On How Much of Intelligence and Personality is Heritable

Pedigree-based analyses found that genetic differences account for 50–80% of the variation of observable (phenotypic) traits. Personality traits account for 34–48% of the variance being explained by genetic differences. Molecular genetic studies have also found that intelligence and personality variables are heritable by 30% and 0-15% respectively. These types of studies may differ because platforms operating genetic makeup are poor at tagging causal, low minor allele frequency, copy number and structural variants. A group genotyped for ~700,000 single-nucleotide polymorphisms (SNPs) was used in order to exploit the high levels of linkage disequilibrium (LD) found in people who are related to evaluate the total effect of genetic variants that are not observable in unrelated individuals. Genetic variants in low LD with SNPs in their genetic makeup explain more than half of the genetic variance in intelligence, education, and neuroticism. These additional genetic effects will aid in approximating the heritability estimates from twin studies for intelligence and education, but not for neuroticism and extraversion. Our findings are then replicated using assigned molecular genetic data from unrelated individuals to show that ~50% of differences in intelligence, and ~40% of the differences in education, can be explained by genetic effects when a larger number of rare SNPs are present. An evolutionary genetic perspective states that a large addition of rare genetic variants to individual differences in intelligence, and education is consistent with a balance of mutation and selection.


Read also: Research

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Toward an Organizational Cognitive Neuroscience

The research strategy adopted in this article is to connect two different discourses and the ideas, methods, and outputs they contain—these being cognitive neuroscience and organization theory. The main contribution of the article is to present an agenda for the field of organizational cognitive neuroscience. We define what is meant by the term, outline its background, identify why it is important as a new research direction, and then conclude by drawing on Damasio’s levels of life regulation as a framework to bind together existing organizational cognitive neuroscience. The article begins by setting the wider debate behind the emergence of organizational cognitive neuroscience by revisiting the nature–nurture debate and uses Pinker to demonstrate that the connection between mind and matter has not been resolved, that new directions are opening up to better understand human nature, and that organizational cognitive neuroscience is one fruitful path forward.


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Blocking a key enzyme reverse memory loss

In the brains of Alzheimer’s patients, many of the genes required to form new memories are shut down by a genetic blockade, contributing to the cognitive decline seen in those patients.

MIT researchers have now shown that they can reverse that memory loss in mice by interfering with the enzyme that forms the blockade. The enzyme, known as HDAC2, turns genes off by condensing them so tightly that they can’t be expressed.


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Pregnant Mothers and Offspring Should Limit Added Sugars in Diet to Protect Childhood Cognition

Researchers warn pregnant women and their children to avoid drinking too many sodas, as excessive amounts of sugar in these drinks can negatively impact memory and learning. However, consuming fruits appears to be beneficial for cognitive development, the study reports.

A new study published in the American Journal of Preventive Medicine has determined that poorer childhood cognition occurred, particularly in memory and learning, when pregnant women or their offspring consumed greater quantities of sugar. Substituting diet soda for sugar-sweetened versions during pregnancy also appeared to have negative effects. However, children’s fruit consumption had beneficial effects and was associated with higher cognitive scores.


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Humans produce new brain cells throughout their lives

Humans continue to produce new neurons in a part of their brain involved in learning, memory and emotion throughout adulthood, scientists have revealed, countering previous theories that production stopped after adolescence. The findings could help in developing treatments for neurological conditions such as dementia.

Many new neurons are produced in the hippocampus in babies, but it has been a matter of hot debate whether this continues into adulthood – and if so, whether this rate drops with age as seen in mice and nonhuman primates.


Read also: The Birth of New Brain Cells

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Brain metabolism predicts intelligence

A healthy brain is critical to a person’s cognitive abilities, but measuring brain health can be a complicated endeavor. A new study by University of Illinois researchers reports that healthy brain metabolism corresponds with fluid intelligence – a measure of one’s ability to solve unusual or complex problems – in young adults.


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The cognitive processes behind mind wandering

It happens innocently enough: One minute you’re working on a report and the next minute you’re thinking about how you need to do laundry. Mind wandering is frequent and common. And while it can be counterproductive, research suggests that mind wandering isn’t necessarily a bad thing. New research explores mind wandering in various contexts, examining how it relates to cognitive processes involved in working memory and executive control.

It happens innocently enough: One minute you’re sitting at your desk, working on a report, and the next minute you’re thinking about how you probably need to do laundry and that you want to try the new restaurant down the street. Mind wandering is a frequent and common occurrence. And while mind wandering in certain situations — in class, for example — can be counterproductive, some research suggests that mind wandering isn’t necessarily a bad thing.


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How Happy Brains Respond to Negative Things

Recent research provides a whole new understanding of the brain’s amygdala—and suggests that happy people take the bad with the good.

You drop a glass while making breakfast. You get stuck in traffic on your way to work. Your boss yells at you for being late. Congratulations! You’re having a bad morning. It happens to everyone, at one time or another. But how we react to the bad things in life reveals a lot about our brains.


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Connections between neurons performing similar tasks shows how brain circuits are wired

Even the simplest networks of neurons in the brain are composed of millions of connections, and examining these vast networks is critical to understanding how the brain works.

An international team of researchers, led by R. Clay Reid, Wei Chung Allen Lee and Vincent Bonin from the Allen Institute for Brain Science, Harvard Medical School and Neuro-Electronics Research Flanders (NERF), respectively, has published the largest network to date of connections between neurons in the cortex, where high-level processing occurs, and have revealed several crucial elements of how networks in the brain are organized.


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Expectation may be essential to memory formation

A theory that links memory encoding to expectations of future relevance may better explain how human memory works, according to a team of Penn State psychologists.

Modern psychology posits two major theories to explain the mechanisms of how memories are formed. The first is object-based encoding, storing all information about an object in working memory. The second is feature-based encoding, selectively remembering aspects of an object. For example, if you watch a group of people playing basketball, under object-based encoding theory, the brain remembers all aspects of the ball. In feature-based encoding, the brain remembers that it saw a ball, but may have no recollection of the color if the color of the ball is an unnecessary feature according to the task at hand.


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