Aquisição da informação visual: controle da postura e do olhar

Postural control is needed to perform various daily activities, from staying in one posture, standing, to sports situations. Many studies have shown that sensory systems help to maintain posture stable; acquisition of perceptual information, particularly through head and eye movements, allows static and dynamic equilibrium. Research related to both motor behavior and physical activities such as gymnastics have contributed to a better understanding of complexities involved in human postural control. The purpose of this study was to review the related literature, searching for possible answers on how everyday and sports actions are performed, with respect to the control and maintenance of posture. Its focus was on how the human body acquires information from the sensory systems, vision in special, and how this information acts to support the control of posture and gaze

Efeito de tarefa dupla no controle postural de adultos idosos: acoplamento sensório-motor

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Postural control and automaticity in dyslexic children: The relationship between visual information and body sway

Difficulty with literacy acquisition is only one of the symptoms of developmental dyslexia. Dyslexic children also show poor motor coordination and postural control. Those problems could be associated with automaticity, i.e., difficulty in performing a task without dispending a fair amount of conscious efforts. If this is the case, dyslexic children would show difficulties in using "unperceived" sensory cues to control body sway. Therefore, the aim of the study was to examine postural control performance and the coupling between visual information and body sway in dyslexic children. Ten dyslexic children and 10 non-dyslexic children stood upright inside a moving room that remained stationary or oscillated back and forward at frequencies of 0.2 or 0.5 Hz. Body sway magnitude and the relationship between the room's movement and body sway were examined. The results indicated that dyslexic children oscillated more than non-dyslexic children in both stationary and oscillating conditions. Visual manipulation induced body sway in all children but the coupling between visual information and body sway was weaker and more variable in dyslexic children. Based upon these results, we can suggest that dyslexic children use visual information to postural control with the same underlying processes as non-dyslexic children; however, dyslexic children show poorer performance and more variability while relating visual information and motor action even in a task that does not require an active cognitive and conscious motor involvement, which may be a further evidence of automaticity problem. (C) 2011 Elsevier Ltd. All rights reserved.

Postural control in Down syndrome: the use of somatosensory and visual information to attenuate body sway

The purpose of this study was to examine the effects of visual and somatosensory information on body sway in individuals with Down syndrome (DS). Nine adults with DS (19-29 years old) and nine control subjects (CS) (19-29 years old) stood in the upright stance in four experimental conditions: no vision and no touch; vision and no touch; no vision and touch; and vision and touch. In the vision condition, participants looked at a target placed in front of them; in the no vision condition, participants wore a black cotton mask. In the touch condition, participants touched a stationary surface with their right index finger; in the no touch condition, participants kept their arms hanging alongside their bodies. A force plate was used to estimate center of pressure excursion for both anterior-posterior and medial-lateral directions. MANOVA revealed that both the individuals with DS and the control subjects used vision and touch to reduce overall body sway, although individuals with DS still oscillated more than did the CS. These results indicate that adults with DS are able to use sensory information to reduce body sway, and they demonstrate that there is no difference in sensory integration between the individuals with DS and the CS.

Physical activity and postural control in the elderly: Coupling between visual information and body sway

Background: Aging is characterized by a decline in the postural control performance, which is based on a coherent and stable coupling between sensory information and motor action. Therefore, changes in postural control in elderlies can be related to changes in this coupling. In addition, it has been observed that physical activity seems to improve postural control performance in elderlies. These improvements can be due to changes in the coupling between sensory information and motor action related to postural control. Objective: the purpose of this study was to verify the coupling between visual information and body sway in active and sedentary elderlies. Methods: Sixteen sedentary elderlies ( SE), 16 active elderlies ( AE) and 16 young adults ( YA) were asked to stand upright inside a moving room in two experimental conditions: ( 1) discrete movement and ( 2) continuous movement of the room. Results: In the continuous condition, the results showed that the coupling between the movement of the room and body sway was stronger and more stable for SE and AE compared to YA. In the discrete condition, SE showed larger body displacement compared to AE and YA. Conclusions: SE have more difficulty to discriminate and to integrate sensory information than AE and YA indicating that physical activity may improve sensory integration. Copyright (C) 2005 S. Karger AG, Basel.

Visual information and body sway coupling in infants during sitting acquisition

The purpose of this study was to examine if there is any developmental change in the coupling between visual information and trunk sway in infants as they acquire the sitting position. Twenty-four infants distributed in four groups (6-, 7-, 8-, and 9-month-old) were sat inside a moving room that oscillated back and forward at frequencies of 0.2 and 0.5 Hz. The results revealed that trunk sway matched to the moving room at both frequencies but did not differ among the four age groups. Coherence and gain revealed that the coupling was weaker at 0.2 than at 0.5 Hz. Relative phase showed that at 0.2 Hz, infants were swaying with no lag but at 0.5 Hz they were lagging the room. These results showed that the coupling between visual information and trunk sway in infants varies with the visual stimulus but does not change as infants acquire the sitting position. © 2001 Elsevier B.V.

Estimation of genetic parameters for body weights, scrotal circumference, and testicular volume measured at different ages in Nellore cattle

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Monocular vision and increased distance reducing the effects of visual manipulation on body sway

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Body sway and sensory motor coupling adaptation in children: Effects of distance manipulation

The purpose of this investigation was to examine coupling between visual information and body sway in children and young adults at various distances from a moving room front wall. Sixty children (from 4 to 14 years old) and 10 young adults stood upright inside a moving room that was oscillated at .2 and .5 Hz, at distances of .25, .5, 1, and 1.5 m from a front wall. Visual information induced body sway in all participants in all conditions. Young children swayed more than older participants, whether the moving room was oscillated or not. Coupling between visual information and body sway became stronger and the room movement influence became weaker with age. Up to the age of 10, coupling strength between visual information and body sway and the room movement influence were distance dependent. Postural control development appears to be dependent on how children reweight the contribution of varying sensory cues available in environment in order to control body sway. (C) 2007 Wiley Periodicals, Inc.

Phylogeny, Ecology, and Heart Position in Snakes

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Effects of season, temperature, and body mass on the standard metabolic rate of tegu lizards (Tupinambis merianae)

This study examined how the standard metabolic rate of tegu lizards, a species that undergoes large ontogenetic changes in body weight with associated changes in life-history traits, is affected by changes in body mass, body temperature, season, and life-history traits. We measured rates of oxygen consumption ((V) over dot o(2)) in 90 individuals ranging in body mass from 10.4. g to 3.75 kg at three experimental temperatures ( 17 degrees, 25 degrees, and 30 degrees C) over the four seasons. We found that standard metabolic rate scaled to the power of 0.84 of body mass at all experimental temperatures in all seasons and that thermal sensitivity of metabolism was relatively low (Q(10) approximate to 2.0-2.5) over the range from 17 degrees to 30 degrees C regardless of body size or season. Metabolic rates did vary seasonally, being higher in spring and summer than in autumn and winter at the same temperatures, and this was true regardless of animal size. Finally, in this study, the changes in life-history traits that occurred ontogenetically were not accompanied by significant changes in metabolic rate.

Scaling in few-body nuclear physics

The nuclear matter calculations with realistic nucleon-nucleon potentials present a general scaling between the nucleon-nucleus binding energy, the corresponding saturation density, and the triton binding energy. The Thomas-Efimov three-body effect implies in correlations among low-energy few-body and many-body observables. It is also well known that, by varying the short-range repulsion, keeping the two-nucleon information (deuteron and scattering) fixed, the four-nucleon and three-nucleon binding energies lie on a very narrow band known as a Tjon line. By looking for a universal scaling function connecting the proper scales of the few-body system with those of the many-body system, we suggest that the general nucleus-nucleon scaling mechanism is a manifestation of a universal few-body effect.

Charged three-body system with arbitrary masses near conformal invariance

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)