Intelligence  

New research shows that infections can impair cognitive ability measured on an IQ scale. The study is the largest of its kind to date, and it shows a clear correlation between infection levels and impaired cognition.

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nyone can suffer from an infection, for example in their stomach, urinary tract or skin. However, a new Danish study shows that a patient’s distress does not necessarily end once the infection has been treated. In fact, ensuing infections can affect your cognitive ability measured by an IQ test:

“Our research shows a correlation between hospitalization due to infection and impaired cognition corresponding to an IQ score of 1.76 lower than the average. People with five or more hospital contacts with infections had an IQ score of 9.44 lower than the average. The study thus shows a clear dose-response relationship between the number of infections, and the effect on cognitive ability increased with the temporal proximity of the last infection and with the severity of the infection. Infections in the brain affected the cognitive ability the most, but many other types of infections severe enough to require hospitalization can also impair a patient’s cognitive ability. Moreover, it seems that the immune system itself can affect the brain to such an extent that the person’s cognitive ability measured by an IQ test will also be impaired many years after the infection has been cured,” explains MD and PhD Michael Eriksen Benrós, who is affiliated with the National Centre for Register-Based Research at Aarhus BSS and the Mental Health Centre Copenhagen, University of Copenhagen.

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He has conducted the research in collaboration with researchers from the University of Copenhagen and Aarhus University. 190,000 Danes participated in the study who have had their IQ assessed between 2006 and 2012. 35% of these individuals had a hospital contact with infections before the IQ testing was conducted.

According to Benrós, part of the explanation of the increased risk of impaired cognition following an infection may be as follows:

“Infections can affect the brain directly, but also through peripheral inflammation, which affects the brain and our mental capacity. Infections have previously been associated with both depression and schizophrenia, and it has also been proven to affect the cognitive ability of patients suffering from dementia. This is the first major study to suggest that infections can also affect the brain and the cognitive ability in healthy individuals.”

"This is the first major study to suggest that infections can also affect the brain and the cognitive ability in healthy individuals."

“We can see that the brain is affected by all types of infections. Therefore, it is important that more research is conducted into the mechanisms which lie behind the connection between a person’s immune system and mental health,” says Benrós.

He hopes that learning more about this connection will help to prevent the impairment of people’s mental health and improve future treatment.

Experiments on animals have previously shown that the immune system can affect cognitive capabilities, and more recent minor studies in humans have also pointed in that direction. Normally, the brain is protected from the immune system, but with infections and inflammation the brain may be affected. Benrós’ research suggests that it may be the immune system that causes the cognitive impairment, not just the infection, because many different types of infections were associated with a decrease in cognitive abilities.

This is the first study to examine these correlations in this manner. The results suggest that the immune system’s response to infections can possibly affect the brain and thereby also the person’s cognitive ability. This is in line with previous studies, some of which have also been conducted by Benrós, which show that infections are associated with an increased risk of developing mental disorders such as depression or schizophrenia.

The researchers behind the study hope that their results may spur on further research on the possible involvement of the pin the development of psychiatric disorders and whether the discovered correlations contribute to the development of mental disorders or whether they may be caused by e.g. genetic liability toward acquiring infections in patients with reduced cognitive ability. The study has been adjusted for social conditions and parental educational levels; however, it cannot be ruled out that heritable and environmental factors associated with infections might also influence the associations.


SOURCE  Aarhus University

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 Intelligence  

The Flynn effect is the substantial increase in average scores on intelligence tests all over the world over the last century. In a recent TED Talk, the discoverer of the effect, James Flynn talks about how changes in the way we think have had surprising (and not always positive) consequences.

The Flynn effect — the fact that each generation scores higher on an IQ test than the generation before it. Are we actually getting smarter, or just thinking differently? In a fast-paced spin through the cognitive history of the 20th century, moral philosopher James Flynn suggests that changes in the way we think have had surprising (and not always positive) consequences.

IQ tests are updated periodically. For example, the Wechsler Intelligence Scale for Children (WISC), originally developed in 1949, was updated in 1974 and 1991. The revised versions are standardized to 100 using new standardization samples.

In ordinary use IQ tests are scored with respect to those standardization samples. The only way to compare the difficulty of two versions of a test is to conduct a separate study in which the same subjects take both versions. Doing so confirms IQ gains over time.

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The average rate of increase seems to be about three IQ points per decade in the US on tests such as the WISC. The increasing raw scores appear on every major test, in every age range and in every modern industrialized country although not necessarily at the same rate as in the US using the WISC.

The increase has been continuous and roughly linear from the earliest days of testing to the present. Though the effect is most associated with IQ increases, a similar effect has been found with increases of semantic and episodic memory.

Flynn is a  New Zealand-based researcher who discovered the effect of intelligence changes, believes that environmental factors play a greater role in intelligence than genetics does.

His latest findings, discussed in his 2012 book Are We Getting Smarter?: Rising IQ in the Twenty-First Century, also suggest that women are not only as intelligent as men, but superior when it comes to executive function. “Women, when exposed to modernity, do equal men for IQ,” Flynn said to TV ONE’s Greg Boyed. “But in the formal educational setting where they apply their intelligence, they’re outperforming men all hollow.”

Flynn, a retired university professor, has written extensively about the connection between ongoing equality and IQ gains, democracy and human rights. He also wrote a compelling book about books, The Torchlight List, in which he lists 200 must-reads.

Flynn also has researched how to improve intelligence. Each day our minds experience a deluge of conversation, lectures, newspapers, TV, the Internet, and more. But what should we really be paying attention to? Flynn poses the most challenging question of all: Who is to be the master of all this information – you or the modern world? It is you, he claims, who must be the gatekeeper that filters out what is worth remembering. Otherwise you may find yourself at the mercy of a life that you can only manage day by day.

His book, How To Improve Your Mind offers great insights into how to become an information master in the age of information overload.


SOURCE  TED

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