inverted-U Relationship Research Articles

High intensity VNS disrupts VNS-mediated plasticity in motor cortex

Vagus nerve stimulation (VNS) paired with motor rehabilitation enhances recovery of function after neurological injury in rats and humans. This effect is ascribed to VNS-dependent facilitation of plasticity in motor networks. Previous studies document an inverted-U relationship between VNS intensity and cortical plasticity, such that moderate intensities increase plasticity, while low or high intensity VNS does not. We tested the interaction of moderate and high intensity VNS trains to probe the mechanisms that may underlie VNS-dependent plasticity. Rats performed a behavioral task where VNS was paired with jaw movement during chewing. For five days, subjects received 100 pairings of moderate intensity VNS (Standard VNS), 100 pairings alternating between moderate and high intensity VNS (Interleaved VNS), or 50 pairings of moderate intensity VNS (Short VNS) approximately every 8 s. After the final behavioral session, intracortical microstimulation (ICMS) was used to evaluate movement representations in motor cortex. 100 pairings of moderate intensity VNS enhanced motor cortex plasticity. Replacing half of moderate intensity stimulation with high intensity VNS blocked this enhancement of plasticity. Removing high intensity stimulation, leaving only 50 pairings of moderate intensity VNS, reinstated plasticity. These results demonstrate that there is a period for at least 8 s after high intensity stimulation in which moderate intensity VNS is not able to engage mechanisms required for synaptic reorganization. More importantly, this study demonstrates that changes in stimulation parameters are a critical determinant of the magnitude of plasticity and likely the efficacy of VNS-enhanced recovery.

Exploring the effects of psychological ownership, gaming motivations, and primary/secondary control on online game addiction

Online gaming has grown to be a very popular electronic entertainment for people throughout the world. However, the burgeoning popularity of online games in some cases leads to addiction, a phenomenon that has received considerable attention. The purpose of this study is to examine the effects of psychological ownership, gaming motivation, and primary–secondary control on online game addiction (OGA). Based on 436 valid responses collected from online questionnaires, the partial least squares structural equation modeling approach was employed to test the research model. Findings show that the motivations of achievement and escapism are positively associated with psychological ownership toward a virtual gaming environment. Of particular interest is the inverted-U relationship between psychological ownership and OGA, suggesting that too little or too much psychological ownership is associated with less OGA. Finally, individuals with high levels of primary (secondary) control are more (less) inclined to be addicted to online games.This study provides practical implications and strategies to address the alarming increase in OGA. First, families, communities, and universities should encourage outdoor activities, such as sports competitions, and offline cosplay games to address the need for achievement and escapism. Second, individuals who play online games for relaxation should choose a relatively easy or hard mode to avoid game addiction. Finally, parents, teachers, and employers are encouraged to pay attention to individuals who have a high level of primary control since they can be susceptible to OGA. This study provides several theoretical contributions. First, the study enriches OGA and the gaming motivation literature by exploring the roles of gaming motivation, psychological ownership, and personal control strategies as they can be a factor in OGA. In addition, this study is the first to investigate the dark side of psychological ownership in terms of negative outcomes for OGA. This study also advances the personal control strategy literature by understanding the roles of primary and secondary control on OGA.

Toward a formal theory of embodied cognition

Since the reduction of uncertainty associated with cognition necessarily implies existence of a ‘dual’ information source, the Source Coding and Rate Distortion Theorems of information theory, in combination with the Data Rate Theorem of control theory, are sufficient to model much of embodied cognition. An iterated Morse Function ‘free energy’ allows construction of a ‘higher entropy’ analog constrained to obey the approximate dynamics of the Onsager gradient model of nonequilibrium thermodynamics. However, since palindromes are unlikely, there is no time reversal symmetry and hence no Onsager reciprocal relations. The group symmetry-breaking associated with physical phase transitions then emerges in terms of groupoids associated with equivalence classes of high probability developmental paths. The formalism is agnostic regarding representation and the Yerkes-Dodson inverted-U relation emerges directly, as do stochastic versions of the underlying dynamics, and a canonical approach to an embodied consciousness model. Contrary to the Western cultural fixation with individual salience at the expense of context, for cognition against and in the real world, context is often central, rather than simply being a screen against which some culturally-specific cartoon is supposed to play.

Exploring the Effects of Psychological Ownership, Gaming Motivations, and Primary/Secondary Control on Online Game Addiction

Online gaming has grown to be a very popular electronic entertainment for people throughout the world. However, the burgeoning popularity of online games in some cases leads to addiction, a phenomenon that has received considerable attention. The purpose of this study is to examine the effects of psychological ownership, gaming motivation, and primary–secondary control on online game addiction (OGA). Based on 436 valid responses collected from online questionnaires, the partial least squares structural equation modeling approach was employed to test the research model. Findings show that the motivations of achievement and escapism are positively associated with psychological ownership toward a virtual gaming environment. Of particular interest is the inverted-U relationship between psychological ownership and OGA, suggesting that too little or too much psychological ownership is associated with less OGA. Finally, individuals with high levels of primary (secondary) control are more (less) inclined to be addicted to online games. This study provides practical implications and strategies to address the alarming increase in OGA. First, families, communities, and universities should encourage outdoor activities, such as sports competitions, and offline cosplay games to address the need for achievement and escapism. Second, individuals who play online games for relaxation should choose a relatively easy or hard mode to avoid game addiction. Finally, parents, teachers, and employers are encouraged to pay attention to individuals who have a high level of primary control since they can be susceptible to OGA. This study provides several theoretical contributions. First, the study enriches OGA and the gaming motivation literature by exploring the roles of gaming motivation, psychological ownership, and personal control strategies as they can be a factor in OGA. In addition, this study is the first to investigate the dark side of psychological ownership in terms of negative outcomes for OGA. This study also advances the personal control strategy literature by understanding the roles of primary and secondary control on OGA.

The effects of bank competition on firm R&D investment: an inverted-U relationship

PurposeBank financing is an important external financing source for firm research and development (R&D) investment. This study aims to use an exponential quadratic specification to investigate the effect of bank competition on firm R&D investment and its underlying mechanisms. Moreover, this study checks bank competition’s heterogeneous effects on firm R&D investment.Design/methodology/approachBased on data of Chinese manufacturing firms and bank branches, this study uses the Tobit estimator, instrumental variable method and Heckman two-step approach to test the relationship between bank competition and firm R&D investment.FindingsThe results show robustness evidence of an inverted-U relationship between bank competition and firm R&D investment. Specifically, increases in bank competition promote firm R&D investment until bank competition reaches the turning point and reduce firm R&D investment after crossing the turning point. Financing costs and financial constraints can explain the inverted-U relationship between bank competition and firm R&D investment. Heterogeneity examinations reveal that R&D investment is more sensitive to bank competition in non-state-owned enterprises, small firms and high-tech firms.Originality/valueThis study contributes to the literature on the relationship between bank competition and firm innovation. The authors investigate the heterogeneity of R&D investment influenced by bank competition and depict the economic effects brought by bank competition. This study sheds light on the real effects of bank competition and the determinants of firm R&D investment in transition economies. The conclusions provide empirical evidence for reducing credit discrimination and improving capital allocation efficiency in developing countries.

Quantile heterogeneous impact of R&D on firm growth in Chinese manufacture: how ownership, firm size and sectors matter?

ABSTRACT This paper explores the heterogeneous impact of R&D on firm growth in Chinese manufacturing industry during the periods 2012–2017. We divide the full sample into sub-samples according to different ownership, firm size and sectors, respectively, which help comprehensive observe the impact of R&D on firm growth. The results indicate that R&D has a significant positive impact on firm growth, and that R&D of private enterprises has a greater impact on firm growth than that of state-owned enterprises across all quantiles. Moreover, we find the R&D effectiveness of non-small and medium-sized enterprises is significantly greater than that of SMEs. Additionally, persuasive evidence proves the existence of an inverted-U relationship between R&D and firm growth, except for higher-growth state-owned SMEs. The results also indicate that R&D plays a more significantly positive role in high-tech industries. Our finding suggests that policymakers should encourage R&D investment in manufacturing industry to promote firm growth. But policymaker must classify firms, observe R&D intensity turning points of firms with different types, formulate meticulous R&D strategies, and maximize R&D utility.

Understanding the emotional and informational influence on customer knowledge contribution through quantitative content analysis

Customers’ knowledge contributions are a vital source of business value. This study is one of the few attempts to study the influence of emotional and informational feedback on knowledge contribution. Through quantitative content analysis, we analyzed content data from 2324 users in a firm-hosted online community. We found that informational support (argument quality and source credibility) and emotional support (emotional approval and emotional asymmetry) significantly affect customers’ knowledge contributions. Moreover, we identified an inverted-U relationship between emotional asymmetry and knowledge contributions in initiated posts. This study has implications for both researchers and practitioners.

Innovation Networks and Business-Stealing

We use the universe of USPTO data on patents and inventors from 1976 to 2017 to look at the dynamics of coauthorship on patents and its relationship with competition. First, we find an inverted-U relationship between competition and the growth in coauthorship: the number of new collaborators on each patent is maximized at intermediate levels of competition. Next, we find that there is a surge of new coauthors at the time of invention, and then persistently fewer than normal new coauthors after a breakthrough invention. Third, the size of the surge in coauthorship are the largest, and subsequent decline the smallest, in industries with intermediate levels of competition. We also present a simple model in which researchers trade off gains from collaboration against threats of business stealing, which provides one explanation for our empirical findings.

The Resilience and Vulnerability of Human Brain Networks Across the Lifespan.

Resilience, the ability for a system to maintain its basic functionality when suffering from lesions, is a critical property for human brain, especially in the brain aging process. This study adopted a novel metric of network resilience, the Resilience Index (RI), to assess human brain resilience with three different lifespan datasets. Based on the structural brain networks constructed from diffusion tensor imaging (DTI), we observed an inverted-U relationship between RI and age, that is, RI increased during development and early adulthood, reached a peak at about 35 years old, and then decreased during aging, which suggested that brain resilience could be quantified by RI. Furthermore, we studied brain network vulnerability by the decreases in RI when virtual lesions occurred to nodes (i.e., brain regions) or edges (i.e., structural brain connectivity). We found that the strong edges were markedly vulnerable, and the homotopic edges were the most prominent representatives of vulnerable edges. In other words, an arbitrary attack on homotopic edges would have a high probability to degrade brain network resilience. These findings suggest the change of human brain resilience across the lifespan and provide a new perspective for exploring human brain vulnerability.

Chinese cities exhibit varying degrees of decoupling of economic growth and CO2 emissions between 2005 and 2015

Summary Cities, contributing more than 75% of global carbon emissions, are at the heart of climate change mitigation. Given cities' heterogeneity, they need specific low-carbon roadmaps instead of one-size-fits-all approaches. Here, we present the most detailed and up-to-date accounts of CO2 emissions for 294 cities in China and examine the extent to which their economic growth was decoupled from emissions. Results show that from 2005 to 2015, only 11% of cities exhibited strong decoupling, whereas 65.6% showed weak decoupling, and 23.4% showed no decoupling. We attribute the economic-emission decoupling in cities to several socioeconomic factors (i.e., structure and size of the economy, emission intensity, and population size) and find that the decline in emission intensity via improvement in production and carbon efficiency (e.g., decarbonizing the energy mix via building a renewable energy system) is the most important one. The experience and status quo of carbon emissions and emission-GDP (gross domestic product) decoupling in Chinese cities may have implications for other developing economies to design low-carbon development pathways.

Net international migration: A panel analysis of economic determinants

Various factors can motivate and encourage individuals to leave their country of origin and engage in the process of international migration. Large migration flows over the past few years, which are a consequence of the so-called refugee crisis in 2015, have resulted in a significant increase in academic interest in international migration. Although many factors can encourage international migration, people?s desire to increase their standard of living is undoubtedly one of the most important causes. This empirical study analyses the economic determinants of net international migration. It was conducted using techniques of econometric analysis of panel data on an extensive balanced panel data sample covering 136 countries over a period of 30 years (1990-2019). Although this study focuses on the analysis of the economic determinants of net international migration, it is necessary to point out that in this case it is not a one-way impact. Apart from the fact that economic indicators affect international migration, it is indisputable that there is an effect in the opposite direction, i.e. that migration flows significantly affect the economic performance of the origin and destination country. This influence can be realised through different mechanisms. The potential presence of reverse causality generates a problem of potentially endogenous regressors, which must be considered when selecting model estimation techniques. The estimation of the models was performed using the following two techniques that allow cross-section dependence: (i) standard common correlated effects pooled estimator (CCEP), which is based on the application of the ordinary least squares method; and (ii) modified common correlated effects pooled estimator, which is based on the application of the two-stage least squares method, allowing the presence of endogenous regressors. The obtained findings suggest that the impact of the unemployment rate on net international migration is negative. Estimates generated by the standard CCEP technique (as well as by the modified CCEP technique) show that an increase in the unemployment rate of 1% results in a decrease in net international migration by about 0.03 migrants (0.06 migrants) per 1,000 inhabitants. Education has a positive impact on net international migration. The standard CCEP technique (modified CCEP technique) points to the fact that a 1% increase in education results in an increase in net international migration of about 0.01-0.02 migrants (0.003 migrants) per 1,000 inhabitants. The level of development of the migrant network has a positive effect on net international migration. The standard and modified CCEP technique show that increasing the stock of migrants by 1% increases net international migration by about 0.04-0.05 migrants, i.e. by about 0.01 migrants per 1,000 inhabitants. Finally, estimates obtained using the standard CCEP technique suggest that a 1% increase in per capita gross domestic product (GDPpc) results in an increase in net international migration of about 0.01 migrants per 1,000 inhabitants, while the results of the modified and more credible CCEP technique show that growth in GDPpc by 1% implies a decrease in net international migration by about 0.02 migrants per 1,000 inhabitants. The negative effect of GDPpc could be rationalised by the existence of an inverted-U relationship between GDPpc and emigration (mobility transition curve). Acceptance of such an explanation requires that the following conditions be met: (i) there is an inverted-U relationship between emigration and GDPpc; (ii) the countries in the sample fit within the growing part of this relationship; and (iii) when GDPpc grows, emigration increases absolutely more than immigration.

Economic Growth and Government Size in OIC Countries: A GMM Application

This study intends to investigate the short and long-term relationship between government size and economic growth in the Islamic Cooperation Organization (OIC) during the 2010 to 2018 period through an empirical approach to 57 OIC countries using the dynamic data panel method GMM Arellano-Bond. The results show that in the short term, government size has a negative and significant effect on economic growth, while government investment has a positive and significant effect on economic growth. The results also show that in the long run, government size has a negative and significant effect on economic growth, while government investment has a positive and significant impact on economic growth. This research also supports the previous study which stated that there is a ‘inverted-U relationship’ between government size and economic growth. Policy recommendations that can be taken from this research are that the governments of OIC countries can make strategic steps in their spending by restructuring taxes and expenditures to maximize the effect on economic growth. Compared with previous research, the author tries to analyze the short and long-term relationship between government size and economic growth in OIC countries, by developing a longer research period and involving all OIC members, totaling 57 countries. This paper is expected to contribute to complementing the existing literature on economic growth in OIC countries

Technical Progress Reduces the Degree of Competition That Maximizes Investment in Innovation

The relationship between competition and investment is generally characterized by an inverted-U relationship. The position of these curves and, in particular their maximum, i.e, the degree of competition that maximizes investment, depends on the degree of technical progress that characterizes each industry. Industries experiencing a high degree of technical progress, as information technologies, maximize their investments in innovation for lower degrees of competition than other industries. Sectoral and competition authorities should take this into account for regulation of competition. Information technologies should not be regulated as brick and mortar industries.

Does Business Model Innovation Enhance the Sustainable Development of New Ventures? Understanding an Inverted-U Relationship

Improving the sustainable development of new ventures and helping them survive and develop in the entrepreneurial environment are important research issues. Business model innovation is considered as a potential way for new ventures to enhance their sustainable development capability and performance. Although previous studies have pointed out that there is a positive linear relationship between business model innovation and sustainable development, little research has found the nonlinear relationship between them, as well as the moderating effects of competitive strategy innovation and strategy flexibility. In this study, an empirical model was established to test our hypotheses and answer our research questions. Analysis of data collected from 326 questionnaires shows that an inverted-U relationship exists between business model innovation and sustainable development such that new ventures with low or high business model innovation have worse sustainable development than new ventures with appropriate business model innovation. Moreover, this paper finds that competitive strategy innovation and strategic flexibility positively moderate the inverted-U relationship between business model innovation and sustainable development of new ventures. From a theoretical perspective, this study offers a model with which to understand the impacts of business model innovation, and contributes significantly to the research on new ven- tures. From a practical perspective, this paper provides new insights into the management of new ventures and recommends several practical strategies for managers and practitioners.

Technical Progress Reduces the Degree of Competition That Maximizes Investment in Innovation

The relationship between competition and investment is generally characterized by an inverted-U relationship. The position of these curves and, in particular their maximum, i.e, the degree of competition that maximizes investment, depends on the degree of technical progress that characterizes each industry. Industries experiencing a high degree of technical progress, as information technologies, maximize their investments in innovation for lower degrees of competition than other industries. Sectoral and competition authorities should take this into account for regulation of competition.Information technologies should not be regulated as brick and mortar industries.

Great minds think alike, or do they often differ? Research topic overlap and the formation of scientific teams.

Over the last century scientific research has become an increasingly collaborative endeavor. Commentators have pointed to different factors which contribute to this trend, including the specialization of science and growing need for diversity of interest and expertise areas in a scientific team. Very few studies, however, have precisely evaluated how the diversity of interest topics between researchers is related to the emergence of collaboration. Existing theoretical arguments suggest a curvilinear relationship between topic similarity and collaboration: too little similarity can complicate communication and agreement, yet too much overlap can increase competition and limit the potential for synergy. We test this idea using data on six years of publications across all disciplines at a large U.S. research university (approximately 14,300 articles, 12,500 collaborations, and 3,400 authors). Employing topic modelling and network statistical models, we analyze the relationship between topic overlap and the likelihood of coauthorship between two researchers while controlling for potential confounders. We find an inverted-U relationship in which the probability of collaboration initially increases with topic similarity, then rapidly declines after peaking at a similarity "sweet spot". Collaboration is most likely at low-to-moderate levels of topic overlap, which are substantially lower than the average self-similarity of scientists or research groups. These findings - which we replicate for different units of analysis (individuals and groups), genders of collaborators, disciplines, and collaboration types (intra- and interdisciplinary) - support the notion that researchers seek collaborators to augment their scientific and technical human capital. We discuss implications for theories of scientific collaboration and research policy.

A Comparison of Dopaminergic and Cholinergic Populations Reveals Unique Contributions of VTA Dopamine Neurons to Short-Term Memory

We systematically compare the contributions of two dopaminergic and two cholinergic ascending populations to a spatial short-term memory task in rats. In ventral tegmental area dopamine (VTA-DA) and nucleus basalis cholinergic (NB-ChAT) populations, trial-by-trial fluctuations in activity during the delay period relate to performance with an inverted-U, despite the fact that both populations have low activity during that time. Transient manipulations reveal that only VTA-DA neurons, and not the other three populations we examine, contribute causally and selectively to short-term memory. This contribution is most significant during the delay period, when both increases and decreases in VTA-DA activity impair short-term memory. Our results reveal a surprising dissociation between when VTA-DA neurons are most active and when they have the biggest causal contribution to short-term memory, and they also provide support for classic ideas about an inverted-U relationship between neuromodulation and cognition.

Double-Layer Learning, Leaders' Forgetting, and Knowledge Performance in Online Work Community Organizations

This paper constructs an online community organizational double-layer learning structure model based on exploration-exploitation models. In this way, the authors examine the effect how double-layer online community learning as well as heterogeneous teams affects online work community organizational knowledge performance (OWCOKP) with leaders forgetting and without leaders forgetting. First, the results suggest an inverted-U relationship between the degree of different team member connectivity and OWCOKP. Second, as the leaders forgetting rate increases, the degree of different team member connectivity, which leads to the optimum OWCOKP also increases. Third, with or without leaders forgetting, moderate learning between members and that between the leader and members can improve OWCOKP within a team of online community. Fourth, in different teams, slow learning between leaders produces higher OWCOKP without leaders forgetting while moderate learning between leaders produces higher OWCOKP with their forgetting.

Entrepreneurial orientation and the interaction of top management team background characteristics

AbstractThe current study draws on the upper echelons theory to examine the nature of the relationship between top management team (TMT) tenure and a firm's level of entrepreneurial orientation (EO). We find evidence of an inverted-U relationship between TMT tenure and EO using data from firms across three industries with varied industry dynamics. We further introduce a contingency element by demonstrating that TMT industry background heterogeneity moderates the relationship between TMT tenure and EO, where the inverted U-shaped relationship will be more pronounced when the heterogeneity is low and will flatten when the heterogeneity is high. The findings demonstrate the complexity CEOs and governing bodies face while shaping a diverse TMT that can affect EO.

Personalized pricing for customer retention: Theory and evidence from mobile communication

This paper analyzes firms' strategies that aim at retaining customers and examines consumers' characteristics that make them ideal targets for companies’ loyalty programs. Our contribution is both theoretical and empirical. On the theoretical side, we develop a formal economic model to study the incentives of firms to offer personalized pricing plans, when consumers are at risk of leaving and are heterogeneous in service usage. On the empirical side, relying on an original dataset of customers of one of the top mobile network operators in the Italian market, we find evidence of an inverted-U relationship between the usage intensity and the probability of being the target of a personalized offer, which is consistent with the theoretical prediction. In addition, we find that anti-churn campaigns have a positive effect on customer retention.