Dual Coding: Learn With Text and Images Combined

Dual coding means processing information through two channels at once – as language (text, spoken words) and as images (a diagram, sketch or mental picture). Combining both lays down two linked memory traces instead of one, so you remember more. Crucially, dual coding is not the debunked myth of learning styles.

What is dual coding?

Dual coding goes back to the Canadian psychologist Allan Paivio, who developed the theory in the late 1960s and laid it out in his 1971 book “Imagery and Verbal Processes.” His core idea: our memory processes information through two separate but connected systems. A verbal system stores language – words, terms, definitions, numbers. A nonverbal system stores the pictorial – mental images, scenes, diagrams, spatial arrangements, colour and movement.

Both systems have their own capacity and run in parallel in working memory. Encode a fact only as text and you use one channel. Link it to an image as well and two memory traces form – one verbal, one visual. On recall you then have two routes to the same information: if the wording escapes you, the picture may help, and vice versa. That places dual coding among the well-evidenced learning methods that build on how memory actually works – not on a supposed learner type.

Why does dual coding work?

The main reason is the picture superiority effect: information encoded as an image is, on average, remembered better than language alone. A picture is often labelled verbally on its own (“that's a heart”), whereas a word does not automatically produce an image. Deliberately combining the two encodes it twice – and that is the heart of Paivio's theory.

Research on multimedia learning by Richard Mayer confirms the idea. His Multimedia Principle states: people learn more deeply from words and pictures together than from words alone. His Modality Principle adds that a diagram with spoken commentary is understood better than the same diagram next to a wall of on-screen text. The reason is the limited capacity of each channel: picture and printed text both compete for the eye, whereas spoken language enters through the ear and frees up the visual channel. In Mayer's experiments, learners did better in seventeen out of seventeen tests when a graphic was accompanied by narration rather than on-screen text.

For you that means: a well-chosen image is not decoration but a second, independent route to memory.

An example: anchoring history visually

Say you are learning the causes of the First World War. In words alone it stays a long list: alliance systems, the arms race, nationalism, the assassination in Sarajevo. With dual coding you sketch a simple map of Europe beside it, colour the two alliance blocs in two colours, connect them with arrows and place a small lightning bolt at one spot for the assassination. Now every cause has a spatial anchor. In the exam you “see” the sketch in front of you and read the terms off it. The text alone would be a chain; the picture turns it into a structure you can take in at a glance.

Is dual coding the same as “learning styles”?

No – and this is the most important point of the article. The learning styles myth claims every person is a fixed “type” (visual, auditory, kinaesthetic) and learns best when teaching matches that type. This so-called meshing hypothesis has been studied thoroughly – and debunked.

The much-cited review by Pashler, McDaniel, Rohrer and Bjork (2008) in the journal Psychological Science in the Public Interest reached a clear verdict: there is no credible evidence that matching a teaching method to a supposed learning style improves learning. The authors found virtually no sign of the crucial interaction pattern and concluded there is “no adequate evidence base” for using learning-style assessments in general educational practice.

Dual coding says something entirely different. It does not claim that some people are “visual learners” and others “verbal.” It says: everyone benefits from combining language and image – regardless of personal preference. The Learning Scientists, a group of memory researchers, make exactly this point: don't think in “learning style” categories; use both formats together. The effect comes from the combination, not from matching a type.

How do you apply dual coding in practice?

The trick is to find a matching visual for every verbal idea and to tie the two together:

1. Draw it yourself instead of only looking at ready-made graphics. A rough sketch forces you to process the content. It need not be pretty.
2. Turn text into diagrams. Processes become flowcharts, comparisons become tables, sequences become timelines, and relationships become mind maps.
3. Label your images in your own words. Only linking picture and language creates the dual code – an unlabelled image on its own is not enough.
4. Explain a graphic out loud in your own words and then compare your explanation with the original. This actively joins both channels.
5. Use concrete mental images for abstract terms. Picturing a vivid scene for a technical term encodes it visually too. This is also the mechanism behind the method of loci, or memory palace, where you “store” content at imagined places.

What matters is that image and word carry the same information and complement each other – not that you pile on as many pictures as possible.

Which mistakes should you avoid?

• Decorative images. A pretty photo with no link to the content does not help – it distracts. The image must carry the meaning.
• Duplicated text. A diagram with a long paragraph beside it overloads the visual channel (Mayer's modality principle). Short labels or a spoken explanation work better.
• Only consuming. Looking at finished infographics is passive. The effect comes when you draw, arrange and label yourself.
• Too much at once. More images are not automatically better. An overloaded chart raises cognitive load instead of lowering it.

Using dual coding with AI

The most laborious part of dual coding is turning text into a meaningful visual structure. This is exactly where AI tools help: an AI mind-map generator turns a script or PDF into a first visual map of the topic in seconds, which you then extend and redraw in your own words – keeping the active processing with you.

With LearnCastAI you can also turn your own material into a learning podcast and read the matching summary alongside it. Spoken language then meets written text and visual structure – precisely the channel combination Paivio and Mayer describe. The podcast does not replace sketching it yourself, but it anchors the material through a second channel.

Conclusion

Dual coding is one of the best-supported ideas in the psychology of learning – and one of the most misunderstood. It is not about matching your “learning type” but about anchoring every piece of content through two channels: language and image. Take your hardest topic, write the core idea in one sentence, and draw a simple picture beside it that shows the same idea. That doubling – not the perfect picture – is the whole effect.