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Learning spatial orientation tasks in the radial-maze and structural variation in the hippocampus in inbred mice

Crusio, Wim E; Schwegler, Herbert
Fonte: BioMed Central Publicador: BioMed Central
Tipo: Artigo de Revista Científica
Publicado em 22/04/2005 EN
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35.85%
In the present paper we review a series of experiments showing that heritable variations in the size of the hippocampal intra- and infrapyramidal mossy fiber (IIPMF) terminal fields correlate with performance in spatial, but not non-spatial radial-maze tasks. Experimental manipulation of the size of this projection by means of early postnatal hyperthyroidism produces the effects predicted from the correlations obtained with inbred mouse strains. Although the physiological mechanisms behind these correlations are unknown as yet, several lines of evidence indicate that these correlations are causal.

A review of the generalization of auditory learning

Wright, Beverly A.; Zhang, Yuxuan
Fonte: The Royal Society Publicador: The Royal Society
Tipo: Artigo de Revista Científica
EN
Relevância na Pesquisa
35.99%
The ability to detect and discriminate attributes of sounds improves with practice. Determining how such auditory learning generalizes to stimuli and tasks that are not encountered during training can guide the development of training regimens used to improve hearing abilities in particular populations as well as provide insight into the neural mechanisms mediating auditory performance. Here we review the newly emerging literature on the generalization of auditory learning, focusing on behavioural investigations of generalization on basic auditory tasks in human listeners. The review reveals a variety of generalization patterns across different trained tasks that can not be summarized with a simple rule, and a diversity of views about the definition, evaluation and interpretation of generalization.

A Neural Correlate of Predicted and Actual Reward-Value Information in Monkey Pedunculopontine Tegmental and Dorsal Raphe Nucleus during Saccade Tasks

Okada, Ken-ichi; Nakamura, Kae; Kobayashi, Yasushi
Fonte: Hindawi Publishing Corporation Publicador: Hindawi Publishing Corporation
Tipo: Artigo de Revista Científica
EN
Relevância na Pesquisa
35.85%
Dopamine, acetylcholine, and serotonin, the main modulators of the central nervous system, have been proposed to play important roles in the execution of movement, control of several forms of attentional behavior, and reinforcement learning. While the response pattern of midbrain dopaminergic neurons and its specific role in reinforcement learning have been revealed, the role of the other neuromodulators remains rather elusive. Here, we review our recent studies using extracellular recording from neurons in the pedunculopontine tegmental nucleus, where many cholinergic neurons exist, and the dorsal raphe nucleus, where many serotonergic neurons exist, while monkeys performed eye movement tasks to obtain different reward values. The firing patterns of these neurons are often tonic throughout the task period, while dopaminergic neurons exhibited a phasic activity pattern to the task event. The different modulation patterns, together with the activity of dopaminergic neurons, reveal dynamic information processing between these different neuromodulator systems.

Institutional review board (IRB) and ethical issues in clinical research

Kim, Won Oak
Fonte: The Korean Society of Anesthesiologists Publicador: The Korean Society of Anesthesiologists
Tipo: Artigo de Revista Científica
EN
Relevância na Pesquisa
35.78%
Clinical research has expanded tremendously in the past few decades and consequently there has been growing interest in the ethical guidelines that are being followed for the protection of human subjects. This review summarizes historical scandals and social responses chronologically from World War II to the Death of Ellen Roche (2001) to emphasize the lessons we must learn from history. International ethical guidelines for studies with human subjects are also briefly described in order to understand the circumstances of clinical research. The tasks and responsibilities of the institutions and investigators in human subject research to preserve the safety and welfare of research subjects are summarized. Next, several debated ethical issues and insights are arranged as controversial topics. This brief review and summary seeks to highlight important arguments and make suggestions to institutional review boards (IRBs) to contribute to the future evolution of ethics in clinical research as we advance forward.

Complex Tasks Force Hand Laterality and Technological Behaviour in Naturalistically Housed Chimpanzees: Inferences in Hominin Evolution

Mosquera, M.; Geribàs, N.; Bargalló, A.; Llorente, M.; Riba, D.
Fonte: The Scientific World Journal Publicador: The Scientific World Journal
Tipo: Artigo de Revista Científica
Publicado em 01/04/2012 EN
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35.89%
Clear hand laterality patterns in humans are widely accepted. However, humans only elicit a significant hand laterality pattern when performing complementary role differentiation (CRD) tasks. Meanwhile, hand laterality in chimpanzees is weaker and controversial. Here we have reevaluated our results on hand laterality in chimpanzees housed in naturalistic environments at Fundació Mona (Spain) and Chimfunshi Wild Orphanage (Zambia). Our results show that the difference between hand laterality in humans and chimpanzees is not as great as once thought. Furthermore, we found a link between hand laterality and task complexity and also an even more interesting connection: CRD tasks elicited not only the hand laterality but also the use of tools. This paper aims to turn attention to the importance of this threefold connection in human evolution: the link between CRD tasks, hand laterality, and tool use, which has important evolutionary implications that may explain the development of complex behaviour in early hominins.

Assessment of Hand Function Through the Coordination of Contact Forces in Manipulation Tasks

Jaric, Slobodan; Uygur, Mehmet
Fonte: Akademia Wychowania Fizycznego w Katowicach Publicador: Akademia Wychowania Fizycznego w Katowicach
Tipo: Artigo de Revista Científica
Publicado em 28/03/2013 EN
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35.97%
Exploration of force coordination has been one of the most often used approaches in studies of hand function. When holding and manipulating a hand-held object healthy individuals are typically able to highly coordinate the perpendicular (grip force; GF) with the tangential component of the contact force (load force; LF). The purpose of this review is to present the findings of our recent studies of GF-LF coordination. Regarding the mechanical factors affecting GF-LF coordination, our data suggest that both different hand segments and their particular skin areas could have markedly different friction properties. It also appears that the absolute, rather than relative safety margin (i.e., how much the actual GF exceeds the minimum value that prevents slipping) should be a variable of choice when assessing the applied magnitude of GF. The safety margin could also be lower in static than in free holding tasks. Regarding the involved neural factors, the data suggest that the increased frequency, rather than an increased range of a cyclic LF could have a prominent detrimental effect on the GF-LF coordination. Finally, it appears that the given instructions (e.g., ‘to hold’ vs. ‘to pull’) can prominently alter GF-LF coordination in otherwise identical manipulation tasks. Conversely...

Errorless learning of everyday tasks in people with dementia

de Werd, Maartje Me; Boelen, Daniëlle; Rikkert, Marcel GM Olde; Kessels, Roy PC
Fonte: Dove Medical Press Publicador: Dove Medical Press
Tipo: Artigo de Revista Científica
EN
Relevância na Pesquisa
35.97%
Errorless learning (EL) is a principle used to teach new information or skills to people with cognitive impairment. In people with dementia, EL principles have mostly been studied in laboratory tasks that have little practical relevance for the participants concerned, yet show positive effects. This is the first paper to exclusively review the literature concerning the effects of EL on the performance of useful everyday tasks in people with dementia. The role of factors such as type of dementia, type of task, training intensity, EL elements, outcome measures, quality of experimental design, and follow-up are discussed. The results indicate that, compared with errorful learning (EF) or no treatment, EL is more effective in teaching adults with dementia a variety of meaningful daily tasks or skills, with gains being generally maintained at follow-up. The effectiveness of EL is highly relevant for clinical practice because it shows that individuals with dementia are still able to acquire meaningful skills and engage in worthwhile activities, which may potentially increase their autonomy and independence, and ultimately their quality of life, as well as reduce caregiver burden and professional dependency. Suggestions for future research are given...

Human Temporal Cortical Single Neuron Activity during Language: A Review

Ojemann, George A.
Fonte: MDPI Publicador: MDPI
Tipo: Artigo de Revista Científica
Publicado em 26/04/2013 EN
Relevância na Pesquisa
35.85%
Findings from recordings of human temporal cortical single neuron activity during several measures of language, including object naming and word reading are reviewed and related to changes in activity in the same neurons during recent verbal memory and verbal associative learning measures, in studies conducted during awake neurosurgery for the treatment of epilepsy. The proportion of neurons changing activity with language tasks was similar in either hemisphere. Dominant hemisphere activity was characterized by relative inhibition, some of which occurred during overt speech, possibly to block perception of one’s own voice. However, the majority seems to represent a dynamic network becoming active with verbal memory encoding and especially verbal learning, but inhibited during performance of overlearned language tasks. Individual neurons are involved in different networks for different aspects of language, including naming or reading and naming in different languages. The majority of the changes in activity were tonic sustained shifts in firing. Patterned phasic activity for specific language items was very infrequently recorded. Human single neuron recordings provide a unique perspective on the biologic substrate for language, for these findings are in contrast to many of the findings from other techniques for investigating this.

Cognitive-Motor Interference in Multiple Sclerosis: A Systematic Review of Evidence, Correlates, and Consequences

Wajda, Douglas A.; Sosnoff, Jacob J.
Fonte: Hindawi Publishing Corporation Publicador: Hindawi Publishing Corporation
Tipo: Artigo de Revista Científica
EN
Relevância na Pesquisa
35.92%
Individuals with multiple sclerosis (MS) regularly exhibit deficits in motor and cognitive function. Recent evidence suggests that these impairments are compounded when motor and cognitive task are performed simultaneously such as walking while talking. The changes incurred during simultaneous performance of motor and cognitive tasks are a result of cognitive-motor interference (CMI) and operationalized as dual task costs (DTC). Recently in MS, research has been conducted to understand and analyze the impact of CMI. The purpose of this paper was to review the current literature related to the evidence, correlates, and consequences of CMI in MS. Relevant literature was collected from the results of a PubMed search for terms including “Cognitive-motor interference” or “Cognitive-motor interaction” or “Dual task” and “multiple sclerosis.” Overall, 20 papers were included for review which focused on CMI during balance and walking tasks. The finding that there is a lack of evidence pertaining to changes in the cognitive domain as well as to the specific consequences of CMI in MS was noted. Future work should aim to fill these gaps and ultimately investigate the usefulness of targeted interventions in reducing the deleterious effects of CMI in individuals with MS.

Upper limb kinematics after cervical spinal cord injury: a review

Mateo, Sébastien; Roby-Brami, Agnès; Reilly, Karen T; Rossetti, Yves; Collet, Christian; Rode, Gilles
Fonte: BioMed Central Publicador: BioMed Central
Tipo: Artigo de Revista Científica
Publicado em 30/01/2015 EN
Relevância na Pesquisa
35.78%
Although a number of upper limb kinematic studies have been conducted, no review actually addresses the key-features of open-chain upper limb movements after cervical spinal cord injury (SCI). The aim of this literature review is to provide a clear understanding of motor control and kinematic changes during open-chain upper limb reaching, reach-to-grasp, overhead movements, and fast elbow flexion movements after tetraplegia. Using data from MEDLINE between 1966 and December 2014, we examined temporal and spatial kinematic measures and when available electromyographic recordings. We included fifteen control case and three series case studies with a total of 164 SCI participants and 131 healthy control participants. SCI participants efficiently performed a broad range of tasks with their upper limb and movements were planned and executed with strong kinematic invariants like movement endpoint accuracy and minimal cost. Our review revealed that elbow extension without triceps brachii relies on increased scapulothoracic and glenohumeral movements providing a dynamic coupling between shoulder and elbow. Furthermore, contrary to normal grasping patterns where grasping is prepared during the transport phase, reaching and grasping are performed successively after SCI. The prolonged transport phase ensures correct hand placement while the grasping relies on wrist extension eliciting either whole hand or lateral grip. One of the main kinematic characteristics observed after tetraplegia is motor slowing attested by increased movement time. This could be caused by (i) decreased strength...

Cloud migration research: a systematic review

Jamshidi, Pooyan; Ahmad, Aakash; Pahl, Claus
Fonte: IEEE Computer Society Publicador: IEEE Computer Society
Tipo: info:eu-repo/semantics/article; all_ul_research; ul_published_reviewed
ENG
Relevância na Pesquisa
35.8%
peer-reviewed; By leveraging cloud services, organizations can deploy their software systems over a pool of resources. However, organizations heavily depend on their business-critical systems, which have been developed over long periods. These legacy applications are usually deployed on-premise. In recent years, research in cloud migration has been carried out. However, there is no secondary study to consolidate this research. This paper aims to identify, taxonomically classify and systematically compare existing research on cloud migration. We conducted a systematic literature review (SLR) of 23 selected studies, published from 2010 to 2013. We classified and compared the selected studies based on a characterization framework that we also introduce in this paper. The research synthesis results in a knowledge base of current solutions for legacy-to-cloud migration. This review also identifies research gaps and directions for future research. This review reveals that cloud migration research is still in early stages of maturity, but is advancing. It identifies the needs for a migration framework to help improving the maturity level and consequently trust into cloud migration. This review shows a lack of tool support to automate migration tasks. This study also identifies needs for architectural adaptation and self-adaptive cloud-enabled systems

Caregiving experiences of families living with persons with schizophrenia: a systematic review

Tungpunkom, P.; Napa, W.; Chaniang, S.; Srikhachin, P.
Fonte: University of Adelaide Publicador: University of Adelaide
Tipo: Artigo de Revista Científica
Publicado em //2013 EN
Relevância na Pesquisa
35.98%
Background Living with and caring for patient with schizophrenia is difficult, often long-term responsibilities. These caregiving experiences have been studied in a holistic and meaningful manner by using qualitative approaches. Aims, objectives This systematic review aims to determine the meaningfulness of caregiving experiences of families living with person with schizophrenia. Background Schizophrenia is one of the most severe chronic mental illnesses, characterized by a disintegration of the process of thinking and of emotional responsiveness. Families are often required to play the major role of taking responsibility for caring for these patients. Objectives The objective of this review was to synthesize the best available evidence on the meaningfulness of caregiving experiences of families living with and taking care of persons with schizophrenia. Inclusion criteria Types of participants Family members of a person, years and older, who has been diagnosed with schizophrenia for at least six months. Types of intervention, s, phenomena of interest The review considered qualitative studies that explore caregiving experiences of families of persons with schizophrenia that related to their caring for, or living with, their family member with schizophrenia. These experiences included caring tasks...

Efficient multitasking: parallel versus serial processing of multiple tasks

Fischer, Rico; Plessow, Franziska
Fonte: Frontiers Media S.A. Publicador: Frontiers Media S.A.
Tipo: Artigo de Revista Científica
EN_US
Relevância na Pesquisa
36.02%
In the context of performance optimizations in multitasking, a central debate has unfolded in multitasking research around whether cognitive processes related to different tasks proceed only sequentially (one at a time), or can operate in parallel (simultaneously). This review features a discussion of theoretical considerations and empirical evidence regarding parallel versus serial task processing in multitasking. In addition, we highlight how methodological differences and theoretical conceptions determine the extent to which parallel processing in multitasking can be detected, to guide their employment in future research. Parallel and serial processing of multiple tasks are not mutually exclusive. Therefore, questions focusing exclusively on either task-processing mode are too simplified. We review empirical evidence and demonstrate that shifting between more parallel and more serial task processing critically depends on the conditions under which multiple tasks are performed. We conclude that efficient multitasking is reflected by the ability of individuals to adjust multitasking performance to environmental demands by flexibly shifting between different processing strategies of multiple task-component scheduling.

Self-Efficacy as a Positive Youth Development Construct: A Conceptual Review

Tsang, Sandra K. M.; Hui, Eadaoin K. P.; Law, Bella C. M.
Fonte: The Scientific World Journal Publicador: The Scientific World Journal
Tipo: Artigo de Revista Científica
Publicado em 29/04/2012 EN
Relevância na Pesquisa
35.85%
Self-efficacy denotes people's beliefs about their ability to perform in different situations. It functions as a multilevel and multifaceted set of beliefs that influence how people feel, think, motivate themselves, and behave during various tasks. Self-efficacy beliefs are informed by enactive attainment, vicarious experience, imaginal experiences, and social persuasion as well as physical and emotional states. These beliefs are mediated by cognitive, motivational, affective, and selection processes to generate actual performance. Self-efficacy development is closely intertwined with a person's experiences, competencies, and developmental tasks in different domains at different stages in life. This paper reviews the literature to outline the definition and theoretical conceptualizations of the construct originally devised by Bandura that have flourished since the 1990s. Drawing from the studies of the construct to assess self-efficacy, and to inform positive youth development, the paper will present the determinants of the development of self-efficacy beliefs and identify the connection between self-efficacy and adolescent developmental outcomes. The paper will conclude with strategies to enhance youth self-efficacy and proposals for future research directions.

A Review of Dual-Task Walking Deficits in People with Parkinson's Disease: Motor and Cognitive Contributions, Mechanisms, and Clinical Implications

Kelly, Valerie E.; Eusterbrock, Alexis J.; Shumway-Cook, Anne
Fonte: Hindawi Publishing Corporation Publicador: Hindawi Publishing Corporation
Tipo: Artigo de Revista Científica
EN
Relevância na Pesquisa
35.92%
Gait impairments in Parkinson's disease (PD) are exacerbated under dual-task conditions requiring the simultaneous performance of cognitive or motor tasks. Dual-task walking deficits impact functional mobility, which often requires walking while performing concurrent tasks such as talking or carrying an object. The consequences of gait impairments in PD are significant and include increased disability, increased fall risk, and reduced quality of life. However, effective therapeutic interventions for dual-task walking deficits are limited. The goals of this narrative review are to describe dual-task walking deficits in people with PD, to discuss motor and cognitive factors that may contribute to these deficits, to review potential mechanisms underlying dual-task deficits, and to discuss the effect of therapeutic interventions on dual-task walking deficits in persons with PD.

Learning tasks as a possible treatment for DNA lesions induced by oxidative stress in hippocampal neurons

Cîrneci, Dragoş; Silaghi-Dumitrescu, Radu
Fonte: Medknow Publications & Media Pvt Ltd Publicador: Medknow Publications & Media Pvt Ltd
Tipo: Artigo de Revista Científica
Publicado em 15/11/2013 EN
Relevância na Pesquisa
35.97%
Reactive oxygen species have been implicated in conditions ranging from cardiovascular dysfunc-tion, arthritis, cancer, to aging and age-related disorders. The organism developed several path-ways to counteract these effects, with base excision repair being responsible for repairing one of the major base lesions (8-oxoG) in all organisms. Epidemiological evidence suggests that cognitive stimulation makes the brain more resilient to damage or degeneration. Recent studies have linked enriched environment to reduction of oxidative stressin neurons of mice with Alzheimer's dis-ease-like disease, but given its complexity it is not clear what specific aspect of enriched environ-ment has therapeutic effects. Studies from molecular biology have shown that the protein p300, which is a transcription co-activator required for consolidation of memories during specific learning tasks, is at the same time involved in DNA replication and repair, playing a central role in the long-patch pathway of base excision repair. Based on the evidence, we propose that learning tasks such as novel object recognition could be tested as possible methods of base excision repair faci-litation, hence inducing DNA repair in the hippocampal neurons. If this method proves to be effective...

Review of the Literature on Temporal Resolution in Listeners With Cochlear Hearing Impairment: A Critical Assessment of the Role of Suprathreshold Deficits

Reed, Charlotte M.; Braida, Louis D.; Zurek, Patrick M.
Fonte: SAGE Publications Publicador: SAGE Publications
Tipo: Artigo de Revista Científica
Publicado em /03/2009 EN
Relevância na Pesquisa
36.02%
A critical review of studies of temporal resolution in listeners with cochlear hearing impairment is presented with the aim of assessing evidence for suprathreshold deficits. Particular attention is paid to the roles of variables—such as stimulus audibility, overall stimulus level, and participant's age—which may complicate the interpretation of experimental findings in comparing the performance of hearing-impaired (HI) and normal-hearing (NH) listeners. On certain temporal tasks (e.g., gap detection), the performance of HI listeners appears to be degraded relative to that of NH listeners when compared at equal SPL (sound pressure level). For other temporal tasks (e.g., forward masking), HI performance is degraded relative to that of NH listeners when compared at equal sensation level. A relatively small group of studies exists, however, in which the effects of stimulus audibility and level (and occasionally participant's age) have been controlled through the use of noise-masked simulation of hearing loss in NH listeners. For some temporal tasks (including gap-detection, gap-duration discrimination, and detection of brief tones in modulated noise), the performance of HI listeners is well reproduced in the results of noise-masked NH listeners. For other tasks (i.e....

Upper Extremity Motor Learning among Individuals with Parkinson's Disease: A Meta-Analysis Evaluating Movement Time in Simple Tasks

Felix, K.; Gain, K.; Paiva, E.; Whitney, K.; Jenkins, M. E.; Spaulding, S. J.
Fonte: Hindawi Publishing Corporation Publicador: Hindawi Publishing Corporation
Tipo: Artigo de Revista Científica
EN
Relevância na Pesquisa
35.92%
Motor learning has been found to occur in the rehabilitation of individuals with Parkinson's disease (PD). Through repetitive structured practice of motor tasks, individuals show improved performance, confirming that motor learning has probably taken place. Although a number of studies have been completed evaluating motor learning in people with PD, the sample sizes were small and the improvements were variable. The purpose of this meta-analysis was to determine the ability of people with PD to learn motor tasks. Studies which measured movement time in upper extremity reaching tasks and met the inclusion criteria were included in the analysis. Results of the meta-analysis indicated that people with PD and neurologically healthy controls both demonstrated motor learning, characterized by a decrease in movement time during upper extremity movements. Movement time improvements were greater in the control group than in individuals with PD. These results support the findings that the practice of upper extremity reaching tasks is beneficial in reducing movement time in persons with PD and has important implications for rehabilitation.

The importance of mental calculation skills: a review of the literature

Gusty, Robert
Fonte: Rochester Instituto de Tecnologia Publicador: Rochester Instituto de Tecnologia
Tipo: Masters Project Formato: 14811446 bytes; application/pdf
EN_US
Relevância na Pesquisa
35.85%
This paper reviewed research related to phonological awareness in deaf and hearing individuals. A number of studies showed that individuals skilled in memory tasks and reading achievement utilize a phonological voice. Often referred to as inner voice or the articulatory loop, phonology was used by both hearing and deaf individuals considered to be skilled readers. The evidence also shows that the use of phonology for coding information is related to the ability to use memory efficiently. As reading achievement is very important in a deaf child's education, so is mathematics. Compared to hearing students, deaf students do not perform at the same academic level in mathematics. While the importance of phonology is known in terms of reading achievement and memory, it is probable that use of the articulatory loop is important in mathematics. This logic led to another potentially important factor of mathematical achievement - mental calculation. Thus, a review of the literature was conducted on the importance of mental calculation and recommended key strategies for teaching mental arithmetic skills.

An evaluation of the effectiveness of teamwork, with an emphasis on peer assessment and peer review, in an introductory engineering course

Daly,C.
Fonte: Journal of the Southern African Institute of Mining and Metallurgy Publicador: Journal of the Southern African Institute of Mining and Metallurgy
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/12/2014 EN
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35.81%
The Faculty of Engineering at the University of New South Wales (UNSW) offers a core first-year engineering design and innovation course, ENGG1000, undertaken during the first and second semesters. This course is highly regarded in the sense that it provides an introduction to many concepts and activities that students will experience over the four-year minimum for which they are undergraduates at UNSW. Approximately 1400 students enrol in the semester 1 course across the Faculty, typically 80 of which undertake the Mining Engineering stream. Students in teams of between six and eight design and construct a physical model to represent an aspect of their chosen discipline. For example, in 2013 the mining engineers designed and built a model dragline. This paper concentrates a major aspect of the course - the involvement of team members in group activities and the development of the associated skills of peer assessment and peer review as the course progresses over a period of 12 weeks. The term 'peer assessment' in this paper refers to the requirement for students to assess the design components of their peers. This course has a structured requirement in terms of how a successful design is a result of a sound design process rather than a 'try and see' approach. Each student must describe in detail the process they undertook to achieve their final design - hence the approach is independent of the discipline and/or project selected. Peer review is a process whereby students review the contribution of their team members to the overall design. This activity encourages team involvement and interaction. The final assessment mark can be moderated by the outcome of this peer review...