nÃo hà / IntroduÃÃo: Sarcopenia, estado inflamaÃÃo crÃnica e diminuiÃÃo da modulaÃÃo autonÃmica cardÃaca sÃo frequentemente descritos em idosos frÃgeis. No entanto, o papel da inflamaÃÃo e diminuiÃÃo da modulaÃÃo autonÃmica em perda de massa muscular associada ao envelhecimento deve ser esclarecido. Objetivo: identificar, em idosos frÃgeis e robustos residentes na comunidade, correlaÃÃes entre alteraÃÃes autonÃmicas, nÃveis sÃricos de marcadores bioquÃmicos de inflamaÃÃo e diminuiÃÃo da forÃa e do desempenho muscular. Resultados: 98 voluntÃrios frÃgeis e robustos com idade de 60 anos ou mais foram submetidos à avaliaÃÃo clÃnica, exames laboratoriais e anÃlise da variabilidade da frequÃncia cardÃaca em decÃbito dorsal e em ortostase. O logaritmo natural do Ãndice de variabilidade da frequÃncia cardÃaca baixa frequÃncia (LF) foi inversamente relacionado com o marcador bioquÃmico da inflamaÃÃo fibrinogÃnio em idosos com fragilidade (p=0,046), mas nÃo em robustos. NÃo houve associaÃÃo entre Ãndices de variabilidade da frequÃncia cardÃaca e marcadores bioquÃmicos de inflamaÃÃo interleucina-6 e proteÃna C reativa ultrassensÃvel. Velocidade da marcha foi negativamente relacionada com o fibrinogÃnio em idosos frÃgeis (p=0,033), mas nÃo em idosos robustos. Em todos os idosos, velocidade da marcha foi negativamente relacionada com o fibrinogÃnio (p=0,017), interleucina-6 (p=0,038) e proteÃna C reativa ultrassensÃvel (p=0,010). ConclusÃo: nossos resultados sugerem que a sarcopenia relacionada inflamaÃÃo pode ser, pelo menos parcialmente, influenciada por diminuiÃÃo da modulaÃÃo autonÃmica em idosos. / Background: sarcopenia, chronic inflammation status and impairment of cardiac autonomic modulation are often described in frailty elderly. However, the role of inflammation and decreased autonomic modulation in loss of muscle mass associated with aging need to be enlightened. Aim: we aimed to identify, in community-dwelling frailty and robust elderly, correlations among autonomic changes, serum levels of biochemical markers of inflammation and decreased muscle strength and performance. Results: 98 volunteers aged 60 or older was assessed by clinical evaluation, laboratory tests and analysis of heart rate variability (HRV) in the supine and standing positions. The natural logarithm of the HRV index Low Frequency (LF) was inversely related with the biochemical marker of inflammation fibrinogen in frail elderly (p=0.049), but not in robust. There was no association between heart rate variability indices and biochemical markers of inflammation interleukin-6 and C-reactive protein high sensitivity. Gait speed was negatively correlated with fibrinogen in frail elderly (p=0.033), but not in elderly robust. In all elderly, gait speed correlated negatively with fibrinogen (p=0.017), IL-6 (p=0.038) and high-sensitivity CRP (p=0.010). Conclusion: our results suggest that inflammation-related sarcopenia can be at least partially influenced by decreased autonomic modulation in the elderly.

Thesis (Ph. D.)--University of Hong Kong, 2007. / Title proper from title frame. Also available in printed format.

This thesis explores the physiologically-mediated interactions between children with profound disabilities and their environment. Using a structure inspired by the musical theme and variation compositional form, the concept of using physiological signals to enrich person-environment interaction will be addressed in two themes. The first theme explores how children with profound disabilities can use their physiological signals to interact with their environment. The variations on this theme: 1) appraise the literature and establish that peripheral autonomic nervous system signals can be controlled by mental activities; 2) present an algorithm that classifies an individual’s mental state using patterns of electrodermal activity to an accuracy of over 80%, and; 3) discusses the challenges with and potential solutions to creating an physiologically-based interaction pathway for children with profound disabilities. The second theme explores how physiological signals can be used to assess the effect of the environmental milieu on a child with profound disabilities. The variations on this theme: 1) demonstrate the effects of the built environment on the life activities of a severely disabled individual by developing and evaluating the effects of a custom-tailored computer access technology; 2) illustrate how the physiological signals of profoundly disabled children are influenced by their social environment by studying the effect of Therapeutic Clowns on children in a long-term rehabilitation setting; and 3) illustrate how differential physiological responses to sounds in the environmental milieu can be used to inform and improve voluntary physiologically-mediated person-environment interaction. The coda of the thesis presents a conceptual framework that has the potential to enrich the interaction between profoundly disabled children and their environment, using music generated from physiological signal patterns to modify their environmental milieu, constructs of personhood and their identity.

This thesis explores the physiologically-mediated interactions between children with profound disabilities and their environment. Using a structure inspired by the musical theme and variation compositional form, the concept of using physiological signals to enrich person-environment interaction will be addressed in two themes. The first theme explores how children with profound disabilities can use their physiological signals to interact with their environment. The variations on this theme: 1) appraise the literature and establish that peripheral autonomic nervous system signals can be controlled by mental activities; 2) present an algorithm that classifies an individual’s mental state using patterns of electrodermal activity to an accuracy of over 80%, and; 3) discusses the challenges with and potential solutions to creating an physiologically-based interaction pathway for children with profound disabilities. The second theme explores how physiological signals can be used to assess the effect of the environmental milieu on a child with profound disabilities. The variations on this theme: 1) demonstrate the effects of the built environment on the life activities of a severely disabled individual by developing and evaluating the effects of a custom-tailored computer access technology; 2) illustrate how the physiological signals of profoundly disabled children are influenced by their social environment by studying the effect of Therapeutic Clowns on children in a long-term rehabilitation setting; and 3) illustrate how differential physiological responses to sounds in the environmental milieu can be used to inform and improve voluntary physiologically-mediated person-environment interaction. The coda of the thesis presents a conceptual framework that has the potential to enrich the interaction between profoundly disabled children and their environment, using music generated from physiological signal patterns to modify their environmental milieu, constructs of personhood and their identity.

This thesis examined Autonomic Nervous System activity evoked by postural instability. Autonomic reactions were assessed using measures of electrodermal activity at the surface of the skin. Perturbation-evoked electrodermal responses (EDRs) were consistently observed in conjunction with both upper and lower limb postural reactions. These autonomic responses were sensitive to perturbation amplitude, as well as experimental manipulations which did not influence the perturbation itself but which affected response execution. In particular, stimulus predictability and movement challenge modulated EDRs, although purely cognitive manipulations did not significantly affect autonomic responses. Probes examining the potential role of such autonomic potentials in compensatory balance control revealed that EDRs evoked during compensatory postural reactions were larger and more consistent than potentials evoked by purely motor or sensory stimuli, suggesting that evoked autonomic activity plays a role in compensatory behavior. While the specific role of autonomic contributions in compensatory balance control require further study, speculative models for autonomic contributions propose either feedback-based pathways for detection of instability to initiate the postural reaction, and/ or an adaptive role to higher centers important for establishing sensorimotor gain in future conditions. This thesis presents new evidence regarding basic neural mechanisms engaged in the recognition and response to postural instability, and future work may extend these findings in clinical populations with high fall incidence and offer clues as to alternative causes for falls and fall prevention.

Thesis (Ph. D.)--Ohio State University, 2003. / Title from first page of PDF file. Document formatted into pages; contains xiii, 127 p.; also includes graphics Includes bibliographical references (p. 91-105). Available online via OhioLINK's ETD Center

Thesis (Ph. D.)--University of Wisconsin--Madison, 1965. / eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 72-80).

Thesis (Ph. D.)--University of Hong Kong, 2007. / Also available online.

A well-developed body of literature has established the deleterious effects of chronic stress on children’s cognitive development. However, there has been almost no research examining the impact of acutely stressful experiences on children’s cognitive performance. This is surprising given evidence in adults that acute stress alters cognition and plausible links between stress system reactivity and cognitive function. Extending such temporally precise acute stress research to the childhood age range may be valuable for identifying new ways to support children’s function across contexts and elucidating how repetitive stress leads to pervasive alterations in cognitive development. The first chapter reviews the theorized links between acute stress and subsequent cognitive vulnerability as well as the possible role of biological stress systems (i.e. autonomic nervous system, ANS; Hypothalamic Pituitary Adrenal Axis, HPA) in supporting cognitive function. The second chapter serves to validate an in-laboratory stressor paradigm (modified from previous research) as effective at inducing biological reactivity across HPA and ANS systems. Validating this ‘matching task’ was important given the challenges of eliciting stress system reactivity in the early childhood age range. In the third chapter, the relevance of stress system reactivity to children’s concurrent performance on a cognitively challenging matching task was examined. This study was conducted to establish profiles of HPA and ANS (parasympathetic, PNS, and sympathetic, SNS, branches) associated with adaptive cognitive function, under stress. Results indicated that indices of both HPA and PNS reactivity were predictive of cognitive performance, with different results by gender. Finally, we examined the extent to which acute stress (versus control) altered children’s subsequent selective attention and inhibitory control performance. Largely consistent with the adult literature employing Go/No-Go tasks, stress-exposed children experienced selective attention impairment, but no inhibitory control change. Amongst stress-exposed children, higher maternal stress predicted selective attention impairment, which highlights the relevance of early caregiving to children’s stress regulatory ability. In contrary to hypotheses, this effect was not mediated by HPA or ANS reactivity. The final chapter concludes with a discussion of broad implications, limitations, and future directions for acute stress research in early childhood. / 10000-01-01

Ninety college Ss were first classically "conditioned" to color names and subsequently transferred to a dichotic listening task requiring shadowing of a five-minute prose passage. Embedded in the non-attended channel were previously shock-associated color words. In one condition (same pitch) both the shadowed and non-attended material was read by the same speaker. In the second condition (different pitch) the shadowed and non-attended channels were read by different speakers. Within conditions right/left ear of presentation of shadowing was factorially arranged. The dependent measure was phasic skin resistance changes in the non-attended channel to previously shock-associated stimuli. Autonomic responding was not affected by pitch characteristics. Ear of presentation showed a strong effect; autonomic responding to non-attended stimuli was enhanced by left ear presentation. The interaction of pitch by ear of presentation was significant; a left ear advantage was favored in the same pitch condition. Shadowing efficiency was not impaired at the time of responding to non-attended material nor was shadowing performance altered by pitch distinctions or ear of presentation. The above findings are discussed in terms of the Deutsch and Deutsch and Treisman theories of selective attention. / Arts, Faculty of / Psychology, Department of / Graduate