scholarly journals Motor expertise facilitates the precision of state extrapolation in perception

2017 ◽  
Author(s):  
Nicolas Ludolph ◽  
Jannis Plöger ◽  
Martin A. Giese ◽  
Winfried Ilg

AbstractPredicting the behavior of objects in the environment is an important requirement to overcome latencies in the sensorimotor system and realize precise actions in rapid situations. Internal forward models that were acquired during motor training might not only be used for efficiently controlling fast motor behavior but also to facilitate extrapolation performance in purely perceptual tasks. In this study, we investigated whether preceding virtual cart-pole balancing training facilitates the ability to extrapolate the pole motion. We compared a group of 10 subjects, proficient in performing the cart-pole balancing task, to 10 naïve subjects. Our results demonstrate that preceding motor training increases the precision of pole movement extrapolation, although extrapolation is not trained explicitly. Additionally, we modelled subjects’ behaviors and show that the difference in extrapolation performance can be explained by individual differences in the accuracy of internal forward models. When subjects are provided with feedback about the true pole movement in a second phase, both groups improve rapidly. The results indicate that the perceptual capability to extrapolate the state of the cart-pole system accurately is implicitly trained during motor learning. We discuss these results in the context of shared representations and action-perception transfer.

2021 ◽  
Author(s):  
Johannes Alfons Karl ◽  
Ronald Fischer

Objectives We present a bibliometric review of research on trait mindfulness published from 2005 till 2021 to determine the current state of the field and identify research trajectories. Methods A search conducted on Jan 30, 2021 using the search terms “trait mindfulness” OR “dispositional mindfulness” in the Web of Science Core Collection identified 1,229 documents. Results Using keyword-based network analyses, the various clusters suggested two major approaches in the field, one focusing on cognitive attentional processes, and a second approach that encompasses a wider field of well-being and clinical research topics. We also increasing consolidation of research fields over time, with research on wider individual differences such as personality being subsumed into clinically and wellbeing-oriented research topics. More recently, a distinct theme focused on the validity of measurement of mindfulness emerged. In addition to general patterns in the field, we examined the global distribution of trait mindfulness research. Research output was substantially skewed towards North American-based researchers with less international collaborations. Chinese researchers nevertheless also produced research at significant rates. Comparing the difference in research topics between China and the US-based researchers we found substantial differences with US research emphasizing meditation and substance abuse issues, whereas researchers from China focused on methodological questions. Conclusions Overall, our review indicates that research on trait mindfulness might profit from conceptual and cultural realignment, with greater focus on individual differences research in other areas of psychology to complement the strong clinical and cognitive focus we well as also stronger cross-cultural and comparative studies.


2016 ◽  
Vol 45 (6) ◽  
pp. 256
Author(s):  
M Mexitalia ◽  
Yohanes Tri Nugroho ◽  
J C Susanto

Background Preschool children are vulnerable in growth. Soy-bean formula (SF) and formula-100 (F100) are supplementary foodswhich contain of high energy and are available at low price; how-ever, they are not widely used for preschool children.Objectives To investigate the effect of SF compared to F100 onthe growth of preschool children.Methods A cross-over trial was conducted on 96 preschool chil-dren aged 4-7 years. Subjects were randomly divided into 2 groupswhich received 200 ml soybean formula (n=49) or F100 (n=47) for1 month and crossed-over after a six-week wash-out period. Bodyweight was measured weekly. Body height and food analysis by 3-day food recall were measured at the beginning and the end of thestudy. The criteria of the acceptability of the formula was eithergood or poor.Results Supplementation with SF as well as F100 induced catchup growth as shown by the increase of Δz-score. There were nosignificant difference of Δ weight for age z-score, Δ height for agez-score, and Δ weight for height z score between groups duringthe first and second phases of the trial. The acceptability of F100was significantly better than that of SF at the beginning; neverthe-less, the difference was not significant at the second phase trial.Conclusions Soybean formula and F100 given for a one monthperiod can induce catch-up growth in preschool children. Soybeanformula as an alternative health food can be accepted by preschoolchildren


1964 ◽  
Vol 14 (1) ◽  
pp. 107-110 ◽  
Author(s):  
Peter J. Donovick ◽  
Leonard E. Ross

The present investigation was concerned with the reduction of inhibition associated with the negative discriminandum in a single stimulus discrimination learning situation. In Phase I 33 female rats were trained on a black-white discrimination problem. In the second phase Ss were divided into three groups which received: (a) 100% reinforcement to both the old positive and negative discriminanda; (b) four trials per day to the old negative, 100% reward; (c) eight trials per day to the old negative, 100% reward. As in previous studies, which employed simultaneous discrimination learning conditions, speed to the old negative remained significantly below speed to the old positive in the second phase. However, unlike the previous results, the difference decreased over trials. No differences were found between the groups that had trials to the old negative cue only, or between these groups and either speed to the old positive or the old negative in the case of the group receiving reward on both cues.


Author(s):  
Oussama Choura ◽  
Caterina Capponi ◽  
Silvia Meniconi ◽  
Sami Elaoud ◽  
Bruno Brunone

Abstract In this paper the results of an experimental validation of a technique for leak detection in polymeric pipes based on the inverse transient analysis (ITA) are presented. In the proposed ITA the Nelder–Mead algorithm is used as a calibration tool. Experimental tests have been carried out in an intact and leaky high-density polyethylene (HDPE) single pipe installed at the Water Engineering Laboratory (WEL) of the University of Perugia, Italy. Transients have been generated by the fast and complete closure of a valve placed at the downstream end section of the pipe. In the first phase of the calibration procedure, the proposed algorithm has been used to estimate both the viscoelastic parameters of a generalized Kelvin–Voigt model and the unsteady-state friction coefficient, by minimizing the difference between the numerical and experimental results. In the second phase of the procedure, the calibrated model allowed the evaluation of leak size and location with an acceptable accuracy. Precisely, in terms of leak location the relative error was smaller than 5%.


2020 ◽  
Author(s):  
Sobanawartiny Wijeakumar ◽  
Eva Rafetseder ◽  
Yee Lee Shing ◽  
Courtney McKay

Visual working memory (VWM) is reliably predictive of fluid intelligence and academic achievements. The objective of the current study was to investigate the nature of individual differences in pre-schoolers by examining the relationship between behaviour-brain function underlying VWM processing and parent-reported measures. We used a portable 8 x 8 channel functional near-infrared spectroscopy system to record from the frontal and parietal cortices of 4.5-year-old pre-school children (N=74) as they completed a colour change detection VWM task in their homes. Parents were asked to fill in questionnaires on temperament, academic aspirations, home environment, and life stress. Children were median-split into a low-performing (LP) and a high-performing (HP) group based on the number of items they could successfully remember during the task. LPs increasingly activated the bilateral frontal and parietal cortices with increasing load, whereas HPs showed no difference in activation across the loads. Our findings suggested that LPs recruited more neural resources when their VWM capacity was challenged. We employed mediation analyses to examine the association between the difference in activation between the highest and lowest loads, and variables from the questionnaires. The difference in activation in the right parietal cortex partially mediated the association between parent-reported stressful life events and VWM performance. Specifically, a higher number of stressful events was associated with lower VWM performance. Critically, our findings show that the association between VWM capacity, right parietal activation, and indicators of life stress is important to understand the nature of individual differences in VWM in pre-school children.


2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Nhat Thanh Hoang Le ◽  
Nhan Thi Ho ◽  
Bryan Grenfell ◽  
Stephen Baker ◽  
Ronald B. Geskus

Abstract Background Infection with measles virus (MeV) causes immunosuppression and increased susceptibility to other infectious diseases. Only few studies reported a duration of immunosuppression, with varying results. We investigated the effect of immunosuppression on the incidence of hospital admissions for infectious diseases in Vietnamese children. Methods We used retrospective data (2005 to 2015; N = 4419) from the two pediatric hospitals in Ho Chi Minh City, Vietnam. We compared the age-specific incidence of hospital admission for infectious diseases before and after hospitalization for measles. We fitted a Poisson regression model that included gender, current age, and time since measles to obtain a multiplicative effect measure. Estimates were transformed to the additive scale. Results We observed two phases in the incidence of hospital admission after measles. The first phase started with a fourfold increased rate of admissions during the first month after measles, dropping to a level quite comparable to children of the same age before measles. In the second phase, lasting until at least 6 years after measles, the admission rate decreased further, with values up to 20 times lower than in children of the same age before measles. However, on the additive scale the effect size in the second phase was much smaller than in the first phase. Conclusion The first phase highlights the public health benefits of measles vaccination by preventing measles and immune amnesia. The beneficial second phase is interesting, but its strength strongly depends on the scale. It suggests a complicated interaction between MeV infection and the host immunity.


2018 ◽  
Vol 192 ◽  
pp. 01022
Author(s):  
Ekkaphon Jaiyen ◽  
Komgrit Leksakul

This research objective is to solve the integer problems by using an algorithm that applied to the element decomposing method (EDCM). Integer problem is a NP-hard when the problem is large-size, more time needed to solve the problem. The EDCM cuts a structure into several elements and reconnects elements at “nodes”. This process can disconnect other nodes that not connected with the element. Moreover, it appropriately need in optimization solutions for applications, in which can give answers faster by cutting the nodes in finding the answers. There’s 2 phases of step on this research. The first phase is input data and simplex method, while the second phase is creating and developing the algorithm from EDCM application. The comparison results show how two methods are carried out between EDCM and B&B Method. The results from two methods are focused on the value and solution step by step. According to the problem, it can be solved within the number of variables 2-15. The value of the difference in the answer is on average at 0.00% and solution step used for solving problem is less on average at 40.89 %.


2020 ◽  
Vol 20 (1) ◽  
Author(s):  
Mohammad Javad Fatemi ◽  
Mostafa Dianatinasab ◽  
Golnaz Sharifnia ◽  
Hossein Moravej ◽  
Mohammad Fararouei

Abstract Background Growth retardation is a common health problem, which requires early prevention and detection. This study was conducted to define the approximate age at which stunting starts among the Iranian boys and girls. Method The second phase of a population-based retrospective cohort nested case-control study on 400 children who were followed from birth to 7 years of age. This study was performed to define the pattern of growth among stunted and normal children and to reveal the age at which stunting starts in each gender. Results Of the selected participants, 53% were girls. Also, about 18% of the children registered by the selected health centers were defined as stunted (under the 3rd percentile of the corresponding sex-age NCHS/WHO growth reference). For boys, the height was relatively similar between the two groups until the age of 6 months at which the difference in height between normal and stunted children starts to become significantly large (difference = 0.70 cm, P = 0.04). For girls, height in the two groups is relatively similar until the age of 9 months at which the difference starts to become significantly large (difference = 0.97 cm, P = 0.01). No significant difference in the weight of the girls was observed between the normal and stunted groups during the study period (difference = 283.21 g, P > 0.05). However, boys from the stunted group were lighter since almost the same time that they started to become significantly shorter (difference = 1265.19 g, P = 0.001). Conclusions Soon after birth (at about the 6 months of age), the growth pattern of some (stunted) children starts to stumble and divert from normal. The sixth month of age is the age at which mothers start weaning with withdrawing breast milk and start supplementary foods and adult diet. A specially designed study is needed to understand the actual reason for observing such a phenomenon among Iranian children.


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