In modern classrooms, PowerPoint and Google Slides have evolved from a simple presentation tool into one of the most widely used teaching resources. When used thoughtfully, it becomes a powerful vehicle for learning especially when supported by strategic use of imagery and colour. But why does this matter so much? The answer lies in how the brain processes and stores information.
Human memory isn’t a filing cabinet, it’s a web. We remember things more easily when they
connect to something we already know, and we see it often. This is called associative memory (Anderson and Bower, 1973), and it’s one of the brain’s strongest learning mechanisms. When class notes include relevant images or colour cues, students can form mental links that help them recall that information later.For example, pairing a concept like cell structure with a clear diagram, or coding important definitions in a consistent accent colour, creates associations that act like memory shortcuts. When students think of the concept, the visual cue is triggered alongside it boosting recall.
Proposed by Allan Paivio,
Dual Coding Theory explains that the brain stores information in two
main forms:1. Verbal (words)
2. Non-verbal (images)
When information is presented using both words and visuals, the brain encodes it twice, making it more likely to stick. This means that slides or notes combining minimal text with supportive imagery are not just more engaging, they are neurologically more effective for learning. This concept is the foundation for Dual Coding, a teaching strategy we teach in our workshops that deliberately integrates text and visuals to improve understanding and memory retention.
Including imagery in class or student study notes is more than a design choice, it’s a cognitive
strategy rooted in how learning happens. Research shows that combining text with visuals reduces cognitive load and supports deeper processing (Additional Resource). Instead of struggling to interpret long, abstract or possibly boring verbal explanations alone, learners can anchor meaning through imagery, making information more concrete and easier to understand.However, it is essential both teachers and students understand dual coding works best when visuals are meaningful, not decorative (Sung and Mayer, 2012). A well-chosen image should be descriptive and clarify the concept with it.
Students cannot learn what they cannot focus on. If notes are dull, cluttered, or visually
uninspiring, attention drops and so does comprehension.But there’s a flip side: when slides or notes are visually interesting and thoughtfully coloured, they naturally draw attention and help maintain engagement.
Yet, if a resource is not captivating, students expend more mental effort in trying to concentrate and stay on task, which is then a distraction limiting them to absorb the information you are trying to teach. (Skulmowski and Xu, 2021)
Whilst engagement is not about entertainment, it is about actively attempting to reduces barriers to focus in the classroom. Incorporating videos and activities into your lesson can also support student engagement and interest in the taught topic.
While imagery and colour enhance learning, there is a limit. Effective learning resources should be:
- Colourful enough to support attention and memory
- Not overwhelming or distracting
- Accessible to all learners including those with colour blindness
To maintain this balance:
- Avoid transitions and animations - they distract rather than teach
- Use high-contrast, colour-blind-friendly palettes (e.g. blue/orange rather than red/green).
- Avoid colour clashing combinations that can confuse or exclude
- Keep text minimal - let visuals carry meaning where possible e.g. use bullet points
- Use colour with consistency, not randomness - think coding, not decorating
- Keep core text black and no smaller than size 12
Too many competing colours, heavy text blocks or decorative images may look attractive, but they can overload working memory and undermine the benefits of dual coding.
Cognitive research supports the idea that less is more when “less” is done right. A slide with 5 words and a strong image teaches more than a paragraph on a screen. A resource that uses 2–3 harmonious colours teaches more effectively than one that uses 10.
Imagery and colour are not just aesthetic enhancements they are cognitive tools that:
- Strengthen students’ associative memory
- Activate Dual Coding, supporting information storage in two formats
- Improve students focus and engagement
- Make learning feel clearer, lighter, and more accessible
When creating teaching resources like PowerPoints or class notes, the goal is not to impress the eyes but to support the brain. Thoughtful design doesn’t distract from learning - It makes learning possible.
