What Does Grey Matter in the Brain Do?

Grey matter is a key component of the brain’s neural tissue. It’s found in both the brain and spinal cord and is composed of the neuronal cell bodies that make up the central nervous system (CNS). The highest concentration of grey matter is in the cerebellum of the brain, and grey matter extends into the spinal cord as well.

“Grey matter refers to the areas of the brain that contain large concentrations of neurons,” says Andrew Tarulli, MD, neurologist and chairman of the department of neuroscience at Overlook Medical Center and director of the neuroscience service for Atlantic Health System. “The cell bodies for most cognitive and emotional functions reside in the grey matter.” Grey matter is essential for all aspects of human behavior, Dr Tarulli notes.

Grey Matter vs. White Matter

Our central nervous system is composed of a combination of white and grey matter. Grey matter is found in the outer layer of the brain and is greyish in color. Both grey and white matter are important components of the brain, but grey matter plays a larger role in our day-to-day functioning.

According to Colleen Hanlon, Ph.D., neurobiologist and BrainsWay Vice President of Medical Affairs, white matter acts like a communicator between different areas of grey matter in the brain. Grey matter can be compared to computer chips, she says, and white matter is like the wires that connect these computer chips to each other.

“If you think about the brain as a big map, the grey matter represents all of the busy towns and cities,” she describes. “The white matter represents the highways and local roads that connect the towns. All of these things have to work smoothly in order for your brain to function at its best capacity.”

What Does Grey Matter in the Brain Do?

Grey matter plays a significant role when it comes to how our mind and body function. It allows people to control their motor movements and it allows us to receive sensory signals from our environment. Grey matter also plays important cognitive and mental health roles.

Cognitive Processing

Grey matter plays a pivotal role in cognition, says Dr. Tarulli. “Grey matter governs intelligent thought,” he explains. Grey matter also contributes to our cognitive processing, including memory, decision-making, language, and attention.

Research has found some interesting links between grey matter and attention in particular, with some studies finding alterations in grey matter among children and adults with attention deficit disorder (ADHD).

Emotional Regulation

Grey matter also plays a significant role in how we regulate our emotions. For example, 2016 research found that emotional regulation was linked to decreases of grey matter in the orbitofrontal cortex part of the brain. Decreased grey matter volume was associated with the ability to process emotions in a healthy way. The researchers also suggested that alterations of grey matter likely contributes to the development of psychiatric conditions that have emotional dysregulation as a main symptom.

Grey Matter's Impact on Mental Health

The way that our nervous system controls our mental health is not known specifically, Dr. Tarulli says. Still, although most mental health conditions do not involve grey matter disturbances, alterations to grey matter can be linked with several mental health challenges. “Injuries to grey matter can produce mental health disorders,” Dr. Tarulli remarked.

Brain Disorders and Grey Matter

Several neurological and psychiatric conditions are linked to grey matter abnormalities. Here’s what to know:

• Alzheimer’s disease is characterized by plaque buildup on the grey matter in the brain, causing significant and life-threatening memory and motor functioning issues
• Major depressive disorder is linked to reduced grey matter volume
• Grey matter alterations are linked to Parkinson’s disease and are responsible for the body shaking that people with this condition exhibit
• Multiple sclerosis is associated with plagues on both grey and white matter in the brain
• There is growing evidence that grey matter changes are associated with schizophrenia

Neuroplasticity

Neuroplasticity is the idea that the brain and its neurons are able to change and adapt based on learning, experience, and environmental factors. Although there is limited data on grey matter and neuroplasticity, there is some evidence that grey matter can be changed in a positive direction.

For example, some studies have found that practicing mindfulness meditation on a long term basis—for several months or years—can cause structural changes in grey matter. A 2020 study found that even brief mindfulness training (of about 10 hours) could prompt grey matter plasticity.

Factors Affecting Grey Matter

There are a handful of factors that affect our grey matter. Some of these factors are in our control and some—such as aging—aren’t. Let’s take a look at the type of factors that can cause changes to our grey matter.

What Causes Loss Of Grey Matter?

It’s a difficult fact, but most adults experience some level of cognitive decline as they age. This may include changes in attention span, working memory, and cognitive processing speed. Not everyone experiences a cognitive decline in the same areas and to the same extent. But the changes in cognition that are typically experienced are linked to the atrophy of grey matter in our brains.

Other factors that can cause loss of grey matter include trauma and PTSD, as well as blunt-force trauma to the head and traumatic brain injuries.

Lifestyle Factors

When it comes to aging and grey matter loss, it’s gloom and doom, Dr. Hanlon assures. “A decrease in grey matter is common as we age, but there are certain things that exacerbate grey matter loss,” she says. Controlling these factors can decrease the extent of your cognitive decline.

Dr. Hanlon says that making certain lifestyle choices can protect the grey matter in your brain. These include:

• Refraining from drinking excess alcohol
• Refraining from illicit drug use
• Making sure you get enough sleep
• Controlling chronic diseases like high blood pressure and diabetes
• Quitting smoking
  

Techniques for Investigating Grey Matter

The grey matter changes that occur with aging and even with some mental health conditions usually don’t require a physician to view your brain and its changes. However, if it’s suspected that you have a condition like multiple sclerosis or Parkinson’s disease, your diagnosis will likely involve some brain imaging methods to identify changes in your brain, including to your grey matter.

Brain Imaging Methods

Some of the imaging techniques used to detect changes in the brain’s grey matter include:

• MRIs (magnetic resonance imaging)
• Functional MRIs
• Voxel-based morphometry
• Positron emission tomography (PET) scans
  

How Can I Improve My Brain's Grey Matter?

There is no known way to improve your brain’s grey matter if it’s been altered or damaged, says Dr. Tarulli. However, there are ways to protect your grey matter and to lead a more “brain-friendly” lifestyle.

First and foremost, you want to protect your cardiovascular health. “The best way to protect grey matter would be to take care of your cardiovascular health, which reduces the risk of stroke,” Dr. Tarulli says. “Examples include adopting a heart-healthy diet, stopping smoking, and controlling blood pressure.”

In addition, says Dr. Tarulli, it’s important to stay physically, socially, and intellectually active. These are all important interventions that can protect grey matter health.

What the Research Says

In particular, research has found that staying physically active, especially as you get older, can protect your grey matter, and decrease your risk of dementia and Alzheimer’s. Studies have also found that alcohol use is strongly associated with decreased grey matter, so limiting your alcohol intake is important.

Finally, research has found a link between excessive stress and grey matter alteration. Moreover, engaging in activities that decrease stress, such as mindfulness meditation, can keep your grey matter healthy.

Cognitive Training

Cognitive training involves any activities that help you maintain your brain’s ability to problem solve, think critically, and utilize memory and attention span. Examples of cognitive training include doing a crossword puzzle every day, reading, doing trivia games, and playing challenging card or puzzle games. Many older individuals make sure to engage in these types of activities to keep their brain sharp.

There is some evidence that engaging in these activities can protect your grey matter specifically. Not only that, but engaging in cognitive training throughout your life can decrease your risk of developing memory issues later, as you age.