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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.
1

Effects of Age and Experience on Memory-Guided Movements

Skakum, Amanda 08 1900 (has links)
The purpose of the present research was threefold: 1) to investigate whether natural aging affects the movements to remembered targets when participants make reaching movements under closed-loop feedback conditions, 2) to determine if experience with visually-guided movements facilitates memory-guided reaching and 3) to determine if age affects this facilitation. Two groups of 10 participants (healthy older and healthy younger) performed a manual aiming task with a mouse on a graphics tablet. A target appeared in one of 6 possible locations on a computer screen and participants had to make aiming movements with a visible cursor in 3 different visual conditions: full vision, immediate recall and delayed recall. In the full vision condition vision of the target was available throughout the movement. In the delay conditions the target disappeared either at the initiation of the aiming movement (immediate recall) or 2 seconds before movement onset (delayed recall). Vision of the hand (cursor) was available in all conditions. Each memory condition was divided into 2 blocks; block 1 was presented before the full vision condition and block 2 was presented after. Endpoint accuracy and variability were measured along with movement kinematics. Results showed no age differences in the kinematics in the full vision condition. For memory dependent pointing age also did not affect the movement kinematics or endpoint accuracy. Movements to remembered targets were significantly more variable in the delay recall compared to the immediate recall condition. A Block by Condition effect showed that the delay effect was present in the first block, but not in the second block, suggesting that variability did not increase with memory delay once participants had experience from full vision reaching. A Group by Condition effect showed the older adults were more variable than younger, although this difference was smaller in the delay condition due to the increase in variability as a function of delay seen in younger but not older adults. These findings suggest that aging does not affect how movements are controlled whether pointing to visible or remembered targets. They also suggest that aging does not affect the accuracy in pointing to remembered targets. Aging does affect the variability of these pointing movements. Finally, experience in pointing at targets with full vision modulates the increase in variability of pointing as a function of delay.
2

Effects of Age and Experience on Memory-Guided Movements

Skakum, Amanda 08 1900 (has links)
The purpose of the present research was threefold: 1) to investigate whether natural aging affects the movements to remembered targets when participants make reaching movements under closed-loop feedback conditions, 2) to determine if experience with visually-guided movements facilitates memory-guided reaching and 3) to determine if age affects this facilitation. Two groups of 10 participants (healthy older and healthy younger) performed a manual aiming task with a mouse on a graphics tablet. A target appeared in one of 6 possible locations on a computer screen and participants had to make aiming movements with a visible cursor in 3 different visual conditions: full vision, immediate recall and delayed recall. In the full vision condition vision of the target was available throughout the movement. In the delay conditions the target disappeared either at the initiation of the aiming movement (immediate recall) or 2 seconds before movement onset (delayed recall). Vision of the hand (cursor) was available in all conditions. Each memory condition was divided into 2 blocks; block 1 was presented before the full vision condition and block 2 was presented after. Endpoint accuracy and variability were measured along with movement kinematics. Results showed no age differences in the kinematics in the full vision condition. For memory dependent pointing age also did not affect the movement kinematics or endpoint accuracy. Movements to remembered targets were significantly more variable in the delay recall compared to the immediate recall condition. A Block by Condition effect showed that the delay effect was present in the first block, but not in the second block, suggesting that variability did not increase with memory delay once participants had experience from full vision reaching. A Group by Condition effect showed the older adults were more variable than younger, although this difference was smaller in the delay condition due to the increase in variability as a function of delay seen in younger but not older adults. These findings suggest that aging does not affect how movements are controlled whether pointing to visible or remembered targets. They also suggest that aging does not affect the accuracy in pointing to remembered targets. Aging does affect the variability of these pointing movements. Finally, experience in pointing at targets with full vision modulates the increase in variability of pointing as a function of delay.
3

Balanced brains: an investigation of visuospatial ability and lateralization in musicians

Patston, Lucy January 2007 (has links)
Musicians comprise a unique population whereby persistent musical practice involving complex cognitive and motor tasks dates back to childhood when the potential for neural plasticity is at its highest. Accordingly, it has been speculated that musical training results in neural structural and functional differences between musicians and non-musicians. In particular, there is evidence to indicate parietal regions are more equally lateralized in musicians, but research investigating visuospatial abilities and lateralization in musicians is scarce. Studies 1 and 2 aimed to assess the visuospatial ability and cognitive processing speed of adult musicians versus ‪demographically and educationally matched non-musicians. ‪Musicians performed more quickly and more accurately than non-musicians in two tasks of visuospatial ability, and completed more items than non-musicians in three tasks of processing speed, suggesting ‪musicians had better ‪visuospatial ability and a faster speed of processing. Studies 3 and 4 aimed to investigate ‪visuospatial attention in ‪these groups using a line-bisection task and a visual discrimination task. On both tasks musicians demonstrated more balanced visuospatial attention with a slight bias to the right hemispace, which was in contrast to the non-musicians’ bias to the left hemispace, a natural phenomenon known as ‘right pseudoneglect’. In Study 5, the laterality of visual processing in musicians and non-musicians was further investigated by comparing electrophysiological interhemispheric transfer time (IHTT) of lateralized visual stimuli across the corpus callosum. Non-musicians had faster right-to-left than left-to-right IHTT consistent with previous research, whilst musicians had more balanced IHTT in both directions and faster left-to-right transfer than non-musicians. Absolute latency patterns revealed similar results and consistently demonstrated more balanced visual processing in musicians. The behavioural data, analysed in Study 6, revealed a tendency (n.s.) for the ‪musician group to respond more quickly to stimuli presented in the right visual field than to stimuli presented in the left visual field, whilst ‪non-musicians did not show this pattern. Overall, the results indicate that musicians have enhanced visuospatial ability and are less lateralized for visuospatial attention and perception than non-musicians. The results are discussed in relation to plastic developmental changes that may be caused by extended musical training from childhood. Specifically, it is proposed that musical training in early life may elicit a process of myelination that is more bilaterally distributed than myelination in non-musicians.
4

Balanced brains: an investigation of visuospatial ability and lateralization in musicians

Patston, Lucy January 2007 (has links)
Musicians comprise a unique population whereby persistent musical practice involving complex cognitive and motor tasks dates back to childhood when the potential for neural plasticity is at its highest. Accordingly, it has been speculated that musical training results in neural structural and functional differences between musicians and non-musicians. In particular, there is evidence to indicate parietal regions are more equally lateralized in musicians, but research investigating visuospatial abilities and lateralization in musicians is scarce. Studies 1 and 2 aimed to assess the visuospatial ability and cognitive processing speed of adult musicians versus ‪demographically and educationally matched non-musicians. ‪Musicians performed more quickly and more accurately than non-musicians in two tasks of visuospatial ability, and completed more items than non-musicians in three tasks of processing speed, suggesting ‪musicians had better ‪visuospatial ability and a faster speed of processing. Studies 3 and 4 aimed to investigate ‪visuospatial attention in ‪these groups using a line-bisection task and a visual discrimination task. On both tasks musicians demonstrated more balanced visuospatial attention with a slight bias to the right hemispace, which was in contrast to the non-musicians’ bias to the left hemispace, a natural phenomenon known as ‘right pseudoneglect’. In Study 5, the laterality of visual processing in musicians and non-musicians was further investigated by comparing electrophysiological interhemispheric transfer time (IHTT) of lateralized visual stimuli across the corpus callosum. Non-musicians had faster right-to-left than left-to-right IHTT consistent with previous research, whilst musicians had more balanced IHTT in both directions and faster left-to-right transfer than non-musicians. Absolute latency patterns revealed similar results and consistently demonstrated more balanced visual processing in musicians. The behavioural data, analysed in Study 6, revealed a tendency (n.s.) for the ‪musician group to respond more quickly to stimuli presented in the right visual field than to stimuli presented in the left visual field, whilst ‪non-musicians did not show this pattern. Overall, the results indicate that musicians have enhanced visuospatial ability and are less lateralized for visuospatial attention and perception than non-musicians. The results are discussed in relation to plastic developmental changes that may be caused by extended musical training from childhood. Specifically, it is proposed that musical training in early life may elicit a process of myelination that is more bilaterally distributed than myelination in non-musicians.
5

Balanced brains: an investigation of visuospatial ability and lateralization in musicians

Patston, Lucy January 2007 (has links)
Musicians comprise a unique population whereby persistent musical practice involving complex cognitive and motor tasks dates back to childhood when the potential for neural plasticity is at its highest. Accordingly, it has been speculated that musical training results in neural structural and functional differences between musicians and non-musicians. In particular, there is evidence to indicate parietal regions are more equally lateralized in musicians, but research investigating visuospatial abilities and lateralization in musicians is scarce. Studies 1 and 2 aimed to assess the visuospatial ability and cognitive processing speed of adult musicians versus ‪demographically and educationally matched non-musicians. ‪Musicians performed more quickly and more accurately than non-musicians in two tasks of visuospatial ability, and completed more items than non-musicians in three tasks of processing speed, suggesting ‪musicians had better ‪visuospatial ability and a faster speed of processing. Studies 3 and 4 aimed to investigate ‪visuospatial attention in ‪these groups using a line-bisection task and a visual discrimination task. On both tasks musicians demonstrated more balanced visuospatial attention with a slight bias to the right hemispace, which was in contrast to the non-musicians’ bias to the left hemispace, a natural phenomenon known as ‘right pseudoneglect’. In Study 5, the laterality of visual processing in musicians and non-musicians was further investigated by comparing electrophysiological interhemispheric transfer time (IHTT) of lateralized visual stimuli across the corpus callosum. Non-musicians had faster right-to-left than left-to-right IHTT consistent with previous research, whilst musicians had more balanced IHTT in both directions and faster left-to-right transfer than non-musicians. Absolute latency patterns revealed similar results and consistently demonstrated more balanced visual processing in musicians. The behavioural data, analysed in Study 6, revealed a tendency (n.s.) for the ‪musician group to respond more quickly to stimuli presented in the right visual field than to stimuli presented in the left visual field, whilst ‪non-musicians did not show this pattern. Overall, the results indicate that musicians have enhanced visuospatial ability and are less lateralized for visuospatial attention and perception than non-musicians. The results are discussed in relation to plastic developmental changes that may be caused by extended musical training from childhood. Specifically, it is proposed that musical training in early life may elicit a process of myelination that is more bilaterally distributed than myelination in non-musicians.
6

Balanced brains: an investigation of visuospatial ability and lateralization in musicians

Patston, Lucy January 2007 (has links)
Musicians comprise a unique population whereby persistent musical practice involving complex cognitive and motor tasks dates back to childhood when the potential for neural plasticity is at its highest. Accordingly, it has been speculated that musical training results in neural structural and functional differences between musicians and non-musicians. In particular, there is evidence to indicate parietal regions are more equally lateralized in musicians, but research investigating visuospatial abilities and lateralization in musicians is scarce. Studies 1 and 2 aimed to assess the visuospatial ability and cognitive processing speed of adult musicians versus ‪demographically and educationally matched non-musicians. ‪Musicians performed more quickly and more accurately than non-musicians in two tasks of visuospatial ability, and completed more items than non-musicians in three tasks of processing speed, suggesting ‪musicians had better ‪visuospatial ability and a faster speed of processing. Studies 3 and 4 aimed to investigate ‪visuospatial attention in ‪these groups using a line-bisection task and a visual discrimination task. On both tasks musicians demonstrated more balanced visuospatial attention with a slight bias to the right hemispace, which was in contrast to the non-musicians’ bias to the left hemispace, a natural phenomenon known as ‘right pseudoneglect’. In Study 5, the laterality of visual processing in musicians and non-musicians was further investigated by comparing electrophysiological interhemispheric transfer time (IHTT) of lateralized visual stimuli across the corpus callosum. Non-musicians had faster right-to-left than left-to-right IHTT consistent with previous research, whilst musicians had more balanced IHTT in both directions and faster left-to-right transfer than non-musicians. Absolute latency patterns revealed similar results and consistently demonstrated more balanced visual processing in musicians. The behavioural data, analysed in Study 6, revealed a tendency (n.s.) for the ‪musician group to respond more quickly to stimuli presented in the right visual field than to stimuli presented in the left visual field, whilst ‪non-musicians did not show this pattern. Overall, the results indicate that musicians have enhanced visuospatial ability and are less lateralized for visuospatial attention and perception than non-musicians. The results are discussed in relation to plastic developmental changes that may be caused by extended musical training from childhood. Specifically, it is proposed that musical training in early life may elicit a process of myelination that is more bilaterally distributed than myelination in non-musicians.
7

Balanced brains: an investigation of visuospatial ability and lateralization in musicians

Patston, Lucy January 2007 (has links)
Musicians comprise a unique population whereby persistent musical practice involving complex cognitive and motor tasks dates back to childhood when the potential for neural plasticity is at its highest. Accordingly, it has been speculated that musical training results in neural structural and functional differences between musicians and non-musicians. In particular, there is evidence to indicate parietal regions are more equally lateralized in musicians, but research investigating visuospatial abilities and lateralization in musicians is scarce. Studies 1 and 2 aimed to assess the visuospatial ability and cognitive processing speed of adult musicians versus ‪demographically and educationally matched non-musicians. ‪Musicians performed more quickly and more accurately than non-musicians in two tasks of visuospatial ability, and completed more items than non-musicians in three tasks of processing speed, suggesting ‪musicians had better ‪visuospatial ability and a faster speed of processing. Studies 3 and 4 aimed to investigate ‪visuospatial attention in ‪these groups using a line-bisection task and a visual discrimination task. On both tasks musicians demonstrated more balanced visuospatial attention with a slight bias to the right hemispace, which was in contrast to the non-musicians’ bias to the left hemispace, a natural phenomenon known as ‘right pseudoneglect’. In Study 5, the laterality of visual processing in musicians and non-musicians was further investigated by comparing electrophysiological interhemispheric transfer time (IHTT) of lateralized visual stimuli across the corpus callosum. Non-musicians had faster right-to-left than left-to-right IHTT consistent with previous research, whilst musicians had more balanced IHTT in both directions and faster left-to-right transfer than non-musicians. Absolute latency patterns revealed similar results and consistently demonstrated more balanced visual processing in musicians. The behavioural data, analysed in Study 6, revealed a tendency (n.s.) for the ‪musician group to respond more quickly to stimuli presented in the right visual field than to stimuli presented in the left visual field, whilst ‪non-musicians did not show this pattern. Overall, the results indicate that musicians have enhanced visuospatial ability and are less lateralized for visuospatial attention and perception than non-musicians. The results are discussed in relation to plastic developmental changes that may be caused by extended musical training from childhood. Specifically, it is proposed that musical training in early life may elicit a process of myelination that is more bilaterally distributed than myelination in non-musicians.
8

Distracting the imagination: does visuospatial or auditory interference influence gesture and speech during narrative production?

Smithson, Lisa Unknown Date
No description available.
9

Gender differences in unconscious visual working memory

Wienen, Renske January 2019 (has links)
Recent research has shown that working memory tasks can be performed with information that hasn’t been consciously perceived. This provides new opportunities in research concerning possible limitations and influential factors on unconscious working memory. Gender has been demonstrated to be a factor affecting conscious visual working memory tasks and could likewise influence unconscious visual working memory. An analysis of behavioral data, obtained in three similar unconscious visual working memory tasks (n = 89), was performed. Three ANCOVAs were conducted to establish whether there was a significant effect of gender on unconscious working memory accuracy, response time (RT) and speed-accuracy tradeoff (SAT) across the three datasets. The analysis demonstrated a significant advantage in response time for female participants compared to male participants. Implications of this observation, such as male and female response strategies and possible social implications of unconscious processes, are discussed in this thesis. / Nyligen har arbetsminnet bevisats fungera omedvetet. Detta öppnar nya dörrar för forskning om möjliga begränsningar och påverkande faktorer på omedvetet arbetsminne. Kön, som har betydande inflytande på medvetet visuellt arbetsminne, kan på samma sätt också påverka det omedvetna visuella arbetsminnet. En analys av data, insamlad vid tre liknande visuella uppgifter där det omedvetna arbetsminnet användes (n = 91), utfördes. ANCOVAs utfördes för att fastställa huruvida det fanns betydande effekter utifrån kön på det omedvetna arbetsminnets noggrannhet, svarstid samt avvägning mellan snabbhet och noggrannhet, oavsett uppgift. Analysen visade ett signifikant övertag vad gäller kvinnors svarstid i jämförelse med manliga deltagare. Detta övertag gäller generell svarstid och en fördelaktig avvägning mellan snabbhet och noggrannhet. Konsekvensen av dessa observationer, såsom olika svarstaktik för män och kvinnor, möjlig samhällspåverkan av omedvetna processer, diskuteras i denna uppsats.
10

Investigating the impact of individual user differences and environmental factors on spatial knowledge acquisition from virtual environments

Kyritsis, Markos-Akrivos January 2010 (has links)
Trying to ‘learn’ the spatial layout of an environment is a common problem in certain application domains, such as military and emergency personnel training. Until recently this training was accomplished solely by providing maps and briefings of an environment. These methods, however, only provide topological (survey) knowledge of the environment, which pays little attention to the details of routes and landmarks that can only be acquired through the acquisition of procedural knowledge via navigation. Unlike previous experiments concerning spatial knowledge acquisition this work does not attempt to determine whether spatial knowledge acquisition is feasible. Such investigations have yielded a variety of results, yet all agree that spatial knowledge acquisition from a virtual environment is feasible if given enough exposure time. Accordingly, the aim of this thesis is to contribute towards a better understanding of how various individual differences and environmental factors impact the exposure time requirements needed for a person to acquire spatial knowledge from a virtual environment. Although the results of our investigation should be used with caution, we show that a one-size-fits-all situation is not possible when estimating the required exposure time that a user needs to acquire spatial knowledge. Moreover we provide a guide that allows a trainer to predict the required exposure time a person will require, by using the person's personal profile, and the environment's particular factors. In addition, we found that one of the tests we used during our investigation caused unnecessary frustration and confusion to our participants. This test is a standard way of finding a participant's orientation skill, and is commonly used in the area of spatial knowledge acquisition. Therefore, by recreating a new electronic version of the test and comparing the scores from both the new test and the old one our investigation showed that the scores on the new test were significantly higher for all participants. The training time was also lowered significantly. Our updated electronic version will be useful in future research. This test is available online at: www.newgztest.com.

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