complexity

Motor imagination is a dynamic mental state that simulates a similar brain mechanism to actual physical movement. This brain mechanism could be traced using Electroencephalography (EEG) recording during motor imagination. Nevertheless, it is still unclear how development changes this mechanism. As the brain mechanism of motor imagination must gain expertise during development to enable a subject to perform better motor actions, we hypothesized that the brain mechanism of imagination in adults must have a more complex pattern of information processing than in children. 

We recorded the EEG signals of 10 boys and 9 male adults during right- and left-hand motor imaginations. Subsequently, the complexity of EEG signals was estimated by applying Higuchi’s fractal dimension (HFD) to the cleaned EEG data. 

The results presented a significant increase of HFD in the adults (P<0.05, family-wised error corrected) in all the EEG channels compared to the children. An increase in HFD presents a more complex pattern of information processing in adults, which advances their ability to perform motor tasks. 

This advancement in adults could be created by information compression at higher levels than in children. We hope these findings pave the way to a better understanding brain functions and mechanisms.

Most people with profound hearing loss have problems in speech intelligibility that related to their phonological ability and linguistic skill. The objectives of this research are to assess the clarity of speech and the complexity of words in children with hearing impairments who use cochlear implants (CI) and those who use hearing aids (HA).

Additionally, it aims to explore the connection between speech clarity and word complexity in these children.

A total of fifty children with hearing loss (average age = 4.5 ± 0.8 years) were divided into two equal groups: One group consisting of 25 children with CI and another group with 25 children using hearing aids. Speech intelligibility of participants was evaluated by the repetitive word list. The criterion for examining the word complexity was the syllable number of each word.

The results showed that the CI group had better speech intelligibility than the HA group. There is a significant positive correlation between word complexity and speech intelligibility in hearing impaired children (P < 0.001).

According to the results of this study, the CI children showed better speech intelligibility than HA because of the effectiveness of implantation on auditory input. On the other hand, the word complexity also contributes to the level of speech intelligibility. Therefore, experts working in the field of management and clinical education of these children need to consider the word complexity and other factors affecting the speech intelligibility.

The editorial by McKee and colleagues is an important call to action to put a spotlight on trust and its role in the function of health systems. The authors make a good case for this focus considering how trust in health systems seems to have eroded in recent years, an erosion accelerated by the COVID-19 pandemic. They recognize that trust is complex given the many forms of trust, the importance of context, and its dynamic and unpredictable nature. However, the solutions they offer including learning how to measure trust and figuring out the causes and consequences of trust are just simple or complicated solutions to this complex challenge. Instead, we need to approach building trust in healthcare by embracing and harnessing complexity. This starts by understanding the difference between complicated and complex challenges and then by applying complex systems frameworks that offer insight into new ways forward.

Stroke is one of the most debilitating diseases among adults worldwide and leads to persistent rehabilitation needs even at the chronic stage. Achieving good postural control is a critical requirement for daily activities which enhances quality of life (QoL) in patients with stroke. There is increasing evidence that transcranial direct current stimulation (tDCS) can be considered a promising adjunct technique to improve motor recovery after stroke. Evidence of augmented neuroplasticity after tDCS suggests that paired rehabilitation followed by consecutive use of tDCS may optimize recovery outcomes. Although a few randomized controlled trials have been conducted on upper limb rehabilitation in chronic stroke using tDCS, no study focused on balance training in chronic stroke patients. The present randomized, sham-controlled, double-blinded clinical study addresses brain stimulation targeting postural control using tDCS in chronic stroke.

The study participants included chronic ischemic stroke individuals with postural control impairments who passed the exclusion criteria. Active or sham anodal tDCS was delivered to the lesioned leg motor cortex combined with balance training. The experimental group received active anodal tDCS stimulation (2 mA) for 20 min, daily for 5 days paired with balance training. Linear and nonlinear approaches were used to analyze postural sway changes pre-and post-intervention. Postural sway fluctuation, functional balance assessment using the Berg balance scale, and timed up-and-go test were conducted to compare the active and sham groups. 

This trial could have significant implications for balance rehabilitation after stroke in the ambulatory setting. If effective, this novel approach may improve rehabilitation protocol in this population.

The flexibility of the heart is important for cardiovascular health. The heart rate variation (HRV) is a metric of heart flexibility. Muslims perform praying (Namaz) which has some significant effects on general health regularity. The study aimed to assess the impact of real Namaz on HRV.

Eighty-two participants who performed Namaz daily were categorized into three groups, including more minor, more than, and equal to the normal cortisol level range based on salivary cortisol. The electrocardiography was recorded before, during (divided into standing, bowing, prostration, and sitting positions), and after a four-cycle Namaz around noon. The linear and non-linear features of HRV were extracted.

The two-way analysis of variance showed that the standard deviation (SD)1 and SD2 of the Poincare plots of all groups increased after Namaz (P<0.0001). During Namaz, the indexes of sympathetic tone decreased in the prostration and bowing compared to the sitting and standing positions (P<0.00001). The SD of the mean of the R peaks interval, SD1, and SD2 of the Poincare plot also increased in those comparisons (P<0.00001). In addition, the spectral entropy was decreased in the bowing and prostration compared with standing and sitting positions (P<0.001).

Namaz significantly increased the performance of the cardiovascular system and decreased the effect of daily stress on it.

Holmström and co-authors argue for the value of integrating system dynamics into action research to deal with increasing complexity in healthcare. We argue that despite merits, the authors overlook the key aspect of normative complexity, which refers to the existence of multiple, often conflicting values that actors in healthcare systems have to pragmatically develop responses to in their daily practices. We argue that a better theoretical and empirical understanding of the multiplicity of values and how actors deal with value conflicts in daily practices can enrich discussions about complexity in healthcare. We introduce the alternative methodology of ‘value exnovation’ for action researchers to broaden the scope of system-based thinking and action research in healthcare.

Social stress affects brain function. Trier social stress test (TSST) is a standard test to assess it. The study aimed to analyze the electroencephalographic (EEG) recording during and after TSST in healthy subjects. The EEG signals of 44 healthy men participating in the study were recorded in the control condition, during and after TSST and after 30 min of recovery. Salivary cortisol (SC) and the Emotional Visual Analog Scale (EVAS) score were measured in the control condition, after TSST, and after the recovery period. The false discovery rate correction was used to control the false positive of significance in EEG. In the comparison control condition, the SC and EVAS levels significantly increased after TSST. The relative Delta band frequency significantly increased during TSST. On the other hand, the Beta bands and, in less amount, the Theta and Gamma 1 (30–40 Hz) oscillations decreased, especially in the frontal region. The nonlinear features such as, approximate and spectral entropy, Katz fractal dimension behaved like Beta band oscillation. All changes returned to baseline after TSST except the increase of Katz in the F3 channel after the recovery period. Thus, stress on EEG increased low frequency (1–4 Hz), decreased high frequency (13–40 Hz), and complexity indices during TSST.

One of the most important topics in the field of movement behavior is the acquisition of movement sequences, which is an important part of every person's life and the basis of many intelligent human behaviors. The aim of the study was to investigate the effectiveness of errorfull and errorless training based on complexity in the acquisition, retention and transfer of a motor sequential task in elderly women with emphasis on processing needs.

This semi-experimental study was conducted on 30 healthy elderly women over 60 years of age that were selected and randomly allocated into errorless and errorful groups. Then, they performed a sequence motor task assigned by the Serial Reaction Time Task software in the three phases of acquisition, retention, and transfer. In order to analyze the data, ANOVA with repeated measures, Wilcoxon test, Mann-Whitney U test and the independent samples t-test were conducted.

A significant improvement was seen in the reaction time and the number of errors in both groups (p < 0.05). Also, the errorless group recorded a shorter reaction time than the errorful group in the acquisition, retention and transfer tests. However, the errorful group made fewer errors in the retention and transfer tests than the errorless group.

Errorfull and errorless training are effective on reaction time and amount of errors in the retention and transfer stages of a motor sequential task in elderly women.  However, It is suggested that trainers use errorfull training methods in motor sequential tasks in order to reduce the error rate and provide a more optimal learning environment.

Waitzberg and colleagues identified strategies that managers and physicians in hospitals apply to reconcile dilemmas between clinical and economic considerations. Contributions that actually acknowledge the institutional complexity of hospitals and describe how to deal with it are rare. This comment explains the reason behind the institutional complexity in healthcare organizations and argues that institutional complexity is a good foundation for a wellfunctioning and sustainable healthcare, as long as we are able to deal with this complexity. This point underscores the importance of their contribution. However, even if the identified strategies on how to reconcile and balance different, competing demands are important, they are not easy to apply in practice. First, the strategies require frequent and high-quality interaction between different actors adhering to different institutional logics. Second, even when the strategies are applied successfully, it is difficult to make them sustainable since they rest on a fragile balance between competing logics. However, these are important avenues for future research for researchers who want to follow the route of Waitzberg and colleagues.

Context matters. Therefore, efforts to develop greater conceptual clarity are important for science and practice. In this commentary, we outline some key issues that were prompted by Squires and colleagues’ contribution. Specifically, we reinforce context as an interactive concept and therefore something that is hard to ‘pin down,’ the problematic nature of conceptualising context in implementation and de-implementation, and a requirement for the development of culturally sensitive understandings. Finally, we suggest it is vital that continued investment into providing a more comprehensive list of determinants needs to be accompanied by an equal effort in developing practical methods and tools to support use and application.

Resilience, a system’s ability to maintain a desired level of performance when circumstances disturb its functioning, is an increasingly important concept in healthcare. However, empirical investigations of resilience in healthcare (RiH) remain uncommon, particularly those that examine how government actions contribute to the capacity for resilient performance in the healthcare setting. We sought to investigate how governmental actions during the coronavirus disease 2019 (COVID-19) pandemic related to the concept of resilience, how these actions contributed to the potential for resilient performance in healthcare, and what opportunities exist for governments to foster resilience within healthcare systems.

We conducted case studies of government actions pertaining to the COVID-19 pandemic in New South Wales, Australia and Ontario, Canada. Using media releases issued by each government between December 2019 and August 2020, we performed qualitative content analysis to identify themes relevant to the resilience potentials (anticipate, monitor, respond, learn) and RiH.

Direct references to the term ‘resilience’ appeared in the media releases of both governments. However, these references focused on the reactive aspects of resilience. While actions that constitute the resilience potentials were evident, the media releases also revealed opportunities to enhance learning (eg, a need to capitalize on opportunities for double-loop learning and identify strategies appropriate for complex systems) and anticipating (eg, incorporating the concept of hedging into frameworks of RiH).

Though fostering RiH through government action remains a challenge, this study suggests opportunities to realize this goal. Articulating a proactive vision of resilience and recognizing the complex nature of current systems could enhance governments’ ability to coordinate resilient performance in healthcare. Reflection on how anticipation relates to resilience appears necessary at both the practical and conceptual levels to further develop the capacity for RiH

Squires et al note that too many people use terms like ‘context’ imprecisely. The result (to avoid) is a catch-all term that lacks explanatory value and hinders the efforts of policy designers. Their list of 66 factors is a useful exercise to unpack what people mean when describing context. However, some problems will arise when the authors seek to move from research to practice. First, the list is too long to serve its purpose. Second, in many cases, it categorises rather than operationalises key terms. The result is the replacement of one vague term with a collection of others. Third, many categories describe what policy designers might need, rather than what they can reasonably expect to happen. In that context, wider studies of implementation and complex systems provide cautionary tales in which the outcomes of research become overwhelming rather than practical.

Renal stone disease is a very common disease, and its lifetime prevalence is 1 - 15%, with a gradual rise in incidence and disease prevalence. There are significant financial implications of its management. Nowadays, for big (typically > 2 cm) renal and upper ureteric stones, PCNL is widely regarded as the first-line treatment. Because most of the intrarenal collecting systems can be accessed by superior calyceal puncture in PCNL, good stone clearance can be achieved. The “Guy’s Stone Score” is a useful technique for categorizing the complexity of PCNL.

This study aimed to evaluate the role of Guys Stone Score based on KUB and intravenous urography to predict the success rate, grading, and complexity of PCNL, which are performed via the upper pole access.

The present prospective, non-randomized observational study was undertaken in the Department of Urology and Renal transplantation, SCBMCH, Cuttack, from 1st November 2017 to 31st October 2019. A total of 104 patients were enrolled in the study in whom PCNL was performed through superior calyceal puncture, based on preoperative intravenous pyelogram. The Guy’s Stone Score was calculated, and the complexity of the procedure was graded using radiological studies, then the outcome was determined accordingly.

In this study, 59.6% of the patients had immediate success among them 29.0% had grade 3, and 6.5% had grade 4 GSS. Moreover, 38.4% of the patients had clinically significant residual fragments among them, 75.0% had grade 4, and 20.0% had grade 3 GSS.23% of the patients underwent REDO-PCNL and 11.5% of the patients underwent accesory/ancillary procedure of ESWL.

The present study shows that an intravenous pyelogram-based Guy’s Stone Score (GSS) is an easy-to-use tool in predicting the early success rate and potential difficulties and complications in PCNL performed through superior calyceal puncture.

The purpose of this review is to establish how the theory of complexity is understood and instituted in dentistry.

The stomatognathic system can be understood as a dynamic, complex, and adaptive system. Each pathological or physiological condition of this system involves physical, chemical, and biological processes in constant, open, and changing interactions with social, emotional, nutritional, political, and economic processes. Against this background, specifically, the following research questions were posed: How do researchers use complexity science in dentistry? How is complexity science described in dentistry articles?.

A brief literature search was implemented, which identified 11 PubMed articles as well as two from the Literatura Latinoamericana y del Caribe en Ciencias de la Salud (LILACS) database and one from the Cochrane Library for a full text review. Studies on complexity in the dental sciences are mostly presented in the form of critical opinion articles, which corresponded to 50% of the reviewed articles. In dentistry, complexity is understood as less of a theory and more as a line of thinking regarding procedures that can become complex at any given time.

This article shows that there are great difficulties in integrating complexity and understanding it in dentistry. There are many aspects from complexity science that still need to be understood in oral health.

Health systems are complex social systems, and values constitute a central dimension of their complexity. Values are commonly understood as key drivers of health system change, operating across all health systems components and functions. Moreover, health systems are understood to influence and generate social values, presenting an opportunity to harness health systems to build stronger, more cohesive societies. However, there is little investigation (theoretical, conceptual, or empirical) on social values in health policy and systems research (HPSR), particularly regarding the capacity of health systems to influence and generate social values. This study develops an explanatory theory for the ‘social value of health systems.’

We present the results of an interpretive synthesis of HPSR literature on social values, drawing on a qualitative systematic review, focusing on claims about the relationship between ‘health systems’ and ‘social values.’ We combined relational claims extracted from the literature under a common framework in order to generate new explanatory theory.

We identify four mechanisms by which health systems are considered to contribute social value to society: Health systems can: (1) offer a unifying national ideal and build social cohesion, (2) influence and legitimise popular attitudes about rights and entitlements with regard to healthcare and inform citizen’s understanding of state responsibilities, (3) strengthen trust in the state and legitimise state authority, and (4) communicate the extent to which the state values various population groups.

We conclude that, using a systems-thinking and complex adaptive systems perspective, the above mechanisms can be explained as emergent properties of the dynamic network of values-based connections operating within health systems. We also demonstrate that this theory accounts for how HPSR authors write about the relationship between health systems and social values. Finally, we offer lessons for researchers and policy-makers seeking to bring about values-based change in health systems.