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Arousal Levels (arousal + level)
Selected AbstractsDifferences in electroencephalogram power densities between genuine narcolepsy and secondary narcolepsyPSYCHIATRY AND CLINICAL NEUROSCIENCES, Issue 3 2000Hiroshi Honma MD Abstract Diagnosing narcolepsy is not always simple. Some patients secondarily show narcoleptic tetrad through irregular sleep patterns or psychotic diseases. The power densities of daytime electroencephalograms in genuine narcolepsy and secondary narcolepsy were analysed and compared. Electroencephalogram power densities for a 6.5-h period after waking in genuine narcoleptic patients were lower than those of secondary narcoleptic patients in the 11.0,12.5 Hz bands. Arousal levels may be lower in genuine narcoleptic patients than in secondary narcoleptic patients. Spectral analysis may be useful in clarifying differences between the two groups. [source] The sleep of co-sleeping infants when they are not co-sleeping: Evidence that co-sleeping is stressfulDEVELOPMENTAL PSYCHOBIOLOGY, Issue 1 2002Melissa Hunsley Abstract Co-sleeping proponents consider the practice to be "natural" and a potential protection against sudden infant death syndrome (SIDS); others consider the practice of an infant sleeping in the parents' bed for prolonged periods at night to place an infant at risk for harm or death. For this study, co-sleeping was investigated from a different perspective, that is, as a significant early experience to investigate as it may have implications for the infant's development. The sleep of 101 normal, full-term infants was recorded nonintrusively in the home for 24 hr periods when they were 5 weeks and 6 months old. Infants were assigned to three groups: short-term co-sleepers, long-term co-sleepers, and non-co-sleepers. Their sleep states and wakefulness were compared at the two ages and over age. At 5 weeks and 6 months, the long-term co-sleeping infants differed significantly from the non-co-sleepers on a number of measures: At 5 weeks, they showed more quiet sleep and longer bouts of quiet sleep; and at 6 months, they also showed less active sleep, fewer arousals in active sleep, and less wakefulness. Each of these differences indicates a markedly lower arousal level in the long-term co-sleeping infants. This sleep pattern has been repeatedly found to be an indicator of stress. We infer that a major source of stress for these infants is the experience of sleep disturbance documented for infants when they were co-sleeping. Based on extensive evidence for long-term effects of early stress, we conclude that co-sleeping should have significant implications for infants' neurobehavioral development. © 2002 John Wiley & Sons, Inc. Dev Psychobiol 40: 14,22, 2002 [source] Effect of caffeine on prospective and retrospective duration judgementsHUMAN PSYCHOPHARMACOLOGY: CLINICAL AND EXPERIMENTAL, Issue 5 2003Ronald P. Gruber Abstract The effects of caffeine on prospective and retrospective duration judgements were evaluated in a double-blind placebo-controlled experiment. After taking either 200,mg caffeine or a placebo, participants touched a 17-sided polygon for 15,s. Then they verbally estimated the number of angles and the duration. Participants in the prospective group were told in advance they would be making a duration estimate, whereas those in the retrospective group were not told. Caffeine reduced duration estimates in the prospective condition but not in the retrospective condition. The effect of caffeine on very long duration comparisons (the past year compared with a year at one-half and one-quarter of one's age) was also evaluated, but none was found. The findings do not support the hypothesis that caffeine affects duration experience by increasing the internal clock rate as a result of its dopamine D2 agonist properties. The hypothesis that caffeine produces its effect by enhancing memory was considered and rejected. The most parsimonious explanation is that caffeine increased arousal level, which led to a narrowing of the focus of attention to the most salient task. Copyright © 2003 John Wiley & Sons, Ltd. [source] Child and family correlates of toddlers' emotional and behavioral responses to a mishapINFANT MENTAL HEALTH JOURNAL, Issue 6 2003Pamela W. Garner This study evaluated the unique and joint contributions of internal state language, externalizing behavior, and maternal talk about emotions to the prediction of toddlers' empathy-related responsiveness. The empathy-based guilt reactions of 47 toddlers (27 boys) were observed in response to distress that they thought they had caused. In addition, mothers reported on the children's internal state language, externalizing behavior, and empathy-based guilt. In a separate observation, the mothers discussed emotional expressions with their children, and the functional significance of their emotional discourse was considered. Results revealed that toddlers' internal state language ability was positively related to their attempts to comprehend another's affective state and to maternal reports of children's sympathy reactions. There was also an unexpected inverse relation between externalizing behavior and arousal level. In terms of the parent measures, maternal explanations of emotions were positively related to children's attempts to comprehend another's affective state, whereas mothers' directives for children to label emotions were positively related to children's expressed emotional concern for others. The implications of these findings for understanding empathy and guilt development in young children are discussed. ©2003 Michigan Association for Infant Mental Health. [source] Experience-dependent plasticity in hypocretin/orexin neurones: re-setting arousal thresholdACTA PHYSIOLOGICA, Issue 3 2010X.-B. Gao Abstract The neuropeptide hypocretin is synthesized exclusively in the lateral hypothalamus and participates in many brain functions critical for animal survival, particularly in the promotion and maintenance of arousal in animals , a core process in animal behaviours. Consistent with its arousal-promoting role in animals, the neurones synthesizing hypocretin receive extensive innervations encoding physiological, psychological and environmental cues and send final outputs to key arousal-promoting brain areas. The activity in hypocretin neurones fluctuates and correlates with the behavioural state of animals and intensive activity has been detected in hypocretin neurones during wakefulness, foraging for food and craving for addictive drugs. Therefore, it is likely that hypocretin neurones undergo experience-dependent changes resulting from intensive activations by stimuli encoding changes in the internal and external environments. This review summarizes the most recent evidence supporting experience-dependent plasticity in hypocretin neurones. Current data suggest that nutritional and behavioural factors lead to synaptic plasticity and re-organization of synaptic architecture in hypocretin neurones. This may be the substrate of enhanced levels of arousal resulting from behavioural changes in animals and may help to explain the mechanisms underlying the changes in arousal levels induced by physiological, psychological and environmental factors. [source] Effects of redundant and nonredundant bimodal sensory stimulation on heart rate in bobwhite quail embryosDEVELOPMENTAL PSYCHOBIOLOGY, Issue 4 2003Greg D. Reynolds Abstract Research with both animal embryos and human infants has provided evidence that information presented redundantly and in temporal synchrony across sensory modalities (intersensory redundancy) can guide selective attention, perceptual learning, and memory during early development. How this facilitation is achieved remains relatively unexamined. This study examined the effects of redundant versus nonredundant bimodal stimulation on a measure of physiological arousal (heart rate) in bobwhite quail embryos. Results show that quail embryos exposed to concurrent but nonredundant auditory and visual stimulation during the late stages of incubation exhibit significantly elevated heart rates following stimulus exposure and during stimulus reexposure when compared to embryos exposed to redundant and synchronous audiovisual stimulation, unimodal auditory stimulation, or no supplemental prenatal sensory stimulation. These findings indicate a functional distinction between redundant and nonredundant bimodal stimulation during early development and suggest that nonredundant bimodal stimulation during the prenatal period can raise arousal levels, thereby potentially interfering with the attentional capacities and perceptual learning of bobwhite quail. In contrast, intersensory redundancy appears to foster arousal levels that facilitate selective attention and perceptual learning during prenatal development. © 2003 Wiley Periodicals, Inc. Dev Psychobiol 43: 304,310, 2003. [source] Hypothalamic,pituitary,adrenal axis activity and early onset of cannabis useADDICTION, Issue 11 2006Anja C. Huizink ABSTRACT Aims To identify early onset cannabis users by measuring basal hypothalamic,pituitary,adrenal (HPA) axis activity, which may be a risk factor for early onset substance use when showing low activity. Design In a prospective cohort study, adolescents who initiated cannabis use at an early age (9,12 years), those who initiated at a later age (13,14 years) and those who did not use cannabis by the age of 14 were compared with respect to HPA axis activity. Setting and participants Data were used from the first and second assessment wave of the TRacking Adolescents' Individual Lives Survey (TRAILS), that included 1768 Dutch young adolescents aged 10,12 years who were followed-up across a period of 2 years. Measurements Cortisol was measured in saliva samples at awakening, 30 minutes later and at 8 p.m. at age 10,12. Self-reported age at first cannabis use was used. Findings The early onset group had lower cortisol levels 30 minutes after awakening than the late onset group (OR = 0.93, 95% CI: 0.86,0.99). Furthermore, compared to non-users, the early and late onset cannabis users had higher levels of cortisol at 8 p.m. (OR = 1.25, 95% CI: 1.03,1.53 and OR = 1.21, 95% CI: 1.01,1.45, respectively). Conclusions Some evidence was found for HPA axis hypo-activity at awakening in adolescents with early onset of cannabis use compared to late onset users, which might indicate an increased risk for early onset users of seeking stimulation to restore arousal levels by using substances. [source] Disparate cholinergic currents in rat principal trigeminal sensory nucleus neurons mediated by M1 and M2 receptors: a possible mechanism for selective gating of afferent sensory neurotransmissionEUROPEAN JOURNAL OF NEUROSCIENCE, Issue 12 2006Kristi A. Kohlmeier Abstract Neurons situated in the principal sensory trigeminal nucleus (PSTN) convey orofacial sensory inputs to thalamic relay regions and higher brain centres, and the excitability of these ascending tract cells is modulated across sleep/wakefulness states and during pain conditions. Moreover, acetylcholine release changes profoundly across sleep/wakefulness states and ascending sensory neurotransmission is altered by cholinergic agonists. An intriguing possibility is, therefore, that cholinergic mechanisms mediate such state-dependent modulation of PSTN tract neurons. We tested the hypotheses that cholinergic agonists can modulate PSTN cell excitability and that such effects are mediated by muscarinic receptor subtypes, using patch-clamp methods in rat and mouse. In all examined cells, carbachol elicited an electrophysiological response that was independent of action potential generation as it persisted in the presence of tetrodotoxin. Responses were of three types: depolarization, hyperpolarization or a biphasic response consisting of hyperpolarization followed by depolarization. In voltage-clamp mode, carbachol evoked corresponding inward, outward or biphasic currents. Moreover, immunostaining for the vesicle-associated choline transporter showed cholinergic innervation of the PSTN. Using muscarinic receptor antagonists, we found that carbachol-elicited PSTN neuron hyperpolarization was mediated by M2 receptors and depolarization, in large part, by M1 receptors. These data suggest that acetylcholine acting on M1 and M2 receptors may contribute to selective excitability enhancement or depression in individual, rostrally projecting sensory neurons. Such selective gating effects via cholinergic input may play a functional role in modulation of ascending sensory transmission, including across behavioral states typified by distinct cholinergic tone, e.g. sleep/wakefulness arousal levels or neuropathic pain conditions. [source] Do weapons automatically capture attention?APPLIED COGNITIVE PSYCHOLOGY, Issue 7 2006Kerri L. Pickel Two experiments explored whether weapons automatically capture attention or whether eyewitnesses can overcome the weapon focus effect if so instructed. Witnesses heard a lecture that either instructed them to attend to the target individual and avoid fixating on the weapon or presented unrelated information. Subsequently, they observed the target carrying either a weapon or a book and attempted to remember his appearance. Control witnesses reported fewer correct and more incorrect details when he carried a weapon rather than the book. However, the reports of educated witnesses did not differ between object conditions. Additionally, witnesses' ability to avoid weapon focus was unaffected by weapon unusualness and elevated arousal levels, and control witnesses provided better descriptions of the weapon than the book. Copyright © 2006 John Wiley & Sons, Ltd. 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