Linking how brain structure is related to basic personality traits is a crucial step to improving our understanding of the link between the brain morphology and particular mood, cognitive, or behavioural disorders.
- Luca Passamonti
According to psychologists, the extraordinary variety of human personality can be broken down into the so-called ‘Big Five’ personality traits, namely neuroticism (how moody a person is), extraversion (how enthusiastic a person is), openness (how open-minded a person is), agreeableness (a measure of altruism), and conscientiousness (a measure of self-control).
In a study published in the journal Social Cognitive and Affective Neuroscience, an international team of researchers from the UK, US, and Italy have analysed a brain imaging dataset from over 500 individuals that has been made publicly available by the Human Connectome Project, a major US initiative funded by the National Institutes of Health. In particular, the researchers looked at differences in the brain cortical anatomy (the structure of the outer layer of the brain) as indexed by three measures – the thickness, area, and amount of folding in the cortex – and how these measures related to the Big Five personality traits.
“Evolution has shaped our brain anatomy in a way that maximizes its area and folding at the expense of reduced thickness of the cortex,” explains Dr Luca Passamonti from the Department of Clinical Neurosciences at the University of Cambridge. “It’s like stretching and folding a rubber sheet – this increases the surface area, but at the same time the sheet itself becomes thinner. We refer to this as the ‘cortical stretching hypothesis’.”
“Cortical stretching is a key evolutionary mechanism that enabled human brains to expand rapidly while still fitting into our skulls, which grew at a slower rate than the brain,” adds Professor Antonio Terracciano from the Department of Geriatrics at the Florida State University. “Interestingly, this same process occurs as we develop and grow in the womb and throughout childhood, adolescence, and into adulthood: the thickness of the cortex tends to decrease while the area and folding increase.”
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Image:Drain Brain Spider
Credit: darkday
Reproduced courtesy of the University of Cambridge
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