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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
231

Vocal response times to acoustic stimuli in white whales and bottlenose dolphins

Blackwood, Diane Joyner 30 September 2004 (has links)
Response times have been used to explore cognitive and perceptual processes since 1850 (Donders, 1868). The technique has primarily been applied to humans, birds, and terrestrial mammals. Results from two studies are presented here that examine response times in bottlenose dolphins (Tursiops truncatus) and white whales (Delphinapterus leucas). One study concerned response times to stimuli well above the threshold of perceptibility of a stimulus, and the other concerned response times to stimuli near threshold. Two white whales (Delphinapterus leucas) and five Atlantic bottlenose dolphins (Tursiops truncatus) were presented stimuli well above threshold. The stimuli varied in type (tone versus pulse), amplitude, duration, and frequency. The average response time for bottlenose dolphins was 231.9 ms. The average response time for white whales was 584.1 ms. There was considerable variation between subjects within a species, but the difference between species was also found to be significant. In general, response times decreased with increasing stimulus amplitude. The effect of duration and frequency on response time was unclear. Two white whales (Delphinapterus leucas) and four Atlantic bottlenose dolphins (Tursiops truncatus) were given audiometric tests to determine masked hearing thresholds in open waters of San Diego Bay (Ridgway et al., 1997). Animals were tested at six frequencies over a range from 400 Hz to 30 kHz using pure tones. Hearing thresholds varied from 87.5 dB to 125.5 dB depending on the frequency, masking noise intensity and individual animal. At threshold, median response time across frequencies within each animal varied by about 150 ms. The two white whales responded significantly slower (∼670 msec, p<0.0001) than the four dolphins (∼410 msec). As in terrestrial animals, reaction time became shorter as stimulus amplitude increased (Wells, 1913; Stebbins, 1966). Across the two studies, the dolphins as a group were faster in the abovethreshold study than in the nearthreshold study. White whales had longer response times than bottlenose dolphins in both studies. Analysis of response time with an allometric relation based on weight shows that the difference in weight can explain a significant part of the difference in response time.
232

The Influence of Lexical Characteristics on Sentence Production in Younger and Older Adults

Cupit, Jennifer 06 August 2010 (has links)
In the study of language production in aging, an important question relates to the relationship between lexical retrieval and syntactic production. Studies have reported changes in syntactic production across the lifespan, but their underlying cause remains unclear. In younger adults, it has been suggested that lexical factors, such as an item‟s semantic or phonological representation influence syntactic production; however, the full nature of this influence remains unclear. Studies investigating the type of sentence produced have found semantic facilitation and phonological interference (e.g., Bock, 1986, 1987), but studies investigating response time (e.g., Meyer, 1996) have found the opposite effects. This investigation sought to examine the influence of lexical level information on sentence production in younger and older adults. This was accomplished by concurrently examining reaction time and sentence type effects. In Experiment 1, 61 adults (mean age: 21.8 years) were presented with pictures and distractor words (unrelated, or semantically or phonologically related). Three stimulus onset asynchronies (SOA) were used (-1000ms, -150ms and 150ms). Participants were required to describe each picture. Using an analysis of variance, response time was compared across the different conditions and using generalized estimating equations, the type of sentence produced and the position of the primed word were compared. In Experiment 2, phonological distractors were excluded, and one SOA (-150ms) was used. Testing involved 83 younger adults (mean age: 22.9 years) and 56 older adults (mean age: 74.7 years). In Experiment 1, semantic distractors resulted in related nouns being produced more often in the subject position. This effect was observed in the analysis of the position of the target noun, but not in the analysis of the type of sentence produced. There were no effects of phonological distractors. In Experiment 2, semantic distractors influenced the type of sentence produced for both age groups. The groups differed only in error production. No reaction time effects were observed in either experiment. This investigation successfully demonstrated an influence of lexical level information on the syntactic productions of younger and older adults. The two groups were similar in their productions, suggesting that aspects of syntactic production are preserved in older adults.
233

Relationship of pauses to problem solving events in mechanical design protocols

Chamberlin, Martha J. 15 May 1990 (has links)
This thesis compares two methods for studying the problem-solving processes of mechanical design engineers. The first method, verbal protocol analysis, was applied by L. Stauffer to construct a problem-solving model of mechanical design. The second method, timing analysis, measures the time intervals separating drawing or speaking actions during the design process. Timing analyisis was applied by the author to the verbal/video design data collected by Stauffer. This thesis demonstrates that the two methods are statistically related, and hence, that employing two different study techniques enhances the reliability of both methods. The two methods have complementary strengths: protocol analysis reveals the content of the design process, while timing analysis is much more complete. Hence, a combination of protocol and timing analysis provides a stronger measure of the design process than either method alone. / Graduation date: 1992
234

The Influence of Lexical Characteristics on Sentence Production in Younger and Older Adults

Cupit, Jennifer 06 August 2010 (has links)
In the study of language production in aging, an important question relates to the relationship between lexical retrieval and syntactic production. Studies have reported changes in syntactic production across the lifespan, but their underlying cause remains unclear. In younger adults, it has been suggested that lexical factors, such as an item‟s semantic or phonological representation influence syntactic production; however, the full nature of this influence remains unclear. Studies investigating the type of sentence produced have found semantic facilitation and phonological interference (e.g., Bock, 1986, 1987), but studies investigating response time (e.g., Meyer, 1996) have found the opposite effects. This investigation sought to examine the influence of lexical level information on sentence production in younger and older adults. This was accomplished by concurrently examining reaction time and sentence type effects. In Experiment 1, 61 adults (mean age: 21.8 years) were presented with pictures and distractor words (unrelated, or semantically or phonologically related). Three stimulus onset asynchronies (SOA) were used (-1000ms, -150ms and 150ms). Participants were required to describe each picture. Using an analysis of variance, response time was compared across the different conditions and using generalized estimating equations, the type of sentence produced and the position of the primed word were compared. In Experiment 2, phonological distractors were excluded, and one SOA (-150ms) was used. Testing involved 83 younger adults (mean age: 22.9 years) and 56 older adults (mean age: 74.7 years). In Experiment 1, semantic distractors resulted in related nouns being produced more often in the subject position. This effect was observed in the analysis of the position of the target noun, but not in the analysis of the type of sentence produced. There were no effects of phonological distractors. In Experiment 2, semantic distractors influenced the type of sentence produced for both age groups. The groups differed only in error production. No reaction time effects were observed in either experiment. This investigation successfully demonstrated an influence of lexical level information on the syntactic productions of younger and older adults. The two groups were similar in their productions, suggesting that aspects of syntactic production are preserved in older adults.
235

The Influence of Task Demands on Manual Asymmetries for Reaching Movements to Tools

Mamolo, Carla Marie January 2008 (has links)
In this dissertation, three experiments were conducted that examined the influence of task demands on manual asymmetries for the performance of reaching movements to tools. In all three experiments, the difference between the hands (in terms of preference for Experiment 1 and performance for Experiments 2 and 3) was studied in response to varying task demands for grasping movements to tools. In the first experiment, 82 right-handed and 60 left-handed university students performed reaching movements to tools and dowels at five positions within working space. Differences in the reaching patterns of the left and right hands to the tools and dowels were examined, as well as the effect of task demands (lift, use) and type of object (tool, dowel) on the reaching patterns. Dowels were used in order to examine if participants would treat a neutral object as if it were a tool in terms of their reaching patterns in working space. Results confirmed and extended prior research on the influence of task demands on reaching patterns within working space. Overall, there were more similarities in the general reaching patterns of left- and right-handed participants than differences. However key differences between the handedness groups emerged in the treatment of the dowel and the frequency of switches (reaching to lift the object with the non-preferred hand and transferring it to the preferred hand to use). Results also showed that tools enjoy a privileged association with the preferred hand, and that the intent of the movement has a very real goal on movement planning. The first experiment examined patterns of hand use across working space in response to differing task demands. In the next experiments performance differences between the hands in terms of movement planning and initiation were examined through the use of reaction time and movement time. In these experiments, reaction time represented the time from the presentation of a go signal to when the participant first lifted their hand, and movement time was the time between lifting the hand to lifting a tool off a sensor. Movement time represented the time to pick up the tool, and did not include the time to use the tool to perform a particular task and complete the reaching movement. In the second experiment, reaction time and movement time to tools placed at the midline position were examined under varying degrees of advance information using a precue paradigm. Three precue conditions were used which presented advance information on the hand to use to perform the movement (left or right) and/or the task (lift, use, or pantomime) to be performed: (1) both hand and task were cued in advance (Both precue); (2) task only was cued in advance (Task precue); and (3) neither hand nor task were cued in advance (No precue). Twenty-four right-handed university students performed reaching movements to tools under the three different precue conditions. The results of Experiment 2 showed that reaction time was sensitive to the amount of advance information presented in the precue. For reaction time manual asymmetries were observed in one condition only – a right hand advantage was present in the No precue condition. In contrast manual asymmetries in favor of the right hand were clearly observed with the movement time results. Experiment 2 was the first experiment reported in the literature to systematically examine reaction time for reaching and grasping movements to tools. In order to further explore these results, in Experiment 3 a fourth precue condition (in which the hand to be used was cued in advance; the Hand precue) was added to the precue paradigm used in Experiment 2. An additional variable called replacement time, which represented the time spent interacting with the tool, was also examined. Forty-two right-handed university students participated in Experiment 3. The results of Experiment 3 largely replicated the findings of Experiment 2, and indicated that both the amount and type of precue information had an effect on reaction time. The addition of the Hand precue condition suggested that having advance knowledge of the hand to be used to perform the task was of greater importance for movement planning than was advance knowledge of the task to be performed. Regarding the movement time results, Experiment 3 was one of the first experiments to show the influence of task demands on the magnitude of manual asymmetries. The lack of differences between the hands for the replacement time results also suggested that the initial execution of the movement (represented by movement time) was most sensitive to manual asymmetries. Overall, these experiments provided further insight into manual asymmetries for the performance of reaching movements, and illustrated how simple manipulations of task demands led to differences between the hands in measures of both preference and performance when interacting with tools.
236

The Influence of Task Demands on Manual Asymmetries for Reaching Movements to Tools

Mamolo, Carla Marie January 2008 (has links)
In this dissertation, three experiments were conducted that examined the influence of task demands on manual asymmetries for the performance of reaching movements to tools. In all three experiments, the difference between the hands (in terms of preference for Experiment 1 and performance for Experiments 2 and 3) was studied in response to varying task demands for grasping movements to tools. In the first experiment, 82 right-handed and 60 left-handed university students performed reaching movements to tools and dowels at five positions within working space. Differences in the reaching patterns of the left and right hands to the tools and dowels were examined, as well as the effect of task demands (lift, use) and type of object (tool, dowel) on the reaching patterns. Dowels were used in order to examine if participants would treat a neutral object as if it were a tool in terms of their reaching patterns in working space. Results confirmed and extended prior research on the influence of task demands on reaching patterns within working space. Overall, there were more similarities in the general reaching patterns of left- and right-handed participants than differences. However key differences between the handedness groups emerged in the treatment of the dowel and the frequency of switches (reaching to lift the object with the non-preferred hand and transferring it to the preferred hand to use). Results also showed that tools enjoy a privileged association with the preferred hand, and that the intent of the movement has a very real goal on movement planning. The first experiment examined patterns of hand use across working space in response to differing task demands. In the next experiments performance differences between the hands in terms of movement planning and initiation were examined through the use of reaction time and movement time. In these experiments, reaction time represented the time from the presentation of a go signal to when the participant first lifted their hand, and movement time was the time between lifting the hand to lifting a tool off a sensor. Movement time represented the time to pick up the tool, and did not include the time to use the tool to perform a particular task and complete the reaching movement. In the second experiment, reaction time and movement time to tools placed at the midline position were examined under varying degrees of advance information using a precue paradigm. Three precue conditions were used which presented advance information on the hand to use to perform the movement (left or right) and/or the task (lift, use, or pantomime) to be performed: (1) both hand and task were cued in advance (Both precue); (2) task only was cued in advance (Task precue); and (3) neither hand nor task were cued in advance (No precue). Twenty-four right-handed university students performed reaching movements to tools under the three different precue conditions. The results of Experiment 2 showed that reaction time was sensitive to the amount of advance information presented in the precue. For reaction time manual asymmetries were observed in one condition only – a right hand advantage was present in the No precue condition. In contrast manual asymmetries in favor of the right hand were clearly observed with the movement time results. Experiment 2 was the first experiment reported in the literature to systematically examine reaction time for reaching and grasping movements to tools. In order to further explore these results, in Experiment 3 a fourth precue condition (in which the hand to be used was cued in advance; the Hand precue) was added to the precue paradigm used in Experiment 2. An additional variable called replacement time, which represented the time spent interacting with the tool, was also examined. Forty-two right-handed university students participated in Experiment 3. The results of Experiment 3 largely replicated the findings of Experiment 2, and indicated that both the amount and type of precue information had an effect on reaction time. The addition of the Hand precue condition suggested that having advance knowledge of the hand to be used to perform the task was of greater importance for movement planning than was advance knowledge of the task to be performed. Regarding the movement time results, Experiment 3 was one of the first experiments to show the influence of task demands on the magnitude of manual asymmetries. The lack of differences between the hands for the replacement time results also suggested that the initial execution of the movement (represented by movement time) was most sensitive to manual asymmetries. Overall, these experiments provided further insight into manual asymmetries for the performance of reaching movements, and illustrated how simple manipulations of task demands led to differences between the hands in measures of both preference and performance when interacting with tools.
237

Does Writing Down Positive Self Talk – Self Reflection Affect Reaction Time? : A laboratory experiment with young Swedish athletes

Åkesdotter, Cecilia January 2012 (has links)
Syfte Syftet med studien är att undersöka om positivt Self-talk (ST) och självreflektion (SR) i form av att skriva i en träningsdagbok kan påverka reaktionstiden hos unga idrottare.   Sker det förändringar i reaktionstid mellan första och andra gången testet genomförs?   Är det en skillnad i hur stora förändringar som sker i reaktionstid när positivt self-talk gruppen och självreflektionsgruppen jämförs med en kontrollgrupp?   Hur upplevde idrottarna uppgiften att skriva träningsdagbok?   Metod Studien är ett randomiserat laboratorieexperiment och skillnader i reaktionstid kan enbart ses på gruppnivå. Deltagarna (n=29) bestod av både manliga och kvinnliga 16 åriga idrottare som randomiserades i två experimentgrupper och en kontrollgrupp. Kvinnor och män var jämt fördelade mellan grupperna. Först genomfördes två olika reaktionstest (Simple RT och 4choice RT) med hjälp av ett datorprogram för alla deltagare.  Experimentgrupp 1 (EG 1) genomförde en intervention där de under en vecka fick skriva ned sitt eget positiva ST i samband med träning. Experimentgrupp 2 (EG2) två skrev under en vecka ner vad de kunde förbättra med sin träning och vilka konsekvenser dessa förändringar kunde leda till. Kontrollgruppen (CG) fick utöver sin träning skriva ner sitt TV-tittande som en placebo. Efter interventionen genomfördes ett eftertest av reaktionstid och en enkät delades ut där deltagarna fick svara på hur de upplevde dagboken och om de trodde den kunde ha effekt på deras prestation.   Resultat Inom grupperna var det enbart EG 2 (de som tillämpade självreflektion) som hade en statistiskt signifikant förbättring av reaktionstid mellan det första och det andra testtillfället. Detta gällde både för Simple RT (p=0.028) och Choice RT (p=0.018). CG och EG 1 hade små förbättringar i RT mellan det första och andra testtillfället men inga som var statistiskt signifikanta. Gällande jämförelser mellan grupper fanns inga statistiskt säkerställda skillnader i förbättring mellan CG och EG 1. I EG 2 fanns ingen skillnad i förbättrad RT jämfört med CG i simple RT dock återfanns en statistiskt säkerställd skillnad i Choice RT där EG 2 hade en större förbättring jämfört med CG (p=0,003). Gällande hur grupperna upplevde interventionen med träningsdagböcker var resultaten relativt lika i de olika grupperna. Generellt upplevde grupperna att dagboken kunde ha en liten effekt på prestation samt att dagboksskrivandet i sig inte var så givande. Intressant var att de som skrev ner vad de såg på TV upplevde att detta kunde påverka deras prestation lika mycket som de som skrev ner positivt ST eller SR.   Slutsats I självreflektionsgruppen hade en statistiskt signifikant förbättring skett både inom gruppen och jämfört med en kontrollgrupp. Inga signifikanta skillnader återfanns i positivt ST gruppen. Resultaten tolkas utifrån teorier som Self-determination, information processning och förmågan att fokusera uppmärksamheten. Styrkor och svagheter behandlas och slutsatsen är att fler upprepade studier behövs för att stärka och förstå sambandet mellan positivt ST och SR kopplat till reaktionstid. Ska denna typ av dagbok föras in i en klubb eller ett lag bör designen göras om så att den blir mer omtyckt av idrottarna. / Aim The aim of this study is to evaluate if positive Self-talk (ST) or Self-Reflection (SR) by writing in a training diary can affect Reaction Time (RT) in young Swedish Athletes.   Does reaction time change between the pre-test and the post-tests?   Is there a difference in reaction time changes between groups when the positive ST group and the SR group are compared to the control group?   How did the athletes experience the intervention?   Experiment design This study is a randomized laboratory experiment. It is a between subjects design and therefore differences will only be seen on a group level. The participants N=29 were male and female 16 year old athletes. They were randomized in to two experiment groups (EG 1, EG 2) and a control group (CG), males and females were evenly distributed between groups. First two different (RT) tests were conducted with a computer program for all participants (Simple RT and 4Choice RT). After this an intervention of positive ST (EG1) or SR (EG2) was conducted with the use of training diaries for one week. The CG wrote down their habits of watching TV and this was used as a placebo. A re-test of RT was conducted after the completion of the intervention. After this an inquiry was handed to the participants to address their thoughts about using the diary and if they believed it could affect their performance.   Results EG2 was the only group that provided a statistically significant decrease in RT time compared to the pre-test in both simple RT (p=0.028) and choice (p=0.018). No statistical significant differences in RT were found in EG1 or in the CG when comparing pre-and post tests of both simple and choice RT. Comparing between groups showed no statistical significant difference in improved RT between the CG and EG 1 in simple RT or in 4choice RT. A statistical significant difference in improved RT was found between CG and EG2 in choice RT (p=0.003) where the EG 2 had a statistical significant improvement in RT compared to the CG. Comparing simple RT no statistical significant differences was found between EG2 and CG. The three groups experienced using the diary in a similar way. In general they found the diary intervention somewhat giving and believed that the diary could have a little affect on performance. Interesting to notice is that the participators that wrote down their TV habits believed this could have the same impact on performance as the participators writing down positive ST or SR.   Conclusions A connection was found between strategies of SR an RT. These results are analyzed regarding the theoretical framework provided by Self-determination theory, information processing and focus of attention. Strength and weakness is discussed and the conclusion is that more and reproduced studies are needed to determine the connection between interventions positive ST, SR and RT. If a training diary would be used in a team or a club some modifications should be done to make them more meaningful for the athletes.
238

Sex Differences In Visual Reaction Time: Effect Of Sport Participation And Driving

Tanyel, Emine Ozge 01 July 2007 (has links) (PDF)
ABSTRACT SEX DIFFERENCES IN VISUAL REACTION TIME: EFFECT OF SPORT PARTICIPATION AND DRIVING Tanyel, Emine &Ouml / zge M.S., Department of Physical Education and Sport Supervisor: Y. Do&ccedil / . Dr. Sadettin Kirazci July 2007, 84 pages The purpose of this study is to investigate whether sport participation and driving has any effect on the differences between sexes in visual reaction time (RT). There were three groups (control, exercise, driver), and 20 males and 20 females in each group. The sport participation group was athletes from taekwondo were training at least for five years, minimum three days per week throughout the year. The driver group was males and females were working as representatives of companies and driving at least 20.000 km. annually for the last four years. Each participant was asked to read and sign informed consent and information form at the beginning of the study. Participants were measured three times for simple visual RT, simple visual RT with movement, two and three visual choices RTs for both hands. Descriptive statistics was performed for the four measures according to the groups and sexes. Group and sex differences were examined with MANOVA. The result indicated statistically significant interaction between sex and group for both hands in favor of males for most of the comparisons. Significant differences were also found between three groups and between two sexs for both hands. This study indicated that long term sport participation requiring visual information and driving extensively shorten visual reaction of the participants compared to their counterparts who were not acting in sport and driving.
239

Pilates Exercise Positively Affects Balance, Reaction Time, Muscle Strength, Number Of Falls And Psychological Parameters In 65+ Years Old Women

Babayigit Irez, Gonul 01 November 2009 (has links) (PDF)
Physical changes such as impairment flexibility, balance, muscle strength and reaction time occur with aging. Regular lifetime physical activity appears to delay these factors. The purpose of this study was to determine if 12 weeks Pilates exercise could improve dynamic balance, reaction time, flexibility, muscle strength, bone density and quality of life in 65+ years old women and to investigate the changes of these parameters in a year follow up. Thirty out of a hundred women living in a Residential House in Ankara were enrolled in the study. Participants attended a 12-week series of one-hour Pilates exercise meeting three times per week. Dynamic balance, flexibility, reaction time, number of falls, muscle strength, bone mineral density, quality of life and anxiety were measured before and after exercise. Results showed that flexibility, balance, simple and choice reaction time, muscle strength, number of falls, quality of life and beck anxiety scores significantly improved in the exercise group. In addition, after a year of follow up, there were prominent decreases in simple reaction time and muscle strength, choice reaction time, number of falls and bone mineral density in control group while there were no evident changes in exercise group. Furthermore, there were significant relationships of balance with muscle strength, choice reaction time and anxiety.As the result of this study, it can be concluded that Pilates exercise can be efficient for preventing falls, increasing muscle strength and dynamic balance, flexibility, reaction time and decreasing anxiety while increasing quality of life. In the long term, Pilates exercise may have very positive effects on bone mineral density.
240

Vocal response times to acoustic stimuli in white whales and bottlenose dolphins

Blackwood, Diane Joyner 30 September 2004 (has links)
Response times have been used to explore cognitive and perceptual processes since 1850 (Donders, 1868). The technique has primarily been applied to humans, birds, and terrestrial mammals. Results from two studies are presented here that examine response times in bottlenose dolphins (Tursiops truncatus) and white whales (Delphinapterus leucas). One study concerned response times to stimuli well above the threshold of perceptibility of a stimulus, and the other concerned response times to stimuli near threshold. Two white whales (Delphinapterus leucas) and five Atlantic bottlenose dolphins (Tursiops truncatus) were presented stimuli well above threshold. The stimuli varied in type (tone versus pulse), amplitude, duration, and frequency. The average response time for bottlenose dolphins was 231.9 ms. The average response time for white whales was 584.1 ms. There was considerable variation between subjects within a species, but the difference between species was also found to be significant. In general, response times decreased with increasing stimulus amplitude. The effect of duration and frequency on response time was unclear. Two white whales (Delphinapterus leucas) and four Atlantic bottlenose dolphins (Tursiops truncatus) were given audiometric tests to determine masked hearing thresholds in open waters of San Diego Bay (Ridgway et al., 1997). Animals were tested at six frequencies over a range from 400 Hz to 30 kHz using pure tones. Hearing thresholds varied from 87.5 dB to 125.5 dB depending on the frequency, masking noise intensity and individual animal. At threshold, median response time across frequencies within each animal varied by about 150 ms. The two white whales responded significantly slower (∼670 msec, p<0.0001) than the four dolphins (∼410 msec). As in terrestrial animals, reaction time became shorter as stimulus amplitude increased (Wells, 1913; Stebbins, 1966). Across the two studies, the dolphins as a group were faster in the abovethreshold study than in the nearthreshold study. White whales had longer response times than bottlenose dolphins in both studies. Analysis of response time with an allometric relation based on weight shows that the difference in weight can explain a significant part of the difference in response time.

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