Category Archives: Science Communicators

Usage of mathematics for an understanding of how the brain functions

When a tree falls in the middle of a forest and nobody heard it falling, can it be considered as a sound? Well, to answer this question, mathematics can guide us to understand how our vision and hearing works.

Priscilla Greenwood, a mathematicians and  Lawrence Ward, a neuroscientist at the University of British Columbia worked together on a research that explains how we perceive the things that occur around us as a part of our brain receives signals. Based on the enough patterns of the signals that occur when we use our senses, it is possible for a computer to imitate a real brain.

A part of our brain that lights up when we perceive things around us
Photo Credit: Flickr

To understand the pattern of the signals that our brains receive, we first need to encounter the shape of a Mexican hat, which is a shape of a tiny area of nerves that changes when we see an image. The pointy part of the diagram below shows the area of focus where the nerves respond the most and the dented area represents the area that we mostly ignore when encountering an image. In other words, as we pay more attention to a specific area, we automatically pay less attention to other areas.

A diagram of the Mexican Hat.
Image from https://commons.wikimedia.org/wiki/Category:Spontaneous_symmetry_breaking#/media/File:Mexican_hat_potential_polar.svg

We had the opportunity to interview Dr. Ward about the research for the better understanding of the concepts. Dr. Ward elaborated more on the activity of the tiny neurons in our brains in patterns, which matches with a shape of sombrero (similar to the Mexican hat shape). Listen to the explanation of their research in the following podcast.

Podcast credit: Kang Zhihao

Why did they choose the Mexican hat equation particularly to explain how we perceive the randomness of things? It is because it is a most suitable way to describe the aspects of brain activity and the pairing of the neurons and to calculate how we perceive sights around us. In the video below, Dr. Ward describes how a form of wave  of neural activity exist in our brain that varies according to the level of activity based on the activity of our senses.

What can we do with the information from this research? The important findings of this study may help us to construct a model that has a similar level of intelligence that a real brain consists. Also, the mathematics can be applied to recreate brain simulations possibly in the future, but the real brain still outlasts the machines. The answer to the question that was asked in the beginning, is that in order for us to hear the tree that falls in the middle of the forest depends on how high can the Mexican hat of our brain be.

-Group 5: Aaron yen, Zhihao Kang, Huanxin Zhang, Victoria Park

Video credit:

o Pattern Dynamics of Reaction Diffusion Equation: ak0amay Published on Oct 10, 2015 o Brain model: Growing a Brain Pattern: Particle Skull, Published on Jul 9, 2014 o What Are Brain Waves?: MinuteEarth, Published on Nov 7, 2017 o The brain waves when noised involved: Relaxing White Noise, Published on Feb 10, 2015 o Brain patterns in math: École polytechnique fédérale de Lausanne (EPFL), Published on Jun 12, 2017 Thanks to Dr. Janet Ochola and Dr. Andrew Trites for guidance and advice during the project. Thanks to Dr. Priscilla Greenwood for the insight and Dr. Lawrence Ward for the explanations.

Audio credit:

The background musics are public domain and licensed from y.qq.com

Video

Stephen Hawking and the ALS disease

Dr Stephen Hawking Physics professor and author at Cambridge University

Less than a week ago, beloved cosmologist and theoretical physicist Stephen Hawking, science’s brightest star, died at the age of 76 in the morning on Mar.14. His brilliance and persistence has inspired people around the world. People who are not specialist in physics may have not heard of his four laws of black hole mechanics or the Hawking radiation, but often have heard of his courageous story and lifelong battle with the amyotrophic lateral sclerosis disease (ALS).

While studying at Oxford, the young Stephen Hawking was diagnosed with ALS – a disease that causes death of neurons and gradually paralyses voluntary muscles – at the age of 21, in 1963. The doctor gave him a life expectancy of less than three years, but Stephen Hawking have defied the odds and coped with the daunting disease for over half a century. He spent 30 years as mathematics professors at the University of Cambridge, published the world-renowned The Universe in a Nutshell and A Briefer History of Time, which introduced cutting edge findings in theoretical physics to millions of readers. While Lou Gehrig and other people that suffer from ALS usually succumb in less than ten years, why has Hawking beat the odds and lived with the formidable disease?

Illustration of a normal nerve structure (left) and an ALS affected nerve cell (right)

Amyotrophic lateral sclerosis is a highly variable disorder and can be classified a few different ways: by where the motor neuron is first affected, and by how fast the disease progresses. Hawking was an outlier, the neurons that control the diaphragm and swallowing muscle are not severely deteriorated, that means breathing muscle functions properly, malnutrition and dehydration which are often found in other cases would not be seen on Hawking.

The disorder progression also tends to be slower in people with onset at less than 40 years old, the reason behind this remains unknown. Hawking’s case is very similar to juvenile amyotrophic lateral sclerosis, which progresses very slowly and have a life expectancy of more than 30 years. And like his mind, Hawking’s illness seems to be singular. Hawking’s longevity is partly due to the excellent care that he received, and more importantly – the biology of his form of the neurodegenerative disease. Stephen Hawking’s case is a unique example of the variability of the disease, he not only gives hope to patient who also suffer from the ALS disease, but also inspires millions for his determination to fight against the odds.

Stephen Hawking’s contribution to physics and cosmology will live in the annals of science forever.

Jogging Your Memory: Aerobic Exercise and Its Positive Implications on Memory Retention

Do you own a pair of runners that haven’t been worn in a while and is now collecting dust on your shoe rack? Science suggests – you may want to put them to use again.

Emerging studies shown that aerobic exercise can slow down aging of the brain and have positive implications on cognitive abilities such as memory retention. Several studies shown that individuals who regularly exercise occupy larger volumes of the brain involved in memory compared to individuals that do not exercise.

What exactly is it about physical exercise that has such an impact you might ask?
Upon light to intense levels of aerobic exercise, the body produces a spectrum of signalling chemicals. One of the chemicals that gets released yields the production of a very important protein called brain-derived neurotrophic factor (BDNF) which gets released in the brain and muscles. When produced in the body, BDNF maintains existing brain cells, promotes the growth of new blood vessels in the brain and encourages growth of the hippocampus, a region of the brain that is associated with memory.

Figure 1. Anatomy of brain. Source: Anatomy & Physiology, Connexions Web site

Why this should concern you.

The size of the hippocampus decreases with age which often leads to memory decline and decrease in mental efficiency. In many older adults, cognitive deficits are commonly associated with old age. Researchers estimate that by 2050, there will be more than 115 million people that will suffer dementia globally. However, evidence shows that memory decline and aging of the hippocampus can be reduced and ultimately lower chances of dementia by exercising regularly.

Is one form of exercise more beneficial than the other?

As of now, researchers have not yet found an answer. The reason being is that most of the studies conducted only experimented with walking and/or running. However, it is suggested from the studies available that any type of exercise that would be able to elevate the heart rate to a certain level would produce these cognitive benefits.

As someone who enjoys being physically active and mainly weight trains, I was astonished about the benefits of aerobic exercise – all of this was new information to me. Ever since I learned further about these benefits of aerobic exercise, I have incorporated running to achieve a healthier, more cognitively efficient brain.

Figure 2. Man running. Source: Kyle Cassidy

If you are physically able to exercise and do not currently do so, I hope this post encourages you to reach for your pair of runners, go out, and “jog your memory”.

It is never too late to start exercising.

– Aron Ha