Monday, 24 November 2008

Magic and the Brain: How Magicians "Trick" the Mind

Magicians have been testing and exploiting the limits of cognition and attention for hundreds of years. Neuroscientists are just beginning to catch up.But the most versatile instrument in their bag of tricks may be the ability to create cognitive illusions. Like visual illusions, cognitive illusions mask the perception of physical reality. Yet unlike visual illusions, cognitive illusions are not sensory in nature. Rather they involve high-level functions such as attention, memory and causal inference. With all those tools at their disposal, well-practiced magicians make it virtually impossible to follow the physics of what is actually happening—leaving the impression that the only explanation for the events is magic.
Neuroscientists are just beginning to catch up with the magician’s facility in manipulating attention and cognition. Of course the aims of neuroscience are different from those of magic; the neuroscientist seeks to understand the brain and neuron underpinnings of cognitive functions, whereas the magician wants mainly to exploit cognitive weaknesses. Yet the techniques developed by magicians over centuries of stage magic could also be subtle and powerful probes in the hands of neuroscientists, supplementing and perhaps expanding the instruments already in experimental use.
Neuroscience is becoming familiar with the methods of magic by subjecting magic itself to scientific study—in some cases showing for the first time how some of its methods work in the brain. Many studies of magic conducted so far confirm what is known about cognition and attention from earlier work in experimental psychology. A cynic might dismiss such efforts: Why do yet another study that simply confirms what is already well known? But such criticism misses the importance and purpose of the studies. By investigating the techniques of magic, neuroscientists can familiarize themselves with methods that they can adapt to their own purposes. Indeed, we believe that cognitive neuroscience could have advanced faster had investigators probed magicians’ intuitions earlier. Even today magicians may have a few tricks up their sleeves that neuroscientists have not yet adopted.
By applying the tools of magic, neuroscientists can hope to learn how to design more robust experiments and to create more effective cognitive and visual illusions for exploring the neural bases of attention and awareness. Such techniques could not only make experimental studies of cognition possible with clever and highly attentive subjects; they could also lead to diagnostic and treatment methods for patients suffering from specific cognitive deficits—such as attention deficits resulting from brain trauma, ADHD (attention-deficit hyperactivity disorder), Alzheimer’s disease, and the like. The methods of magic might also be put to work in “tricking” patients to focus on the most important parts of their therapy, while suppressing distractions that cause confusion and disorientation (Full text).

Friday, 21 November 2008

LIFE photo archive

Search millions of photographs from the LIFE photo archive, stretching from the 1750s to today. Most were never published and are now available for the first time through the joint work of LIFE and Google (go).

Saturday, 4 October 2008

The Collegiate Church of Saint Isidoro

At the northeast side of the roman encampment Legio VII Gemina (Leon) (now in Spain), by the camp wall, King Sancho the Fat (dead in 966), son of Ramiro 2nd, built a monastery for sheltering the rests of the martyr boy from Cordoba, St. Pelayo (we can see a sculpture of him in the front of the church). Her sister, a nun called Elvira Ramirez, moved with all the nuns of her elder monastery, Palat del Rey, to the new one. In the last Xth century, due to the arrival of Almanzor's army, the nuns went to Oviedo for refuge. The monastery of St. Pelayo in Leon was razed by the Arabic chief troops. King Alfonso the Vth (999-1027) rebuilt the monastery using very poor materials, like clay and bricks. Once more, a community of nuns established there, for taking care of the Royal cemetery, where the King had moved the rests of his predecessors, who were dispersed along various kingdom churches; even his parents's, Vermudo the IInd and Elvira.

The daughter of Alfonso the Vth, Doña Sancha, first infant and after the Queen herself, tried to exalt the monastery to the highest dignity, helped by her husband, King Fernando the Ist (1037-1065).

They rebuilt the elder brick monastery out of stone and so began the romanic style in their kingdom. They choose the portic of the church as a cemetery and ordered to be buried there. .


They wanted to dignify their church with relevant saints relics; they achieved the moving of St. Isidoro's corpse from Sevilla and St. Vicente's from Avila. They made an extraordinary feast in december, 21st, 1063, and next day they celebrated the moving of St. Isidoro. For this special event, they made splendid donations, jewels and ornaments, that we know nowadays as the Treasure of Leon.

Fernando and Sancha's daughter, infant Urraca Fernandez (dead in 1101), enlarged the church and made splendid donations, like the well known chalice. Another infant, Doña Sancha Raimundez (dead in 1159), with her brother, Emperor Alfonso the VIIth, continued the works in the elder church, began by her grand aunt Doña Urraca, and consecrated the new church in 1149. A year before they had substituted the benedictine female comunity in the monastery by an ordinary prebendaries Council. They ruled the temple and the abbey until 1956, when the council was changed into a secular priests institution, and since then it takes care of the liturgical and intellectual life of the Collegiate Church, the Temple, the Museums open to thousands of visitors, both national and foreign, the Archives and the Library at the disposal of researchers, the Isidorian Editorial and Bookstore, with the main purpose of divulging the history and the art the Collegiate Church and the life of Saint Isidoro.

Wednesday, 24 September 2008

Codex Ixtlilxochitl

This is a manuscript with illustrations on European paper in folio, text in the Spanish language and is a fragment of a codex attributed by Leon y Parma to Don Fernando de Alva Ixtlilxochitl who was a "nobleman" of the Confederation of Culhua Mexica ("Aztec Empire") and the outstanding native historian of the early years of the Spanish Conquest. The codex deals with people and events of the pre-Conquest "Aztec Empire", which Ixtlilxochitl remembered. This will, naturally, be indispensible for any complete Latin American Library.

Saturday, 5 July 2008

Does the Sun look smaller to you?

Criminy, I almost forgot: today, July 4th, at roughly 08:00 UT, the Earth was at aphelion.

Uh, what? I hear you ask. OK, brief astrolesson for ya, then back to the grill!

The Earth does not orbit the Sun in a perfect circle. The orbit is slightly elliptical. If you were to draw the Earth’s orbit on a piece of paper, you’d need a sharp eye to detect its non-circularity, but deviant it is. What this means in real terms is that the Earth ranges from about 148 to about 152 million kilometers from the Sun over the course of six months (which is how long it takes to get from one side of the orbit to the other, of course).

When the Earth is closest to the Sun it’s at perihelion, and when it’s farthest it’s called aphelion (I usually pronounce that app-helion, if you care, though I’ve heard others say aff-helion). So today we passed aphelion, and slowly but inexorably, over the next six months we’ll draw slightly closer to the Sun, and then the whole thing repeats.

That 4 million km difference sounds like a lot. But over the 150 million average radius of the orbit it’s only a slight difference by eye. The Sun will look about 3% larger at perihelion versus aphelion, and you’d never notice that, especially since the change is slow and takes six months. The amount of sunlight hitting the Earth does increase at perihelion, being about 5% greater than at aphelion. That’s quite a bit! But the effect isn’t as bad as you’d think. Why not?

For us northern hemisphere folks, we are farthest from the Sun in summer, and closest in winter, so that mitigates the temperature extreme. On average, winters are a bit warmer and summers a bit cooler. But wait! In the southern hemisphere, the seasons are reversed! So they should have extra hot summers and extra cold winters.

But they don’t. Why not? Because the southern hemisphere is mostly water. Go ahead, find a globe and take a look; it’s incredible how much of that half the Earth is water bound. Water absorbs and releases heat slowly, so all summer the oceans suck down that extra solar energy, and release it all winter. That helps balance out the temperature extremes.

Oh, one more thing: the Earth precesses, that is, the axis of rotation moves like a wobbling top. It takes a long time for the wobble to make one cycle, well over 20,000 years. But this changes the timing of the seasons compared to the orbit. In a few millennia, we’ll have perihelion at the same time as northern summer, and aphelion at northern winter. It’s hard to say what effect this will have on the environment, since it brings extra-hot summers and extra-cold winters. However, the last time this happened was around the same time the Sahara forest went away and was replaced by, well, guess.

But for today, don’t fret too much about wandering poles and aphelion… except to say, if you’re out sweltering in the Sun today celebrating the holiday in the U.S., you might want to take just a moment and be glad our orbit isn’t more elliptical, or that it isn’t 15,000 AD.

Tuesday, 1 July 2008

Sleep paralysis

Sleep paralysis is a condition characterized by temporary paralysis of the body shortly after waking up (known as hypnopompic paralysis) or, less often, shortly before falling asleep (known as hypnagogic paralysis).[1] Physiologically, it is closely related to the paralysis that occurs as a natural part of REM (rapid eye movement) sleep, which is known as REM atonia. Sleep paralysis occurs when the brain awakes from a REM state, but the bodily paralysis persists. This leaves the person fully aware, but unable to move. In addition, the state may be accompanied by hypnagogic hallucinations. More often than not, sleep paralysis is believed by the person affected by it to be no more than a dream. This explains many dream recountings which describe the person lying frozen and unable to move. The hallucinatory element to sleep paralysis makes it even more likely that someone will interpret the experience as a dream, since completely fanciful, or dream-like, objects may appear in the room alongside one's normal vision.
Possible causesSleep paralysis occurs during REM sleep, thus preventing the body from manifesting movements made in the subject's dreams. Very little is known about the physiology of sleep paralysis. However, some have suggested that it may be linked to post-synaptic inhibition of motor neurons in the pons region of the brain. In particular, low levels of melatonin may stop the depolarization current in the nerves, which prevents the stimulation of the muscles, to prevent the body from enacting the dreamt activity (e.g. preventing a sleeper from flailing his legs when dreaming about running). Many people who commonly enter sleep paralysis also suffer from narcolepsy. Especially in African-Americans panic disorder often co-occurs with sleep paralysis[2]. However, various studies suggest that many or most people will experience sleep paralysis at least once or twice in their lives. Some reports read that various factors increase the likelihood of both paralysis and hallucinations. These include: [3]
Sleeping in an upwards supine position
Irregular sleeping schedules; naps, sleeping in, sleep deprivation
Increased stress
Sudden environmental/lifestyle changes
A lucid dream that immediately precedes the episode. Also conscious induction of sleep paralysis is a common technique to enter a state of lucid dreams, also known as WILD .
Artificial sleeping aids, ADD medications and/or antihistamines
Recent use of hallucinogenic drugs
TreatmentDuring paralysis episodes, patients may be advised to try moving the facial muscles and moving eyes from one side to the other. This may hasten the termination of the attack. Clonazepam is highly effective in the treatment of sleep paralysis.[4] The initial dose is 0.5 mg at bedtime, while an increase to 1 mg per night might be necessary to maintain potency. Anecdotal reports indicate SSRIs such as fluoxetine markedly decrease the incidence of sleep paralysis. Several people who have been both on and off SSRIs have reported corresponding decreases and increases in sleep paralysis episodes. Others report no effects at all.
Cultural referencesComplete references to many cultures are given in the References section
In Vietnamese, sleep paralysis is referred to as "ma de", meaning "held down by a ghost". Most people in this culture believe that a ghost has entered your body, causing the paralysis state.
In Japanese, sleep paralysis is referred to as kanashibari (, literally "bound or fastened in metal," from kane "metal" and shibaru "to bind, to tie, to fasten"). This term is occasionally used by English speaking authors to refer to the phenomenon both in academic papers and in pop psych literature.
In Hungarian folk culture sleep paralysis is called "lidércnyomás" ("lidérc pressing") and can be attributed to a number of supernatural entities like "lidérc", "boszorkány" (witch), "tündér" (fairy) or "ördögszerető".[5] The word "boszorkány" itself stems from the Turkish root "bas-", meaning "to press".[6]
Kurdish people call this phenomenon a "mottaka", they believe that some one, in a form of a ghost or perhaps an evil spirit, turns up on top the of the person in the middle of the night and suffocates him/her. Apparently this happens usually when some one has done something bad.
In New Guinea, people refer to this phenomenon as "Suk Ninmyo", believed to originate from sacred trees that use human essence to sustain its life. The trees are said to feed on human essence during night as to not disturb the human's daily life, but sometimes people wake unnaturally during the feeding, resulting in the paralysis.
In Turkey this is called "karabasan" ("black-pressing"). It is believed that it is a creature which attacks people in their sleep.
In Mexico, it's believed that sleep paralysis is in fact the spirit of a dead person getting on the person and impeding movement, calling this "se me subió el muerto" (the dead person got on me).
Ogun Oru is a traditional explanation for nocturnal disturbances among the Yoruba of Southwest Nigeria; ogun oru (nocturnal warefare) involves an acute night-time disturbance that is culturally attributed to demonic infiltration of the body and psyche during dreaming. Ogun oru is characterized by its occurrence, a female preponderance, the perception of an underlying feud between the sufferer's earthly spouse and a ;spiritual' spouse, and the event of bewitchment through eating while dreaming. The condition is believed to be treatable through Christian prayers or elaborate traditional rituals designed to exorcise the imbibed demonic elements. [7]
Several studies have shown that African-Americans may be predisposed to isolated sleep paralysis also known as "the witch is riding you," or "the haint is riding you." [8] In addition, other studies have shown that African-Americans who have frequent episodes of isolated sleep paralysis, i.e., reporting having one or more sleep paralysis episodes per month coined as "sleep paralysis disorder," were predisposed to having panic attacks. [9] This finding has been replicated by other independent researchers [10] [11]
Sleep paralysis in literature, art and music
(1605) Miguel de Cervantes makes mention of the phenomenon in Don Quixote when a tavern wench jumps into the bed of the soundly sleeping Sancho Panza, who, started, and feeling a prodigious weight upon him, thought he was labouring under the nightmare.
(1851) There is a particularly fascinating account of sleep paralysis in Herman Melville's novel Moby-Dick. Chapter 4 (The Counterpane) is an account of Ishmael's meditation on an episode of sleep paralysis in the middle of which he could not distinguish the difference between Queequeg's arm and the quilt. Indeed, he could not even distinguish the difference between his own body and his surroundings. He then recalls an earlier episode of sleep paralysis from his childhood, which he determines was the precise moment he discovered the feeling of "otherness" of his own body with respect to his surroundings.
(1936) An account can also be found in Ernest Hemingway's The Snows of Kilimanjaro, in which death approaches and sits upon the narrator's chest so that he cannot breathe.
(1969) The main character in Kingsley Amis' novel The Green Man also suffers from the affliction.
(1975) Maxine Hong Kingston recounts an episode in her book The Woman Warrior where her mother, Brave Orchid, suffers a night of sleep paralysis in the "Haunted Room", in which she claims she battles a "Sitting Ghost".
In Zimbabwean Shona culture the word Madzikirira is used referring to the fact that something will really be pressing you down and mostly they refer to the spiritual world where some other spirit especially evil one will be trying to use you. The people believe that witches can only be people of close relations to be effective and hence a witch can try to use your spirit to bewitch your relatives.
(2001) The progressive rock band Dredg explores the different aspects of sleep paralysis, on their album El Cielo. The booklet with El Cielo contains letters written by sufferers of sleeping disorders with descriptions of various experiences with or relating to sleep paralysis. Singer Gavin Hayes incorporates and expands upon the material found in the booklet for the lyrics to the album; all of the songs on the album (except the instrumentals) contain snippets of the text in the booklet.
(2006) Experimental band Fear Before the March of Flames talk about the struggles of dealing with constant sleep paralysis on their album "The Always Open Mouth". One of the songs is even called "Drowning the Old Hag".
Notes
1. ^ When considered a disease, isolated sleep paralysis is classified as: Diseases Database 12182, MeSH D0201882. ^ Friedman, S. & Paradis, C. (2002). Panic disorder in African-Americans: Symptomatology and isolated sleep paralysis. Culture, Medicine and Psychiatry, 26,179-198.3. ^ J. A. Cheyne. Preventing and Coping with Sleep Paralysis. Retrieved on 17 July, 2006.4. ^ Wills L, Garcia J. (2002) Parasomnias: epidemiology and management16(12):803-10.5. ^ lidérc, Magyar Néprajzi Lexikon, Akadémiai Kiadó, Budapest 1977, ISBN6. ^ boszorkány, Magyar Néprajzi Lexikon, Akadémiai Kiadó, Budapest 1977, ISBN7. ^ Aina OF, Famuyiwa OO (2007). "Ogun Oru: a traditional explanation for nocturnal neuropsychiatric disturbances among the Yoruba of Southwest Nigeria". Transcultural psychiatry 44 (1): 44-54. DOI:10.1177/1363461507074968. PMID 17379609. 8. ^ Bell CC, Shakoor B, Thompson B, Dew D, Hughley E, Mays R, Shorter-Gooden K (1984). "Prevalence of isolated sleep paralysis in black subjects". Journal of the National Medical Association 76 (5): 501-508. PMID 6737506. 9. ^ Bell CC, Dixie-Bell DD, Thompson B (1986). "Further studies on the prevalence of isolated sleep paralysis in black subjects". Journal of the National Medical Association 78 (7): 649-659. PMID 3746934. 10. ^ Paradis CM, Friedman S (2006). "Sleep Paralysis in African Americans with Panic Disorder". Transcultural psychiatry 43 (4): 692-694. PMID 15881272. 11. ^ Friedman S, Paradis CM, Hatch M (1994). "Characteristics of African-Americans and white patients with panic disorder and agoraphobia". Hospital and Community Psychiatry 45 (8): 798-803. PMID 7982696.
References
Bower, Bruce (July 9, 2005). "Night of the Crusher." Science News.
Conesa, J. (2000). Geomagnetic, cross-cultural and occupational faces of sleep paralysis: An ecological perspective. Sleep and Hypnosis, 2, (3), 105-111.
Conesa, J. (2002). Isolated Sleep Paralysis and Lucid Dreaming: Ten-year longitudinal case study and related dream frequencies, types, and categories. Sleep and Hypnosis, 4, (4), 132-143.
Conesa, J. (2003). Sleep Paralysis Signaling (SPS) As A Natural Cueing Method for the Generation and Maintenance of Lucid Dreaming. Presented at The 83rd Annual Convention of the Western Psychological Association, May 1 - 4, 2003 in Vancouver, BC, Canada.
Conesa-Sevilla, Jorge (2004). Wrestling With Ghosts: A Personal and Scientific Account of Sleep Paralysis. Pennsylvania: Xlibris/Randomhouse.
Firestone K. The “Old Hag”: sleep paralysis in Newfoundland. The Journal of Psychoanalytic Anthropology 1985; 8:47-66.
Fukuda K, Miyasita A, Inugami M, Ishihara K. High prevalence of isolated sleep paralysis: kanashibari phenomenon in Japan. Sleep 1987; 10:279-286.
Hartmann E. The nightmare: the psychology and biology of terrifying dreams. New York:Basic,1984.
Hufford D.J. The terror that comes in the night: an experience-centered study of supernatural assault traditions. Philadelphia:University of Pennsylvania Press, 1982
Kettlewell, N; Lipscomb, S; Evans, E. (June, 1993). "Differences in neuropsychological correlates between normals and those experiencing "Old Hag Attacks'." Perceptual and Motor Skills. 76 (3 Pt 1): 839-45; discussion 846. PMID 8321596
Ness RC. “The Old Hag” phenomenon as sleep paralysis: a bicultural interpretation . Culture, Medicine and Psychiatry 1978; 2:15-39.
Ohayon MM, Zulley J, Guilleminault C, Smirne, S. Prevalence and pathologic associations of sleep paralysis in the general population. Neurology, 1999; 52:1194-1200.
Sagan, Carl (1997). The Demon-Haunted World: Science as a Candle in the Dark.
Schneck JM. Sleep paralysis and microsomatognosia with special reference to hypnotherapy . The International Journal of Clinical and Experimental Hypnosis 1977; XXV:72-77.
Takeuchi T, Miyasita A, Sasaki Y, Inugami M, Fukuda K. Isolated sleep paralysis elicited by sleep interruption. American Sleep Disorders Association and Sleep Research Society, 1992; 15: 217-225.

Sunday, 17 February 2008

Atlas of Human History

Where do you really come from? And how did you get to where you live today? DNA studies suggest that all humans today descend from a group of African ancestors who—about 60,000 years ago—began a remarkable journey.
The Genographic Project is seeking to chart new knowledge about the migratory history of the human species by using sophisticated laboratory and computer analysis of DNA contributed by hundreds of thousands of people from around the world. In this unprecedented and real-time research effort, the Genographic Project is closing the gaps of what science knows today about humankind's ancient migration stories.
The Genographic Project is a five-year research partnership led by National Geographic Explorer-in-Residence Dr. Spencer Wells. Dr. Wells and a team of renowned international scientists and IBM researchers, are using cutting-edge genetic and computational technologies to analyze historical patterns in DNA from participants around the world to better understand our human genetic roots. The three components of the project are: to gather field research data in collaboration with indigenous and traditional peoples around the world; to invite the general public to join the project by purchasing a Genographic Project Public Participation Kit; and to use proceeds from Genographic Public Participation Kit sales to further field research and the Genographic Legacy Fund which in turn supports indigenous conservation and revitalization projects. The Project is anonymous, non-medical, non-political, non-profit and non-commercial and all results will be placed in the public domain following scientific peer publication.
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