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Recent advances in our understanding of the human brain suggest that adolescence is a unique period of development during which both environmental and genetic influences can leave a lasting impression. To advance the goal of integrating brain and prevention science, two areas of research which do not usually communicate with one another, the Annenberg Public Policy Center's Adolescent Risk Communication Institute held a conference with the purpose of producing an integrated book on this interdisciplinary area. Contributors were asked to address two questions: What neurodevelopmental processes in children and adolescents could be altered so that mental disorders might be prevented? And what interventions or life experiences might be able to introduce such changes? The book deals with the following: biological and social universals in development; characteristics of brain and behavior in development; effects of early maltreatment and stress on brain development; effects of stress and other environmental influences during adolescence on brain development; and reversible orders of brain development.

What is attention? How does it go wrong? Do attention deficits arise from genes or from the environment? Can we cure it with drugs or training? Are there disorders of attention other than deficit disorders? The past decade has seen a burgeoning of research on the subject of attention. This research has been facilitated by advances on several fronts: New methods are now available for viewing brain activity in real time, there is expanding information on the complexities of the biochemistry of neural activity, individual genes can be isolated and their functions identified, analysis of the component processes included under the broad umbrella of “attention” has become increasingly sophisticated, and ingenious methods have been devised for measuring typical and atypical development of these processes, from infancy into childhood, and then into adulthood. This book is concerned with attention and its development, both typical and atypical, particularly in disorders with a known genetic etiology or assumed genetic linkage. Tremendous advances across seemingly diverse disciplines — molecular genetics, pediatric neurology, child psychiatry, developmental cognitive neuroscience, and education s— have culminated in a wealth of new methods for elucidating disorders at multiple levels, possibly paving the way for new treatment options. The book uses three specific-yet-interlinking levels of analysis: genetic blueprint (genotype), the developing brain, and the behavioral-cognitive outcomes (phenotype), as the basis for charting the attention profiles of six well-documented neurodevelopmental disorders: ADHD, autism, fragile X syndrome, Down syndrome, Williams syndrome, and 22_q11 deletion syndrome.

Sound is dynamic and as such has temporal and spectral content. The auditory system extracts the spectral aspects and the temporal ones in parallel in the cochlea and auditory nerve. For frequencies below about 1.5 kHz, the spectral and temporal representations of sound are potentially redundant and both represent the pitch of speech and music. Auditory temporal processing determines our understanding of speech, our appreciation of music, being able to localize a sound source, and to listen to a person in a noisy crowd. The underlying basic capabilities of the auditory system include precise representation of sound onsets and offsets, representing gap durations in sound, and being able to code fast amplitude- and frequency- modulations of sound. The co-occurrence of such onsets and modulations of sound determine auditory objects and allow separating those from other auditory streams. Problems with precise temporal representations of sound occur in auditory neuropathy and multiple sclerosis and lead to a mismatch between auditory sensitivity and speech discrimination. In dyslexia, specific language impairment and auditory processing disorders, similar problems occur early in life and set up additional cognitive speech processing problems. General neurological disorders such as autism, schizophrenia and epilepsy, display temporal processing deficits, generally though as a result of local and global neural synchrony problems. These synchrony problems are reflected in various cortical rhythm abnormalities and lead to cognitive dysfunctions. They also present auditory temporal processing problems, particularly in the amplitude modulation domain.

This book presents a simple description of the biological mechanisms that are involved in the determination of sexual orientation in animals and also presumably in humans. Using scientific studies published over the last few decades, it argues that sexual orientation, both homosexual and heterosexual, is under the control of embryonic endocrine and genetic phenomena in which there is little room for individual choice. The book begins with animal studies of the hormonal and neural mechanisms that control the so-called instinctive behaviors and analyzes how this animal work may potentially apply to humans. The book does not focus exclusively on homosexuality, however. Instead, the book acts as a broader guide to the biological basis of sexual orientation, and also discusses important gender differences that may influence sexual orientation.

What is intelligence? How did it begin and evolve to human intelligence? Does a high level of biological intelligence require a complex brain? Can man-made machines be truly intelligent? Is artificial intelligence (AI) fundamentally different from human intelligence? Rapid expansion of AI applications has made these questions pressing. To better prepare for the future society and its technology, including how the use of AI will impact our lives, it is essential to understand the biological root and limits of human intelligence. After systematically reviewing biological and computational underpinnings of decision-making and intelligent behaviors, this book proposes that true intelligence requires life.

This is the first book about both normal development of the nervous system and how early exposure to alcohol and nicotine interferes with this development. The developing nervous system is highly dynamic and vulnerable to genetic and epigenetic factors that can be additive or synergistic. Disruption of normal brain development leads to an array of developmental disorders. One of the most common of these is mental retardation, the prime cause of which is prenatal exposure to alcohol. As chapters in this book show, alcohol has direct effects on the developing neural system and it affects genetic regulation. Another common neurotoxin is nicotine, and it is discussed in this book for three reasons: (1) the number of adolescents who smoke cigarettes is rising in some populations; (2) prenatal exposure to nicotine affects neurotransmitter systems that are critical for normal brain development and cognition; and (3) prenatal exposure to nicotine is often accompanied by prenatal exposure to alcohol. The mature brain is the culmination of an orderly sequence of basic ontogenetic processes—cell proliferation, migration, differentiation, and death. Neural stem cells and progenitors proliferate in discrete sites; then, young neurons migrate long distances to their residences where they form neural networks. During this sequence many immature cells die, presumably eliminating unsuitable or non-competitive cells. Each process is regulated by genetic and environmental factors. When this regulation goes awry, a dysmorphic and dysfunctional brain results. Though this can be tragic in clinical settings, in experimental contexts it provides keen insight into normal brain development. The book is divided into three parts. The first describes neural ontogeny in the normal brain. The second and third deal with the consequences of early exposure to alcohol and nicotine. Though there are similarities in the effects of these two toxins, there are also intriguing differences. The commonalities reflect the plasticity and resilience of the developing brain while the differences point to the targeted effects of the two toxins. Exploring these effects brings a richer appreciation of brain development.

How important are biological factors, such as hormones, in shaping our sexual destinies? This book brings social developmental, biological, and clinical psychological perspectives to bear on the factors that shape our development as male or female and that cause individuals within each sex to differ from one another in sex-related behaviors. Topics covered include sexual orientation, childhood play; spatial, mathematical, and verbal abilities; nurturance, aggression, dominance, handedness, brain structure, and gender identity.

Does the brain create the mind, or is some external entity involved? In addressing this hard problem of consciousness, we face a central human challenge: what do we really know and how do we know it? Tentative answers in this book follow from a synthesis of profound ideas, borrowed from philosophy, religion, politics, economics, neuroscience, physics, mathematics, and cosmology, the knowledge structures supporting our meager grasp of reality. This search for new links in the web of human knowledge extends in many directions: the shadows of our thought processes revealed by brain imagining, brains treated as complex adaptive systems that reveal fractal-like behavior in the brain's nested hierarchy, resonant interactions facilitating functional connections in brain tissue, probability and entropy as measures of human ignorance, fundamental limits on human knowledge, and the central role played by information in both brains and physical systems. The author discusses the possibility of deep connections between relativity, quantum mechanics, thermodynamics, and consciousness; all entities involved with fundamental information barriers. This study elaborates on possible new links in this nested web of human knowledge that may tell us something new about the nature and origins of consciousness. In the end, does the brain create the mind? Or is the mind already out there?

Scientific research shows how experience shapes the organization of the human brain through mechanisms of neural plasticity, which capture the information of the world within the connections among neurons. To understand this plasticity, it is important to look to the developmental mechanisms through which the brain grows from a single cell in embryogenesis to achieve the complex architecture of the human brain. The process of neural morphogenesis involves exuberant formation of neuronal connections, and then subtractive elimination of unused connections. This process is continued after birth, providing the neural plasticity of learning that allows cognitive development in infancy and childhood. Recognizing this continuity suggests an interesting insight—cognition is a reflection of neural development throughout the life span. This book examines the embryonic development of the brain to appreciate the dimensions of developmental momentum that shape the neural and psychological development of our lives. Human brain embryogenesis involves gradients of trophic factors that guide the migration of neurons from ventricular proliferative zones to organize the architecture of the cerebral hemispheres. The architecture of human cognition involves a functional differentiation of dorsal (pyramidal) and ventral (granular) corticolimbic divisions. This differentiation is a defining feature of not just human but mammalian neuroanatomy. The separation of pyramidal and granular cortical architectures appeared with the evolution of the six-layered mammalian neocortex from the three-layered primitive general cortex of reptiles and amphibians. The functional differentiation of the dorsal and ventral divisions of the cerebral hemispheres has been shown to be integral to multiple levels of psychological function, from elementary motivation to the most complex forms of executive self-regulation.

Until very recently, our knowledge about the neural basis of cognitive aging was based on two disciplines that had very little contact with each other. Whereas the neuroscience of aging investigated the effects of aging on the brain independently of age-related changes in cognition, the cognitive psychology of aging investigated the effects of aging on cognition independently of age-related changes in the brain. The lack of communication between these two disciplines is currently being addressed by an increasing number of studies that focus on the relationships between cognitive aging and cerebral aging. This rapidly growing body of research has come to constitute a new discipline, which may be called cognitive neuroscience of aging. The goal of this book is to introduce this new discipline. This book is divided into four main sections. The first section describes non-invasive measures of cerebral aging, including structural (e.g., volumetric MRI), chemical (e.g., dopamine PET), electrophysiological (e.g., ERPs), and hemodynamic (e.g., fMRI), and discusses how they can be linked to behavioral measures of cognitive aging. The second section reviews evidence for the effects of aging on neural activity during different cognitive functions, including perception and attention, imagery, working memory, long-term memory, and prospective memory. The third section focuses on clinical and applied topics, such as the distinction between healthy aging and Alzheimer's disease and the use of cognitive training to ameliorate age-related cognitive decline. The last section describes theories that relate cognitive and cerebral aging, including models accounting for functional neuroimaging evidence and models supported by computer simulations.

This book reviews a number of clinical neuropsychiatric conditions in which brain oscillations play an essential role. It discusses how the intrinsic properties of neurons, and the interactions between neurons – mediated by both chemical synapses and by gap junctions – can lead to oscillations in populations of cells. The discussion is based largely on data derived from in vitro systems (hippocampus, cerebral and cerebellar cortex) and from network modeling. Finally, the book considers how brain oscillations can provide insight into normal brain function as well as pathophysiology.

Neuronal responses to identically presented stimuli are extremely variable. This variability has in the past often been regarded as “noise.” At the single neuron level, interspike interval (ISI) histograms constructed during either spontaneous or stimulus-evoked activity reveal a Poisson type distribution. These observations have been taken as evidence that neurons are intrinsically “noisy” in their firing properties. More recent attempts to measure the information content of single neuron spike trains have revealed that a surprising amount of information can be coded in spike trains even in the presence of trial-to-trial variability. Multiple single unit recording experiments have suggested that variability formerly attributed to noise in single cell recordings may instead simply reflect system-wide changes in cellular response properties. These observations raise the possibility that, at least at the level of neuronal coding, the variability seen in single neuron responses may not simply reflect an underlying noisy process. They further raise the very distinct possibility that noise may in fact contain real, meaningful information which is available for the nervous system in information processing. To understand how neurons work in concert to bring about coherent behavior and its breakdown in disease, neuroscientists now routinely record simultaneously from hundreds of different neurons and from different brain areas, and then attempt to evaluate the network activities by computing various interdependence measures including cross correlation, phase synchronization, and spectral coherence. This book examines neuronal variability from theoretical, experimental, and clinical perspectives.

The concepts of dynamical systems have been influential in the way psychologists, cognitive scientists, and neuroscientists think about sensorimotor behavior and its development. This book introduces the reader to a new approach to understanding cognitive and neural dynamics using the concepts of dynamic field theory (DFT), a theoretical framework of embodied cognition that is firmly grounded in neurophysiology. Dynamic neural fields are formalizations of how neural populations represent the continuous dimensions that characterize perceptual features, movements, and cognitive decisions. Activation patterns in neural fields evolve continuously in time under the influence of inputs as well as strong neuronal interaction. Elementary forms of cognition such as detection, selection, and working memory emerge in DFT from dynamical instabilities. The concepts of DFT establish links between brain and behavior, helping to define paradigms where signatures of specific neural mechanisms can be observed. These paradigms can be modeled with dynamic neural fields, deriving testable predictions and providing quantitative accounts of behavior.

What produces emotions? Why do we have emotions? How do we have emotions? Why do emotional states feel like something? What is the relation between emotion, and reward value, and subjective feelings of pleasure? How is the value of a good represented in the brain? Will neuroeconomics replace classical microeconomics? How does the brain implement decision-making? Are gene-defined rewards and emotions in the interests of the genes, and does rational multistep planning enable us to go beyond selfish genes to long-term plans and social contracts in the interests of the individual? This book seeks explanations of emotion and decision-making by considering these questions.

Clinical observations and animal experiments have shaped the prevailing view of human memory. This doctrine holds that the “medial temporal lobe” subserves one memory system for explicit or declarative memories while the basal ganglia subserves a separate memory system for implicit or procedural memories, including habits. Cortical areas outside the medial temporal lobe are said to function in perception, motor control, attention, or other aspects of executive function, but not in memory. The Evolution of Memory Systems advances dramatically different ideas on all counts. It proposes that several memory systems arose during evolution and that they did so for the same general reason: to transcend problems and exploit opportunities encountered by specific ancestors at particular times and places in the distant past. Instead of classifying cortical areas in terms of mutually exclusive perception, executive, or memory functions, the authors show that all cortical areas contribute to memory and that they do so in their own ways—using specialized neural representations. The book also presents a proposal on the evolution of explicit memory. According to this idea, explicit (declarative) memory depends on interactions between a phylogenetically ancient navigation system and a representational system that evolved in humans to represent one’s self and others. As a result, people embed representations of themselves into the events they experience and the facts they learn, which leads to the perception of participating in events and knowing facts.

The cerebellum is an intriguing component of the brain. In humans, it occupies only 10% of the brain volume, yet has approximately 69 billion neurons, i.e. 80% of the nerve cells in the brain! A functional understanding of the cerebellum is enabled by the fact it is made up of a repeated array of neuronal networks, or motifs, each of which may function as an adaptive filter. In short, the cerebellum can be thought of a massive array of adaptive filters that can contribute across a wide range of brain tasks and functionality. Understanding the evolutionary origins of the cerebellum supports this overview of cerebellar function. The cerebellum first arose in jawed vertebrates such as sharks, and sharks have an additional cerebellum-like structure that clearly works as an adaptive filter. The function of shark cerebellum-like structures is to discriminate ‘self’ from ‘other’ in sensory inputs. With the evolution of the true cerebellum, the adaptive filter functionality was adopted for motor control and paved the way for athleticism and movement finesse that we see in swimming, running, climbing, and flying vertebrates. Distinguishing ‘self’ from ‘other’ in our interactions with the physical world extends to the identified role of the cerebellum in model systems, but also into some aspects of cognitive function. It is this view of the cerebellar function that defines the cerebellar sense of self.

This book describes current information about the three areas mentioned in the title: neuronal migration and development, degenerative brain diseases, and neural plasticity and regeneration. The chapters in the first section of the book examine the cellular and molecular mechanisms by which neurons are generated from the ventricular zone in the forebrain and migrate to their destinations in the cerebral cortex. This description of cortical development also includes discussions of the Cajal-Retzius cell. Another chapter provides insight about the development of another forebrain region, the hypothalamus. The remaining chapters of the first section examine the clinical relevance of brain development in certain disease states in humans. The second section begins with details about the dopaminergic neurons in the substantia niger and their loss in Parkinson's disease. Two subsequent chapters describe changes in brain aging, including changes in the numbers of myelinated axons. Other chapters in this section describe important cellular and molecular changes found in Alzheimer's disease and human epilepsy. The last section begins with a chapter on how the brain's own stem cells provide newly generated neurons to the hippocampal dentate gyrus and how these neurons become integrated into neural circuitry. Then two chapters examine some of the neuroplastic changes that take place in motor and sensory cortices of awake behaving primates. The concluding two chapters address the issue of regeneration in the injured spinal cord and the factors that may contribute to its success.

With the advent of methods from behavioral genetics, molecular biology, and cognitive neuroscience, affective science has recently started to approach genetic influences on emotion, and the underlying intermediate neural mechanisms through which genes and experience shape emotion. The aim of this volume is to offer a comprehensive account of current research in the genetics of emotion, written by leading researchers, with extensive sections focused on methods, intermediate phenotypes, and clinical and translational work. Major methodological approaches are reviewed in the first section, including the two traditional “workhorses” in the field, twin studies and gene–environment interaction studies, and the more recently developed epigenetic modification assays, genome-wide association studies, and optogenetic methods. Parts 2 and 3 focus on a variety of psychological (e.g. fear conditioning, emotional action control, emotion regulation, emotional memory, decision-making) and biological (e.g. neural activity assessed using functional neuroimaging, electroencephalography, and psychophysiological methods; telomere length) mechanisms, respectively, that may be viewed as intermediate phenotypes in the pathways between genes and emotional experience. Part 4 concentrates on the genetics of emotional dysregulation in neuropsychiatric disorders (e.g. post-traumatic stress disorder, eating disorders, obsessive–compulsive disorder, Tourette’s syndrome), including factors contributing to the risk and persistence of these disorders (e.g. child maltreatment, personality, emotional resilience, impulsivity). In addition, two chapters in Part 4 review genetic influences on the response to psychotherapy (i.e. therapygenetics) and pharmacological interventions (i.e. pharmacogenetics) in anxiety and affective disorders.

Since the 1980s, MRI scanners have told us much about brain function and played an important role in the clinical diagnosis of a number of conditions — both in the brain and the rest of the body. Their routine use has made the diagnosis of brain tumours and brain damage both quicker and more accurate. However, some neuroscientific advances, in particular those that relate specifically to the mind have provoked excitement and discussion in a number of disciplines. One of the most thought provoking developments in recent neuroscience has been the progress made with ‘mind-reading’. There seems nothing more private than one's thoughts, some of which we might choose to share with others, and some not. Yet, until now, little has been published on the particular issue of privacy in relation to ‘brain’ or ‘mind’ reading. This book presents an interdisciplinary account of the neuroscientific evidence on ‘mind reading’, as well as a thorough analysis of both legal and moral accounts of privacy. The book considers such issues as the use of imaging to detect awareness in those considered to be in a vegetative state. It looks at issues of mental imaging and national security, the neurobiology of violence, and issues regarding diminished responsibility in criminals, and thus reduced punishment. It also considers how the use of neuroimaging can and should be regulated.