The Pharmaceutical Journal
Vol 276 No 7400 p572
13 May 2006

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Mystery of IQ and the shape of the brain more
Puzzling patterns in the desert are the work of prehistoric artists more
Ancient stones marked with a message more
Brain teaser more

Mystery of IQ and the shape of the brain

A fascinating investigation by psychiatrists in Maryland and Quebec is published in Nature for 30 March. The results suggest that the intelligence quotient in an individual is associated with changes that the brain undergoes during adolescence.

The study, which was carried out at the US National Institute of Mental Health, in Bethesda, Maryland, finds connections of intelligence with changes in the brain over the period of adolescence of a person. A group of some 300 children aged 6 to 19 were given tests of verbal and non-verbal abilities while the size of brain structures was determined by magnetic resonance imaging at two-year intervals. More than half the children had at least two scans and a third had three or more.

When groups were picked according to their initial IQ scores a characteristic pattern of changes in the brains of those with the highest scores emerged. The cortex, initially thinner than in children in other groups, rapidly gained depth to become thicker than normal during early teens. By the age of 19 all children had cortices of roughly equal thickness. The greatest development occurred in the prefrontal cortex, which controls planning and reasoning.

The social applications of the results are controversial. Although they might suggest new therapies for recovery after stroke, linking IQ and intellect may remain scientifically dubious and socially dangerous, according to some neuroscientists. Many other factors should be taken into account.

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Puzzling patterns in the desert are the work of prehistoric artists

In the 18 March issue of New Scientist there is an account of the mysterious designs that adorn the hills of the Atacama Desert in Chile — giant figures of people and animals that were apparently carved out of the landscape by prehistoric artists. The purpose of the carvings remains unknown. Some observers have pronounced them to be directions, designed by nomadic tribes to guide passing llama caravans through the intolerably dry wilderness. Others, more fancifully, have suggested some kind of communication with aliens from another world.

However, intense debate reigns over who was responsible for these so-called geoglyphs and how long ago they were undertaken. It is agreed that dating them is difficult, according to an expert from the University of California in Los Angeles who has made a study of geoglyphs in the Tarapacá region of north Chile. And if dating proves impossible, there is only a scant chance of discovering who made them. Most of the stylised representations of people and animals were made by scraping away an oxidised layer of soil.

Another expert, from the University of Tarapacá, Arica, has made a systematic study of thousands of geoglyphs in southern Peru and northern Chile. The concentration found in the Atacama makes a contrast with the few such figures known to exist elsewhere in the world, such as the famous chalk figures in southern England. Atacama geoglyphs show regional patterns, some being geometric and others depicting eagles, herons, monkeys and humans, suggestive of the Amazon region. Some outline squares, which have a filling of fine gravel, have been regarded as representative of a ritual corral like that used by the Incas.

The fact that the geoglyphs often occur near fresh water supports the theory that they were caravan guideposts. But equally, they might be due to different ethnic groups marking out symbolic territories, and therefore be attributable to settled farmers rather than wandering nomads. Since irrigation cultures in the desert probably derive from about 1000BC, we might be able to put a date to some geoglyphs.

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Ancient stones marked with a message

Ogham, or Ogam, is the name of the alphabet in use among the ancient Irish and British inhabitants of our islands. It comprised 20 characters, each of which contained one to five thin strokes grouped above, below or across a horizontal line. Their name derives from the name of a Gaulish god, Ogma, who was claimed to be similar to Hercules, and who was adept at languages and eloquence.

Tall stones bearing these strange markings, and presenting the earliest evidence of a written Celtic language, have been discovered in many places in Ireland and Scotland. The ancient Irish believed the stones were ceremonial objects carved by pre-Christian pagans, but more recent research suggests they were in fact carved by early Christians.

According to Professor Damien McManus of Trinity College, Dublin, in a note published in Science for 7 April, the stones were carved not for rituals but to mark territory and burial sites. Altogether, about 400 Ogham stones have been found, ranging in length from one to five metres and weighing up to two tons.

McManus examined a collection of 28 newly cleaned and restored Oghams held at University College, Cork. These have Celtic crosses etched into them, and the words inscribed have Latin endings. The texts of the later stones show Latin as well as Ogham texts and the evidence indicates that they were inscribed by early Irish Christians between the fifth and seventh centuries.

The crosses are thought to have been added by Christians who sought to erase pagan signs from their own culture. Their prime purpose, it has been concluded, was to mark territorial boundaries and/or the site of a burial.

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And I quote…

Brain teaser
“Because we don’t understand the brain very well we’re constantly tempted to use the latest technology as a model for trying to understand it. In my childhood we were always assured that the brain was a telephone switchboard. (What else could it be?) And I was amused to see that Sherrington, the great British neuroscientist, thought that the brain worked like a telegraph system. Freud often compared the brain to hydraulic and electromagnetic systems. Leibniz compared it to a mill, and now, obviously, the metaphor is the digital computer.”

—John R. Searle, professor of philosophy, University of California, Berkeley (born 1932).

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