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1.
Biol Bull ; 243(1): 76-83, 2022 08.
Artigo em Inglês | MEDLINE | ID: mdl-36108037

RESUMO

AbstractCoral populations are declining worldwide as a result of increased environmental stressors, including disease. Coral health is greatly dependent on complex interactions between the host animal and its associated microbial symbionts. While relatively understudied, there is growing evidence that the coral microbiome contributes to the health and resilience of corals in a variety of ways, similar to more well-studied systems, such as the human microbiome. Many of these interactions are dependent upon the production and exchange of natural products, including antibacterial compounds, quorum-sensing molecules, internal signaling molecules, nutrients, and so on. While advances in sequencing, culturing, and metabolomic techniques have aided in moving forward the understanding of coral microbiome interactions, current sequence and metabolite databases are lacking, hindering detailed descriptions of the microbes and metabolites involved. This review focuses on the roles of coral microbiomes in health and disease processes of coral hosts, with special attention to the coral metabolome. We discuss what is currently known about the relationship between the coral microbiome and disease, of beneficial microbial products or services, and how the manipulation of the coral microbiome may chemically benefit the coral host against disease. Understanding coral microbiome-metabolome interactions is critical to assisting management, conservation, and restoration strategies.


Assuntos
Antozoários , Produtos Biológicos , Microbiota , Animais , Antibacterianos , Bactérias , Humanos , Metaboloma
2.
Healthcare (Basel) ; 8(4)2020 Oct 06.
Artigo em Inglês | MEDLINE | ID: mdl-33036233

RESUMO

Quantification of gait changes in response to altered environmental stimuli may allow for improved understanding of the mechanisms that influence gait changes and fall occurrence in older adults. This study explored how systematic manipulation of a single dimension of one's environment affects spatiotemporal gait parameters. A total of 20 older adult participants walked at a self-selected pace in a constructed research hallway featuring a mobile wall, which allowed manipulation of the hallway width between three conditions: 1.14 m, 1.31 m, and 1.48 m. Spatiotemporal data from participants' walks were captured using an instrumented GAITRite mat. A repeated measures ANOVA revealed older adults spent significantly more time in double support in the narrowest hallway width compared to the widest, but did not significantly alter other spatiotemporal measures. Small-scale manipulations of a single dimension of the environment led to subtle, yet in some cases significant changes in gait, suggesting that small or even imperceptible environmental changes may contribute to altered gait patterns for older adults.

3.
Motor Control ; 24(1): 57-74, 2020 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-31323642

RESUMO

Reaching and grasping are often completed while walking, yet the interlimb coordination required for such a combined task is not fully understood. Previous studies have produced contradictory evidence regarding preference for support of the lower limb ipsilateral or contralateral to the upper limb when performing a reaching task. This coordinative aspect of the combined task provides insight into whether the two tasks are mutually modified or if the reach is superimposed upon normal arm swinging. Collectively, 18 right-handed young adults walked slower, took shorter steps, and spent more time in double support during the combined task compared with walking alone. The peak grasp aperture was larger in walking reach-to-grasp trials compared with standing trials. There was not a strong trend for lower limb support preferences at the reach initiation or object contact. The participants could begin walking with either foot and demonstrated variability of preferred gait initiation patterns. There was a range of interlimb coordination patterns, none of which could be generalized to all young adults. The variability with which healthy right-handed young adults execute a combined walking reach-to-grasp task suggests that the cyclical (walking) and discrete (prehension) motor tasks may have separate motor control mechanisms, as proposed in the two primitives theory.


Assuntos
Marcha/fisiologia , Adulto , Feminino , Humanos , Masculino , Adulto Jovem
4.
Res Autism Spectr Disord ; 51: 9-17, 2018 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-30333859

RESUMO

BACKGROUND: Postural stability difficulties are commonly reported in people on the autism spectrum. However, it is unclear whether unsteady surfaces may exacerbate postural stability difficulties in children and adolescents with autism spectrum disorder (ASD). Understanding balance on unsteady surfaces is important because uneven surfaces are commonly encountered in daily life. METHODS: Twenty-one youth on the autism spectrum and 16 youth with typical development (ages 6-16 years, IQ ≥ 79) stood on both a fixed and unsteady (tiltable) platform, and center of pressure was measured. RESULTS: The group with ASD exhibited differentially more postural sway on the unsteady surface compared to the group with typical development. However, there was substantial variability within the ASD group. Follow-up analyses suggested that much of the variability in postural sway in the ASD group was accounted for by IQ. CONCLUSIONS: Clinically, these findings suggest that not all individuals with ASD struggle more with postural stability on unsteady surfaces. Instead children and adolescents with ASD and below-average IQ may have particular difficulty on unsteady surfaces and may require accommodations. Further, these findings lay the groundwork for future research to investigate the underlying mechanisms of poorer balance across the autism spectrum.

5.
Front Psychol ; 9: 2720, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30705654

RESUMO

Reaching and grasping (prehension) is one of the earliest developing motor skills in humans, but continued prehension development in childhood and adolescence enables the performance of increasingly complex manual tasks. In individuals with autism spectrum disorder (ASD) atypical unimanual reaching and grasping has been reported, but to date, no studies have investigated discrete bimanual movements. We examined unimanual and bimanual reach to grasp tasks in youth with ASD to better understand how motor performance might change with increasing complexity. Twenty youth with ASD (10.1 ± 2.4 years) and 17 youth with typical development (TD) (9.6 ± 2.6 years) were instructed to reach and grasp cubes that became illuminated. Participants were asked to reach out with the right and/or left hands to grasp and lift targets located at near (18 cm) and/or far (28 cm) distances. For the unimanual (simplest) condition, participants grasped one illuminated cube (with either the left or right hand). For the bimanual conditions, participants grasped two illuminated cubes located at the same distance from the start position (bimanual symmetric condition) or two illuminated cubes located at different distances (bimanual asymmetric condition). Significant interactions among diagnostic group, task complexity, and age were found for initiation time (IT) and movement time (MT). Specifically, the older children in both groups initiated and performed their movements faster in the unimanual condition than in the bimanual conditions, although the older children with ASD produced slower ITs and MTs compared to typically developing peers across all three conditions. Surprisingly, the younger children with ASD had similar ITs and MTs as their peers for the unimanual condition but did not considerably slow these times to adjust for the complexity of the bimanual tasks. We hypothesize that they chose to re-use the motor plans that were generated for the unimanual trials rather than generate more appropriate motor plans for the bimanual tasks. An atypical spatiotemporal relationship between MT and peak aperture (PA) was also found in the ASD group. Together, our results suggest deficits in motor planning that result in subtle effects on performance in younger children with ASD that become more pronounced with age.

6.
J Autism Dev Disord ; 48(1): 163-175, 2018 01.
Artigo em Inglês | MEDLINE | ID: mdl-28921103

RESUMO

The present study examined the effects of a visual-based biofeedback training on improving balance challenges in autism spectrum disorder (ASD). Twenty-nine youth with ASD (7-17 years) completed an intensive 6-week biofeedback-based videogame balance training. Participants exhibited training-related balance improvements that significantly accounted for postural-sway improvements outside of training. Participants perceived the training as beneficial and enjoyable. Significant moderators of training included milder stereotyped and ritualistic behaviors and better starting balance. Neither IQ nor BMI moderated training. These results suggest that biofeedback-based balance training is associated with balance improvements in youth with ASD, most robustly in those with less severe repetitive behaviors and better starting balance. The training was perceived as motivating, further suggesting its efficacy and likelihood of use.


Assuntos
Transtorno do Espectro Autista/psicologia , Transtorno do Espectro Autista/terapia , Biorretroalimentação Psicológica/métodos , Biorretroalimentação Psicológica/fisiologia , Equilíbrio Postural/fisiologia , Jogos de Vídeo/psicologia , Adolescente , Transtorno do Espectro Autista/diagnóstico por imagem , Criança , Feminino , Humanos , Imageamento por Ressonância Magnética/métodos , Masculino , Motivação/fisiologia , Estimulação Luminosa/métodos
7.
Rural Remote Health ; 17(3): 4044, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28780876

RESUMO

INTRODUCTION: Tobacco smoking has a range of known and predictable adverse outcomes, and across the world sustained smoking reduction campaigns are targeted towards reducing individual and public risk and harm. Conversely, more than 87 million women, mostly in low- and middle-income countries, use smokeless tobacco, yet the research examining the effect of this form of tobacco exposure on women is remarkably scant. In central Australia, the chewing of wild Nicotiana spp., a tobacco plant, commonly known as pituri and mingkulpa, is practised by Aboriginal groups across a broad geographical area. Until recently, there had been no health research conducted on the effects of chewing pituri. METHODS: This article reports on one component of a multidimensional pituri research agenda. A narrative approach utilising the methodology of the Learning Circle was used to interview three key senior central Australian Aboriginal women representative of three large geographical language groupings. The participants were selected by a regional Aboriginal women's organisation. With the assistance of interpreters, a semistructured interview, and specific trigger resources, participants provided responses to enable an understanding of the women's ethnobotanical pituri knowledge and practices around the use of pituri within the context of Aboriginal women's lives. Data were transcribed, and by using a constant comparison analysis, emergent themes were categorised. The draft findings and manuscript were translated into the participants' language and validated by the participants. RESULTS: Three themes around pituri emerged: (a) the plants, preparation and use; (b) individual health and wellbeing; and (c) family and community connectedness. The findings demonstrated similar participant ethnobotanical knowledge and practices across the geographical area. The participants clearly articulated the ethnopharmacological knowledge associated with mixing pituri with wood ash to facilitate the extraction of nicotine from Nicotiana spp., the results of which were biochemically verified. The participants catalogued the pleasurable and desired effects obtained from pituri use, the miscellaneous uses of pituri, as well as the adverse effects of pituri overdose and toxicity, the catalogue of which matched those of nicotine. The participants' overarching pituri theme was related to the inherent role pituri has in the connectiveness of people to family, friends and community. CONCLUSIONS: Central Australian Aboriginal women have a firmly established knowledge and understanding of the pharmacological principles related to the content of Nicotiana spp. and the extraction of nicotine from the plant. Widespread use of Nicotiana spp. as a chewing tobacco by Aboriginal populations in the southern, central and western desert regions of Australia is attested to by participants who assert that everyone uses it, with girls in these remote areas commencing use between 5 and 7 years of age. Central Australian Aboriginal people who chew Nicotiana spp. do not consider it to be a tobacco plant, and will strongly refute that they are tobacco users. Central Australian Aboriginal people do not consider that the Western health information regarding tobacco (as a smoked product) is applicable or aligned to their use of pituri. Nicotiana spp. users will deny tobacco use at health assessment. There is a requirement to develop and provide health information on a broader range of tobacco and nicotine products in ways that are considered credible by the Aboriginal population. Health messages around pituri use need to account for the dominant role that pituri occupies in the context of central Australian Aboriginal women's lives.
Information for readers: A consultative organisation of Aboriginal women has as a strategic intent and operational agenda the improvement of Aboriginal women's and children's health across the research region. The group seeks opportunities to enhance their knowledge based on legitimate collaborative research; accordingly, they sought to participate in a range of research activities regarding the use of pituri and women's health outcomes. Of particular note, the group's participants chose to be identified by name in the publication of this research activity. In this article, the term 'Aboriginal' has been chosen by the central Australian women to refer to both themselves and the Aboriginal people in their communities; 'Indigenous' has been chosen to refer to the wider Australian Aboriginal and Torres Strait Islander people. The term Nicotiana spp. is used when referring to the plants from a Western perspective; pituri is used when referring to the plants, the tobacco quid, and the practice of chewing from a general Aboriginal perspective; and mingkulpa is used when the participants are voicing their specific knowledge and practices.


Assuntos
Conhecimentos, Atitudes e Prática em Saúde/etnologia , Havaiano Nativo ou Outro Ilhéu do Pacífico/psicologia , Participação Social/psicologia , Tabaco sem Fumaça/estatística & dados numéricos , Austrália/epidemiologia , Relações Familiares/psicologia , Feminino , Nível de Saúde , Humanos , Tabaco sem Fumaça/efeitos adversos
8.
IEEE Trans Neural Syst Rehabil Eng ; 25(8): 1240-1248, 2017 08.
Artigo em Inglês | MEDLINE | ID: mdl-28113774

RESUMO

This study examined how individuals with and without neck pain performed exercises under the influence of altered visual feedback in virtual reality. Chronic neck pain (n=9) and asymptomatic (n=10) individuals were recruited for this cross-sectional study. Participants performed head rotations while receiving programmatically manipulated visual feedback from a head-mounted virtual reality display. The main outcome measure was the control-display gain (ratio between actual head rotation angle and visual rotation angle displayed) recorded at the just-noticeable difference. Actual head rotation angles were measured for different gains. Detection of the manipulated visual feedback was affected by gain. The just-noticeable gain for asymptomatic individuals, below and above unity gain, was 0.903 and 1.159, respectively. Head rotation angle decreased or increased 5.45° for every 0.1 increase or decrease in gain, respectively. The just-noticeable gain for chronic pain individuals, below unity gain, was 0.950. The head rotation angle increased 4.29° for every 0.1 decrease in gain. On average, chronic pain individuals reported that neck rotation was feasible for 84% of the unity gain trials, 66% of the individual just-noticeable difference trials, and 50% of the "nudged" just-noticeable difference trials. This research demonstrated that virtual reality may be useful for promoting the desired outcome of increased range of motion in neck rehabilitation exercises by altering visual feedback.

9.
IEEE Trans Neural Syst Rehabil Eng ; 25(8): 1240-1248, 2017 08.
Artigo em Inglês | MEDLINE | ID: mdl-27810828

RESUMO

This study examined how individuals with and without neck pain performed exercises under the influence of altered visual feedback in virtual reality. Chronic neck pain (n=9) and asymptomatic (n=10) individuals were recruited for this cross-sectional study. Participants performed head rotations while receiving programmatically manipulated visual feedback from a head-mounted virtual reality display. The main outcome measure was the control-display gain (ratio between actual head rotation angle and visual rotation angle displayed) recorded at the just-noticeable difference. Actual head rotation angles were measured for different gains. Detection of the manipulated visual feedback was affected by gain. The just-noticeable gain for asymptomatic individuals, below and above unity gain, was 0.903 and 1.159, respectively. Head rotation angle decreased or increased 5.45° for every 0.1 increase or decrease in gain, respectively. The just-noticeable gain for chronic pain individuals, below unity gain, was 0.950. The head rotation angle increased 4.29° for every 0.1 decrease in gain. On average, chronic pain individuals reported that neck rotation was feasible for 84% of the unity gain trials, 66% of the individual just-noticeable difference trials, and 50% of the "nudged" just-noticeable difference trials. This research demonstrated that virtual reality may be useful for promoting the desired outcome of increased range of motion in neck rehabilitation exercises by altering visual feedback.

10.
J Neurotrauma ; 34(7): 1448-1456, 2017 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-27825289

RESUMO

This single-center prospective observational study aims to describe the prevalence of vitamin D deficiency (VDD) in the traumatic brain injury (TBI) population and identify any relationship between vitamin D and severity of head injury or quality of life. One hundred twenty-four TBI patients had serum vitamin D (25-OHD) levels measured at the local post-TBI endocrine screening clinic over 20 months. Quality of Life after Brain Injury questionnaires were completed by the patient concurrently. A multivariate regressional analysis was performed, controlling for age, season, ethnicity, time since injury, TBI severity, and gender. A total of 34% (n = 42) of the cohort were vitamin D deficient (25-OHD <25 nmol/L), with a further 23% (n = 29) having insufficient levels (25-OHD 25-50 nmol/L). Vitamin D was significantly lower in patients with severe TBI than in patients with mild TBI (n = 95; p = 0.03; confidence interval [CI] 95% -23.60 to -1.21; mean effect size 12.40 nmol/L). There was a trend for self-reported quality of life to be better in patients with optimum vitamin D levels than in patients with deficient vitamin D levels, controlling for severity of injury (n = 81; p = 0.05; CI 95% -0.07 to 21.27). This is the first study to identify a significant relationship between vitamin D levels and severity of head injury. Clinicians should actively screen for and treat VDD in head-injured patients to reduce the risk of further morbidity, such as osteomalacia and cardiovascular disease. Future research should establish the natural history of vitamin D levels following TBI to identify at which stage VDD develops and whether vitamin D replacement could have a beneficial effect on recovery and quality of life.


Assuntos
Lesões Encefálicas Traumáticas/fisiopatologia , Calcifediol/sangue , Qualidade de Vida , Índice de Gravidade de Doença , Deficiência de Vitamina D/sangue , Adulto , Lesões Encefálicas Traumáticas/epidemiologia , Comorbidade , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Reino Unido/epidemiologia , Deficiência de Vitamina D/epidemiologia , Adulto Jovem
11.
Am J Surg ; 211(2): 445-50, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26701699

RESUMO

BACKGROUND: The aim of this study was to evaluate working volume as a potential assessment metric for open surgical tasks. METHODS: Surgical attendings (n = 6), residents (n = 4), and medical students (n = 5) performed a suturing task on simulated connective tissue (foam), artery (rubber balloon), and friable tissue (tissue paper). Using a motion tracking system, effective working volume was calculated for each hand. Repeated measures analysis of variance assessed differences in working volume by experience level, dominant and/or nondominant hand, and tissue type. RESULTS: Analysis revealed a linear relationship between experience and working volume. Attendings had the smallest working volume, and students had the largest (P = .01). The 3-way interaction of experience level, hand, and material type showed attendings and residents maintained a similar working volume for dominant and nondominant hands for all tasks. In contrast, medical students' nondominant hand covered larger working volumes for the balloon and tissue paper materials (P < .05). CONCLUSIONS: This study provides validity evidence for the use of working volume as a metric for open surgical skills. Working volume may provide a means for assessing surgical efficiency and the operative learning curve.


Assuntos
Competência Clínica , Educação Médica , Eficiência , Técnicas de Sutura/educação , Estudos de Tempo e Movimento , Lateralidade Funcional , Humanos , Curva de Aprendizado , Treinamento por Simulação
12.
J Surg Res ; 198(2): 294-8, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-26003012

RESUMO

BACKGROUND: The aim of this study was to investigate how tissue characteristics influence psychomotor planning and performance during a suturing task. Our hypothesis was that participants would alter their technique based on tissue type with each subsequent stitch placed while suturing. MATERIALS AND METHODS: Surgical attendings (n = 6), residents (n = 4), and medical students (n = 5) performed three interrupted sutures on different simulated materials as follows: foam (dense connective tissue), rubber balloons (artery), and tissue paper (friable tissue). An optical motion tracking system captured performance data from participants' bilateral hand movements. Path length and suture time were segmented by each individual stitch placed to investigate changes to psychomotor performance with subsequent stitch placements. Repeated measures analysis of variance was used to evaluate for main effects of stitch order on path length and suture time and interactions between stitch order, material, and experience. RESULTS: When participants sutured the tissue paper, they changed their procedure time (F(4,44) = 5.14, P = 0.017) and path length (F(4,44) = 4.64, P = 0.003) in a linear fashion with the first stitch on the tissue paper having the longest procedure time and path length. Participants did not change their path lengths and procedure times when placing subsequent stitches in the foam (P = 0.910) and balloon materials (P = 0.769). CONCLUSIONS: This study demonstrates quantifiable real-time adaptation by participants to material characteristics during a suturing task. Participants improved their motion-based performance with each subsequent stitch placement indicating changes in psychomotor planning or performance. This adaptation did not occur with the less difficult tasks. Motion capture technology is a promising method for investigating surgical performance and how surgeons adapt to operative complexity.


Assuntos
Técnicas de Sutura , Competência Clínica , Humanos , Duração da Cirurgia , Desempenho Psicomotor
13.
Am J Surg ; 209(4): 645-51, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25725505

RESUMO

BACKGROUND: The aim of this study was to evaluate validity evidence using idle time as a performance measure in open surgical skills assessment. METHODS: This pilot study tested psychomotor planning skills of surgical attendings (n = 6), residents (n = 4) and medical students (n = 5) during suturing tasks of varying difficulty. Performance data were collected with a motion tracking system. Participants' hand movements were analyzed for idle time, total operative time, and path length. We hypothesized that there will be shorter idle times for more experienced individuals and on the easier tasks. RESULTS: A total of 365 idle periods were identified across all participants. Attendings had fewer idle periods during 3 specific procedure steps (P < .001). All participants had longer idle time on friable tissue (P < .005). CONCLUSIONS: Using an experimental model, idle time was found to correlate with experience and motor planning when operating on increasingly difficult tissue types. Further work exploring idle time as a valid psychomotor measure is warranted.


Assuntos
Competência Clínica/estatística & dados numéricos , Técnicas de Sutura/normas , Humanos , Modelos Anatômicos , Projetos Piloto , Fatores de Tempo
14.
Front Psychol ; 6: 92, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25713546

RESUMO

The completion of many goal oriented skills requires the tight coordination of the right and left hands to achieve the task objective. Although the coordination of wrist transport and orientation of the hand before object contact has been studied in detail for discrete bimanual tasks, as yet, very few studies have examined bimanual coordination when the target is already in hand. It has been shown that congruency of the goal facilitates the production of discrete bimanual responses. The purpose of this study was to investigate the role of goal congruency on precision bimanual transport and rotate tasks. In the current investigation, participants transported two cubic objects while rotating them laterally to place them into tight-fitting targets. The magnitude of the rotation could be the same for both hands (i.e., both 45 or 90(∘)) or different (i.e., one 45 and 90(∘)) and the endpoint orientations (i.e., goal) could either be congruent or incongruent. Results indicated that when the endpoint orientation was congruent for the two hands, movement times were similar regardless of hand (left or right), rotation magnitude (45, 90(∘)) and whether the rotation magnitude for the two hands was the same or different. These results suggest that congruency of the endpoint goal facilitates the temporal synchronization of the transport component for two limbs. In contrast, a different pattern of results was obtained when considering the rotation component. Specifically, regardless of whether the hands were rotating the same magnitude or ending in congruent endpoint positions, the coordination of the rotation component between the hands was asynchronous. We hypothesize that the greater requirement to shift visual fixation from one hand/target to the other to ascertain the separate goal orientations may explain these differences. These results provide further evidence that multiple constraints act to influence the performance of skilled bimanual tasks.

15.
Exp Brain Res ; 231(2): 153-64, 2013 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-23979013

RESUMO

The performance of many everyday activities requires the coordination of the two upper limbs to achieve the goal of the task. Although bimanual performance has been studied in detail in adults, few studies have examined how children coordinate the movements of the two hands during symmetric and asymmetric bimanual prehension. With the current study, we asked younger (4-6 years, n = 14) and older (7-10 years, n = 16) children to complete a discrete bimanual task. Specifically, they reached to grasp cylinders located at near and far positions in either unimanual or bimanual condition. During bimanual symmetric conditions, participants performed movements with both hands toward two objects located at the same distance (both near or both far), while in the bimanual asymmetric conditions, they reached for objects at different distances. Results of the kinematic analyses indicated that the young children consistently experienced the "two target" effect, whereby bimanual movements were executed more slowly than unimanual movements to the same distance. Older children employed a hybrid strategy, exhibiting slower movements in bimanual congruent conditions, but larger non-dominant apertures in bimanual incongruent conditions. This hybrid strategy was hypothesized to stem from developmental changes occurring in the integration of sensory information around 8 years of age. While older children exhibited temporal and spatial coordination patterns that were similar to patterns reported in adults, large relative timing differences at the start and end of bimanual movements and considerably weaker spatial coupling were seen in the younger children.


Assuntos
Lateralidade Funcional/fisiologia , Desempenho Psicomotor/fisiologia , Envelhecimento/psicologia , Fenômenos Biomecânicos , Criança , Pré-Escolar , Interpretação Estatística de Dados , Feminino , Dedos/fisiologia , Objetivos , Humanos , Masculino , Extremidade Superior/fisiologia
16.
Exp Brain Res ; 215(3-4): 257-67, 2011 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-21984054

RESUMO

Task-switching paradigms have generally been used to investigate cognitive processes involved in decision making or allocating attention. This work extended the task-switching paradigm into the motor domain in order to investigate the consequences of an unexpected environmental perturbation on reaction time and movement time. Typically, task-switching paradigms have investigated consequences of rearranging task sets from one trial to the next; this work explored rearranging planned movements within the context of a single trial. Of particular interest was how the motor system reorganizes coordination patterns when reaching amplitude congruency is manipulated between the two hands. Results for Experiment 1 and the far distance in Experiment 2 indicated that reaction time switch costs were the smallest during congruent task-switch trials, where reaching amplitudes between the two hands were the same. This implies that a planned movement parameter for one hand is accessible for the other hand in the circumstance of an unexpected task switch. However, the reversed congruency effects found for the near distance in Experiment 2 suggest that the ability to capitalize on stored parameter information to decrease reaction time is dependent on environmental factors and task instructions. Movement time results showed that even if a movement with one hand is aborted in mid-execution, it can still influence the performance of the other hand during a task switch. This suggests that bimanual coordination can affect prehensile performance even though only one hand has a goal to achieve.


Assuntos
Lateralidade Funcional/fisiologia , Mãos/fisiologia , Destreza Motora/fisiologia , Desempenho Psicomotor/fisiologia , Adulto , Feminino , Humanos , Masculino , Testes Neuropsicológicos/normas , Adulto Jovem
17.
Hum Mov Sci ; 29(4): 502-17, 2010 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-20576299

RESUMO

In this series of studies on the coordination of the two hands during a bimanual perturbation task, 10 right-handed volunteers were asked to reach to grasp and lift two illuminated cubic objects. Upon initiation of the reach a perturbation could occur by extinguishing one or both objects and illuminating new objects located directly away from the start position in the para-sagittal plane (Experiment 1) or toward the start position in the para-sagittal plane (Experiment 2). In Experiment 2 we also manipulated position of the targets within the visual span by having the targets move toward the midline or away from the midline. Dependent measures included kinematic data for the reach movement as well as the timing of eye movements. Results of both experiments indicated little interference between the hands when one object was perturbed while the other remained stationary. We hypothesize that when visual feedback about limb movement is available, participants can independently reorganize the trajectory of the perturbed limb with minimal interference on the non-perturbed limb. Furthermore, results of Experiment 2 indicated that the position of the targets within the visual span at the final target location dictates the number of eye movements made to acquire both targets and can lead to asynchronies at movement termination in a task-dependent manner. Finally, we found that when targets were perturbed away from the body movement time results indicated a right-hand advantage for dealing with a single perturbation. In contrast, perturbations toward the body abolished the movement time advantage. We suggest that differences in the use of visual feedback when working in the upper versus lower visual fields may influence hand advantages.


Assuntos
Fenômenos Biomecânicos , Retroalimentação Sensorial , Força da Mão , Remoção , Orientação , Desempenho Psicomotor , Percepção Visual , Movimentos Oculares , Feminino , Lateralidade Funcional , Humanos , Masculino , Adulto Jovem
18.
Exp Brain Res ; 201(4): 797-807, 2010 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-19953229

RESUMO

An experiment was designed to investigate the temporal and spatial couplings of the transport and grasp components for bimanual movements performed by children. Thirty-one participants aged 4-6 (younger) and 7-10 (older) performed the unimanual task of reaching for, grasping, and lifting a small or large cylinder with the right or left hands or the bimanual task of reaching for, grasping and lifting two small cylinders, two large cylinders, or one small and one large cylinder with the right and left hands. Kinematic measures, relative timing differences between the hands, spatial plots and cluster analysis were used to quantify both temporal and spatial couplings of the limbs. While average kinematic results indicated that children in the 4-6 and 7-10 age range performed bimanual movements similarly to each other, spatio-temporal coupling measures indicated that the younger children performed the bimanual movements in a more sequential (serial) fashion. Kinematic results also indicated that the cost of the increase in task complexity normally seen in adults when grasping two targets bimanually compared to a single target unimanually are not consistently present for children. Instead, the cost associated with increases in task complexity appear to be mediated by whether the bimanual task imposes significantly greater demands on attentional processes. These results indicate that attention demands of the task as well as the intrinsic dynamics of the individual determine the degree of interlimb coupling of children during bimanual reach-to-grasp of different-sized objects.


Assuntos
Mãos , Destreza Motora , Envelhecimento , Fenômenos Biomecânicos , Criança , Pré-Escolar , Análise por Conglomerados , Feminino , Lateralidade Funcional , Mãos/fisiologia , Humanos , Masculino , Destreza Motora/fisiologia , Psicofísica , Fatores de Tempo
19.
Q J Exp Psychol (Hove) ; 62(7): 1328-42, 2009 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-19214834

RESUMO

The performance of bimanual movements involving separate objects presents an obvious challenge to the visuo-motor system: Visual feedback can only be obtained from one target at a time. To overcome this challenge overt shifts in visual attention may occur so that visual feedback from both movements may be used directly (Bingham, Hughes, & Mon-Williams, 2008; Riek, Tresilian, Mon-Williams, Coppard, & Carson, 2003). Alternatively, visual feedback from both movements may be obtained in the absence of eye movements, presumably by covert shifts in attention (Diedrichsen, Nambisan, Kennerley, & Ivry, 2004). Given that the quality of information falls with increasing distance from the fixated point, can we obtain the level of information required to accurately guide each hand for precision grasping of separate objects without moving our eyes to fixate each target separately? The purpose of the current study was to examine how the temporal coordination between the upper limbs is affected by the quality of visual information available during the performance of a bimanual task. A total of 11 participants performed congruent and incongruent movements towards near and/or far objects. Movements were performed in natural, fixate-centre, fixate-left, and fixate-right vision conditions. Analyses revealed that the transport phase of incongruent movements was similar across vision conditions for the temporal aspects of both the transport and grasp, whereas the spatial aspects of grasp formation were influenced by the quality of visual feedback. We suggest that bimanual coordination of the temporal aspects of reach-to-grasp movements are not influenced solely by overt shifts in visual attention but instead are influenced by a combination of factors in a task-constrained way.


Assuntos
Força da Mão/fisiologia , Movimento/fisiologia , Desempenho Psicomotor/fisiologia , Visão Ocular/fisiologia , Atenção/fisiologia , Fenômenos Biomecânicos , Movimentos Oculares/fisiologia , Lateralidade Funcional , Humanos
20.
Clin Nurs Res ; 18(1): 26-43, 2009 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-19208819

RESUMO

The primary purpose of this pilot study was to examine the influence of maternal health status on health services use in children with the diagnosis of asthma. A secondary purpose was to assess both preventive and illness-related child health services use patterns. Fifty-two asthmatic children and 43 mothers met the inclusion criteria. The majority of mothers (72%, n = 31/43) rated their own overall health as good to excellent. Eighty-six percent (n = 38/44) of the children had a medical home, 20% had peak flow meters, 26% had been to see a specialist, and 4% were currently under the care of a specialist. This pilot study raises important questions about the influence of maternal health on child health services use patterns for asthmatic children from low-income families. Understanding the influence of maternal health on health-seeking patterns for children with asthma is important for nursing intervention.


Assuntos
Asma/terapia , Proteção da Criança , Serviços de Saúde/estatística & dados numéricos , Bem-Estar Materno , Adulto , Criança , Feminino , Nível de Saúde , Humanos , Pessoa de Meia-Idade , Nebraska , Projetos Piloto
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