Every part of the brain works together to support intelligence
12-13-2024

Every part of the brain works together to support intelligence

It’s fascinating to think about how our brains work. This squishy, soft organ tucked away in our skulls holds the reins of our thoughts, decisions, and knowledge. Despite how much our brains can do, there is still so much we don’t understand about them or their intelligence.

Jonas Thiele and Dr. Kirsten Hilger, who lead the “Networks of Behavior and Cognition” group at Julius-Maximilians-Universität Würzburg (JMU), are working to unlock the secrets of the brain.

The team’s recent study offers remarkable insights into intelligence and brain connectivity.

Predicting intelligence from brain connections

The study utilized data from the Human Connectome Project, a large-scale U.S.-based data-sharing initiative. Over 800 participants underwent fMRI scans, which measure changes in brain activity both at rest and while performing tasks.

The researchers focused on brain connectivity – the communication strength between different brain regions – to predict individual intelligence scores.

“Many studies predicting intelligence from brain connections have been published in the last years and they also achieve quite good predictive performance,” said Dr. Hilger.

Fundamental brain processes and intelligence

However, she noted that such predictions lack deeper meaning, as they fall short of matching the accuracy of traditional intelligence tests.

“We therefore intended to move away from the pure prediction of intelligence scores and instead better understand the fundamental processes in the brain. We hope that this will give us a better understanding of the neural code of individual differences in intelligence.”

Dr. Hilger encourages her peers to make it a priority to improve the conceptual understanding of human cognition, emphasizing interpretability in future studies.

Three types of intelligence

The study categorized intelligence into three distinct types:

  1. Fluid intelligence: This involves solving logical problems, recognizing patterns, and processing new information independent of prior knowledge or learned skills.
  2. Crystallized intelligence: This includes knowledge and skills acquired through life, such as general knowledge, experience, and language comprehension.
  3. General intelligence: A combination of fluid and crystallized intelligence.

The team achieved the best predictive performance with general intelligence, followed by crystallized and fluid intelligence.

Brain connections and intelligence

The JMU researchers explored various brain connections based on theoretical considerations and randomly selected connections.

A crucial finding emerged: the distribution and number of connections across the brain were more significant predictors of intelligence than the specific regions connected.

“The interchangeability of the selected connections suggests that intelligence is a global property of the whole brain,” said Dr. Hilger.

“We were able to predict intelligence not just from a specific set of brain connections, but from different combinations of connections distributed throughout the brain.”

Challenging established theories

Traditional intelligence theories often emphasize specific brain regions, such as the prefrontal cortex. However, this study’s findings suggest that additional brain regions’ connections also play a critical role.

“The connections of brain regions proposed in the most popular neurocognitive models of intelligence produced better results than randomly selected connections. However, the results were even better when complementary connections were added,” explained Dr. Hilger.

Path to future discoveries

The study’s results show that intelligence involves more complex and widespread brain connectivity than previously understood. These findings pave the way for future research into unexplored aspects of intelligence.

As Dr. Hilger emphasized, moving beyond predictive performance to deeper explanations is essential for advancing our understanding of human cognition.

Multiple factors that influence intelligence

Some studies suggest that genetics play a significant role in intelligence, with heritability estimates ranging from 50% to 80% in adults. Environmental factors, such as nutrition, education, and social interactions, also significantly impact intellectual development.

Studies have shown that bilingual individuals often exhibit better cognitive flexibility and problem-solving skills. Additionally, sleep quality directly affects cognitive functions like memory and decision-making.

Emotional intelligence, which involves understanding and managing emotions, is another critical aspect that contributes to overall success in personal and professional life.

Advanced imaging techniques have also revealed that higher intelligence is often associated with efficient neural networks rather than sheer brain activity. These findings continue to shape our understanding of intelligence, demonstrating its multifaceted nature.

The study is published in the journal PNAS Nexus.

—–

Like what you read? Subscribe to our newsletter for engaging articles, exclusive content, and the latest updates.

Check us out on EarthSnap, a free app brought to you by Eric Ralls and Earth.com.

—–

News coming your way
The biggest news about our planet delivered to you each day
Subscribe