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- Creators: Santello, Marco
Description
Humans are capable of transferring learning for anticipatory control of dexterous object manipulation despite changes in degrees-of-freedom (DoF), i.e., switching from lifting an object with two fingers to lifting the same object with three fingers. However, the role that tactile information plays in this transfer of learning is unknown. In this study, subjects lifted an L-shaped object with two fingers (2-DoF), and then lifted the object with three fingers (3-DoF). The subjects were divided into two groups--one group performed the task wearing a glove (to reduce tactile sensibility) upon the switch to 3-DoF (glove group), while the other group did not wear the glove (control group). Compensatory moment (torque) was used as a measure to determine how well the subject could minimize the tilt of the object following the switch from 2-DoF to 3-DoF. Upon the switch to 3-DoF, subjects wearing the glove generated a compensatory moment (Mcom) that had a significantly higher error than the average of the last five trials at the end of the 3-DoF block (p = 0.012), while the control subjects did not demonstrate a significant difference in Mcom. Additional effects of the reduction in tactile sensibility were: (1) the grip force for the group of subjects wearing the glove was significantly higher in the 3-DoF trials compared to the 2-DoF trials (p = 0.014), while the grip force of the control subjects was not significantly different; (2) the difference in centers of pressure between the thumb and fingers (ΔCoP) significantly increased in the 3-DoF block for the group of subjects wearing the glove, while the ΔCoP of the control subjects was not significantly different; (3) lastly, the control subjects demonstrated a greater increase in lift force than the group of subjects wearing the glove (though results were not significant). Combined together, these results suggest different force modulation strategies are used depending on the amount of tactile feedback that is available to the subject. Therefore, reduction of tactile sensibility has important effects on subjects' ability to transfer learned manipulation across different DoF contexts.
ContributorsGaw, Nathan (Author) / Helms Tillery, Stephen (Thesis advisor) / Santello, Marco (Committee member) / Kleim, Jeffrey (Committee member) / Arizona State University (Publisher)
Created2014
Description
Biculturalism embodies the degree to which individuals adapt to living within two cultural systems and develop the ability to live effectively across those two cultures. It represents, therefore, a normative developmental task among members of immigrant and ethnic-racial minority groups, and has important implications for psychosocial adjustment. Despite a strong theoretical focus on contextual influences in biculturalism scholarship, the ways in which proximal contexts shape its development are understudied. In my dissertation, I examine the mechanisms via which the family context might influence the development of bicultural competence among a socio-economically diverse sample of 749 U.S. Mexican-origin youths (30% Mexico-born) followed for 7 years (Mage = 10.44 to 17.38 years; Wave 1 to 4).
In study 1, I investigated how parents’ endorsements of values associated with both mainstream and heritage cultures relate to adolescents’ bicultural competence. Longitudinal growth model analyses revealed that parents’ endorsements of mainstream and heritage values simultaneously work to influence adolescents’ bicultural competence. By examining the effect of multiple and often competing familial contextual influences on adolescent bicultural competence development, this work provides insights on intergenerational cultural transmission and advances scholarship on the culturally bounded nature of human development.
In study 2, I offer a substantial extension to decades of family stress model research focused on how family environmental stressors may compromise parenting behaviors and youth development by testing a culturally informed family stress model. My model (a) incorporates family cultural and ecological stressors, (b) focuses on culturally salient parenting practices aimed to teach youth about the heritage culture (i.e., ethnic socialization), and (c) examines bicultural competence as a developmental outcome. Findings suggest that parents’ high exposure to ecological stressors do not compromise parental ethnic socialization or adolescent bicultural competence development. On the other hand, mothers’ exposures to enculturative stressors can disrupt maternal ethnic socialization, and in turn, undermine adolescents’ bicultural competence. By examining the influence of multiple family environmental stressors on culturally salient parenting practices, and their implications for adolescent bicultural competence development, this work provides insights on ethnic-racial minority and immigrant families’ adapting cultures and advances scholarship on the family stress model.
In study 1, I investigated how parents’ endorsements of values associated with both mainstream and heritage cultures relate to adolescents’ bicultural competence. Longitudinal growth model analyses revealed that parents’ endorsements of mainstream and heritage values simultaneously work to influence adolescents’ bicultural competence. By examining the effect of multiple and often competing familial contextual influences on adolescent bicultural competence development, this work provides insights on intergenerational cultural transmission and advances scholarship on the culturally bounded nature of human development.
In study 2, I offer a substantial extension to decades of family stress model research focused on how family environmental stressors may compromise parenting behaviors and youth development by testing a culturally informed family stress model. My model (a) incorporates family cultural and ecological stressors, (b) focuses on culturally salient parenting practices aimed to teach youth about the heritage culture (i.e., ethnic socialization), and (c) examines bicultural competence as a developmental outcome. Findings suggest that parents’ high exposure to ecological stressors do not compromise parental ethnic socialization or adolescent bicultural competence development. On the other hand, mothers’ exposures to enculturative stressors can disrupt maternal ethnic socialization, and in turn, undermine adolescents’ bicultural competence. By examining the influence of multiple family environmental stressors on culturally salient parenting practices, and their implications for adolescent bicultural competence development, this work provides insights on ethnic-racial minority and immigrant families’ adapting cultures and advances scholarship on the family stress model.
ContributorsSafa Pernett, Maria Dalal (Author) / White, Rebecca M. B. (Thesis advisor) / Knight, George P. (Committee member) / Updegraff, Kimberly A. (Committee member) / Wilkens, Natalie D. (Committee member) / Arizona State University (Publisher)
Created2019
Description
A previous study demonstrated that learning to lift an object is context-based and that in the presence of both the memory and visual cues, the acquired sensorimotor memory to manipulate an object in one context interferes with the performance of the same task in presence of visual information about a different context (Fu et al, 2012).
The purpose of this study is to know whether the primary motor cortex (M1) plays a role in the sensorimotor memory. It was hypothesized that temporary disruption of the M1 following the learning to minimize a tilt using a ‘L’ shaped object would negatively affect the retention of sensorimotor memory and thus reduce interference between the memory acquired in one context and the visual cues to perform the same task in a different context.
Significant findings were shown in blocks 1, 2, and 4. In block 3, subjects displayed insignificant amount of learning. However, it cannot be concluded that there is full interference in block 3. Therefore, looked into 3 effects in statistical analysis: the main effects of the blocks, the main effects of the trials, and the effects of the blocks and trials combined. From the block effects, there is a p-value of 0.001, and from the trial effects, the p-value is less than 0.001. Both of these effects indicate that there is learning occurring. However, when looking at the blocks * trials effects, we see a p-value of 0.002 < 0.05 indicating significant interaction between sensorimotor memories. Based on the results that were found, there is a presence of interference in all the blocks but not enough to justify the use of TMS in order to reduce interference because there is a partial reduction of interference from the control experiment. It is evident that the time delay might be the issue between context switches. By reducing the time delay between block 2 and 3 from 10 minutes to 5 minutes, I will hope to see significant learning to occur from the first trial to the second trial.
The purpose of this study is to know whether the primary motor cortex (M1) plays a role in the sensorimotor memory. It was hypothesized that temporary disruption of the M1 following the learning to minimize a tilt using a ‘L’ shaped object would negatively affect the retention of sensorimotor memory and thus reduce interference between the memory acquired in one context and the visual cues to perform the same task in a different context.
Significant findings were shown in blocks 1, 2, and 4. In block 3, subjects displayed insignificant amount of learning. However, it cannot be concluded that there is full interference in block 3. Therefore, looked into 3 effects in statistical analysis: the main effects of the blocks, the main effects of the trials, and the effects of the blocks and trials combined. From the block effects, there is a p-value of 0.001, and from the trial effects, the p-value is less than 0.001. Both of these effects indicate that there is learning occurring. However, when looking at the blocks * trials effects, we see a p-value of 0.002 < 0.05 indicating significant interaction between sensorimotor memories. Based on the results that were found, there is a presence of interference in all the blocks but not enough to justify the use of TMS in order to reduce interference because there is a partial reduction of interference from the control experiment. It is evident that the time delay might be the issue between context switches. By reducing the time delay between block 2 and 3 from 10 minutes to 5 minutes, I will hope to see significant learning to occur from the first trial to the second trial.
ContributorsHasan, Salman Bashir (Author) / Santello, Marco (Thesis director) / Kleim, Jeffrey (Committee member) / Helms Tillery, Stephen (Committee member) / Barrett, The Honors College (Contributor) / W. P. Carey School of Business (Contributor) / Harrington Bioengineering Program (Contributor)
Created2014-05