Electric Brain

What is as unique as your fingerprints and more revealing than your diary? Hint: Your body is emitting them right now and has been every single day of your life. Brainwaves. Analyzing brainwaves, the imperceptible waves of electricity surging across your scalp, has been possible for nearly a century. But only now are neuroscientists becoming aware of the wealth of information brainwaves hold about a person's life, thoughts, and future health. From the moment a reclusive German doctor discovered waves of electricity radiating from the heads of his patients in the 1920s, brainwaves have sparked astonishment and intrigue, yet the significance of the discovery and its momentous implications have been poorly understood. Now, it is clear that these silent broadcasts can actually reveal a stunning wealth of information about any one of us. In Electric Brain, world-renowned neuroscientist and author R. Douglas Fields takes us on an enthralling journey into the world of brainwaves, detailing how new brain science could fundamentally change society, separating fact from hyperbole along the way. In this eye-opening and in-depth look at the most recent findings in brain science, Fields explores groundbreaking research that shows brainwaves can: • Reveal the type of brain you have—its strengths and weaknesses and your aptitude for learning different types of information • Allow scientists to watch your brain learn, glean your intelligence, and even tell how adventurous you are • Expose hidden dysfunctions—including signifiers of mental illness and neurological disorders • Render your thoughts and transmit them to machines and back from machines into your brain • Meld minds by telepathically transmitting information from one brain to another • Enable individuals to rewire their own brains and improve cognitive performance Written by one of the neuroscientists on the cutting edge of brainwave research, Electric Brain tells a fascinating and obscure story of discovery, explains the latest science, and looks to the future—and the exciting possibilities in store for medicine, technology, and our understanding of ourselves.

The gripping and revelatory story of the dramatic race to merge the human brain with machines Leading neuroscience researchers are racing to unlock the secrets of the mind. On the cusp of decoding brain signals that govern motor skills, they are developing miraculous technologies to enable paraplegics and wounded soldiers to move prosthetic limbs, and the rest of us to manipulate computers and other objects through thought alone. These fiercely competitive scientists are vying for Defense Department and venture capital funding, prestige, and great wealth. Part life-altering cure, part science fiction, part military dream, these cutting-edge brain-computer interfaces promise to improve lives—but also hold the potential to augment soldiers' combat capabilities. In The Brain Electric, Malcolm Gay follows the dramatic emergence of these technologies, taking us behind the scenes into the operating rooms, start-ups, and research labs where the future is unfolding. With access to many of the field's top scientists, Gay illuminates this extraordinary race—where science, medicine, profit, and war converge—for the first time. But this isn't just a story about technology. At the heart of this research is a group of brave, vulnerable patient-volunteers whose lives are given new meaning through participating in these experiments. The Brain Electric asks us to rethink our relationship to technology, our bodies, even consciousness itself—challenging our assumptions about what it means to be human.

It is common to study the electric activity of neurons by measuring the electric potential in the extracellular space of the brain. However, interpreting such measurements requires knowledge of the biophysics underlying the electric signals. Written by leading experts in the field, this volume presents the biophysical foundations of the signals as well as results from long-term research into biophysics-based forward-modeling of extracellular brain signals. This includes applications using the open-source simulation tool LFPy, developed and provided by the authors. Starting with the physical theory of electricity in the brain, this book explains how this theory is used to simulate neuronal activity and the resulting extracellular potentials. Example applications of the theory to model representations of real neural systems are included throughout, making this an invaluable resource for students and scientists who wish to understand the brain through analysis of electric brain signals, using biophysics-based modeling.

Deep brain stimulation (DBS) is an established surgical therapy for movement disorders such as Parkinson’s disease (PD) and essential tremor (ET). A thin electrode is implanted in a predefined area of the brain with the use of stereotactic neurosurgery. In the last few years new DBS electrodes and systems have been developed with possibilities for using more parameters for control of the stimulation volume. In this thesis, simulations using the finite element method (FEM) have been developed and used for investigation of the electric field (EF) extension around different types of DBS lead designs (symmetric, steering) and stimulation modes (voltage, current). The electrode surrounding was represented either with a homogeneous model or a patient-specific model based on individual preoperative magnetic resonance imaging (MRI). The EF was visualized and compared for different lead designs and operating modes. In Paper I, the EF was quantitatively investigated around two lead designs (3389 and 6148) simulated to operate in voltage and current mode under acute and chronic time points following implantation.Simulations showed a major impact on the EF extension between postoperative time points which may explain the clinical decisions to change the stimulation amplitude weeks after implantation. In Paper II, the simulations were expanded to include two leads having steering function (6180, Surestim1) and patient-specific FEM simulations in the zona incerta. It was found that both the heterogeneity of the tissue and the operating mode, influence the EF distribution and that equivalent contact configurations of the leads result in similar EF. The steering mode presented larger volumes in current mode when using equivalent amplitudes. Simulations comparing DBS and intraoperative stimulation test using a microelectrode recording (MER) system (Paper III), showed that several parallel MER leads and the presence of the non-active DBS contacts influence the EF distribution and that the DBS EF volume can cover, but also extend to, other anatomical areas. Paper IV introduces a method for an objective exploitation of intraoperative stimulation test data in order to identify the optimal implant position in the thalamus of the chronic DBS lead. Patient-specific EF simulations were related to the anatomy with the help of brain atlases and the clinical effects which were quantified by accelerometers. The first results indicate that the good clinical effect in ET is due to several structures around the ventral intermediate nucleus of the thalamus.

This work investigates the connections between psychology and physiology. Topics include synaptic sources, electrode placement, choice of reference, volume conduction, power and coherence, projection of scalp potentials to dura surface, dynamic signatures of conscious experience and more.

This open access book describes modern applications of computational human modeling with specific emphasis in the areas of neurology and neuroelectromagnetics, depression and cancer treatments, radio-frequency studies and wireless communications. Special consideration is also given to the use of human modeling to the computational assessment of relevant regulatory and safety requirements. Readers working on applications that may expose human subjects to electromagnetic radiation will benefit from this book’s coverage of the latest developments in computational modelling and human phantom development to assess a given technology’s safety and efficacy in a timely manner. Describes construction and application of computational human models including anatomically detailed and subject specific models; Explains new practices in computational human modeling for neuroelectromagnetics, electromagnetic safety, and exposure evaluations; Includes a survey of modern applications for which computational human models are critical; Describes cellular-level interactions between the human body and electromagnetic fields.

Like all cellular organisms humans run on electricity. Cells work like batteries: slight imbalances of electric charge across cell membranes, caused by ions moving in and out of cells, result in sensation, movement, awareness, and thinking—the things we associate with being alive. Robert Campenot offers an accessible overview of animal electricity.