Human brain and Where I Stood: Difference between pages

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Revision as of 22:11, 28 June 2007

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{{Infobox Single <!-- See Wikipedia:WikiProject_Songs -->

[[Image:Human brain NIH.jpg|thumb|right|300px|The human brain.]]

| Name = Where I Stood EP

The '''human brain''' is the center of the [[central nervous system]] in [[human]]s as well as the primary control center for the [[peripheral nervous system]].

| Artist = [[Missy Higgins]]

| from Album = [[On a Clear Night]]

| Released = 25th June 2007

| Format = [[CD single]]<br>[[Digital download]]

| Recorded = [[Los Angeles, California]], [[2006 in music|2006]]

| Genre = [[Piano pop]]

| Length = 4:17

| Label = [[Eleven: A Music Company|Eleven]]

| Writer = [[Missy Higgins]]

| Producer = [[Mitchell Froom]]

| Certification =

| Chart position =

| Last single = "[[Steer (song)|Steer]]"<br>([[2007]])

| This single = "[[Where I Stood]]"<br>([[2007]])

| Next single =

| Misc

| Type = studio =

}}

The [[brain]] controls "lower" or involuntary activities such as [[heartbeat]], [[respiration]], and [[digestion]] - these are known as [[Autonomic nervous system|autonomic functions]]. The brain also controls "higher" order, conscious activities, such as [[thought]], [[reason]]ing, and [[Abstraction|abstract]]ion. The human brain is more capable of these higher order activities than any other species.

On June 19 2007, Higgins announced that her second single from her sophomore album [[On a Clear Night|On A Clear Night]] would be "'''Where I Stood'''". The song was released to commercial radio on June 25 2007. The song was also featured on a promo for [[Desperate Housewives|Desperate Housewives]] in Australia.

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== Overview ==

Human [[encephalization]] is especially pronounced in the [[neocortex]], the most complex portion of the [[cerebral cortex]]. Singular among those of all [[animal]]s, the human brain possesses the largest and most massive neocortex . Humans thus enjoy unique neural capacities, despite that much of the human neuroarchitecture resembles that of more primitive [[species]]. Basic systems that alert the nervous system to stimuli, that sense events in the environment, and that monitor the condition of the body are similar in some ways to those of the most basic [[vertebrate]]s. Human [[consciousness]] involves both the extended capacity of the modern neocortex in particular as well as profoundly developed prototypical structures of the [[brain stem]]. But the human brain is unique, in part, because it relies on some million billion [[synapse|synaptic]] connections, making it among the most intricate and densely connected networks among natural and fabricated systems found on Earth.

==Music Anatomy Video==

The video premiered at midnight (12am AEST) on 26th June 2007 via Higgins' [[Myspace]] page. The video was directed by Australian filmmakers Paul Goldman and Alice Bell.

[[Image:labeledbrain-english.jpg|thumb|250px|Sagittal slice from a [[MRI]] scan of a human brain. [[Commons:Image:brain_chrischan_300.gif|Click here]] for an animated sequence of slices.]]

The normal adult human brain typically weighs between 1 and 1.5 kg (three pounds) and has an average volume of 1,600 cm&sup3; (98 in&sup3;). The male brain has approximately 4% more brain cells and 100 grams more brain tissue than the equivalent female brain. The mature brain consumes some 20% of the [[energy]] used by the [[body]], while the developing brain of an [[infant]] consumes around 60%. Such heavy energy usage generates large quantities of [[heat]], which must be continually removed to prevent [[brain damage]].

A bulbous [[cerebral cortex]] is composed of convoluted [[grey matter]] internally supported by deep brain [[white matter]] and separated by a prominent [[central fissure]]. A well-developed [[cerebellum]] is visible at the back of the brain. Brain stem structures are almost completely enveloped by the cerebellum and telencephalon, with only the [[medulla oblongata]] visible as it merges with the [[spinal cord]].

The blood supply to the brain involves several [[artery|arteries]] that enter the brain and communicate in a circle called the [[circle of Willis]]. Blood is then drained from the brain through a [[network]] of [[sinus|sinuses]] that drain into the right and left [[internal jugular vein]]s.

The brain is suspended in [[cerebrospinal fluid]] (CSF) which also fills spaces called [[ventricle|ventricles]] inside it. The dense fluid protects the brain and spinal cord from shock; a brain that weighs 1,500 g in air weighs only 50 g when suspended in CSF. (Livingston, 1965). Fluid movement within the brain is limited by the [[blood-brain barrier]], [[brain-cerebrospinal fluid barrier]] and the [[blood-cerebrospinal fluid barrier]].

The brain is easily damaged by compression, so the fluid surrounding the central nervous system must be maintained at a constant volume. Humans are estimated to produce about 500 ml or more of cerebrospinal fluid each day, with only about 15 percent of the body's estimated 150 ml of CSF at any given time located in the ventricles of the brain. The remainder fills the subarachnoid space which separates the soft tissues of the brain and spinal cord from the hard surrounding bones (skull and vertebrae). Elevated levels of CSF are associated with [[brain injury|traumatic brain injuries]] and a [[pediatric]] disease known as [[hydrocephalus]]. Increased fluid pressure can result in permanent brain injury and death.

The exceptional size of the human brain resulted in some anatomical compromises. At birth, an infant's skull is as large as it can be without causing undue peril to the mother and child. However, prior to the intervention of modern medicine, [[childbirth]] was a dangerous event that frequently resulted in the death of the mother. The difficulty experienced by humans in giving birth is nearly unique in the animal kingdom. Female humans have large pelvic openings to accommodate the birth of large-headed children, but the larger this opening, the more the ability of the mother to run is compromised.

At birth, the human skull is rather soft, and it deforms somewhat during its passage through the birth canal, then recovers its shape. This allows it to expand to make room for the brain, which continues to grow, at the same rate as that of an unborn fetus, for an additional year. In all other animals, the growth rate of the brain slows significantly at birth.

== Function ==

[[Image:brain-anatomy.jpg|right|250px]]

The human brain is the seat of the human [[mind]] - the set of cognitive processes related to perception, interpretation, imagination and [[memories]], of which a person might or might not be aware. Beyond cognitive functions, the brain regulates autonomic processes related to essential body functions such as respiration and heartbeat.

Extended neocortical capacity allows humans some control over [[emotion]]al behavior, but neural pathways between emotive centers of the brain stem and cerebral motor control areas are shorter than those connecting complex cognitive areas in the [[neocortex]] with incoming sensory information from the [[brain stem]]. Powerful emotional pathways can modulate spontaneous emotive expression regardless of attempts at cerebral self-control. Emotive stability in humans is associated with planning, experience and an environment that is both stable and stimulating, especially during early developmental years.

The [[19th century]] discovery of a primary motor control area mapped to correspond with regions of the body led to popular belief that the brain was organized around a [[homunculus]]. A distorted figure drawn to represent the body's motor map in the pre-frontal cortex was popularly recognized as the brain's homunculus, but function of the human brain is far more complex.

The human brain appears to have no localized center of conscious control. Like the brains of other vertebrates, it derives [[consciousness]] from interaction among numerous systems within the brain. Executive decision-making functions rely on cerebral activities, especially those of the [[frontal lobes]], but redundant and complementary processes within the brain result in a diffuse assignment of executive control that can be difficult to attribute to any single locale.

Mid-brain functions include routing, selecting, mapping and cataloguing information, including information perceived from the environment and information that is remembered and processed throughout the cerebral cortex. [[Endocrine_gland|Endocrine]] functions housed in the mid-brain play a leading role in modulating arousal of the cortex and of autonomic systems.

Nerves from the brain stem complex where autonomic functions are modulated join nerves routing messages to and from the cerebrum in a bundle that passes through the [[Spine_(anatomy)|spinal column]] to related parts of a body. Twelve pairs of [[cranial nerves]], including some that innervate parts of the head, follow pathways from the [[medulla oblongata]] outside the [[spinal cord]].

A definite description of the biological basis for consciousness so far eludes the best efforts of the current generation of researchers. But reasonable assumptions based on observable behaviors and on related internal responses have provided the basis for general classification of elements of consciousness and of likely neural regions associated with those elements. Researchers know people lose consciousness and regain it, they have identified partial losses of consciousness associated with particular neuropathologies and they know that certain conscious activities are impossible without particular neural structures.

A common [[mind myths|myth]] is that human beings only use ten percent of our brains. This is false; we use our entire brains. The myth likely had its source in an advertisement or a misunderstanding of neurological research in the late [[1800s]] or early [[1900s]]. Some [[parapsychology|psychics]] help to prolong this myth by asserting that the "unused" ninety percent of the human brain is capable of exhibiting psychic powers, and can be trained to perform [[psychokinesis]] and [[extra-sensory perception]]. A less literal interpretation of the statement is, however, valid. It can be reasonably claimed that most people only use a very small fraction of the ''[[cognitive]] potential'' of their brain, even though all individual brain neurons are busily working. Various cultural inventions enable humans to better utilise their cognitive potential, such as [[reading (activity)|reading]], [[education]], solving [[puzzle]]s, [[critical thinking]], etc.

== Study of the brain ==

[[image:brain.png|thumb|250px|Picture of a human brain generated from [[MRI]] data]]

Although folklore about putatively 90% dormant human brain has proven scientifically unfounded, researchers until the [[1990s|mid 1990s]] focused on only a small portion of the brain in efforts to understand its computational capacity.

Grey matter, the thin layer of cells covering the cerebrum, was believed by most scholars to be the primary center of cognitive and conscious processing. White matter, the mass of [[glial cell]]s that support the cerebral grey matter, was assumed to primarily provide nourishment, physical support and connective pathways for the more functional cells on the cerebral surface. But research fueled by the interest of Dr. Mary Diamond in the glial structure of [[Albert Einstein|Albert Einstein's]] brain led to a line of research that offered strong evidence that glial cells serve a computational role beyond merely transmitting processed signals between more functional parts of the brain. In [[2004]], [[Scientific American]] published an article suggesting scientists in the early [[21st century]] are only beginning to study the "other half of the brain."

For many millennia, the function of the brain was unknown. Ancient Egyptians threw the brain away prior to the process of [[mummy|mummification]]. Ancient thinkers such as [[Aristotle]] imagined that mental activity took place in the [[heart]]. Greek scholars assumed correctly that the brain serves a role in cooling the body, but incorrectly presumed the brain to function as a sort of [[radiator]], rather than as a [[thermostat]], as is now understood. The [[Alexandria]]n biologists [[Herophilus]] and [[Erasistratus]] were among the first to conclude that the brain was the ''seat of intelligence''. [[Galen]]'s theory that the brain's cavities, or ''[[Ventricle (brain)|ventricles]]'', were the sites of [[thought]] and [[emotion]] prevailed until the work of the Renaissance anatomist [[Vesalius]].

[[Image:User-FastFission-brain-frame44.png|frame|right|250px|A slice of a [[fMRI]] scan of the brain. [[:Image:User-FastFission-brain.gif|Click here]] to view an animation of the scan from top to bottom.]]

The brain is now studied in [[neurology]] and [[psychiatry]], and is known to be the organ responsible for the phenomena of [[consciousness]], [[thought]] and [[emotion]]. Studies of brain damage resulting from accidents led to the identification of specialized areas of the brain devoted to functions such as the processing of seeing and hearing.

[[Brain imaging]] has allowed the function of the living brain to be studied in detail without damaging the brain. New imaging techniques allowed blood flow within the brain to be studied in detail during a wide range of psychological tests. [[Functional neuroimaging]], including ([[fMRI]]), allows researchers to monitor activities in a brain while they are happening (''see also [[history of brain imaging]]'').

Molecular analysis of the brain has provided insight into some aspects of what the brain does as an organ, but not how it functions as the seat of human consciousness. Further, the molecular and [[Cell biology|cell biological]] examination of brain pathology is hindered by the scarcity of appropriate samples for study, the (usual) inability to [[biopsy]] the brain from a living person suffering from a malady, and an incomplete description of the brain's microanatomy. With respect to the normal brain, comparative [[transcriptome]] analysis between the human and chimpanzee brain and between brain and [[liver]] (a common molecular baseline organ) has revealed specific and consistent differences in gene expression between human and chimpanzee brain and a general increase in the gene expression of many genes in humans as compared to chimpanzees. Furthermore, variations in gene expression in the [[cerebral cortex]] between individuals in either species is greater than between sub-regions of the cortex of a single individual{{ref|comparativetranscriptomeanalysis}}.

In addition to [[pathology|pathological]] and imaging studies, the study of [[computational neuroscience|computational network]]s, largely in [[computer science]]s, provided a third key to unlocking many of the secrets of how the human brain functions. A body of knowledge developed for the production of electronic mathematic computational systems provided a basis for researchers to develop and refine hypotheses about the computation function of biological computational networks. The study of [[neural network]]s now involves study of both biological and artificial computational systems.

A new discipline of [[cognitive science]] has started to fuse the results of these investigations with observations from [[psychology]], [[philosophy]], [[linguistics]] and [[computer science]].

Recently the brain was used in [[bionics]] by several groups of researchers. In a particular example, a joint team of U.S. Navy researchers and Russian scientists from [[Nizhny Novgorod State University]] worked to develop an artificial analogue of olivocerebellar circuit, a part of the brain responsible for balance and limb movement. The researchers plan to use it to control autonomous underwater vehicles.

=== Myths ===

The following are some common myths or misconceptions about the mind and brain, perpetuated through common or [[urban myths]], the [[media]], and the promotion of dubious products to consumers (Sala, 1999). A number of practitioners of [[pseudoscience]], [[new age]] philosophies, and mystical or [[occult]] practices are known to use some of these myths as a part of their belief systems. Also see [[popular psychology]].

* Myth: ''The human brain is firm and grey.'' The fresh/living brain is actually very soft, jelly-like and deep red. They do not become firm and grey until they have been preserved with various chemicals/resins.

* Myth: ''Humans use only 10% or 1% of their brain.'' Though the brain still holds mysteries that are being studied, every part of the brain is known to have a function. A possible origin of this myth is the fact that only about 10% of the [[neurons]] in the brain are firing at any given time. However, if all of your neurons began firing at once, you would not become smarter, but instead suffer an [[epileptic seizure]]. In fact studies have shown that the brains of more intelligent people are less active than the brains of less intelligent people, when working on the same problems.

* Myth: ''Mental abilities are separated into the left and right [[cerebral hemisphere]]s.'' Some mental functions, like language production and comprehension, tend to be localized to specific areas in one hemisphere. If this hemisphere is damaged at a very early age, however, these functions can often be recovered by the other hemisphere. Other abilities like motor control, memory, and general reasoning are spread equally across the two hemispheres.

* Myth: ''[[Creativity]] can be easily developed using the simple brainstorming/lateral thinking techniques.''

* Myth: ''[[Learning]] can be achieved more powerfully through subliminal techniques.'' Technically, information that is entirely subliminal cannot be perceived at all. The extent to which subliminal techniques can influence learning depends largely on what level of [[perception]] the techniques affect.

* Myth: ''[[Hypnosis]] can lead to perfect recall of details.'' Not only is this not entirely true, an incompetent or deceptive hypnotist can actually implant memories of events that never occurred.

== Brain enhancement ==

Various methods have been proposed to improve the cognitive performance of the human brain, including pharmocological methods ([[nootropic]] drugs), electric stimulation ([[direct current polarization]]) and surgery. More advanced methods of [[brain enhancement]] may be possible in the future, perhaps including direct [[brain-computer interface]]s. These proposed enhancements are a major focus of [[Transhumanism]].

== Related topics ==

* [[list of regions in the human brain|Regions in the human brain]]

* [[Functional neuroimaging]]

* [[Cephalic disorders]]

* [[Memory-prediction_framework|The Memory-Prediction Framework - An Acclaimed Work on Cognitive Neuroscience]]

* [[Encephalization]]

== References ==

=== Books ===

* Simon, Seymour (1999). ''The Brain''. HarperTrophy. ISBN 0688170609

* Thompson, Richard F. (2000). ''The Brain : An Introduction to Neuroscience''. Worth Publishers. ISBN 0716732262

* Campbell, Neil A. and Jane B. Reece. (2005). ''Biology''. Benjamin Cummings. ISBN 0805371710

=== External links ===

* [http://www.med.harvard.edu/AANLIB/home.html The Whole Brain Atlas]

* [http://www.sylvius.com Sylvius: 400+ structure neuroanatomical visual glossary; used by over half of U.S. medical schools]

* [http://primate-brain.org High-Resolution Cytoarchitectural Primate Brain Atlases]

* [http://faculty.washington.edu/chudler/facts.html Brain Facts and Figures]

* [http://www.thedoctorslounge.net/studlounge/articles/cerebcirc/index.htm Blood supply of the human brain]

* [http://vadim.www.media.mit.edu/MAS862/Project.html Estimating the computational capabilites of the human brain]

* [http://www.transhumanist.com/volume1/moravec.htm When will computer hardware match the human brain?] &ndash; an article by [[Hans Moravec]]

* [http://science.howstuffworks.com/brain.htm How the human brain works]

* [http://www.solbaram.org/articles/humind.html More about the Human brain!]

* [http://www.snopes.com/science/stats/10percnt.htm The Ten-Percent Myth], Snopes, by Benjamin Radford, [[8 February]] [[2000]].

== Notes ==

# {{note|comparativetranscriptomeanalysis}} Khaitovich, P., et al. 2004. "Regional patterns of gene expression in human and chimpanzee brains". ''Genome Research,'' '''14''':1462-1473. <small>refers to four studies of comparative transcriptome analysis prior to publication of the findings in the cited manuscript</small>

[[Category:Central nervous system]]

[[pl:Mózg człowieka]]

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