the ITI was approximately 1600 msec. Each subject was tested in both tasks and on all three probability conditions (P = .33, .50, .67). Sixteen students and staff of the University of British Columbia served as subjects. The results, which were somewhat tenuous due to equipment malfunctions, indicated that there was no RE in either the discrete or serial CRT task. This suggested that there were no differences in the subjects response strategies in either the discrete or serial task. The model of motor memory retrieval was not supported by this investigation. / Education, Faculty of / Curriculum and Pedagogy (EDCP), Department of / Graduate

Thesis is focused on the impact of the inside noise of the car on conditional driver safety, which is presented by reaction times on simulated stimulus. In introduction, there is a theoretical definition of the security of the vehicles, inside noise, and its methods of measurement. Practical part consists of description and realization of the measurements of the impact on the inside noise in the car on reaction time of drivers. Conclusion includes evaluations of the measurements and findings, which results from them.

The reaction time of four groups of elderly human subjects were examined to determine the effects of stimulus presentation and task practice. Each group practiced different tasks, each requiring a response when more than one alternative was available. Two tasks involved making responses based on either visually or auditorily presented stimuli only. One task required decisions to be made on the basis of both auditory and visual stimuli. The fourth group acted as a comparison group and did not practice a reaction-time task; although they did perform a task on the computer and their reaction times were measured. Before and after practicing these tasks, each group was given a single trial involving a completely different decision-making task, and reaction time was measured. Results show that practice led to decreased reaction times on the practiced task in all treatment groups. The comparison group did not improve. Practicing any of the three reaction time tasks also led to decreased reaction time on the unpracticed task. These findings indicate that elderly individuals can decrease their reaction time with practice and that after practicing one task, changes will generalize to a different task. If the older population can alter performance on this task, then they nay also be capable of altering performance on other tasks.

No description available.

Change in prediction confidence was studied as a determinant of the sequential effects of prediction outcome (PO) in a two-stimulus, two-response reaction time task. In a between-groups experiment, the RTs of "consonant" Ss, whose average confidence in a stimulus prediction increased following correct POs and decreased following incorrect POs, were reliably influenced by preceding PO. In contrast, "dissonant" Ss, whose average confidence decreased following correct POs and increased following incorrect POs, exhibited no reliable effect of preceding PO on RT. Analogous results were obtained in a within-Ss experiment when each trial was categorized according to the relationship between preceding PO and Ss statements of having "more" or “less" prediction confidence than on the previous trial. “Consonant” trials, on which Ss indicated “more" confidence following correct POs and "less" following incorrect POs evidenced a significantly greater preceding PO effect on RT than did "dissonant" trials. The results partially support a continuous expectancy model of the sequential effects of PO on choice RT. / Master of Science

Tyrimo tikslas - nustatyti paros laiko įtaką trumpųjų nuotolių bėgikų reakcijos trukmei. Tyrimo uždaviniai: 1. Ištirti ir palyginti 2009 m. Universiados vyrų 100 m. bėgimo rezultatų ir reakcijos trukmių kaitą nuo parengiamojo iki finalinio bėgimų. 2. Ištirti ir palyginti 2011 m. Universiados vyrų 100 m. bėgimo rezultatų ir reakcijos trukmių kaitą nuo parengiamojo iki finalinio bėgimų. 3. Ištirti ir palyginti 2009 m. ir 2011 m. Universiadų vyrų 100 m. bėgimo rezultatų ir reakcijos trukmių kaitą nuo parengiamojo iki finalinio bėgimų. 4. Ištirti ir palyginti kaip kinta trumpųjų nuotolių bėgikų bei nesportuojančių asmenų reakcijos trukmės, atliekant ranka skirtingu paros laiku (ryte, diena, vakare). 5. Ištirti ir palyginti kaip kinta trumpųjų nuotolių bėgikų bei nesportuojančių asmenų reakcijos trukmės, atliekant koja skirtingu paros laiku (ryte, diena, vakare). Tyrimo organizavimas: Reakcijos trukmė nustatoma naudojant reakciometrą RA-1. Reakcijos trukmės nustatymui tiriamasis atliko po 10 judesių dešine ranka, po to dešine koja. Trumpųjų nuotolių bėgikai buvo testuojami poilsio dieną, ryte (8:00 – 9:00) per pietus (14:00 – 15:00) ir vakare (21:00 – 22:00). Rezultatai: Išanalizavus 2009 m. pasaulio universiados vyrų 100 m bėgimo rezultatus, pastebėjome, kad prasčiausi rezultatai demonstruojami parengiamuosiuose bėgimuose. Taip pat nustatėme, kad statistiškai reikšmingai rezultatai skyrėsi tik iki pusfinalio (p < 0,05), o finale sportininkų vidutinis bėgimo rezultatas nesiskyrė... [toliau žr. visą tekstą] / The aim of the study: to establish the effects of time of day on reaction times in short distance runners. The goals of the study: 1. To examine and compare men’s 100 meters running performance and reaction times from race preparation to final race in Universiade 2009. 2. To examine and compare men’s 100 meters running performance and reaction times from race preparation to final race in Universiade 2011. 3. To examine and compare men’s 100 meters running performance and reaction times from race preparation to final race in Universiade 2009 and 2011. 4. To examine reaction times in short distance runners and compare the results with reaction times in non-athletes, in the hand test during the different times of the day (morning, afternoon, evening). 5. To examine reaction times in short distance runners and compare the results with reaction times in non-athletes, in the foot test during the different times of the day (morning, afternoon, evening). The organization of research: Reaction time measurement device RA-1 was used to measure reaction time. The subjects had to do 10 hand movements, then 10 foot movements. The sprinters were tested on their day-off, in the morning (8:00-9:00), in the afternoon (14:00-15:00) and in the evening (21:00-22:00). Results: After the analysis of men‘s race results in the Universiade, 2009 it was obvious that the worst results were in race preparation stage. We also found out that the differences according to statistics were significant only... [to full text]

Thesis (Ph. D.)--Columbia University, 1919. / Vita. "Reprinted from vol. I, no. 3 ... and vol. I, no. 9 ... The Neurological bulletin ... c1918." Bibliography: p. 157-158.

Dissertation (Ph.D.)--The University of North Carolina at Greensboro, 2009. / Directed by Richard M. Luecht; submitted to the Dept. of Educational Research Methodology. Title from PDF t.p. (viewed May 17, 2010). Includes bibliographical references (p. 58-62).