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Introduction to Cognitive Neuroscience
Cognitive neuroscience is an academic field concerned with the scientific study of biological substrates underlying cognition[1], with a specific focus on the neural substrates of mental processes. It addresses the questions of how psychological/cognitive functions are produced by the brain. Cognitive neuroscience is a branch of both psychology and neuroscience, overlapping with disciplines such as physiological psychology, neuroscience, cognitive psychology and neuropsychology [2]. Cognitive neuroscience relies upon theories in cognitive science coupled with evidence from neuropsychology, neuroscience and computational modelling[2].
Due to its multidisciplinary nature cognitive neuroscientists may have various backgrounds. Other than the associated disciplines just mentioned, cognitive neuroscientists may have backgrounds in these disciplines: neurobiology, psychiatry, neurology, physics, computer science, linguistics, philosophy and mathematics.
Methods employed in cognitive neuroscience include experimental paradigms from psychophysics and cognitive psychology, functional neuroimaging, electrophysiology, cognitive genomics and behavioral genetics. Studies of patients with cognitive deficits due to brain lesions constitute an important aspect of cognitive neuroscience (see neuropsychology). Theoretical approaches include computational neuroscience and cognitive psychology.
Historical Origins
Central to cognitive neuroscience is the view that specific cognitive functions correspond to specific areas of the brain. This view has emerged from various theories. The phrenologist movement failed to supply a scientific basis for their theories and has since been rejected. However, the phrenologist main assumption that specific areas of the brain correspond to specific functions still applies, although today measurements at the skull are carried out electrophysiologically and what is being measured has more to do with the brain than the appearance of the outer skull.
Phrenology
Main article: Phrenology
The first roots of cognitive neuroscience lie in phrenology, which was a pseudoscientific approach that claimed that behavior could be determined by the shape of the scalp. In the early 19th century, Franz Joseph Gall and J. G. Spurzheim believed that the human brain was localized into approximately 35 different sections. In his book, The Anatomy and Physiology of the Nervous System in General, and of the Brain in Particular, Gall claimed that a larger bump in one of these areas meant that that area of the brain was used more frequently by that person. This theory gained significant public attention, leading to the publication of phrenology journals and the creation of phrenometers, which measured the bumps on a human subject's head.
Aggregate field View
Pierre Flourens, a French experimental psychologist, was one of many scientists that challenged the views of the phrenologists. Through his study of living rabbits and pigeons, he discovered that lesions to particular areas of the brain produced no discernible change in behavior. He proposed the theory that the brain is an aggregate field, meaning that different areas of the brain participated in behavior.
Localizationist View
Studies performed in Europe by scientists such as John Hughlings Jackson caused the localizationist view to re-emerge as the primary view of behavior. Jackson studied patients with brain damage, particularly those with epilepsy. He discovered that the epileptic patients often made the same clonic and tonic movements of muscle during their seizures, leading Jackson to believe that they must be occurring in the same place every time. Jackson proposed that specific functions were localized to specific areas of the brain[3], which was critical to future understanding of the brain lobes.
The Emergence of Neuropsychology
Broca's area and Wernicke's area.
In 1861, French neurologist Paul Broca came across a man who was able to understand language but unable to speak. The man could only produce the sound "tan". It was later discovered that the man had damage to an area of his left frontal lobe now known as Broca's area. Carl Wernicke, a German neurologist, found a similar patient, except that this patient could speak fluently but non-sensibly. The patient had been the victim of a stroke, and could not understand spoken or written language. This patient had a lesion in the area where the left parietal and temporal lobes meet, now known as Wernicke's area. These cases strongly supported the localizationists' views, because a lesion caused a specific behavioral change in both of these patients. The studies of Broca and Wernicke spawned a new research field, which studies the relationship between psychological phenomena and lesions (or otherwise induced deficits) of the brain: neuropsychology.
Mapping the Brain
In 1870, German physicians Eduard Hitzig and Gustav Fritsch published their findings about the behavior of animals. Hitzig and Fritsch ran an electrical current through the cerebral cortex of a dog, causing the dog to produce characteristic movements based on where the current was applied. Since different areas produced different movements, the physicians concluded that behavior was rooted at the cellular level. German neuroanatomist Korbinian Brodmann used tissue staining techniques developed by Franz Nissl to see the different types of cells in the brain. Though this study, Brodmann concluded in 1909 that the human brain consisted of fifty-two distinct areas, now named Brodmann areas. Many of Brodmann's distinctions were very accurate, such as differentiating Brodmann area 17 from Brodmann area 18.
The Neuron Doctrine
Main article: Neuron doctrine
In the early 20th century, Santiago Ramón y Cajal and Camillo Golgi began working on the structure of the neuron. Golgi developed a silver staining method that could entirely stain several cells in a particular area, leading him to believe that neurons were directly connected with each other in one cytoplasm. Cajal challenged this view after staining areas of the brain that had less myelin and discovering that neurons were discrete cells. Cajal also discovered that cells transmit electrical signals down the neuron in one direction only. Both Golgi and Cajal were awarded a Nobel Prize in Physiology or Medicine in 1906 for this work on the neuron doctrine. The neuron doctrine has ever since provided a fundamental theory for understanding neurophysiology
The Birth of Cognitive Science
On September 11, 1956, a large-scale meeting of cognitivists took place at the Massachusetts Institute of Technology. George A. Miller presented his "The Magical Number Seven, Plus or Minus Two" paper while Noam Chomsky and Newell & Simon presented their findings on computer science. Ulric Neisser commented on many of the findings at this meeting in his 1967 book Cognitive Psychology. The term "psychology" had been waning in the 1950s and 1960s, causing the field to be referred to as "cognitive science". Behaviorists such as Miller began to focus on the representation of language rather than general behavior. David Marr's proposal of the hierarchical representation of memory caused many psychologists to embrace the idea that mental skills required significant processing in the brain, including algorithms.
Cognitive Neuroscience
Before the 1980s interaction between neuroscience and cognitive science was scarce[4]. The term 'cognitive neuroscience' was coined by George Miller and Michael Gazzaniga[4] "in the back seat of a New York City taxi"[5] toward the end of the 1970s. Cognitive neuroscience began to integrate the newly laid theoretical ground in cognitive science, that emerged between the 1950s and 1960s, with approaches in experimental psychology, neuropsychology and neuroscience. (Neuroscience was not established as a unified discipline until 1971[6]). In the very late 20th century new technologies either evolved that are now the mainstay of the methodology of cognitive neuroscience, including TMS (1985) and fMRI (1991). Earlier methods used in cognitive neuroscience includes EEG (human EEG 1920) and MEG (1968). Occasionally cognitive neuroscientists utilize other brain imaging methods such as PET and SPECT. In some animals Single-unit recording can be used. Other methods include microneurography, facial EMG, and eye-tracking. Integrative neuroscience attempts to consolidate data in databases, and form unified descriptive models from various fields and scales: biology, psychology, anatomy, and clinical practice.
Cognitive Neuroscience Topics
- attention
- change blindness
- consciousness
- decision-making
- learning
- memory
- mirror neurons
- mismatch negativity
Cognitive Neuroscience Methods
Experimental methods of specific psychology fields include:
- Psychophysics
- Cognitive psychology
- Cognitive neuropsychology
- Cognitive psychophysiology
Cognitive neuroscience was called cognitive psychophysiology before the advent of functional MRI.factCognitive psychophysiology research mainly used EEG and other electrophysiological methods.
Related WikiBooks
- wikibooks:Cognitive Psychology and Cognitive Neuroscience
- Wikibook on consciousness
- Cognitive Neuroscience chapter of the Neuroscience WikiBook
See Also
Notes
- ^ Gazzaniga, Ivry and Mangun 2002, cf. title
- ^ a b Gazzaniga 2002, p. xv
- ^ Enersen, O. D. 2009
- ^ a b http://www.petemandik.com/philosophy/papers/brookmandik.pdf
- ^ Gazzaniga et al. 2002, p.1
- ^ Society for Neuroscience. Date of the first meeting of the Sociefy for Neuroscience
References
- http://en.wikipedia.org/wiki/Cognitive_neuroscience
- Churchland, P.S. & Sejnowski, T.J. (1992). The Computational Brain, The MIT Press, ISBN 0-262-03188-4.
- Code, C. (1996). Classic Cases: Ancient & Modern Milestones in the Development of Neuropsychological Science. In: Code, C. et al. Classic Cases in Neuropsychology.
- Gazzaniga, M. S., Ivry, R. B. & Mangun, G. R. (2002). Cognitive Neuroscience: The biology of the mind (2nd ed.). New York: W.W.Norton.
- Gazzaniga, M. S., The Cognitive Neurosciences III, (2004), The MIT Press, ISBN 0-262-07254-8
- Gazzaniga, M. S., Ed. (1999). Conversations in the Cognitive Neurosciences, The MIT Press, ISBN 0-262-57117-X.
- Miller, G. A. (1956). The magical number seven, plus or minus two: Some limits on our capacity for processing information. Psychological Review, 63, 81-97
- Parkin, A.J. (1996). Explorations in Cognitive Neuropsychology, pp. 1–23.
- Sternberg, Eliezer J. Are You a Machine? The Brain, the Mind and What it Means to be Human. Amherst, NY: Prometheus Books.
- Ward, Jamie (2006). The Student's Guide to Cognitive Neuroscience. Psychology Press. ISBN978-1-84169-535-8.
- Handbook of Functional Neuroimaging of Cognition By Roberto Cabeza, Alan Kingstone
- Principles of neural science By Eric R. Kandel, James H. Schwartz, Thomas M. Jessell
- The Cognitive Neuroscience of Memory By Amanda Parker, Edward L. Wilding, Timothy J. Bussey
- Neuronal Theories of the Brain By Christof Koch, Joel L. Davis
- Cambridge Handbook of Thinking and Reasoning By Keith James Holyoak, Robert G. Morrison
- Handbook of Mathematical Cognition By Jamie I. D. Campbell
- Cognitive Psychology By Michael W. Eysenck, Mark T. Keane
- Development of Intelligence By Mike Anderson
- Development of Mental Processing By Andreas Demetriou, et. al.
- Memory and Thinking By Robert H. Logie, K. J. Gilhooly
- Memory Capacity By Nelson Cowan
- Proceedings of the Nineteenth Annual Conference of the Cognitive Science
- Models of Working Memory By Akira Miyake, Priti Shah
- Memory and Thinking By Robert H. Logie, K. J. Gilhooly
- Variation in Working Memory By Andrew R. A. Conway, et. al.
- Memory Capacity By Nelson Cowan
- Cognition and Intelligence By Robert J. Sternberg, Jean E. Pretz
- General Factor of Intelligence By Robert J. Sternberg, Elena Grigorenko
- Neurological Basis of Learning, Development and Discovery By Anton E. Lawson
- Memory and Human Cognition By John T. E. Richardson
- Enersen, O. D. (2009). John Hughlings Jackson. In: Who Named It. http://www.whonamedit.com/doctor.cfm/2766.html Retrieved 14 August 2009
- Society for Neuroscience. http://www.sfn.org/index.cfm?pagename=about_sfn#timeline Retrieved 14 August 2009
External links
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