911 resultados para physiological measures
Resumo:
The effect of electrolytic lesion of the median raphe nucleus was measured on behavioral and physiological parameters related to stress 24 h after the lesion. In of the elevated plus-maze the lesion decreased the percentage of open arm entries and tended to shorten the time spent on the open arms indicating an increase in anxiety. In contrast, the lesion markedly increased the time spent in the bright (aversive) compartment of the light-dark box and decrease in attempts to cross from the dark toward the bright compartment, an anxiolyic effect. With the exception of plasma prolactin level, which was lowered by the lesion, the physiological measures used in the present study indicate that the lesioned animals are under stress. Thus, death rate and weight loss after the surgery were higher in lesioned than in control animals. In addition, lesioned animals showed higher plasma corticosterone levels, a high incidence of gastric ulcers in the fundus and a depressed immune response to the mitogen concavaline A. These results highlight the importance of the median raphe nucleus in the regulation of stress and anxiety. They also show that behavioral and physiological measures of stress may be dissociated.
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We investigated whether amygdala activation, autonomic responses, respiratory responses, and facial muscle activity (measured over the brow and cheek [fear grin] regions) are all sensitive to phobic versus nonphobic fear and, more importantly, whether effects in these variables vary as a function of both phobic and nonphobic fear intensity. Spider-phobic and comparably low spider-fearful control participants imagined encountering different animals and rated their subjective fear while their central and peripheral nervous system activity was measured. All measures included in our study were sensitive to variations in subjective fear, but were related to different ranges and positions on the subjective fear level continuum. Left amygdala activation, heart rate, and facial muscle activity over the cheek region captured fear intensity variations even within narrowly described regions on the fear level continuum (here within extremely low levels of fear and within considerable phobic fear). Skin conductance and facial muscle activity over the brow region did not capture fear intensity variations within low levels of fear: skin conductance mirrored only extreme levels of fear, and activity over the brow region distinguished phobic from nonphobic fear but also low-to-moderate and high phobic fear. Finally, respiratory measures distinguished phobic from nonphobic fear with no further differentiation within phobic and nonphobic fear. We conclude that a careful consideration of the measures to be used in an investigation and the population to be examined can be critical in order to obtain significant results.
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This study focused on the possible relationship between certain physiological and psychological variables and the cessation of smoking. The population studied was employees enrolled in a multimodality smoking cessation program at the local offices of a major American corporation. In order to be eligible to participate, each individual must have become a non-smoker by the end of the smoking cessation program.^ Three physiological measures were taken on each individual while performing a relaxation exercise; (1) Electromyogram (EMG), (2) Galvanic Skin Response (GSR), and (3) Skin Temperature. The psychological measure consisted of the variable "anxiety" in the Cattell 16-PF personality inventory. Individual's self report of their smoking status was verified through a test for expired carbon monoxide levels.^ For the total population (N-31) no significant relationships were found between the physiological and psychological variable measured and cessation; however, with the removal of two cases discovered during the post-test interview to be influenced by external factors of high caffeine level and a severe family crisis, the measure of EMG, attained significance in discriminating between the successful and unsuccessful in Smoking Cessation. ^
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How long induced moods last is a critical question for mood research but has been only poorly addressed. In particular, physiological parameters have been rarely included to assess the effectiveness of mood induction procedures. Adopting a dimensional model of mood, we investigated the persistence of four different moods (positive higharousal, positive low-arousal, negative high-arousal, negative lowarousal) induced by four film clips ("sport", "nature", "torture", "slum") during a 9-minute computer task. We measured subjective mood state (valence and arousal), respiration, skin conductance level (SCL), heart rate, and corrugator activity in 76 subjects. Viewing of the selected film clips induced the expected effects both subjectively and physiologically. Corrugator activity was higher at the end of the negative clips than the positive clips, and ventilation and SCL were higher for the arousing clips than for the less arousing clips. People who watched the negative clips still reported more negative valence after the computer task and also showed more facial frowning (cf. figure) and lower SCL during the task than people who watched the positive clips. No arousal effects persisted throughout the task. The results suggest that induced changes in the valence dimension of moods are maintained throughout an intervening task and are physiologically best reflected by corrugator activity and SCL, whereas induced changes in the arousal dimension dissipate quickly. The findings of this study enrich, first, our knowledge concerning the relationships between subjective feelings and their physiological substrate. Second, they inform us about the effectiveness of film clips as a mood induction instrument. Third and most important, they suggest that induced changes in valence last longer than induced changes in arousal. High-arousal moods can last for an extended period of time in daily life, but they seem to be short-lived when induced in the lab. An important methodological consequence is that investigating the effect of the arousal dimension of a person's mood induced in the lab may be only possible when the subsequent task is relatively short. Finally, the findings show which physiological measures may be useful in tracking mood states.
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The objective of this study was to evaluate the effects of posteroventral pallidotomy on perceptual and physiological measures of articulatory function and speech intelligibility in Parkinson disease (M). The study examined 11 participants with M who underwent posteroventral pallidotomy Physiological measures of hp and tongue function. and perceptual measures of speech intelligibility were obtained prepallidotomy and 3 months postpallidotomy. The participants with PD were also assessed on the Unified Parkinsons Disease Rating Scale (UPDRS Part III) In addition, the study included a group of 16 participants with PD who did not undergo pallidotomy and a group of 30 nonneurologically impaired participants. Analyses of physiological articulatory function and speech intelligibility did not reveal corresponding improvements in motor speech function as observed in general limb motor function postpallidotomy. Overall, individual reliable change analyses revealed that the majority of surgical PD participants demonstrated no reliable change on perceptual and physiological measures of articulation. The cur rent study revealed preliminary evidence that articulatury function and speech intelligibility did not change following posteroventral pallidotomy in a group of individuals with PD.
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Introduction. Potentially modifiable physiological variables may influence stroke prognosis but their independence from modifiable factors remains unclear. Methods. Admission physiological measures (blood pressure, heart rate, temperature and blood glucose) and other unmodifiable factors were recorded from patients presenting within 48 hours of stroke. These variables were compared with the outcomes of death and death or dependency at 30 days in multivariate statistical models. Results. In the 186 patients included in the study, age, atrial fibrillation and the National Institutes of Health Stroke Score were identified as unmodifiable factors independently associated with death and death or dependency. After adjusting for these factors, none of the physiological variables were independently associated with death, while only diastolic blood pressure (DBP) >= 90 mmHg was associated with death or dependency at 30 days (p = 0.02). Conclusions. Except for elevated DBP, we found no independent associations between admission physiology and outcome at 30 days in an unselected stroke cohort. Future studies should look for associations in subgroups, or by analysing serial changes in physiology during the early post-stroke period.
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Recent reports have shown neurodegenerative disorders to be associated with abnormal expansions of a CAG trinucleotide repeat allele at various autosomal loci. While normal chromosomes have 14 to 44 repeats, disease chromosomes may have 60 to 84 repeats. The number of CAG repeats on mutant chromosomes correlates with increasing severity of disease or decreasing age at onset of symptoms. Since we are interested in identifying the many quantitative trait loci (QTL) influencing brain functioning, we examined the possibility that the number of CAG repeats in the normal size range at these loci are relevant to "normal" neural functioning. We have used 150 pairs of adolescent (aged 16 years) twins and their parents to examine allele size at the MJD, SCA1, and DRPLA loci in heterozygous normal individuals. These are part of a large ongoing project using cognitive and physiological measures to investigate the genetie influences on cognition, and an extensive protocol of tests is employed to assess some of the key components of intellectual functioning. This study selected to examine full-scale psychometric IQ (FSIQ) and a measure of information processing (choice reaction time) and working memory (slow wave amplitude). CAG repeat size was determined on an ABI Genescan system following multiplex PCR amplification. Quantitative genetic analyses were performed to determine QTL effects of MJD, SCA1, and DRPLA on cognitive functioning. Analyses are in progress and will be discussed.
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Generalized Social Anxiety Disorder (SAD) is one of the most common anxiety conditions with impairment in social life. Cannabidiol (CBD), one major non-psychotomimetic compound of the cannabis sativa plant, has shown anxiolytic effects both in humans and in animals. This preliminary study aimed to compare the effects of a simulation public speaking test (SPST) on healthy control (HC) patients and treatment-naive SAD patients who received a single dose of CBD or placebo. A total of 24 never-treated patients with SAD were allocated to receive either CBD (600 mg; n = 12) or placebo (placebo; n = 12) in a double-blind randomized design 1 h and a half before the test. The same number of HC (n = 12) performed the SPST without receiving any medication. Each volunteer participated in only one experimental session in a double-blind procedure. Subjective ratings on the Visual Analogue Mood Scale (VAMS) and Negative Self-Statement scale (SSPS-N) and physiological measures (blood pressure, heart rate, and skin conductance) were measured at six different time points during the SPST. The results were submitted to a repeated-measures analysis of variance. Pretreatment with CBD significantly reduced anxiety, cognitive impairment and discomfort in their speech performance, and significantly decreased alert in their anticipatory speech. The placebo group presented higher anxiety, cognitive impairment, discomfort, and alert levels when compared with the control group as assessed with the VAMS. The SSPS-N scores evidenced significant increases during the testing of placebo group that was almost abolished in the CBD group. No significant differences were observed between CBD and HC in SSPS-N scores or in the cognitive impairment, discomfort, and alert factors of VAMS. The increase in anxiety induced by the SPST on subjects with SAD was reduced with the use of CBD, resulting in a similar response as the HC. Neuropsychopharmacology (2011) 36, 1219-1226; doi: 10.1038/npp.2011.6; published online 9 February 2011
Resumo:
Objectives and Methods: Self-report studies have shown an association between music performance anxiety (MPA) and hyperventilation complaints. However, hyperventilation was never assessed physiologically in MPA. This study investigated the self-reported affective experience, self-reported physiological symptoms, and cardiorespiratory variables including partial pressure of end-tidal CO(2) (Petco(2)), which is an indicator for hyperventilation, in 67 music students before a private and a public performance. The response coherence between these response domains was also investigated.ResultsFrom the private to the public session, the intensity of all self-report variables increased (all p values < .001). As predicted, the higher the musician's usual MPA level, the larger were these increases (p values < .10). With the exception of Petco(2), the main cardiorespiratory variables also increased from the private to the public session (p values < .05). These increases were not modulated by the usual MPA level (p values > .10). Petco(2) showed a unique response pattern reflected by an MPA-by-session interaction (p < .01): it increased from the private to the public session for musicians with low MPA levels and decreased for musicians with high MPA levels. Self-reported physiological symptoms were related to the self-reported affective experience (p values < .05) rather than to physiological measures (p values > .17).ConclusionsThese findings show for the first time how respiration is stimulated before a public performance in music students with different MPA levels. The hypothesis of a hyperventilation tendency in high-performance-anxious musicians is supported. The response coherence between physiological symptoms and physiological activation is weak.
Resumo:
Despite the central role that emotional reactivity plays in adaptation, few studies have examined age differences in this capacity under well-controlled laboratory conditions, on the basis of standardized emotion-evoking stimuli and assessing experiential, expressive, and physiological measures. 212 adults ranging in age from 20 to 81 years were exposed to 14 picture series, each lasting 60 s and of a different valence and arousal. We assessed valence and arousal ratings, cardiovascular, respiratory and electrodermalmeasures, facial muscle activity and gaze activity. Here, we present findings for 22 younger (mean age=24.0) and 22 older (mean age=72.1) adults for valence and arousal ratings, systolic bloodpressure (SBP) andheart rate (HR).Compared to younger adults, older adults rated unpleasant seriesmore negatively and showed a smaller range in arousal for pleasant series. SBP linearly increased with increasing appetitive activation. HR showed the expected deceleration from the pleasant to the unpleasant series.However, this effect was clearer for the younger adults than the older adults. For older adults, if something is pleasant, it is also judged to be generally lower in arousal, whereas, if something is unpleasant, it is also judged to be generally higher in arousal. The results for SBP indicate that the association between arousal and sympathetic outflow to the cardiovascular system might be similar in younger and older adults. The results for HR suggest that the parasympathetic activation might be attenuated in older adults as compared to younger adults.
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Aerobic exercise training performed at the intensity eliciting maximal fat oxidation (Fatmax) has been shown to improve the metabolic profile of obese patients. However, limited information is available on the reproducibility of Fatmax and related physiological measures. The aim of this study was to assess the intra-individual variability of: a) Fatmax measurements determined using three different data analysis approaches and b) fat and carbohydrate oxidation rates at rest and at each stage of an individualized graded test. Fifteen healthy males [body mass index 23.1±0.6 kg/m2, maximal oxygen consumption ([Formula: see text]) 52.0±2.0 ml/kg/min] completed a maximal test and two identical submaximal incremental tests on ergocycle (30-min rest followed by 5-min stages with increments of 7.5% of the maximal power output). Fat and carbohydrate oxidation rates were determined using indirect calorimetry. Fatmax was determined with three approaches: the sine model (SIN), measured values (MV) and 3rd polynomial curve (P3). Intra-individual coefficients of variation (CVs) and limits of agreement were calculated. CV for Fatmax determined with SIN was 16.4% and tended to be lower than with P3 and MV (18.6% and 20.8%, respectively). Limits of agreement for Fatmax were -2±27% of [Formula: see text] with SIN, -4±32 with P3 and -4±28 with MV. CVs of oxygen uptake, carbon dioxide production and respiratory exchange rate were <10% at rest and <5% during exercise. Conversely, CVs of fat oxidation rates (20% at rest and 24-49% during exercise) and carbohydrate oxidation rates (33.5% at rest, 8.5-12.9% during exercise) were higher. The intra-individual variability of Fatmax and fat oxidation rates was high (CV>15%), regardless of the data analysis approach employed. Further research on the determinants of the variability of Fatmax and fat oxidation rates is required.
Resumo:
Objectiu general: desenvolupament del Programa Pacient Expert en obesitat. Objectius específics: es basaran amb el compliment de la dieta i l’activitat física, les mesures fisiològiques, la capacitat d’autogestió i el grau de satisfacció. Metodologia: - Àmbit d’estudi: Atenció Primària en Salut. - Disseny: estudi quantitatiu de tipus assaig clínic aleatoritzat. - Participants: adults amb obesitat. - Obtenció de dades: per l’anàlisi de variància per mesures repetides, l’anàlisi del discurs i l’observació estructurada. Limitacions de l’estudi: possible buit de dades per la pèrdua de participants o per la falta de continuïtat d’aquests.
Resumo:
Studies on the potential benefits of conveying biofeedback stimulus using a musical signal have appeared in recent years with the intent of harnessing the strong effects that music listening may have on subjects. While results are encouraging, the fundamental question has yet to be addressed, of how combined music and biofeedback compares to the already established use of either of these elements separately. This experiment, involving young adults (N = 24), compared the effectiveness at modulating participants' states of physiological arousal of each of the following conditions: A) listening to pre-recorded music, B) sonification biofeedback of the heart rate, and C) an algorithmically modulated musical feedback signal conveying the subject's heart rate. Our hypothesis was that each of the conditions (A), (B) and (C) would differ from the other two in the extent to which it enables participants to increase and decrease their state of physiological arousal, with (C) being more effective than (B), and both more than (A). Several physiological measures and qualitative responses were recorded and analyzed. Results show that using musical biofeedback allowed participants to modulate their state of physiological arousal at least equally well as sonification biofeedback, and much better than just listening to music, as reflected in their heart rate measurements, controlling for respiration-rate. Our findings indicate that the known effects of music in modulating arousal can therefore be beneficially harnessed when designing a biofeedback protocol.
Resumo:
Previous work has reported that it is not difficult to give people the illusion of ownership over an artificial body, providing a powerful tool for the investigation of the neural and cognitive mechanisms underlying body perception and self consciousness. We present an experimental study that uses immersive virtual reality (IVR) focused on identifying the perceptual building blocks of this illusion. We systematically manipulated visuotactile and visual sensorimotor contingencies, visual perspective, and the appearance of the virtual body in order to assess their relative role and mutual interaction. Consistent results from subjective reports and physiological measures showed that a first person perspective over a fake humanoid body is essential for eliciting a body ownership illusion. We found that the illusion of ownership can be generated when the virtual body has a realistic skin tone and spatially substitutes the real body seen from a first person perspective. In this case there is no need for an additional contribution of congruent visuotactile or sensorimotor cues. Additionally, we found that the processing of incongruent perceptual cues can be modulated by the level of the illusion: when the illusion is strong, incongruent cues are not experienced as incorrect. Participants exposed to asynchronous visuotactile stimulation can experience the ownership illusion and perceive touch as originating from an object seen to contact the virtual body. Analogously, when the level of realism of the virtual body is not high enough and/or when there is no spatial overlap between the two bodies, then the contribution of congruent multisensory and/or sensorimotor cues is required for evoking the illusion. On the basis of these results and inspired by findings from neurophysiological recordings in the monkey, we propose a model that accounts for many of the results reported in the literature.
Resumo:
Studies on the potential benefits of conveying biofeedback stimulus using a musical signal have appeared in recent years with the intent of harnessing the strong effects that music listening may have on subjects. While results are encouraging, the fundamental question has yet to be addressed, of how combined music and biofeedback compares to the already established use of either of these elements separately. This experiment, involving young adults (N = 24), compared the effectiveness at modulating participants' states of physiological arousal of each of the following conditions: A) listening to pre-recorded music, B) sonification biofeedback of the heart rate, and C) an algorithmically modulated musical feedback signal conveying the subject's heart rate. Our hypothesis was that each of the conditions (A), (B) and (C) would differ from the other two in the extent to which it enables participants to increase and decrease their state of physiological arousal, with (C) being more effective than (B), and both more than (A). Several physiological measures and qualitative responses were recorded and analyzed. Results show that using musical biofeedback allowed participants to modulate their state of physiological arousal at least equally well as sonification biofeedback, and much better than just listening to music, as reflected in their heart rate measurements, controlling for respiration-rate. Our findings indicate that the known effects of music in modulating arousal can therefore be beneficially harnessed when designing a biofeedback protocol.