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Transcranial Magnetic Stimulation (TMS) is a non-invasive neurostimulatory and neuromodulatory technique increasingly utilized in clinics and research laboratories around the world. Exploiting the properties of electromagnetic induction, TMS can transiently or lastingly modulate cortical excitability (either increasing or decreasing it) via the application of localized, time-varying magnetic field pulses. Until recently, the ethical considerations guiding the practice and application of TMS were largely concerned with aspects of subject safety and patient population in controlled clinical trials or experimental protocols. While safety remains of paramount importance, the recent approval by the Food and Drug Administration (FDA) in the United States of the Neuronetics NeuroStar. TMS device for the treatment of certain patients with medication-resistant depression has engendered a surfeit of unexamined ethical concerns. Some of these are nuanced elaborations of previously-addressed issues, but others-such as matters of training and certification, marketing, and possible off-label use-represent recent and complex concerns. These issues are likely to be relevant to a rapidly-growing number of patients, as the possible uses for TMS and other developing forms of brain stimulation (both invasive and non-invasive) expand to include the treatment of a wide range of neuropsychiatric conditions. This chapter provides an overview of these emerging issues and discusses ways in which some of them might best be addressed.

This chapter shows that short lasting, reversible functional lesions can be safely produced in healthy humans, too, by means of transcranial magnetic stimulation (TMS). TMS thus establishes a novel method to associate animal studies with those on patients and to create a new discipline, experimental neuropsychology, in humans. The role of the parietal cortex in visual attention is a question of central concern. TMS has many uses in the vision sciences that demand the attention of researchers. The impact of learning and plasticity are good paradigms for studying cortical change and the potential for combining TMS with other neuroimaging techniques will widen the scope of its utility in the study of vision.

The sixth part of the book reviews applications of the described approach to atypical and changing movements. It starts with a discussion of the notion of normality and its applicability to motor synergies. An argument is made that “normal synergies” do not exist. Further, plasticity within the central nervous system is discussed with a Digression on transcranial magnetic stimulation, a commonly used tool to study brain plasticity. The next three sections within this part deal with effects of healthy aging, atypical development (Down syndrome), and neurological disorder (stroke) on movement patterns and motor synergies. Finally, the effects of practice on motor synergies are discussed with examples that document two stages in motor learning, the creation and strengthening of appropriate synergies, and the apparent weakening of the synergies when movement patterns are optimized with respect to other factors such as energy expenditure, fatigue, esthetics, etc.

It is clear that management of tinnitus requires alterations of neural activity in the CNS. The neural substrates of tinnitus suggest various approaches to modify neural processing and change the properties of tinnitus and so obtain some alleviation of it. The interventions for tinnitus include compensation of missing activity in the output of the cochlea via specially tailored acoustic environments, and via amplification of environmental sounds in the hearing frequency range, i.e., by hearing aids. In deaf persons the missing sounds can be applied by a cochlear implant. A non-invasive method that may be useful to suppress tinnitus is based on trans cranial magnetic stimulation. Tinnitus Retraining Therapy and cognitive behavioral therapy are effective in reducing the annoyance and impact of tinnitus. Pharmacological approaches have so far produced disappointing results in humans and the somewhat more promising findings in animals.

The seventh part of this book deals with possible neurophysiological mechanisms involved in motor synergies. It starts with a discussion of the structure-function controversy in neurophysiology. Then, it presents reviews of the literature on the role in synergy formation of different structures within the central nervous system such as the spinal cord, the cerebellum, the basal ganglia, and the cortex of the large hemispheres. The review covers animal studies, studies of patients with different neurological disorders, and studies of healthy persons. Studies using transcranial magnetic stimulation are reviewed with respect to the equilibrium-point hypothesis of movement control. Relations between neuronal population vectors and performance variables are discussed. There is one more Digression in this part addressing the issue of localization of functions within brain structures.

This chapter describes how electroencephalography (EEG) was the first “objective” measure to be used to infer asymmetry of neuronal firing in the two hemispheres, and also considers its similarity with magnetoencephalography (MEG). The high temporal resolution of EEG and MEG allows the recording of brain rhythms, the use of which for the assessment of hemispheric activation asymmetries is investigated. EEG and MEG offer valuable supports for noninvasive language assessment in healthy and difficult populations. The chapter suggests that tryptophan-depletion-induced changes in frontal EEG asymmetry may offer a more sensitive indicator of risk for imminent depression than symptomatic response to tryptophan depletion. The potential of EEG and MEG in the investigation of hemispheric asymmetries can be improved by integrating them with other techniques, such as functional magnetic resonance imaging (fMRI), positron emission tomography, and transcranial magnetic stimulation.

The application of neurotechnologies in the Israeli context concentrates key economic, social, and ideological forces. The Israeli brain research and technology landscape excels in two main areas: the brain–machine interface and therapeutic neurostimulation. However, concomitant ethical reflection at important scientific research institutes is relatively deficient. Seeking to redress this deficiency, this chapter provides a reflection on the moral context of cognitive enhancement technologies in Israel through focusing on the innovative application of transcranial magnetic stimulation (TMS) by two Israeli companies, Brainsway and Neuronix. This analysis provides the basis for reflection on whether the Israeli context provides a particular cultural or historical experience that informs, or even should inform, the development and application of cognitive enhancement technologies. The author argues that the Israeli cognitive enhancement enterprise covers the tension between the industrial impetus for technological innovation and the Jewish moral imperative to heal a broken world (tikkun olam).

The phrase “brain stimulation” conjures a vast range of emotions from different segments of society, with fear or apprehension being a common and understandable reaction. The brain reigns as the control center for breathing, eating, and moving, to relating, feeling, and understanding. Changing these functions with electricity or magnetism can fundamentally change how we interact with our environment and one another. Even if this change is beneficial, there can still be a cause for concern. Brain stimulation technologies are currently used for several therapeutic purposes, but they also have the potential for enhancing those without an illness. Enjoying the advantages that enhancement might bring could be intoxicating, as can be the case with having great wealth, prestige, beauty, or athletic ability. This chapter explores the implications of such possible enhancement uses, as well as the notion that it could create a dependence on the stimulation akin to an addiction.

The discovery of mirror neurons in the macaque monkey, or neurons in the premotor cortex that respond during the execution and perception of motor acts, established the first neurophysiological integration of action and perception. Subsequent research has identified and characterized a similar mirror neuron system in human observers that is experience-dependent in that it responds most strongly during the observation of actions that fall within the observer’s motor repertoire. Furthermore, evidence is reviewed that indicates that the mirror neuron system plays a key role in the understanding of other people’s intentions from their actions.

This chapter explores the applications of magnetoencephalography (MEG) to the study of the brain mechanisms for language functions. Language mapping with MEG has proved helpful in presurgical estimates of the location and extent of language-related cortex as well as in the intraoperative identification of these cortical patches. In fact, in several neurosurgical centers around the world, such assessments are part of the protocol of surgical interventions, especially in the case of epilepsy. Moreover, MEG alone or in combination with other imaging methods, such as functional magnetic resonance imaging (fMRI) and transcranial magnetic stimulation (TMS), is extensively used for the testing of alternative models of cortical organization for language in normal populations. However, applications of MEG to language mapping face most of the limitations that characterize brain imaging techniques relying on hemodynamic measures. Perhaps the most fundamental of these limitations concerns the degree of specificity of results: Activation profiles feature brain regions that may not be indispensable for a particular target function. This problem is particularly serious in the case of language mapping and to a lesser degree in motor cortex mapping.

The study of visual consciousness relies on methodological approaches such as psychophysical, brain-imaging/recording, objective behavioral, and subjective descriptive ones. However, because the conscious registration of a stimulus requires its prior processing for many tens or several hundreds of milliseconds at unconscious levels, an overarching methodological approach is the microtemporal approach. After a stimulus attains registration in consciousness, it also can be processed at later and higher conscious levels. The microgenetic approach has been useful especially in studying visual masking. The microgenetic approach is premised on an analogy between microgenetic “evolution” of the processing of a stimulus and the macroevolutions of consciousness on phylogenetic and ontogenetic time scales. The microtemproal approach strives to delineate the processing at these various unconscious and conscious stages and levels, using, for example, simple and choice reaction times, visual masking techniques, transcranial magnetic stimulation, electroencephalographic recordings, magnetoencephalographic recordings, as well as eclectrophysiological recordings of individual neurons.

Although the visibility of the form and surface features of a temporally prior stimulus can be completely suppressed by a temporally following one, some pre- or non-conscious processing of the former nonetheless survives perceptual suppression. Among these are neural processes that enable it to be located in the visual field, to contribute to motion perception, and to act, in turn, as a mask of a third stimulus. Moreover, a masked stimulus can pre-consciously prime feature-selective responses to the form or color of a probe stimulus following the following masked one. The suppressive effects of visual masking can be systematically related to other techniques of rendering stimuli invisible, such as binocular-rivalry suppression or application to transcranial magnetic stimulation to the occipital pole.

This chapter translates the theoretical principles illustrated in Chapter 5 into an empirical measure that can be applied to real human brains. It explains how transcranial magnetic stimulation (TMS) and simultaneous electroencephalography (EEG) can be employed to derive a surrogate measure of information integration, the perturbational complexity index (PCI). By describing the results of a series of experiments, it demonstrates that PCI can discriminate with very high accuracy between consciousness and unconsciousness, across many different conditions, ranging from wakefulness to sleep, dreaming esthesia and coma patients. The chapter ends by suggesting that principled measures of brain complexity can also help understanding the mechanisms of loss and recovery of consciousness in both physiological and pathological conditions.

The chapter first describes the policy options that are available to policy makers to regulate research, marketing, and individual use of cognitive enhancement technologies. It then examines the current legal landscape regarding these technologies and the range of policy issues they raise. In order to illuminate the difficulties and subtleties facing policy makers, the chapter then analyzes the policy options pertinent to a range of drugs, devices, and procedures used for enhancement Although all potential enhancement techniques elicit similar broad policy concerns, they differ widely in efficacy, potential usage, and risk. The chapter also discusses competing ethical frameworks that might guide public policy on cognitive enhancement drugs or devices and examines what, if any, boundaries of social justification there are for mandatory use, regulations, economic incentives and disincentives, or prohibition of cognitive enhancement technologies.

This chapter reviews recent evidence of top-down control over the motor cortex during action selection under conflict and action inhibition and describes the role of the pre-supplementary motor area (pre-SMA) and right inferior frontal gyrus (rIFG) in mediating this control. It focuses on the insights gained from transcranial magnetic stimulation (TMS) of action reprogramming. The chapter also looks at the interactions within the frontal lobe and discusses how they influence top-down control.

This chapter discusses the close connection between numbers and space. First, it demonstrates the automaticity of numerical-spatial interactions via the spatial numerical association of response codes (SNARC) effect. It then reviews recent behavioral, patient, and transcranial magnetic stimulation (TMS) studies that suggest that numerical manipulations are dependent upon intact spatial representations. Studies that support the role of the parietal cortex in number processing are also examined.

Imaging is one of the major tools for neuroscience but it should be seen against the background of neuroscience in general. The brain can be studied by charting its connections, by recording its activity, or by intervening in its workings. In animals the connections can be demonstrated by tracer techniques, recordings can be taken of the activity of single cells, and lesions can be placed in selective cytoarchitectonic areas. Brain imaging provides methods for studying the human brain. Connections can be inferred using diffusion weighted imaging, activations can be recorded using functional magnetic resonance imaging, and transcranial magnetic brain stimulation can be used to intervene. The development of these methods has provided the means for studying the neural basis of cognitive abilities, including those that are unique to the human brain.

In this dialogue, the Harvard neuroscientist, Alvaro Pascual-Leone initially reflects on the importance of ‘unlearning’ and forgetting. He then gives a detailed explanation of, and how he carries out, transcraneal magnetic stimulation (TMS) and how he uses this technology to fight diseases, as well as explaining his experiments on inattentional blindness. He then discusses how the brain acts as a hypothesis generator and whether the brain, the mind and the soul are different things or not. Later reflect on the questions: Is the mind and what we are a consequence of the brain’s structure?  Do changes in the brain change our reality? And why are a person’s dreams important? Then he explains how freewill and decision-making work from the brain, and relates his vision of intelligence and where it may be generated from, explaining the differences between the mind and the brain. He finally reflects on what is known so far about the brain’s “dark energy” and the way we are continuously being surprised by the wonders of the brain's plasticity.

This chapter describes neuroimaging as a tool for functionally decomposing cognitive processes. It looks into neuroimaging’s contribution to understanding and explaining cognitive mechanisms, and discusses the use and abuse of neuroimaging. The chapter presents a critique of neuroimaging studies as well as an analysis of such studies—for example, single-cell recording and transcranial magnetic stimulation. These studies demonstrate the insignificant contribution of neuroimaging to the maturation of cognitive theories.