scholarly journals Increase in weighting of vision vs. proprioception associated with force field adaptation

2019 ◽  
Author(s):  
Brandon M. Sexton ◽  
Yang Liu ◽  
Hannah J. Block

AbstractHand position can be encoded by vision, via an image on the retina, and proprioception (position sense), via sensors in the joints and muscles. The brain is thought to weight and combine available sensory estimates to form an integrated multisensory estimate of hand position with which to guide movement. Force field adaptation, a form of cerebellum-dependent motor learning in which reaches are systematically adjusted to compensate for a somatosensory perturbation, is associated with both motor and proprioceptive changes. The cerebellum has connections with parietal regions thought to be involved in multisensory integration; however, it is unknown if force adaptation is associated with changes in multisensory perception. One possibility is that force adaptation affects all relevant sensory modalities similarly, such that the brain’s weighting of vision vs. proprioception is maintained. Alternatively, the somatosensory perturbation might be interpreted as proprioceptive unreliability, resulting in vision being up-weighted relative to proprioception. We assessed visuo-proprioceptive weighting with a perceptual estimation task before and after subjects performed straight-ahead reaches grasping a robotic manipulandum. Each subject performed one session with a clockwise or counter-clockwise velocity-dependent force field, and one session in a null field to control for perceptual changes not specific to force adaptation. Subjects increased their weight of vision vs. proprioception in the force field session relative to the null field session, regardless of force field direction, in the straight-ahead dimension (F1,44 = 5.13, p = 0.029). This suggests that force field adaptation is associated with an increase in the brain’s weighting of vision vs. proprioception.

2019 ◽  
Author(s):  
Andria J. Farrens ◽  
Fabrizio Sergi

AbstractNeurorehabilitation is centered on motor learning and control processes, however our understanding of how the brain learns to control movements is still limited. Motor adaptation is a rapid form of motor learning that is amenable to study in the laboratory setting. Behavioral studies of motor adaptation have coupled clever task design with computational modeling to study the control processes that underlie motor adaptation. These studies provide evidence of fast and slow learning states in the brain that combine to control neuromotor adaptation.Currently, the neural representation of these states remains unclear, especially for adaptation to changes in task dynamics, commonly studied using force fields imposed by a robotic device. Our group has developed the MR-Softwrist, a robot capable of executing dynamic adaptation tasks during functional magnetic resonance imaging (fMRI) that can be used to localize these networks in the brain.We simulated an fMRI experiment to determine if signal arising from a switching force field adaptation task can localize the neural representations of fast and slow learning states in the brain. Our results show that our task produces reliable behavioral estimates of fast and slow learning states, and distinctly measurable fMRI activations associated with each state under realistic levels of behavioral and measurement noise. Execution of this protocol with the MR-Softwrist will extend our knowledge of how the brain learns to control movement.


Author(s):  
Juliana Widyastuti Wahyuningsih Juliana Widyastuti Wahyuningsih

ABSTRAK Tidur merupakan kebutuhan yang harus terpenuhi terutama pada fase perkembangan karena selama tidur akan terjadi perkembangan otak maupun tubuh, sehingga gangguan tidur merupakan masalah yang akan menimbulkan dampak buruk terhadap pertumbuhan dan perkembangan bayi. Kualitas tidur bayi yang baik dapat diciptakan dengan memberikan pemijatan bayi secara rutin. Penelitian ini bertujuan untuk membuktikan bahwa pemijatan dapat mempengaruhi kualitas tidur bayi umur 0-3 bulan. Penelitian ini menggunakan desain penelitian Quasy Eksperimental dengan metode One Group Pretest-Postest. Sampel 22 bayi yang dipilih dengan tehnik Total Sampling yang di observasi sebelum dan sesudah diberikan pemijatan. Variabel yang diukur dalam penelitian ini adalah kualitas tidur bayi 0-3 bulan. Hasil penelitian menunjukkan bahwa ada pengaruh pijat bayi terhadap kualitas tidur bayi umur 0-3 bulan (p value  0,008 < α = 0,05).Berdasarkan hasil penelitian ini disarankan agar keluarga dan masyarakat memberikan pemijatan secara rutin dan mandiri untuk meningkatkan kebutuhan tidur bayi yang berkualitas.   ABSTRACT Sleep is a human necessity that must be met, especially in the development phase because during sleep will occur the brain and body developments, so that sleep disturbance is a problem that would cause adverse effects on infants’ growth and development. The good quality of sleep can be created by providing the infants massage routinely. This study aimed to prove that the massage could affect the quality of sleep on the 0-3 months old baby. This study used Quasy-experimental design with One Group Pretest-Posttest. The sample 22 infants selected by total sampling technique observed on before and after the massage. The variables measured in this study are the quality of sleep. The results of study indicate that there is an effect of infant massage to the sleep quality on 0-3 months old babies (p value 0,008 < α = 0,05).Based on the results of this study it recommended for the families and communities to provide infant massage regularly and independently to increase the quality of sleep on the baby.  


Author(s):  
Bruno and

Synaesthesia is a curious anomaly of multisensory perception. When presented with stimulation in one sensory channel, in addition to the percept usually associated with that channel (inducer) a true synaesthetic experiences a second percept in another perceptual modality (concurrent). Although synaesthesia is not pathological, true synaesthetes are relatively rare and their synaesthetic associations tend to be quite idiosyncratic. For this reason, studying synaesthesia is difficult, but exciting new experimental results are beginning to clarify what makes the brain of synaesthetes special and the mechanisms that may produce the condition. Even more importantly, the related phenomenon known as ‘natural’ crossmodal associations is instead experienced by everyone, providing another useful domain for studying multisensory interactions with important implications for understanding our preferences for products in terms of spontaneously evoked associations, as well as for choosing appropriate names, labels, and packaging in marketing applications.


2002 ◽  
Vol 13 (04) ◽  
pp. 188-204 ◽  
Author(s):  
Shigeyuki Kuwada ◽  
Julia S. Anderson ◽  
Ranjan Batra ◽  
Douglas C. Fitzpatrick ◽  
Natacha Teissier ◽  
...  

The scalp-recorded amplitude-modulation following response (AMFR)” is gaining recognition as an objective audiometric tool, but little is known about the neural sources that underlie this potential. We hypothesized, based on our human studies and single-unit recordings in animals, that the scalp-recorded AMFR reflects the interaction of multiple sources. We tested this hypothesis using an animal model, the unanesthetized rabbit. We compared AMFRs recorded from the surface of the brain at different locations and before and after the administration of agents likely to enhance or suppress neural generators. We also recorded AMFRs locally at several stations along the auditory neuraxis. We conclude that the surface-recorded AMFR is indeed a composite response from multiple brain generators. Although the response at any modulation frequency can reflect the activity of more than one generator, the AMFRs to low and high modulation frequencies appear to reflect a strong contribution from cortical and subcortical sources, respectively.


2021 ◽  
Vol 11 (6) ◽  
pp. 784
Author(s):  
Govindasamy Balasekaran ◽  
Ahmad Arif Bin Ibrahim ◽  
Ng Yew Cheo ◽  
Phua Kia Wang ◽  
Garry Kuan ◽  
...  

The purpose of this study was to investigate the effects of classroom-based Brain Breaks® Physical Activity Solution in Southeast Asia Singaporean primary school students and their attitude towards physical activity (PA) over a ten-week intervention. A total of 113 participants (8–11 years old) were randomly assigned to either an experimental (EG) or a control group (CG), with six classes to each group; the Brain Breaks® group (EG: six classes) and the Control group (CG: six classes). All EG members participated in a Brain Breaks® video intervention (three–five min) during academic classes and the CG continued their lessons as per normal. The student’s attitudes towards PA in both research conditions were evaluated using the self–reported Attitudes toward Physical Activity Scale (APAS), applied before and after intervention. The effects of the intervention on APAS scores were analysed using a mixed model analysis of variance with Time as within-subject and Group as between-subject factors. The analysis revealed evidence in support of the positive effect of classroom video interventions such as Brain Breaks® on student’s attitudes toward benefits, importance, learning, self-efficacy, fun, fitness, and trying to do their personal best in PA. The Brain Breaks® intervention provided a positive significant impact on students in Singapore. This study also revealed that interactive technology tools implemented into the school curriculum benefit students in terms of health and education.


2009 ◽  
Vol 297 (5) ◽  
pp. R1312-R1321 ◽  
Author(s):  
Gurjit Nagra ◽  
Lena Koh ◽  
Isabelle Aubert ◽  
Minhui Kim ◽  
Miles Johnston

In some tissues, the injection of antibodies to the β1-integrins leads to a reduction in interstitial fluid pressure, indicating an active role for the extracellular matrix in tissue pressure regulation. If perturbations of the matrix occur in the periventricular area of the brain, a comparable lowering of interstitial pressures may induce transparenchymal pressure gradients favoring ventricular expansion. To examine this concept, we measured periventricular (parenchymal) and ventricular pressures with a servo-null micropipette system (2-μm tip) in adult Wistar rats before and after anti-integrin antibodies or IgG/IgM isotype controls were injected into a lateral ventricle. In a second group, the animals were kept for 2 wk after similar injections and after euthanization, the brains were removed and assessed for hydrocephalus. In experiments in which antibodies to β1-integrins ( n = 10) but not isotype control IgG/IgM ( n = 7) were injected, we observed a decline in periventricular pressures relative to the preinjection values. Under similar circumstances, ventricular pressures were elevated ( n = 10) and were significantly greater than those in the periventricular interstitium. We estimated ventricular to periventricular pressure gradients of up to 4.3 cmH2O. In the chronic preparations, we observed enlarged ventricles in many of the animals that received injections of anti-integrin antibodies (21 of 29 animals; 72%) but not in any animal receiving the isotype controls. We conclude that modulation/disruption of β1-integrin-matrix interactions in the brain generates pressure gradients favoring ventricular expansion, suggesting a novel mechanism for hydrocephalus development.


Vestnik ◽  
2021 ◽  
pp. 190-195
Author(s):  
М.С. Кулбаева ◽  
А.Н. Курал ◽  
Л.Б. Умбетьярова ◽  
Н.Т. Аблайханова ◽  
Г.К. Атанбаева ◽  
...  

Человека давно интересует вопрос о том, как умственная нагрузка влияет на организм. Известно, что при длительной умственной работе преобразуется сила процессов возбуждения и торможения, изменяется соотношение между ними. С возникновением утомления в головном мозгу нарушаются взаимосвязи между корой больших полушарий и подкорковыми образованиями. При этом наблюдается снижение регулирующего влияния больших полушарий на все функции организма и уменьшение активизирующих воздействий подкорковых отделов мозга. Кроме того, длительное сидячие положение, состояние низкой двигательной активности ведут к значительному уменьшению центростремительных импульсов с рецепторов мышц, сухожилий, суставов. В исследовании приняли участие 17 относительно здоровые, имеющие стабильное физиологическое состояние девушек-студенток в возрасте от 21 до 25 лет. Для исследования были взяты 16 биологически активных точек на стандартных меридианах, связаных с определенным органом. Для оценки физиологического состояния органов до и после умственной нагрузки были исследованы показатели ЭП БАТ на коже. Выявлено снижение показателей каждого органа после умственной нагрузки по сравнению с показателями до ее выполнения со статистической достоверностью во всех исследуемых органах (р<0,05). Особенно низкие значения показателей ЭП БАТ после умственной нагрузки были выявлены в биоактивных точках меридиана печени F.3 Тай-Чун, меридиана толстой кишки GI.5 Ян-Си и GI.4 Хэ-Гу, меридиана сердца С.7 Шэнь-Мэнь, меридиана тонкой кишки IG.1 Шао-Цзе и IG.2 Цянь-Гу, меридиана почек R.1 Юн-Цюань и Р.2 Жань-Гу. Humans has long been interested in the question of how mental activity affects the body It is known that with prolonged mental work, the strength of the processes of excitation and inhibition is transformed, the ratio between them changes. With the onset of fatigue in the brain, the relationship between the cerebral cortex and subcortical formations is disrupted. At the same time, there is a decrease in the regulatory influence of the large hemispheres on all body functions and a decrease in the activating effects of the subcortical parts of the brain. In addition, prolonged sitting, a state of low motor activity leads to a significant decrease in centripetal impulses from the receptors of muscles, tendons, and joints. The study involved 17 relatively healthy, stable physiological condition of female students aged 21 to 25 years. For the study, 16 biologically active points were taken from standard meridians associated with a specific organ. To assess the physiological state of the organs before and after the load of mental labor, the indicators of EC BAP on the skin. A decrease in the indicators of each organ after mental labor was revealed in comparison with the indicators before mental labor with statistical reliability in all the studied organs (p˂0.05). Especially low values of the EC BAP values after a load of mental labor were found in the bioactive points of the liver meridian F. 3 Tai-Chun, the colon meridian GI.5 Yang-Si and GI. 4 He-Gu, the heart meridian C. 7 Shen-Men, the small intestine meridian IG.1 Shao-tse and IG.2 Qian-Gu, the meridian of the kidneys R. 1 Yun-Chuan and R. 2 Zhan-Gu.


2004 ◽  
Vol 5 (3) ◽  
pp. 143 ◽  
Author(s):  
Sunseob Choi ◽  
Haiying Liu ◽  
Tae Beom Shin ◽  
Jin Hwa Lee ◽  
Seong Kuk Yoon ◽  
...  

PLoS Biology ◽  
2021 ◽  
Vol 19 (11) ◽  
pp. e3001465
Author(s):  
Ambra Ferrari ◽  
Uta Noppeney

To form a percept of the multisensory world, the brain needs to integrate signals from common sources weighted by their reliabilities and segregate those from independent sources. Previously, we have shown that anterior parietal cortices combine sensory signals into representations that take into account the signals’ causal structure (i.e., common versus independent sources) and their sensory reliabilities as predicted by Bayesian causal inference. The current study asks to what extent and how attentional mechanisms can actively control how sensory signals are combined for perceptual inference. In a pre- and postcueing paradigm, we presented observers with audiovisual signals at variable spatial disparities. Observers were precued to attend to auditory or visual modalities prior to stimulus presentation and postcued to report their perceived auditory or visual location. Combining psychophysics, functional magnetic resonance imaging (fMRI), and Bayesian modelling, we demonstrate that the brain moulds multisensory inference via 2 distinct mechanisms. Prestimulus attention to vision enhances the reliability and influence of visual inputs on spatial representations in visual and posterior parietal cortices. Poststimulus report determines how parietal cortices flexibly combine sensory estimates into spatial representations consistent with Bayesian causal inference. Our results show that distinct neural mechanisms control how signals are combined for perceptual inference at different levels of the cortical hierarchy.


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