Dynamics of inter-modality re-weighting during human postural control

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Age-related changes in postural control sensory reweighting

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Elaboração e validação de escala diagramática para quantificação da mancha alvo em folhas de acerola

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

Chemical transfer of warning information in non-injured fish

In this study we describe pacus, Piaractus mesopotamicus, detecting the presence of a predator by conspecific alerting pheromone. Moreover, we investigate whether this chemical information indicates the presence of a specific predator, or whether it indicates general disturbance. We exposed groups of pacus to the view of a predator fish (trahira, Hoplias malabaricus), a non-predator fish (piracanjuba, Brycon orbignyanus) or an aquarium without any fish (control), and then we transferred their water to isolated conspecifics. We set up six trials of each condition in which we analysed the dispersion and the distance from the visual stimulus in water-donor fish and the distance from the chemical stimulus in water-receiver pacus. This study showed that pacus visually identified the presence of another fish and recognised it as predator or non-predator. This is interpreted as an innate response. Such heterospecific detection affects the behaviour of pacus, which release chemicals that induce conspecifics to adopt a similar behavioural response. At least two chemicals might be involved, one of them possibly an alerting pheromone.

Influence of Imposed Optic Flow Characteristics and Intention on Postural Responses

This study examined the influence of both optic flow characteristics and intention on postural control responses. Two groups of 10 adults each were exposed to the room's movement either at 0.6 cm/s (low velocity group) or 1.0 cm/s (high velocity group). All the participants stood in the upright stance inside of a moving room and were informed about the room movement only after the fourth trial as they were asked to resist to its influence. Results revealed that participants from both groups were influenced by the imposed visual stimulus in the first trials, but the coupling strength was weaker for the high velocity group. The request to resist the visual influences decreased visual influences oil body sway, but only for the low velocity group. These results indicate that intention might play a role in stimulus influences on body sway but it is stimulus dependent.

Ingestão de ração e comportamento de larvas de pacu em resposta a estímulos químicos e visuais

Este estudo foi realizado com o objetivo de comparar a influência dos estímulos visual e/ou químico de náuplios de Artemia e de dieta microencapsulada sobre a taxa de ingestão da dieta microencapusulada por larvas de pacu Piaractus mesopotamicus. Utilizou-se um esquema fatorial 7 x 4 (estímulos e idades) com duas repetições. Verificou-se efeito da idade das larvas e dos estímulos, mas não houve efeito para a interação idade ´ estímulos. O estímulo químico da Artemia e ambos os estímulos da Artemia resultaram em maior taxa de ingestão de dieta inerte. Resultado intermediário foi obtido com o estímulo visual da dieta microencapsulada. O estímulo químico, em comparação ao estímulo visual da Artemia, resultou em maiores taxas de ingestão da dieta. Com o aumento da idade, houve incremento na taxa de ingestão. Os estímulos visual e químico dos náuplios e o estímulo visual da ração aumentaram a ingestão de dieta inerte por larvas de pacu. Náuplios de Artemia devem ser oferecidos antes do fornecimento da dieta inerte, pois podem auxiliar no processo de transição alimentar. Os resultados deste trabalho apontaram novas possibilidades de estudos com larvas de peixes neotropicais visando a substituição precoce do alimento vivo para o inerte.

Postural control as a function of self- and object-motion perception

The goals of this study were to examine the visual information influence on body sway as a function of self- and object-motion perception and visual information quality. Participants that were aware (object-motion) and unaware (self-motion) of the movement of a moving room were asked to stand upright at five different distances from its frontal wall. The visual information effect on body sway decreased when participants were aware about the sensory manipulation. Moreover, while the visual influence on body sway decreased as the distance increased in the self-motion perception, no effects were observed in the object-motion mode. The overall results indicate that postural control system functioning can be altered by prior knowledge, and adaptation due to changes in sensory quality seem to occur in the self- but not in the object-motion perception mode. (C) 2004 Elsevier B.V.. All rights reserved.

Relational learning in children with deafness and cochlear implants

This four-experiment series sought to evaluate the potential of children with neurosensory deafness and cochlear implants to exhibit auditory-visual and visual-visual stimulus equivalence relations within a matching-to-sample format. Twelve children who became deaf prior to acquiring language (prelingual) and four who became deaf afterwards (postlingual) were studied. All children learned auditory-visual conditional discriminations and nearly all showed emergent equivalence relations. Naming tests, conducted with a subset of the: children, showed no consistent relationship to the equivalence-test outcomes.. This study makes several contributions: to the literature on stimulus equivalence. First; it demonstrates that both pre- and postlingually deaf children-can: acquire auditory-visual equivalence-relations after cochlear implantation, thus demonstrating symbolic functioning. Second, it directs attention to a population that may be especially interesting for researchers seeking to analyze the relationship. between speaker and listener repertoires. Third, it demonstrates the feasibility of conducting experimental studies of stimulus control processes within the limitations of a hospital, which these children must visit routinely for the maintenance of their cochlear implants.

Chemical communication in Apis mellifera: Temporal modulation of alarm behaviors

The effect of pheromones and their chemical analogues in honeybee alarm behaviors was studied in observation boxes. Defensive behaviors, as follows: a) attraction to scent source, b) elevation of wings in 'V', c) abdomen elevation, d) abdomen elevation and pumping and e) first leg pair elevation had been temporarily registered when the following compounds were presented: isoamyl alcohol, octyl alcohol, benzyl alcohol, n-butyl acetate, n-octyl acetate, isopentyl acetate, benzyl acetate and 2-heptanone. The results were as follows: 1. the bees elicited some characteristic behaviors when chemical alarm messages were presented, 2. agression (stinging) was not completed with any compound tested, probably because there was not a target (visual stimulus), 3. in all situations the attraction to scent source was low, 4. all the behaviors were elicited in a temporarily different way, 5. the compounds that elicited stronger responses and a greater number of the investigated behaviors were: isopentyl acetate, 2-heptanone, octyl acetate and n-octyl alcohol. In all situations, the first behavior response (and the most intense one) was the elevation and pumping the abdomen. This suggests that the chemical message was promptly recognized and then transmitted to each worker. So, the results obtained in the present work, suggest that chemical alarm messages may be recognized by different mechanisms of neural integration.

Composição de dicionários visuais utilizando agrupamento de dados por Florestas de Caminhos Ótimos

Pós-graduação em Ciência da Computação - IBILCE

Processos adaptativos no sistema de controle postural de bebês, crianças e adultos: Paula Fávaro Polastri Zago. -

Pós-graduação em Ciências da Motricidade - IBRC

Avaliação de desempenho de respostas motoras combinadas à digitação em diferentes teclados utilizados em dispositivos móveis

Pós-graduação em Desenvolvimento Humano e Tecnologias - IBRC

Sleep deprivation affects sensorimotor coupling in postural control of young adults

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

Influência de movimentos oculares sacádicos no equilíbrio postural de idosos praticantes de vôlei adaptado e idosos sedentários

Pós-graduação em Desenvolvimento Humano e Tecnologias - IBRC

O competidor interespecífico pode alterar a agressividade intraespecífica? um estudo com caranguejos do gênero Uca

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)