Over 30,000 years old, this paleolithic sculpture of a horse was discovered in the Vogelherd caves of southern Germany. Measuring only 5 cm and carved from mammoth ivory, this elegant sculpture is evidence of early human's capacity for remarkable perceptiveness and creativity. (Reproduced, with permission, from the University of Tübingen, copyright for Vogelherd, Horse. Photo: Hilde Jensen.)
During the second half of the 20th century, the central focus of biology was on the gene. Now in the first half of the 21st century, the central focus of biology has shifted to neural science and specifically to the biology of the mind. We need to understand the processes by which we perceive, act, learn, and remember. How does the brain—an organ weighing only three pounds—conceive of the infinite, discover new knowledge, and produce the remarkable individuality of human thoughts, feelings, and actions? How are these extraordinary mental capabilities distributed within the organ? How are different mental processes localized to specific combinations of regions in the brain? What rules relate the anatomical organization and the cellular physiology of a region to its specific role in mentation? To what extent are mental processes hardwired into the neural architecture of the brain? What do genes contribute to behavior, and how is gene expression in nerve cells regulated by developmental and learning processes? How does experience alter the way the brain processes subsequent events, and to what degree is that processing unconscious? Finally, what is the neural basis underlying neurological and psychiatric disease? In this introductory section of Principles of Neural Science, we attempt to address these questions. In so doing, we describe how neural science is attempting to link the logic of neural circuitry to the mind—how the activities of nerve cells within defined, neural circuits are related to the complexity of mental processes.
In the last several decades, technological advances have opened new horizons for the scientific study of the brain. Today, it is possible to link the molecular dynamics of interconnected circuits of cells to the internal representations of perceptual and motor acts in the brain and to relate these internal mechanisms to observable behavior. New imaging techniques permit us to visualize the human brain in action—to identify specific regions of the brain associated with particular modes of thinking and feeling and their patterns of interconnections.
In the first part of this book, we consider the degree to which mental functions can be located in specific regions of the brain. We also examine the extent to which the behavior so localized can be understood in terms of the properties of individual nerve cells and their interconnections in their specific region of the brain. In the later parts of the book, we examine in detail the cognitive and affective functions of the brain: perception, action, motivation, emotion, development, learning, and memory.
The human brain is a network of ...