Cognitive Neuroscience Essay, Research Paper
Cognitive Neuroscience I. IntroductionA. DefinitionB. Topics II. BodyA. Origins1. Localization of Function2. Neuron Doctrine3. Sensation, Association, Perception, and MeaningB. Today1. Sensation2. Perception3. Forming a Decision to Act4. Motor Control5. Learning and MemoryC. Future III. ConclusionA. RestatementB. Conclusion Cognitive Neuroscience is a large field of study. It unites such a range of concepts and techniques from many disciplines that its boundaries are loosely defined. However, in the heart of this study there is only the fundamental question of knowledge and its representation by the brain. Cognitive Neuroscience at its most basic level is the study of information processing. Using this definition, several key questions, which are also classic areas of study, can be seen: How information is acquired Sensation, interpreted Perception/Recognition, stored or modified Learning/Memory, used to cogitate Thinking/Consciousness, used to predict the future Decision Making, used to guide behavior Motor Control, and used to communicate Language. All these realms of Cognitive are intertwined and together begin to give us an understanding of as the most mysterious thing in the world. (William James 1890)The origins of Cognitive Neuroscience go back to George A. Miller, who is considered to be the father of cognitive psychology. It is said that he coined the term in the late seventies during discussions at Rockefeller University. The field can be traced even farther back though. During the nineteenth and early twentieth centuries the physiology of the human body was being recorded. One hot topic during that period was the idea of localization of function. This concept states that different regions of the brain perform different functions. Another discovery of this time was the neuron. The neuron became the new method to characterize the fine structure of the nervous system in exquisite detail. Other important advancements that brought us to the present day were the proposition that things perceived rely not on the external world but on the states of the sense organs and the intermediary nerves. This seemingly obvious concept fueled many debates over this associationism . And so it was from these converging lines of inquiry that Cognitive Science as we know it today began. The current state of it can be summarized through a survey of the processes involved in the acquisition, storage, and use of information by the nervous system: sensation, perception, decision formation, motor control, memory, language, emotions, and consciousness.We acquire information from the world around us through our senses. So, it is not a surprise that sensory processes are among the most thoroughly studied in Cognitive Neuroscience. Acquisition of information about the world around us, by all sensory modalities, starts with a process know as transduction. This occurs when forms of physical energy alter the state of a sensory neuron. In the case of vision, phototranduction occurs in the retina. A specialized set of neurons transforms the photons of the light into electrical impulses of the neural network. All sets of these sensory neural networks have common functions. One of these is contrast detection, or the detection of spatial or temporal variation of the incoming signal. Obviously if there is nothing changing over space or time there is nothing worthy of detection. In this case the networks adapt and there is a resulting loss of sensation (e.g. Snow blindness). Another is the organization of each of the sensory networks. Topographic organization is one of the evolutionary adaptations that the brain benefits from. This is the coincidence of related senses networks connected to one another. Modular and columnar organization is also a common feature of the sensory networks. Each of the sections of the sensory neocortex is subdivided into smaller and smaller parts of the whole. The visual cortex of monkeys alone has been divided into thirty smaller distinguishable parts.
Perception is the ability to derive meaning from the sensory experience in the form of information about structure and causality in the perceiver’s environment, and of the sort necessary to guide behavior. Operationally, we can distinguish sensation from perception by the nature of their internal representations: the former encodes the physical properties of the immediate sensory stimulus (the retinal image, in the case of vision), while the latter reflect the world that likely hides behind the sensory stimulus (the visual scene). Perception is simply an inference about the probable cause of the sensation. Even more amazing is the fact that this inference is a result of previous sensations.Sensory-Perceptual Plasticity states that the processes by which information is acquired and interpreted by the brain are modifiable throughout life and on many time scales. The development of the mammalian nervous system is a complex, multi-staged process, which extends from embryogenesis through early post-natal life. The process starts with the division of cells and the creation of neurons. The patterned brain begins to emerge as the cells migrate to their predestined locations. Finally these neurons begin to create connections with others and these connections are finely tuned during early post-natal life. Another recent development in Cognitive Neuroscience is the work being done on the concept of forming a decision to act. This idea states that the meaning of many sensations can be found solely in their symbolic and experience-dependent mapping onto actions (e.g. green = go, red = stop). These mappings are commonly many-to-one and/or one-to-many (e.g. whistle and green light = go). The selection of the desired outcome based on the sensory stimulus is a learned behavior and the decision part of the process. Motor control is another critical part to the field. Incoming sensory information ultimately leads to action, and actions, in turn, are often initiated in order to acquire additional sensory information. While these systems have often been studied in relative isolation from sensory processes, this sensory-motor loop suggests that they should be viewed as different parts of a processing continuum. Many important research topics have come from this transition, such as spatial learning and motor learning. Learning and memory are two more critical parts to understanding the brain. These neural mechanisms enable information about the world to be stored and retrieved for later use. Memory also exists in various forms, which have been classified on the basis of their relation to other cognitive functions, the degree to which they are explicitly encoded and available for use in a broad range of contexts, and their longevity. All these things apply to Cognitive Neuroscience, which is a thriving new science. Many questions remain unanswered, however, and the applications of new experimental techniques have often raised more new questions than they have answered. Among the major research goals of the next century will be to interpret how these highly differentiated cognitive systems arise in ontogeny, the degree to which they are maturationally constrained, and the nature and the timing of the role of input from the environment in neural development. (Pinker)Cognitive Neuroscience is a broad modern science that answers the seemingly recursive questions of what knowledge is and how it is represented in the brain.