Cognition is a word we often hear when talking about brain health, but what does it really mean? Simply put, cognition refers to the mental skills we use every day to make sense of the world around us. These include our ability to pay attention, remember things, solve problems, communicate, and plan ahead.

When someone experiences a stroke, a traumatic brain injury, or develops a neurodegenerative disease like Alzheimer’s, their cognitive abilities can be affected. These changes can be life-altering—not only for the person experiencing them but also for their loved ones and caregivers.

In this blog series, Professor Michael Fraas, Ph.D., a leading expert in brain injury and cognitive rehabilitation, will help us better understand how cognition works, what happens when it’s disrupted, and what assessments and treatments can help.

What Is Cognition?

According to Professor Fraas, cognition is how we take in, process, and respond to the world around us. Every action we take—from having a conversation to making a grocery list—involves a series of cognitive processes working together.

Researchers have identified several key areas of cognition, called cognitive domains, including:

• Attention (focusing and filtering information)
• Memory (storing and retrieving information)
• Executive Function (planning, organizing, problem-solving)
• Visuospatial Function (understanding shapes, spaces, and how things relate to one another visually)
• Social Communication (understanding and using language in social settings)

These areas don’t work in isolation. Instead, they depend on one another—and on things like our emotional state and physical health—to help us function well in everyday life.

Why Attention Matters

Let’s begin by focusing on attention, a foundational skill that supports all the others. After a brain injury, stroke, or during cognitive decline, attention problems are very common and often show up alongside difficulties with memory, learning, and decision-making.

Experts like Sohlberg and Mateer (2001) have developed a helpful model to explain the different types of attention. Here’s a breakdown of the five main types, using real-world examples to make them easier to understand:

1. Focused Attention

This is the most basic level of attention. It’s our ability to respond to a specific sound or sight—like turning your head when you hear someone call your name or when a doorbell rings.

People who are recovering from serious brain injuries or emerging from a coma may have difficulty with this level of attention.

2. Sustained Attention

This refers to our ability to stay focused on a task over time. Think about following a recipe from start to finish without losing track of the steps—that’s sustained attention.

It also involves something called working memory, which is our ability to hold and use information in our minds in the short term.

3. Selective Attention

This skill helps us filter out distractions. Imagine trying to read a book while someone is mowing the lawn outside. If you’re able to tune out the noise and stay focused on the page, you’re using selective attention.

4. Alternating Attention

Sometimes we need to switch between different tasks that require different types of thinking. For example, a receptionist might go back and forth between answering the phone and typing an email. That flexibility is thanks to alternating attention.

5. Divided Attention

This is our ability to handle multiple tasks at the same time—like driving, listening to a podcast, and sipping coffee all at once.

However, researchers still debate whether true multitasking is possible, or if we’re really just switching attention very quickly between tasks. Because of this, newer models tend to emphasize the brain’s executive control over attention rather than treating divided attention as its own category.

Looking Ahead

In upcoming blog posts, Professor Fraas will dive deeper into other cognitive skills like memory, executive function, and communication—explaining how they work, what happens when they’re disrupted, and how rehabilitation can help.

Whether you’re a patient, a caregiver, or simply curious about brain health, we hope this series helps you better understand the complex but fascinating world of cognition.