Area Of Brain Research Research Articles

Complexity Measures for EEG Microstate Sequences: Concepts and Algorithms

EEG microstate sequence analysis quantifies properties of ongoing brain electrical activity which is known to exhibit complex dynamics across many time scales. In this report we review recent developments in quantifying microstate sequence complexity, we classify these approaches with regard to different complexity concepts, and we evaluate excess entropy as a yet unexplored quantity in microstate research. We determined the quantities entropy rate, excess entropy, Lempel–Ziv complexity (LZC), and Hurst exponents on Potts model data, a discrete statistical mechanics model with a temperature-controlled phase transition. We then applied the same techniques to EEG microstate sequences from wakefulness and non-REM sleep stages and used first-order Markov surrogate data to determine which time scales contributed to the different complexity measures. We demonstrate that entropy rate and LZC measure the Kolmogorov complexity (randomness) of microstate sequences, whereas excess entropy and Hurst exponents describe statistical complexity which attains its maximum at intermediate levels of randomness. We confirmed the equivalence of entropy rate and LZC when the LZ-76 algorithm is used, a result previously reported for neural spike train analysis (Amigó et al., Neural Comput 16:717–736, https://doi.org/10.1162/089976604322860677, 2004). Surrogate data analyses prove that entropy-based quantities and LZC focus on short-range temporal correlations, whereas Hurst exponents include short and long time scales. Sleep data analysis reveals that deeper sleep stages are accompanied by a decrease in Kolmogorov complexity and an increase in statistical complexity. Microstate jump sequences, where duplicate states have been removed, show higher randomness, lower statistical complexity, and no long-range correlations. Regarding the practical use of these methods, we suggest that LZC can be used as an efficient entropy rate estimator that avoids the estimation of joint entropies, whereas entropy rate estimation via joint entropies has the advantage of providing excess entropy as the second parameter of the same linear fit. We conclude that metrics of statistical complexity are a useful addition to microstate analysis and address a complexity concept that is not yet covered by existing microstate algorithms while being actively explored in other areas of brain research.

Intelligent BCI Headphone for a Healthier and a Deeper Immersive Gameplay

The developments in the area of brain research by analysing brain activity of individuals have given rise to many useful applications, such as diagnosing mental disorders more efficiently, treatment of cognitive disorders, and developing of brain-computer interfaces for treatment, communication and entertainment purposes. However, the development of such applications is hindered by a shortage of easy-to-use and comfortable sensors, as well as a lack of high-quality brain activity data. In the first part of this paper, a review of the status of BCI applications is presented followed by a proposal of a framework for developing an intelligent BCI headphone that takes leverages of the huge amount of data coming from playing video games to let the players experience a full immersive gaming experience.

Does telomerase protein protect our neurons?

Telomerase is best known for its canonical function in telomere maintenance. However, a growing number of non-telomeric functions have been described. Several groups have found the telomerase protein TERT to persist in adult brain neurons. A protective role for the telomerase protein TERT had been demonstrated in cultivated mouse neurons during brain development, against excitotoxic stresses from N-methyl-D-aspartate (NMDA) and glutamate and agents known to be involved in neurodegenerative diseases such as beta amyloid peptides and hyperphosphorylated tau. In contrast, lack of telomerase and TERT protein increase oxidative stress and decrease neuronal survival. Research on telomerase and TERT protein in human neurodegenerative diseases is a relatively new field. However, there is emerging evidence of a beneficial role of telomerase in human brains and animal models of neurodegenerative diseases that suggests to explore the possibility of using telomerase activators as neuroprotective agents to combat brain ageing and to ameliorate neurodegenerative diseases such as Parkinson’s and Alzheimer’s diseases. The current mini-review summarises the knowledge about this developing novel area of brain research.

Psychological Science and Religious Education in a Devout University: The Case of Pain Overlap Theory and the Talmud

Educators employed in devoutly religious institutions often teach students who view even their secular higher education through a uniquely religious lens. Based on his own experiences teaching psychological science at a Jewish university, the author suggests enhancing student interest and enthusiasm by wedding secular curricula with religious education, where feasible. By way of illustration, the current article shows how a cutting edge area of brain research could be taught in the context of ancient and medieval Jewish sources. This example is especially appropriate, given the recent special interest among leaders in the field of religious education in the potential relationships between their own discipline and the field of neuroscience, as well as the fact that the literatures of the histories of neuroscience and related disciplines have long noted the relevance of Jewish religious sources.

The neuroscience global village

before they will consider an application and then take several months to give their decision, making the procedure complex and uncertain. The IBRO program removes these hurdles, thus offering a new level of encouragement and support. Adding yet further to the value of the program for young investigators, a number of workshops were organised devoted to topics relating to education and career development, including funding opportunities, communication of research results, graduate and postdoctoral training, how to establish a new laboratory, ethical issues and the use of animals in research. These are often neglected in ‘conventional’ University courses in developing countries, but a lack of knowledge about these crucial topics can be as much of a hindrance to career development as a lack of scientific resources. Sparing the environment: Beneficiaries one and all As a side note, the IBRO World Congress organizing committee made diligent efforts to be environmentally friendly, saving paper by using e-mail to communicate with the participants and providing abstracts on a CD, promoting the use of reusable and recyclable material, saving electricity and banning toxic chemicals [5]. This World Congress had been an eye-opener for many of us and set an excellent example of how to organize a big conference without compromising the environment. Past activities and future perspectives Since the 1990s, IBRO has emerged as a world federation of neuroscience societies and associations, devoted to the promotion of neuroscience in countries with limited resources, and with a focus on young investigators. In 2011, which marks the 50th anniversary of IBRO, the 8th IBRO World Congress was hosted by the Italian Society of Neuroscience (SINS) [6] and held in Florence, Italy (July 14–18). Convened every four years, the World Congress is a unique global event symbolizing IBRO’s primary objectives of promoting neuroscience research, and facilitating YIP participants with Prof. Marina Bentivoglio, IBRO Secretary-General (past). Group photo of YIP participants and YIP committee members at the IBRO Congress in Florence, 18 July 2011. J. K. Sinha et al. Insights & Perspectives..... 8 Bioessays 34: 7–9, 2011 WILEY Periodicals, Inc. E x la b o ra to ri o international collaboration and exchange of scientific information in all areas of brain research. The 8th Congress saw the participation of scientists from 86 countries, with 4,200 participants, 1,500 of whom were from economically disadvantaged countries [4]. Although science has no borders, countries do. Electronic communication breaks these down, but large amounts of dedication, vision and creativity are still needed. The Young Investigator Program has these qualities in abundance, and has translated them into an outstanding programme that recognises the practical steps needed to bring young scientists from developing countries ‘in from the cold’. By facilitating short stays in cutting edge laboratories, and arranging participation in a prominent international conference, it has transformed the scenario for these young investigators and enabled them to truly experience and fully join the global community of neuroscience. As participants in the YIP, many PhD students and post-docs have greatly profited from this, and we solicit similar initiatives from the many other international societies and research organizations in other fields of science. Acknowledgments The views expressed therein are those of the authors and YIP participants. Authors acknowledge Prof. Marina Bentivoglio, Prof. Caroline Fall and Dr. Andrew Moore for their constructive criticism in refining and editing the manuscript and IBRO for support in YIP. JKS acknowledges ISN and ICMR – SRF for financial support in research.

Gd-DTPA T1 relaxivity in brain tissue obtained by convection-enhanced delivery, magnetic resonance imaging and emission spectroscopy

A common approach to quantify gadolinium (Gd) contrast agents involves measuring the post-contrast change in T1 rate and then using the constant T1 relaxivity R to determine the contrast agent concentration. Because this method is fast and non-invasive, it could be potentially valuable in many areas of brain research. However, to accurately measure contrast agent concentrations in the brain, the T1 relaxivity R of the specific agent must be accurately known. Furthermore, the macromolecular content and compartmentalization of the brain extracellular space (ECS) are expected to significantly alter R from values measured in aqueous solutions. In this study, the T1 relaxivity R of gadolinium-diethylene-triamine penta-acetic acid (Gd-DTPA) was measured following direct interstitial infusions of three different contrast agent concentrations to the parenchyma of rat brains. Changes in magnetic resonance (MR) T1 values were compared to brain slice concentrations determined with inductively coupled plasma atomic emission spectroscopy (ICP-AES) to determine R in 15 rats. Additionally, samples of cerebrospinal fluid, blood and urine were analyzed to evaluate possible Gd-DTPA clearance from the brain. The T1 relaxivity R of Gd-DTPA in the brain ECS was measured to be 5.35 (mM s)−1 in a 2.4 T field. This value is considerably higher than estimations used in studies by other groups. Measurements of brain Gd-DTPA tissue concentrations using MRI and ICP-AES demonstrated a high degree of coincidence. Clearance of Gd-DTPA was minimal at the time point immediately after infusion. These results suggest that the environment of the brain does in fact significantly affect Gd T1 relaxivity, and that MRI can accurately measure contrast agent concentrations when this relaxivity is well characterized.

Educating Our Youngest Citizens

ANYONE who has spent even a little bit of time with a 3- or 4-year-old knows that young children are miniature learning machines. They seem to have an endless capacity to explore, to tinker with things, and to fill the time with their own fantasies, explanations for phenomena, and questions. Their awareness is developmental, researchers confirm. Like the constructivist learning that is fostered in formal schools, their new knowledge develops naturally from what they already know. Their brains, tiny sponges that absorb everything in the early months, are still maturing rapidly, and the experiences of these young children have an impact on how effectively their brains are wired. Most educators are familiar with this area of brain research, and most parents have an intuitive understanding of it. Without the benefit of such scientific research, though, almost 40 years ago, the pioneering Head Start program also put together principles for early childhood development, largely by means of intuition. From the beginning, the Head Start approach was comprehensive and family-oriented. The architects of the program showed an awareness of all the sensory influences on both the social and intellectual growth of young children. They also knew that the family must provide most of these early experiences. So the developers designed Head Start to rely on the creation of good feelings between parents and the programs so that children would have better chances to succeed in school. While much of the debate over the reauthorization of Head Start has focused on governance -- who will control the program and fund it -- the fear of proponents of the program, which serves almost 900,000 poor children, is that the proposed changes would upset the relationships that have meant so much to those served by Head Start. In an earlier column on this subject, I criticized the Bush Administration's move to evaluate Head Start programs on the basis of pre- and posttests of cognitive readiness. Not only are assessment tools for this age group still in the developmental stage themselves, but such a change also narrows Head Start's focus to just one of its goals, cognitive development. And the use of test results alone to decide whether to continue the support of particular Head Start programs can be seen as threatening and certainly undermines the ability of Head Start to develop trust with poor families. This test-based accountability is just another vestige of the one-model-fits-all attitude of the Texans who are in charge of our national education policy. Theirs is a model that apparently hasn't helped improve Texas' SAT scores; the 2003 scores were worse than five years ago and placed Texas near the bottom of the list of all states. To be fair, federal officials do have some statistics on their side that question the effectiveness of Head Start in preparing poor children for academic work in regular school. Compared to similar children not served by Head Start, those who have participated in the program do better on measures of vocabulary, letter recognition, early writing, and early math. In none of these areas, however, do they get out of the lowest quartile. Yet the Bush Administration's focus on a more rigorous curriculum for Head Start reflects the narrow, utilitarian view of education that the K-12 system is now grappling with across the country. Some of the other issues that arose in the debate about Head Start in Congress can be resolved without much controversy. Greater collaboration among state and federal programs would be welcome. (The General Accounting Office found 69 federal programs in nine agencies serving children under 5 years old.) No one disputes the need for better teachers or for successful Head Start programs to share their practices with others. …

Recent advances in MEG studies of the human somatosensory cortex: noninvasive monitoring of cortical plasticity

There have been converging lines of evidence that horizontal collateral fibers of pyramidal cells and inhibitory interneurons in the cortex play important roles in cortical plasticity. In this review article, I will present data suggesting that the activity of the two above neural elements can be recorded noninvasively with magnetoencephalography (MEG). First, I will discuss that fast-spiking GABAergic inhibitory interneurons in area 3b generate somatic high-frequency oscillations (300–900 Hz) to an electrical stimulation of the median nerve. Second, I will describe that horizontal fibers of the pyramidal neurons in area 3b mediate sequential activation of pyramidal cells in layer 3, which is visualized by the dynamic movement of equivalent current dipole (ECD) sources of N20m primary response. These results suggest that the process of cortical reorganization can be monitored by measuring MEG in real time. Finally, I will stress that the above findings were made possible for the first time noninvasively by magnetic recordings, opening up a new area of brain research.

A dynamical system theory approach to cognitive neuroscience

Neural organization contains a wealth of facts from all areas of brain research and provides a useful overview of physiological data for those working outside the immediate field. Furthermore, it gives a good example that the approach of dynamical system theory together with the concepts of cooperative and competitive interaction can be fruitful for an interdisciplinary approach to cognition.

Tyrosine hydroxylase polymorphism and phenotypic heterogeneity in bipolar affective disorder: a multicenter association study.

Tyrosine hydroxylase (TH), the rate-limiting enzyme in the metabolism of catecholamines, is considered a candidate gene in bipolar affective disorder (BPAD) and has been the subject of numerous linkage and association studies. Taken together, most results do not support a major gene effect for the TH gene in BPAD. Genetic and phenotypic heterogeneity may partially explain the difficulty of confirming the exact role of this gene using both association and linkage methods. Four hundred one BPAD patients and 401 unrelated matched controls were recruited within a European collaborative project (BIOMED1 project in the area of brain research, European Community grant number CT 92-1217, project leader: J. Mendlewicz) involving 14 centers for a case-control association study with a tetranucleotide polymorphism in the TH gene. Patients and controls were carefully matched for geographical origin. Phenotypic heterogeneity was considered and subgroup analyses were performed with relevant variables: age at onset, family history, and diagnostic stability. No association was observed in the total sample or for subgroups according to age at onset (n = 172), family history alone (n = 159), or high degree of diagnostic stability and a positive family history (n = 131). The results of this association study do not confirm the possible implication of TH polymorphism in the susceptibility to BPAD.

The demise of Dualism: Toward a convergence of brain research and therapy

Abstract During the past ten years, research into the workings of the brain has yielded much new information. Two areas of brain research that have implications for therapy are those of hemisphericity and clinical neurotransmitters. This article provides a simple introduction to braining functioning in these two areas, summarizes major findings of research in these areas as they impact on death educators and counselors, and describes two therapeutic approaches developed in the past decade which recognize these research findings. Implications for the Cartesian mind-body controversy and for future therapeutic directions are discussed.

Sex differences in brain organization: implications for human communication.

This article reviews current knowledge in two major research domains: sex differences in neuropsychophysiology, and in human communication. An attempt was made to integrate knowledge from several areas of brain research with human communication and to clarify how such a cooperative effort may be beneficial to both fields of study. By combining findings from the area of brain research, a communication paradigm was developed which contends that brain-related sex differences may reside largely in the area of communication of emotion.

Light element abundance in brain nuclei using energy dispersive x-ray analysis and atomic absorption spectrophotometry.

A comparative study of light element (congruent to ion) abundance in isolated brain nuclei, using atomic absorption (AA) spectrophotometry and the scanning electron microscope mode of energy dispersive x-ray analysis (EDXA), demonstrated similar statistical trends in the abundance of Na, Mg, and K at 0 time and at 4 min of total brain ischemia. The obtained correlation strengthens the validity of the comparison of quantitative and semi-quantitative procedures. The EDXA technique represents a new approach to the study of ionic shifts in brain ischemia that may prove useful in other areas of brain research as well.

Literature in the area of brain research

Literature in the area of brain research