Information addiction: How information is like snacks, money, and drugs to your brain

“To the brain, information is its own reward, above and beyond whether it’s useful,” said Assoc. Prof. Ming Hsu, a neuroeconomist whose research employs functional magnetic imaging (fMRI), psychological theory, economic modeling, and machine learning. “And just as our brains like empty calories from junk food, they can overvalue information that makes us feel good but may not be useful–what some may call idle curiosity.”


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Genetics of Personality

In this article, the findings from behavioral genetic studies of personality are summarized, including twin and adoption studies estimating heritability as well as molecular genetic studies of candidate genes and genome-wide association studies. Studies of biological markers and other personality correlates are also reviewed, with suggestions for future directions in genetic studies of personality. An overview of personality theories and assessment instruments of personality is also provided.


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The causal influence of brain size on human intelligence

There exists a moderate correlation between MRI-measured brain size and the general factor of IQ performance (g), but the question of whether the association reflects a theoretically important causal relationship or spurious confounding remains somewhat open. Previous small studies (n 〈100) looking for the persistence of this correlation within families failed to find a tendency for the sibling with the larger brain to obtain a higher test score. We studied the within-family relationship between brain volume and intelligence in the much larger sample provided by the Human Connectome Project (n = 1022) and found a highly significant correlation (disattenuated ρ = 0.18, p<.001). We replicated this result in the Minnesota Center for Twin and Family Research (n = 2698), finding a highly significant within-family correlation between head circumference and intelligence (disattenuated ρ = 0.19, p<.001). We also employed novel methods of causal inference relying on summary statistics from genome-wide association studies (GWAS) of head size (n ≈ 10,000) and measures of cognition (257,000 <n< 767,000). Using bivariate LD Score regression, we found a genetic correlation between intracranial volume (ICV) and years of education (EduYears) of 0.41 (p<.001). Using the Latent Causal Variable method, we found a genetic causality proportion of 0.72 (p<.001); thus the genetic correlation arises from an asymmetric pattern, extending to sub-significant loci, of genetic variants associated with ICV also being associated with EduYears but many genetic variants associated with EduYears not being associated with ICV. This is the pattern of genetic results expected from a causal effect of brain size on intelligence. These findings give reason to take up the hypothesis that the dramatic increase in brain volume over the course of human evolution has been the result of natural selection favoring general intelligence.


Posted in Brains, Intelligence | Tagged ,

The Mystery of Intelligence

Few questions have generated such passionate discussions in the scientific community than those related to intelligence and intelligence testing. To give some examples: Arthur Jensen (1969) published an article in the Harvard Educational Review (HER) titled “How much can we boost IQ and scholastic achievement?,” in which he argued that compensatory education in the US failed to produce lasting beneficial effects on children’s intelligence quotient (IQ) and achievement, therefore the premises on which these programs were based should be reexamined. Nine years later, he admitted that the firestorm that was ignited by his writing came as an unpleasant surprise. Less than 10% of the 123 pages long article dealt with ethnical differences suggesting that genetic factors may be the reason for the one standard deviation lower performance of Afro-Americans as compared to whites. The reaction was “swift and severe,” with regular near-riotous demonstrations by students at colleges where Jensen was invited to speak. His office was picketed and his classes were regularly disrupted or when lecturing at other universities, canceled at the last minute. Students’ newspapers were filled for weeks with fierce statements against his research, suggesting that the university should get rid of him. The violence of student activists escalated to the point to which it threatened to get out of control. At that time, the campus police assigned two bodyguards to accompany Jensen around campus (Snyderman and Rothman, 1988). Even 9 years later and, as far as Australia, there was still a need for police protection (Jensen, 1978).


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The Idea of Social Science

Can human studies be scientific? The question is addressed by considering four others. What does it take for a subject to be scientific? Why does the issue matter? What are the impediments to human studies achieving standing as sciences? How are human studies to be classified if not as sciences? The potential impediments are the complexity of human phenomena, their instability over time, and the fact that they are always already ‘pre-interpreted’ by ordinary social agents. Alternative understandings of human studies are literature, critique, and ideology. Crucially, the issue matters because of the institutional status which being a science confers.


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The adaptive Human Parental Brain: implications for children’s social development

Although interest in the neurobiology of parent-infant bonding is a century old, neuroimaging of the human parental brain is recent. After summarizing current comparative research into the neurobiology of parenting, here I chart a global ‘parental caregiving’ network that integrates conserved structures supporting mammalian caregiving with later-evolving networks and implicates parenting in the evolution of higher order social functions aimed at maximizing infant survival. The response of the parental brain to bonding-related behavior and hormones, particularly oxytocin, and increased postpartum brain plasticity demonstrate adaptation to infant stimuli, childrearing experiences, and cultural contexts. Mechanisms of biobehavioral synchrony by which the parental brain shapes, and is shaped by, infant physiology and behavior emphasize the brain basis of caregiving for the cross-generation transmission of human sociality.


Posted in Human brains, human parental brain, Parental care, Parents | Tagged , , ,

Neural Reuse and the Evolution of Higher Cognition

Harvard psychologist Steven Pinker recently examined a problem with understanding human cognition, particularly how the processes of biological evolution could explain the human ability to think abstractly, including the higher cognitive abilities for logic and math (hereafter, HCAs). Pinker credits the formulation of the problem of understanding human cognition and the evolutionary development of HCAs to the co-discoverer of evolution by natural selection, Alfred Russell Wallace. Pinker states the following response to the question raised by Wallace:

…Nonetheless it is appropriate to engage the profound puzzle [Wallace] raised; namely, why do humans have the ability to pursue abstract intellectual feats such as science, mathematics, philosophy, and law, given that opportunities to exercise these talents did not exist in the foraging lifestyle in which humans evolved and would not have parlayed themselves into advantages in survival and reproduction even if they did?


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Children’s brains – Just How Bad Is Kids’ Smartphone Addiction?

The average American teenager who uses a smartphone receives her first phone at age 10 and spends over 4.5 hours a day on it (excluding texting and talking). 78% of teens check their phones at least hourly and 50% report feeling ‘addicted’ to their phones. It would defy common sense to argue that this level of usage, by children whose brains are still developing, is not having at least some impact, or that the maker of such a powerful product has no role to play in helping parents to ensure it is being used optimally. It is also no secret that social media sites and applications for which the iPhone and iPad are a primary gateway are usually designed to be as addictive and time-consuming as possible, as many of their original creators have publicly acknowledged.


Posted in Brains, Children, Smartphone | Tagged , ,

Nutrition and the Brain

Your brain is like a car. A car needs a gasoline, oil, brake fluid and other materials to run properly. Your brain also needs special materials to run properly: glucose, vitamins, minerals and other essential chemicals. For example, the fuel (energy) for your brain is glucose. You can get glucose by eating carbohydrates or other foods that can be converted to glucose.

Your brain must manufacture the right proteins and fats to do things such as grow new connections or add myelin, the fatty sheath to axons. You do this by digesting proteins and fats in food and using the pieces, that is, the amino acids and fatty acids, to make the new brain proteins and fats. Without the correct amount and balance of particular building blocks, your brain will not work properly. Too little (deficiency) or too much (overabundance) of the necessary nutrient can affect the nervous system. (For a table that shows the effects of too little or too much of specific nutrients, please see Nutrient Effects on the Nervous System.)


Read also: Foods that Help Keep Your Mind Healthy

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Art, Music, and the Brain: Biological Benefits of Making Music

Nina Kraus, professor at Northwestern University, discusses how our brains process sound, and how making music can help offset language deficiencies.

Posted in Arts, Biology, Brains, Music | Tagged , , ,