Association between Working Memory and Obesity among Secondary School Children

Introduction: Obesity is not just a term but a threat faced by the younger generation. It affects the vital systems of our body and very importantly impairs the cognitive functions of our brain. Lack of exercise, lethargy, increased usage of electronic gadgets is some of the notable reasons for childhood obesity. This study has been designed to find out how obesity is playing a role in a child’s short term memory skills. Materials and Methods: A Cross sectional epidemiological study was conducted among 125 secondary school children from random urban south Indian population. The students were asked to fill in their general details along with height, weight, hip circumference, waist circumference and asked to play a set of matching games and put in their score to measure working memory. Results: Association between corresponding memory task scores and BMI indicates a strong negative correlation (r = -.008) and (r = -.07). Conclusion: The present results therefore indicate that there is an association between obesity and poorer working memory performance in secondary school children. Therefore to conclude, the extent to which children are physically active is influenced by a multiple and interrelated factors. Addressing physical inactivity and its contribution to childhood overweight obesity requires a broad and holistic approach.

Do You Know What I Know? Children Use Informants’ Beliefs About Their Abilities to Calibrate Choices During Pedagogy

Models of pedagogy highlight the reciprocal reasoning underlying learner-teacher interactions, including that learners’ inferences should be shaped by what they believe a teacher knows about them. Yet, little is known about how this influences learning, despite the fact that even young children make rapid inferences about teaching from sparse data. In the current work, six- to eight-year-olds’ performance on a picture-matching game was either overestimated, underestimated, or accurately represented by a confederate (the “Teacher”), who then presented three new matching games of varying assessed difficulty (too easy, too hard, just right). A simple model of this problem predicts that while children should follow the recommendation of an accurate Teacher, learners should choose easier games when the Teacher overestimated their abilities, and harder games when she underestimated them. Results from our experiment support these predictions, providing insight into children’s ability to consider teachers’ knowledge when learning from pedagogy.

Stabilizing Weighted Graphs

An edge-weighted graph [Formula: see text] is called stable if the value of a maximum-weight matching equals the value of a maximum-weight fractional matching. Stable graphs play an important role in network bargaining games and cooperative matching games, because they characterize instances that admit stable outcomes. We give the first polynomial-time algorithm to find a minimum cardinality subset of vertices whose removal from G yields a stable graph, for any weighted graph G. The algorithm is combinatorial and exploits new structural properties of basic fractional matchings, which are of independent interest. In contrast, we show that the problem of finding a minimum cardinality subset of edges whose removal from a weighted graph G yields a stable graph, does not admit any constant-factor approximation algorithm, unless P = NP. In this setting, we develop an O(Δ)-approximation algorithm for the problem, where Δ is the maximum degree of a node in G.

Scratch Card Game Type Impacts Psychophysiological Reactivity, but Not Subjective Evaluations of Experienced Outcomes

Although many types of scratch cards exist, research on gamblers’ physiological responses to scratch card wins, losses, and near misses has been limited to a single type of game. We created two distinct scratch card types. In a “Match Three” game, we expected arousal to rise with each successive matching symbol—hence arousal would change even before the final outcome was known. In a “Number Matching” game, where players were given a set of lucky numbers and hoped to find a match within a scratch-off play area, we expected arousal to rise only once a match was made. A near miss in a Match Three game involved uncovering two large-prize symbols (but not the third). A near miss in a Number Matching game involved just missing a match (lucky number 18, uncovering a 17). For each game type, participants played four cards (small win, near miss, and two losses) while their physiological arousal was recorded. Participants rated each outcome on a number of subjective measures. For wins, arousal changes occurred as predicted (pre-outcome changes for Match Three vs. only post-outcome changes for Number Matching games). Participants rated near-miss outcomes in both card types as being more subjectively arousing, disappointing, negative, frustrating, and urge inducing than for regular losses, but we found no strong evidence for physiological near-miss effects. We provide evidence that the structure of scratch card games influences the timing of individuals’ physiological responses to various outcomes.RésuméBien qu’il existe de nombreux modèles de cartes à gratter, les recherches menées jusqu’ici sur les réactions physiologiques des joueurs face à un gain, une perte ou un quasi-gain se limitent à un seul type de jeu. Nous avons conçu deux jeux de cartes à gratter distincts. Le premier était un jeu « à trois correspondances »; nous nous attendions à ce que le degré d’excitation monte à chaque apparition d’un symbole identique - et ce, avant même que le résultat final soit connu. Le second jeu consistait à donner aux joueurs un jeu de chiffres chanceux avec instruction de dévoiler un chiffre correspondant dans la partie à gratter de la carte; nous nous attendions à ce que l’excitation monte seulement après le dévoilement d’une correspondance. Dans le premier jeu, un quasi-gain consistait en la découverte de deux symboles représentant un lot important (mais pas du troisième). Dans le second jeu, un quasi-gain consistait en l’obtention d’un nombre très proche du chiffre gagnant (obtention d’un 17 alors que le gagnant est le 18). Les participants ont été invités à gratter quatre cartes par jeu (un petit gain, un quasi-gain et deux pertes) tandis qu’on enregistrait leurs réactions physiologiques, puis à donner une évaluation subjective de chaque résultat. Les réactions anticipées se sont produites dans le cas des gains (soit avant le dévoilement du résultat dans le premier jeu et seulement après dans le second). Peu importe le type de carte, les sujets ont qualifié le quasi-gain, comparativement aux pertes régulières, d’expérience excitante, décevante, négative, frustrante et propre à attiser le désir de jouer, mais nous n’avons recueilli aucune preuve de réaction physiologique dans ce cas précis. Selon nos conclusions, la structure des jeux de cartes à gratter a une incidence sur le moment de la réaction physiologique aux différents résultats de jeu.

Convexity of b-matching Games

The b-matching game is a cooperative game defined on a graph. The game generalizes the matching game to allow each individual to have more than one partner. The game has several applications, such as the roommate assignment, the multi-item version of the seller-buyer assignment, and the international kidney exchange. Compared with the standard matching game, the b-matching game is computationally hard. In particular, the core non-emptiness problem and the core membership problem are co-NP-hard. Therefore, we focus on the convexity of the game, which is a sufficient condition of the core non-emptiness and often more tractable concept than the core non-emptiness. It also has several additional benefits. In this study, we give a necessary and sufficient condition of the convexity of the b-matching game. This condition also gives an O(n log n + m α(n)) time algorithm to determine whether a given game is convex or not, where n and m are the number of vertices and edges of a given graph, respectively, and α(・) is the inverse-Ackermann function. Using our characterization, we also give a polynomial-time algorithm to compute the Shapley value of a convex b-matching game.