871 resultados para sleep dependent motor skill learning
Resumo:
PURPOSE:Pregnant women have a 2-3 fold higher probability of developing restless legs syndrome (RLS – sleep-related movement disorders) than general population. This study aims to evaluate the behavior and locomotion of rats during pregnancy in order to verify if part of these animals exhibit some RLS-like features.METHODS:We used 14 female 80-day-old Wistar rats that weighed between 200 and 250 g. The rats were distributed into control (CTRL) and pregnant (PN) groups. After a baseline evaluation of their behavior and locomotor activity in an open-field environment, the PN group was inducted into pregnancy, and their behavior and locomotor activity were evaluated on days 3, 10 and 19 of pregnancy and in the post-lactation period in parallel with the CTRL group. The serum iron and transferrin levels in the CTRL and PN groups were analyzed in blood collected after euthanasia by decapitation.RESULTS:There were no significant differences in the total ambulation, grooming events, fecal boli or urine pools between the CTRL and PN groups. However, the PN group exhibited fewer rearing events, increased grooming time and reduced immobilization time than the CTRL group (ANOVA, p<0.05).CONCLUSION:These results suggest that pregnant rats show behavioral and locomotor alterations similar to those observed in animal models of RLS, demonstrating to be a possible animal model of this sleep disorder.
Resumo:
This dissertation examined skill development in music reading by focusing on the visual processing of music notation in different music-reading tasks. Each of the three experiments of this dissertation addressed one of the three types of music reading: (i) sight-reading, i.e. reading and performing completely unknown music, (ii) rehearsed reading, during which the performer is already familiar with the music being played, and (iii) silent reading with no performance requirements. The use of the eye-tracking methodology allowed the recording of the readers’ eye movements from the time of music reading with extreme precision. Due to the lack of coherence in the smallish amount of prior studies on eye movements in music reading, the dissertation also had a heavy methodological emphasis. The present dissertation thus aimed to promote two major issues: (1) it investigated the eye-movement indicators of skill and skill development in sight-reading, rehearsed reading and silent reading, and (2) developed and tested suitable methods that can be used by future studies on the topic. Experiment I focused on the eye-movement behaviour of adults during their first steps of learning to read music notation. The longitudinal experiment spanned a nine-month long music-training period, during which 49 participants (university students taking part in a compulsory music course) sight-read and performed a series of simple melodies in three measurement sessions. Participants with no musical background were entitled as “novices”, whereas “amateurs” had had musical training prior to the experiment. The main issue of interest was the changes in the novices’ eye movements and performances across the measurements while the amateurs offered a point of reference for the assessment of the novices’ development. The experiment showed that the novices tended to sight-read in a more stepwise fashion than the amateurs, the latter group manifesting more back-and-forth eye movements. The novices’ skill development was reflected by the faster identification of note symbols involved in larger melodic intervals. Across the measurements, the novices also began to show sensitivity to the melodies’ metrical structure, which the amateurs demonstrated from the very beginning. The stimulus melodies consisted of quarter notes, making the effects of meter and larger melodic intervals distinguishable from effects caused by, say, different rhythmic patterns. Experiment II explored the eye movements of 40 experienced musicians (music education students and music performance students) during temporally controlled rehearsed reading. This cross-sectional experiment focused on the eye-movement effects of one-bar-long melodic alterations placed within a familiar melody. The synchronizing of the performance and eye-movement recordings enabled the investigation of the eye-hand span, i.e., the temporal gap between a performed note and the point of gaze. The eye-hand span was typically found to remain around one second. Music performance students demonstrated increased professing efficiency by their shorter average fixation durations as well as in the two examined eye-hand span measures: these participants used larger eye-hand spans more frequently and inspected more of the musical score during the performance of one metrical beat than students of music education. Although all participants produced performances almost indistinguishable in terms of their auditory characteristics, the altered bars indeed affected the reading of the score: the general effects of expertise in terms of the two eye- hand span measures, demonstrated by the music performance students, disappeared in the face of the melodic alterations. Experiment III was a longitudinal experiment designed to examine the differences between adult novice and amateur musicians’ silent reading of music notation, as well as the changes the 49 participants manifested during a nine-month long music course. From a methodological perspective, an opening to research on eye movements in music reading was the inclusion of a verbal protocol in the research design: after viewing the musical image, the readers were asked to describe what they had seen. A two-way categorization for verbal descriptions was developed in order to assess the quality of extracted musical information. More extensive musical background was related to shorter average fixation duration, more linear scanning of the musical image, and more sophisticated verbal descriptions of the music in question. No apparent effects of skill development were observed for the novice music readers alone, but all participants improved their verbal descriptions towards the last measurement. Apart from the background-related differences between groups of participants, combining verbal and eye-movement data in a cluster analysis identified three styles of silent reading. The finding demonstrated individual differences in how the freely defined silent-reading task was approached. This dissertation is among the first presentations of a series of experiments systematically addressing the visual processing of music notation in various types of music-reading tasks and focusing especially on the eye-movement indicators of developing music-reading skill. Overall, the experiments demonstrate that the music-reading processes are affected not only by “top-down” factors, such as musical background, but also by the “bottom-up” effects of specific features of music notation, such as pitch heights, metrical division, rhythmic patterns and unexpected melodic events. From a methodological perspective, the experiments emphasize the importance of systematic stimulus design, temporal control during performance tasks, and the development of complementary methods, for easing the interpretation of the eye-movement data. To conclude, this dissertation suggests that advances in comprehending the cognitive aspects of music reading, the nature of expertise in this musical task, and the development of educational tools can be attained through the systematic application of the eye-tracking methodology also in this specific domain.
Resumo:
Fencamfamine (FCF) is a central stimulant that facilitates central dopaminergic transmission through inhibition of dopamine uptake and enhanced release of the transmitter. We evaluated the changes in the inhibition of uptake and the release of striatal [3H]-dopamine at 9:00 and 21:00 h, times corresponding to maximal and minimal behavioral responses to FCF, respectively. Adult male Wistar rats (200-250 g) maintained on a 12-h light/12-h dark cycle (lights on at 7:00 h) were used. In the behavioral experiments the rats (N = 8 for each group) received FCF (3.5 mg/kg, ip) or saline at 9:00 or 21:00 h. Fifteen minutes after treatment the duration of activity (sniffing, rearing and locomotion) was recorded for 120 min. The basal motor activity was higher (28.6 ± 4.2 vs 8.4 ± 3.5 s) after saline administration at 21:00 h than at 9:00 h. FCF at a single dose significantly enhanced the basal motor activity (38.3 ± 4.5 vs 8.4 ± 3.5 s) and increased the duration of exploratory activity (38.3 ± 4.5 vs 32.1 ± 4.6 s) during the light, but not the dark phase. Two other groups of rats (N = 6 for each group) were decapitated at 9:00 and 21:00 h and striata were dissected for dopamine uptake and release assays. The inhibition of uptake and release of [3H]-dopamine were higher at 9:00 than at 21:00 h, suggesting that uptake inhibition and the release properties of FCF undergo daily variation. These data suggest that the circadian time-dependent effects of FCF might be related to a higher susceptibility of dopamine presynaptic terminals to the action of FCF during the light phase which corresponds to the rats' resting period
Resumo:
Lack of the physiological nocturnal fall in blood pressure (BP) has been found in diabetics and it seems to be related to the presence of diabetic complications. The present study examined the changes in the nocturnal BP pattern of 8 normotensive insulin-dependent diabetic adolescents without nephropathy following improvement in glycemic control induced by an 8-day program of adequate diet and exercise. The same number of age- and sex-matched control subjects were studied. During the first and eighth nights of the program, BP was obtained by ambulatory BP monitoring. After a 10-min rest, 3 BP and heart rate (HR) recordings were taken and the mean values were considered to represent their awake values. The monitor was programmed to cuff insufflation every 20 min from 10:00 p.m. to 7:00 a.m. The glycemic control of diabetics improved since glycemia (212.0 ± 91.5 to 140.2 ± 69.1 mg/dl, P<0.03), urine glucose (12.7 ± 11.8 to 8.6 ± 6.4 g/24 h, P = 0.08) and insulin dose (31.1 ± 7.7 to 16.1 ± 9.7 U/day, P<0.01) were reduced on the last day. The mean BP of control subjects markedly decreased during the sleeping hours of night 1 (92.3 ± 6.4 to 78.1 ± 5.0 mmHg, P<0.001) and night 8 (87.3 ± 6.7 to 76.9 ± 3.6 mmHg, P<0.001). Diabetic patients showed a slight decrease in mean BP during the first night. However, the fall in BP during the nocturnal period increased significantly on the eighth night. The average awake-sleep BP variation was significantly higher at the end of the study (4.2 vs 10.3%, P<0.05) and this ratio turned out to be similar to that found in the control group (10.3 vs 16.3%). HR variation also increased on the eighth night in the diabetics. Following the metabolic improvement obtained at the end of the period, the nocturnal BP variation of diabetics was close to the normal pattern. We suggest that amelioration of glycemic control may influence the awake-sleep BP and HR differences. This effect may be due at least in part to an attenuated insulin stimulation of sympathetic activity
Resumo:
This article is a transcription of an electronic symposium held on February 5, 2001 by the Brazilian Society of Neuroscience and Behavior (SBNeC) during which eight specialists involved in clinical and experimental research on sleep and dreaming exposed their personal experience and theoretical points of view concerning these highly polemic subjects. Unlike most other bodily functions, sleep and dreaming cannot, so far, be defined in terms of definitive functions that play an ascribable role in maintaining the organism as a whole. Such difficulties appear quite clearly all along the discussions. In this symposium, concepts on sleep function range from a protective behavior to an essential function for maturation of the nervous system. Kleitman's hypothesis [Journal of Nervous and Mental Disease (1974), 159: 293-294] was discussed, according to which the basal state is not the wakeful state but sleep, from which we awake to eat, to protect ourselves, to procreate, etc. Dreams, on the other hand, were widely discussed, being considered either as an important step in consolidation of learning or simply the conscious identification of functional patterns derived from the configuration of released or revoked memorized information.
Resumo:
We have tested the hypothesis that restless leg syndrome (RLS) is related to quality of sleep, fatigue and clinical disability in multiple sclerosis (MS). The diagnosis of RLS used the four minimum criteria defined by the International Restless Legs Syndrome Study Group. Fatigue was assessed by the Fatigue Severity Scale (FSS >27), quality of sleep by the Pittsburgh Sleep Quality Index (PSQI >6), excessive daytime sleepiness by the Epworth Sleepiness Scale (ESS >10) and clinical disability by the Expanded Disability Status Scale (EDSS). Forty-four patients (32 women) aged 14 to 64 years (43 ± 14) with disease from 0.4 to 23 years (6.7 ± 5.9) were evaluated. Thirty-five were classified as relapsing-remitting, 5 as primary progressive and 4 as secondary progressive. EDSS varied from 0 to 8.0 (3.6 ± 2.0). RLS was detected in 12 cases (27%). Patients with RLS presented greater disability (P = 0.01), poorer sleep (P = 0.02) and greater levels of fatigue (P = 0.03). Impaired sleep was present in 23 (52%) and excessive daytime sleepiness in 3 cases (6.8%). Fatigue was present in 32 subjects (73%) and was associated with clinical disability (P = 0.000) and sleep quality (P = 0.002). Age, gender, disease duration, MS pattern, excessive daytime sleepiness and the presence of upper motor neuron signs were not associated with the presence of RLS. Fatigue was best explained by clinical disability and poor sleep quality. Awareness of RLS among health care professionals may contribute to improvement in MS management.
Resumo:
The brain is a complex system, which produces emergent properties such as those associated with activity-dependent plasticity in processes of learning and memory. Therefore, understanding the integrated structures and functions of the brain is well beyond the scope of either superficial or extremely reductionistic approaches. Although a combination of zoom-in and zoom-out strategies is desirable when the brain is studied, constructing the appropriate interfaces to connect all levels of analysis is one of the most difficult challenges of contemporary neuroscience. Is it possible to build appropriate models of brain function and dysfunctions with computational tools? Among the best-known brain dysfunctions, epilepsies are neurological syndromes that reach a variety of networks, from widespread anatomical brain circuits to local molecular environments. One logical question would be: are those complex brain networks always producing maladaptive emergent properties compatible with epileptogenic substrates? The present review will deal with this question and will try to answer it by illustrating several points from the literature and from our laboratory data, with examples at the behavioral, electrophysiological, cellular and molecular levels. We conclude that, because the brain is a complex system compatible with the production of emergent properties, including plasticity, its functions should be approached using an integrated view. Concepts such as brain networks, graphics theory, neuroinformatics, and e-neuroscience are discussed as new transdisciplinary approaches dealing with the continuous growth of information about brain physiology and its dysfunctions. The epilepsies are discussed as neurobiological models of complex systems displaying maladaptive plasticity.
Resumo:
Infant rats must learn to identify their mother’s diet-dependent odor. Once learned, maternal odor controls pups’ approach to the mother, their social behavior and nipple attachment. Here we present a review of the research from four different laboratories, which suggests that neural and behavioral responses to the natural maternal odor and neonatal learned odors are similar. Together, these data indicate that pups have a unique learning circuit relying on the olfactory bulb for neural plasticity and on the hyperfunctioning noradrenergic locus coeruleus flooding the olfactory bulb with norepinephrine to support the neural changes. Another important factor making this system unique is the inability of the amygdala to become incorporated into the infant learning circuit. Thus, infant rats appear to be primed in early life to learn odors that will evoke approach responses supporting attachment to the caregiver.
Resumo:
People who suffer from traumatic brain injury (TBI) often experience cognitive deficits in spatial reference and working memory. The possible roles of cyclooxygenase-1 (COX-1) in learning and memory impairment in mice with TBI are far from well known. Adult mice subjected to TBI were treated with the COX-1 selective inhibitor SC560. Performance in the open field and on the beam walk was then used to assess motor and behavioral function 1, 3, 7, 14, and 21 days following injury. Acquisition of spatial learning and memory retention was assessed using the Morris water maze on day 15 post-TBI. The expressions of COX-1, prostaglandin E2 (PGE2), interleukin (IL)-6, brain-derived neurotrophic factor (BDNF), platelet-derived growth factor BB (PDGF-BB), synapsin-I, and synaptophysin were detected in TBI mice. Administration of SC560 improved performance of beam walk tasks as well as spatial learning and memory after TBI. SC560 also reduced expressions of inflammatory markers IL-6 and PGE2, and reversed the expressions of COX-1, BDNF, PDGF-BB, synapsin-I, and synaptophysin in TBI mice. The present findings demonstrated that COX-1 might play an important role in cognitive deficits after TBI and that selective COX-1 inhibition should be further investigated as a potential therapeutic approach for TBI.
Resumo:
This study aims to extend prior knowledge on the learning and developmental outcomes of the experiential learning cycle of David Kolb by the analysis of its practical realization at Team Academy. The study is based on the constructivist approach to learning and considers, among others, the concepts of autonomy support, Nonaka and Takeuchi's knowledge creation model, Luft and Ingham's Johari Window and Deci and Ryan's Self-determination theory. For the investigation deep interviews were carried out with the participants of Team Academy, both learners and coaches. Taking the interview results and the above described theories into consideration this study concludes that experiential learning results not only in effective learning, but also in a remarkable soft skill acquisition, self-development and increase in motivation with an internal locus of causality. Real-life projects permit the learners to experience real challenges. By the practical activities and teamwork they also get the possibility to find out their personal strengths, weaknesses and unique capacities.
Resumo:
Recent dose-response sleep restriction studies, in which nightly sleep is curtailed to varying degrees (e.g., 3-, 5-, 7-hours), have found cumulative, dose-dependent changes in sleepiness, mood, and reaction time. However, brain activity has typically not been measured, and attentionbased tests employed tend to be simple (e.g., reaction time). One task addressing the behavioural and electrophysiological aspects of a specific attention mechanism is the Attentional Blink (AB), which shows that the report accuracy of a second target (T2) is impaired when it is presented soon after a first target (Tl). The aim of the present study was to examine behavioural and electrophysioiogical responses to the AB task to elucidate how sleep restriction impacts attentional capacity. Thirty-six young-adults spent four consecutive days and nights in a sleep laboratory where sleep, food, and activity were controlled. Nightly sleep began with a baseline sleep (8 hours), followed by two nights of sleep restriction (3,5 or 8 hours of sleep), and a recovery sleep (8 hours). An AB task was administered each day at 11 am. Results from a basic battery oftests (e.g., sleepiness, mood, reaction time) confirmed the effectiveness of the sleep restriction manipulation. In terms of the AB, baseline performance was typical (Le., T2 accuracy impaired when presented soon after Tl); however, no changes in any AB behavioural measures were observed following sleep restriction for the 3- or 5-hour groups. The only statistically significant electrophysiological result was a decrease in P300 amplitude (for Tl) from baseline to the second sleep restriction night for the 3-hour group. Therefore, following a brief, two night sleep restriction paradigm, brain functioning was impaired for the TI of the AB in the absence of behavioural deficit. Study limitations and future directions are discussed.
Resumo:
This thesis is a narrative inquiry of learning English as an adult. It stories the journey of 7 women, including me, and unravels lived experiences that serve as learning models. Learning English as an adult presents challenges and results in lifelong implications both in personal and professional life. Every learner's experience is imique and, when reflected upon, each experience is a valuable source of knowledge for constructing meanings and forging new identities. The stories are testimony to the participants' lives: interrupted yet improvised, silenced yet roused, dependent yet independent, intimidated yet courageous, vulnerable yet empowered. The personal experiences elucidate the passion, the inner voices, the dreams, and the rewards that compel persistence in learning a new language and releaming new social roles. The stories provide encouragement and hope to other women who are learning or will learn English in their adult years, and the lived experiences will offer insights for English language teachers. This thesis employs the phenomenology methodology of research with heuristic (discovery) and hermeneutical (interpretative) approaches using the reflective-responsivereflexive writing and interviewing methods for data gathering and unravelling. The narrative inquiry approach reaffirms that storytelling is an important tool in conducting research and constructing new knowledge. This thesis narrates a new story about sharing experiences, interconnecting, and continuing to learn.
Resumo:
The freshwater mollusc Lymnaea stagnalis was utilized in this study to further the understanding of how network properties change as a result of associative learning, and to determine whether or not this plasticity is dependent on previous experience during development. The respiratory and neural correlates of operant conditioning were first determined in normally reared Lymnaea. The same procedure was then applied to differentially reared Lymnaea, that is, animals that had never experienced aerial respiration during their development. The aim was to determine whether these animals would demonstrate the same responses to the training paradigm. In normally reared animals, a behavioural reduction in aerial respiration was accompanied by numerous changes within the neural network. Specifically, I provide evidence of changes at the level of the respiratory central pattern generator and the motor output. In the differentially reared animals, there was little behavioural data to suggest learning and memory. There were, however, significant differences in the network parameters, similar to those observed in normally reared animals. This demonstrated an effect of operant conditioning on differentially reared animals. In this thesis, I have identified additional correlates of operant conditioning in normally reared animals and provide evidence of associative learning in differentially reared animals. I conclude plasticity is not dependent on previous experience, but is rather ontogenetically programmed within the neural network.
Resumo:
~ This study focuses on the process of self-directed learning that individuals go through as they adapt to new work situations. This is a study of how one critical incident, specifically the transition from a traditional office structure to a home office structure, affected employees and what their learning process was as they adapted to the new environment. This study has 3 educational foundations: adult learning, self-directed learning, and the social context from which the learning will occur. Six women and 2 men were interviewed approximately 1 year following the transition. Analysis of the data revealed 5 themes of: impacts of the self-directed environment on participants' personal lives, their roles, skill set, productivity, and the physical environment; support offered by the organization, family, and office administration; personal development, specific learning needs, and personal skills; boundaries as they relate to family and work; and skill set and orientation requirements of new home office employees. The findings revealed the learning processes of the 8 participants. The learning processes of these participants were discussed within a theoretical framework of the learners, their immediate surroundings, and the larger social environment. The results indicated that the transition from a directed work environment to a self directed work environment is a complex, interrelated process. An element found throughout the theoretical framework is that of control. A second critical element is the need for participants to have a clearly defined work role and an opportunity to engage in discussion with peers and the community. Further findings reinforced the importance of climate and found that the physical environment is a key factor in a successful selfdirected work environment. The findings of this study revealed that no one factor makes an individual function successfully in a self-directed work environment, but that it is a complex interplay among the leamer, their immediate surroundings, and the social environment that will have the greatest impact on success. Recommendations are made which can be used to guide organizational leaders in facilitating employees' transition from a directed to a self-directed work environment. Additionally, recommendations are made for further research in the area of self-directed work environments.
Resumo:
Intracerebroventricular (ICV) administration of bombesin (BN) induces a
syndrome characterized by stereotypic locomotion and grooming,
hyperactivity and sleep elimination, hyperglycemia and hypothermia,
hyperhemodynamics, feeding inhibition, and gastrointestinal function
changes. Mammalian BN-like peptides (MBNs), e.g. gastrin-releasing
peptide (GRP), Neuromedin C (NMC), and Neuromedin B (NMB), have been
detected in the central nervous system. Radio-labeled BN binds to specific
sites in discrete cerebral regions. Two specific BN receptor subtypes (GRP
receptor and NMB receptor) have been identified in numerous brain regions.
The quantitative 2-[14C]deoxyglucose ([14C]20G) autoradiographic
method was used to map local cerebral glucose utilization (LCGU) in the
rat brain following ICV injection of BN (vehicle, BN O.1Jlg, O.5Jlg). At each
dose, experiments were conducted in freely moving or restrained
conditions to determine whether alterations in cerebral function were the
result of BN central administration, or were the result of BN-induced
motor stereotypy. The anteroventral thalamic nucleus (AV) (p=O.029),
especially its ventrolateral portion (AVVL) (p