The Times Australia
The Times World News

.
The Times Real Estate

.

Have we got the brain all wrong? A new study shows its shape is more important than its wiring

  • Written by James Pang, Research Fellow in Psychology, Monash University
Have we got the brain all wrong? A new study shows its shape is more important than its wiring

The human brain is made up of around 86 billion neurons, linked by trillions of connections. For decades, scientists have believed that we need to map this intricate connectivity in detail to understand how the structured patterns of activity defining our thoughts, feelings and behaviour emerge.

Our new study, published in Nature[1], challenges this view. We have discovered that patterns of activity in our neurons are more influenced by the shape of the brain – its grooves, contours, and folds – than by its complex interconnections.

The conventional view is that specific thoughts or sensations elicit activity in specific parts of the brain. However, our study reveals structured patterns of activity across nearly the entire brain, relating to thoughts and sensations in much the same way that a musical note arises from vibrations occurring along the entire length of a violin string, not just an isolated segment.

Function follows form

We uncovered this close relationship between shape and function by examining the natural patterns of excitation that can be supported by the anatomy of the brain. In these patterns, called “eigenmodes”, different parts of the brain are all excited at the same frequency.

Consider the musical notes played by a violin string. The notes arise from preferred vibrational patterns of the string that occur at specific, resonant frequencies. These preferred patterns are the eigenmodes of the string. They are determined by the string’s physical properties, such as its length, density, and tension.

In a similar way, the brain has its own preferred patterns of excitation, which are determined by its anatomical and physical properties. We set out to identify which specific anatomical properties of the brain most strongly affect these patterns.

A tale of two brains

According to conventional wisdom, the brain’s complex web of connections fundamentally sculpts its activity[2].

This perspective views the brain as a collection of discrete regions[3], each specialised for a specific function, such as vision or speech. These regions communicate[4] via interconnecting fibres called axons.

An illustration of a brain, showing one half as a web of dots and lines, and the other as a convoluted surface with wave patterns regions shaded red and blue.
Conventional models divide the brain into a web of discrete nodes. Our analysis suggests large-scale brain activity is instead dominated by waves of excitation. James Pang, Author provided

An alternative view, embodied by an approach to modelling brain activity called neural field theory[5], eschews this division of the brain into discrete areas.

This view focuses on how waves of cellular excitation[6] move continuously through brain tissue, like the ripples formed by raindrops falling into a pond. Just as the shape of the pond constrains the possible patterns formed by the ripples, wavelike patterns of activity are influenced by the three-dimensional shape[7] of the brain.

Comparing the two views

To compare the two views of the brain, we tested how easily the conventional, discrete view and the continuous, wave-based view can explain more than 10,000 different maps of brain activity[8]. The activity maps were obtained from thousands of functional magnetic resonance imaging (fMRI) experiments as people performed a wide array of cognitive, emotional, sensory, and motor tasks.

Read more: Electricity flow in the human brain can be predicted using the simple maths of networks, new study reveals[9]

We attempted to describe each activity map using eigenmodes based on the brain’s connectivity and eigenmodes based on the brain’s shape. We found that eigenmodes of brain shape – not connectivity – offer the most accurate account of these different activation patterns.

Brain waves and icebergs

We used computer simulations to confirm that the close link between brain shape and function is driven by wavelike activity propagating throughout the brain.

The simulations relied on a simple wave model that is widely used to study other physical phenomena, such as earthquakes and ocean currents. The model only uses the shape of the brain to constrain how the waves evolve through time and space.

An animation showing multicoloured waves of activity propagating around the brain. Simulations of waves in the brain resemble real activity. James Pang, Author provided

Despite its simplicity, this model explained brain activity better than a more sophisticated, state-of-the-art model[10] that tries to capture key physiological details of neuronal activity and the intricate pattern of connectivity between different brain regions.

We also found that most of the 10,000 different brain maps that we studied were associated with activity patterns spanning nearly the entire brain. This result again challenges conventional wisdom that activity during tasks occurs in discrete, isolated regions of the brain. In fact, it indicates that traditional approaches to brain mapping[11] may only reveal the tip of the iceberg when it comes to understanding how the brain works.

Together, our findings suggest that current models of brain function need to be updated. Rather than focusing solely on how signals pass between discrete regions, we should also investigate how waves of excitation travel through the brain.

In other words, ripples in a pond may be a more appropriate analogy for large-scale brain function than a telecommunication network.

A new approach to brain mapping

Our approach draws on centuries of work in physics and engineering. In these fields, the function of a system is understood with respect to the constraints imposed by its structure, as embodied by the system’s eigenmodes.

This approach has not been traditionally used in neuroscience. Instead, typical brain mapping methods rely on complex statistics to quantify brain activity[12] without any reference to the underlying physical and anatomical basis of those patterns.

The use of eigenmodes offers a way to use physical principles to understand how diverse patterns of activity arise from brain anatomy.

Our discovery also offers immediate practical benefits, since eigenmodes of brain shape are much simpler to quantify than those of brain connectivity.

This new approach opens possibilities for studying how brain shape affects function through evolution, development and ageing, and in brain disease.

Read more: Illuminating the brain one neuron and synapse at a time – 5 essential reads about how researchers are using new tools to map its structure and function[13]

References

  1. ^ Nature (doi.org)
  2. ^ fundamentally sculpts its activity (www.pnas.org)
  3. ^ discrete regions (www.nature.com)
  4. ^ communicate (www.nature.com)
  5. ^ neural field theory (mna.episciences.org)
  6. ^ waves of cellular excitation (www.nature.com)
  7. ^ influenced by the three-dimensional shape (www.sciencedirect.com)
  8. ^ 10,000 different maps of brain activity (neurovault.org)
  9. ^ Electricity flow in the human brain can be predicted using the simple maths of networks, new study reveals (theconversation.com)
  10. ^ state-of-the-art model (www.jneurosci.org)
  11. ^ traditional approaches to brain mapping (www.sciencedirect.com)
  12. ^ complex statistics to quantify brain activity (onlinelibrary.wiley.com)
  13. ^ Illuminating the brain one neuron and synapse at a time – 5 essential reads about how researchers are using new tools to map its structure and function (theconversation.com)

Read more https://theconversation.com/have-we-got-the-brain-all-wrong-a-new-study-shows-its-shape-is-more-important-than-its-wiring-206573

The Times Features

Why Regional Small Businesses in Bendigo Deserve Better Access to Finance in 2025

In the heart of regional Victoria, Bendigo has long stood as a beacon of innovation, resilience and community spirit. As we step further into 2025, the importance of nurturing sm...

Is It Time for a Deep Cleaning? Signs You Shouldn’t Ignore

Most people know they should visit the dentist for a regular check-up and cleaning every six months. But sometimes, a standard cleaning isn’t enough. When plaque and tartar build...

The Hidden Meaning Behind Popular Engagement Ring Cuts

When it comes to engagement rings, the cut of the diamond is not just about aesthetics. Each shape carries its own symbolism and significance, making it an important decision for...

Annual Health Exams in the Office: How They Can Reduce Sick Days and Healthcare Costs

Regular health check-ups, especially annual health exams in the office, can significantly impact the overall well-being of your workforce. A proactive approach to employee health...

Best Deals on Home Furniture Online

Key Highlights Discover the best deals on high-quality outdoor furniture online. Transform your outdoor space into a stylish and comfortable oasis. Explore a wide range of d...

Discover the Best Women's Jumpers for Every Season

Key Highlights Explore lightweight jumpers for spring and summer, ensuring breathability and ease. Wrap up warm with cozy wool jumpers for the chilly autumn and winter season...

Times Magazine

The Essential Guide to Transforming Office Spaces for Maximum Efficiency

Why Office Fitouts MatterA well-designed office can make all the difference in productivity, employee satisfaction, and client impressions. Businesses of all sizes are investing in updated office spaces to create environments that foster collaborat...

The A/B Testing Revolution: How AI Optimized Landing Pages Without Human Input

A/B testing was always integral to the web-based marketing world. Was there a button that converted better? Marketing could pit one against the other and see which option worked better. This was always through human observation, and over time, as d...

Using Countdown Timers in Email: Do They Really Increase Conversions?

In a world that's always on, where marketers are attempting to entice a subscriber and get them to convert on the same screen with one email, the power of urgency is sometimes the essential element needed. One of the most popular ways to create urg...

Types of Software Consultants

In today's technology-driven world, businesses often seek the expertise of software consultants to navigate complex software needs. There are several types of software consultants, including solution architects, project managers, and user experienc...

CWU Assistive Tech Hub is Changing Lives: Win a Free Rollator Walker This Easter!

🌟 Mobility. Independence. Community. All in One. This Easter, the CWU Assistive Tech Hub is pleased to support the Banyule community by giving away a rollator walker. The giveaway will take place during the Macleod Village Easter Egg Hunt & Ma...

"Eternal Nurture" by Cara Barilla: A Timeless Collection of Wisdom and Healing

Renowned Sydney-born author and educator Cara Barilla has released her latest book, Eternal Nurture, a profound collection of inspirational quotes designed to support mindfulness, emotional healing, and personal growth. With a deep commitment to ...

LayBy Shopping