The Knowledge Architects: Building Wisdom in the Information Age


Episode Summary

Say the word "elephant," and somewhere behind your eyes, gray and enormous, an elephant appears. Now say the word "justice." Nothing shows up, does it? Just the word. That difference, between the words that paint pictures and the words that do not, turns out to be one of the most powerful levers in all of learning. It is the reason a diagram next to a paragraph can double what you remember.

In this episode we open Arc 3 of the series, "Building Better," with the theory that anchors much of what follows: Allan Paivio's Dual Coding Theory. After two arcs spent on how the mind works and why text only methods so often fail, we turn to the first evidence based answer. Paivio's claim is deceptively simple: the mind runs on two cooperating systems, one for language and one for mental imagery, and information encoded in both is remembered far better than information encoded in only one. We follow how a bodybuilder turned psychologist resurrected mental imagery as a respectable scientific topic at the height of behaviorism, how he proved his case, what brain imaging adds and what it cannot settle, and why Dual Coding is not the same thing as the debunked "visual learner" myth.


Key Topics Covered

  • How behaviorism banished the mind's eye: John B. Watson, B.F. Skinner, and the long exile of mental imagery
  • The Würzburg School, "imageless thought," and Daniel Dennett's label of "iconophobia"
  • Allan Paivio, the bodybuilder psychologist who won the title of "Mr. Canada" in 1948
  • How Paivio beat the behaviorists at their own game by tying imagery to measurable word properties
  • The two systems of cognition: the verbal system (logogens) and the nonverbal imagery system (imagens)
  • The three kinds of connection: representational, referential, and associative
  • The additivity hypothesis: an idea coded twice lays down two memory traces and two independent routes to recall
  • The conceptual peg hypothesis: concrete words give you a hook to hang information on
  • The concreteness effect: concrete words are remembered far better than abstract words
  • The 925 noun norms and the asymmetry of paired associate learning
  • Just tell people to picture it: Gordon Bower's imagery instructions roughly doubling recall
  • Lee Brooks and the block letter "F": selective interference as proof of two separate channels
  • The concreteness effect in the brain, and why it is not a simple "left brain, right brain" story
  • ERP timing: the N400 and N700 as the imagery code coming online
  • Why the neuroscience is consistent with Dual Coding but does not uniquely prove it
  • From theory to classroom: pair concise words with relevant visuals, not decoration
  • The most important distinction: Dual Coding is NOT "learning styles"
  • Competing theories: common coding, context availability, and grounded cognition
  • The sharpest recent challenges: distinctiveness and aphantasia

Researchers Mentioned

  • Allan Paivio (1925-2016, University of Western Ontario) : Originator of Dual Coding Theory, former "Mr. Canada" 1948
  • John B. Watson (Johns Hopkins) : Founder of behaviorism, who sought to banish imagery from psychology
  • B.F. Skinner : Redescribed imagery as covert behavior, "seeing in the absence of the thing seen"
  • Daniel Dennett : Coined the label "iconophobia" for the behaviorist attitude toward imagery
  • Roger Shepard and Jacqueline Metzler (Stanford) : The 1971 mental rotation study that made imagery measurable
  • John Morton : The logogen model of word recognition, from which Paivio borrowed the term
  • Gordon Bower (Stanford) : Imagery instructions roughly double recall of word pairs
  • Lee Brooks (McMaster) : The block letter "F" crossover interference experiment
  • James M. Clark (University of Winnipeg) : Co-author of the bridge from theory to education
  • Mark Sadoski (Texas A&M) : Extended Dual Coding into reading and writing
  • John Kounios and Phillip Holcomb : ERP evidence for concreteness effects (N400, N700)
  • Harold Pashler and Robert Bjork : The landmark review debunking learning styles
  • Zenon Pylyshyn : The propositional, single code critique of mental imagery
  • Lawrence Barsalou : Perceptual symbol systems and grounded cognition
  • Ian Neath and Tyler Ensor : The distinctiveness account that challenges Dual Coding

Key Studies and Sources

  • Paivio, A. (1969). "Mental imagery in associative learning and memory." Psychological Review, 76(3), 241-263.
  • Paivio, A. (1971). Imagery and Verbal Processes. New York: Holt, Rinehart and Winston.
  • Paivio, A. (1986). Mental Representations: A Dual Coding Approach. New York: Oxford University Press.
  • Paivio, A., Yuille, J.C., and Madigan, S.A. (1968). "Concreteness, imagery, and meaningfulness values for 925 nouns." Journal of Experimental Psychology Monograph Supplement, 76(1, Pt. 2).
  • Bower, G.H. (1972). "Mental imagery and associative learning." In L.W. Gregg (Ed.), Cognition in Learning and Memory.
  • Brooks, L.R. (1968). "Spatial and verbal components of the act of recall." Canadian Journal of Psychology, 22, 349-368.
  • Wang, J., Conder, J.A., Blitzer, D.N., and Shinkareva, S.V. (2010). "Neural representation of abstract and concrete concepts: A meta-analysis of neuroimaging studies." Human Brain Mapping, 31(10), 1459-1468.
  • Kounios, J., and Holcomb, P.J. (1994). "Concreteness effects in semantic processing: ERP evidence supporting dual-coding theory." Journal of Experimental Psychology: Learning, Memory, and Cognition, 20(4), 804-823.
  • Clark, J.M., and Paivio, A. (1991). "Dual coding theory and education." Educational Psychology Review, 3(3), 149-210.
  • Pashler, H., McDaniel, M., Rohrer, D., and Bjork, R. (2008/2009). "Learning Styles: Concepts and Evidence." Psychological Science in the Public Interest, 9(3), 105-119.
  • Higdon, K.F., Neath, I., Surprenant, A.M., and Ensor, T.M. (2025). "Distinctiveness, not dual coding, explains the picture-superiority effect." Quarterly Journal of Experimental Psychology, 78(1), 180-191.
  • Yan, M., Roberts, B.R., and Bainbridge, W.A. (2026). "Challenging dual-coding theory: Picture superiority effects persist in aphantasia." Neuropsychologia, 225, 109391.

Key Numbers to Remember

  • Two functionally independent but interconnected systems: verbal and nonverbal
  • 1948 : the year Allan Paivio won the title of "Mr. Canada" as a competitive bodybuilder
  • 925 nouns rated for concreteness, imagery, and meaningfulness (Paivio, Yuille, and Madigan 1968)
  • r is about 0,8 : the correlation between concreteness and imageability, which is why they must be teased apart
  • Roughly double : the recall advantage from a single instruction to form interacting images (Bower 1972)
  • 19 fMRI and PET studies pooled in the Wang et al. (2010) meta-analysis
  • 300 to 500 ms : the window of the N400 brain wave after a word appears
  • N = 1.011 : the resting state study showing there is no "left brained" or "right brained" person (Nielsen et al. 2013)
  • 131 people, 62 with aphantasia : the 2026 study where the picture advantage persisted even in people who cannot visualize
  • Zero : the credible evidence that matching teaching to a learner's "style" improves learning

Memorable Quotes

"Human cognition is unique in that it has become specialized for dealing simultaneously with language and with nonverbal objects and events."
Allan Paivio, Mental Representations (1986)

"To convince the behaviourist sceptics of the day, Al initially approached the study of mental imagery from a strict operational perspective... the only way to convince the scholars of the day of the psychological reality of mental imagery was to be a rigorous experimentalist."
Albert Katz, memorial for PaivioDual coding and learning styles 

"sound similar, but are not quite the same thing... dual coding has scientific evidence backing its use, [while] learning styles has been repeatedly tested and shown not to improve learning."
Megan Sumeracki, The Learning Scientists (2019)

The concreteness effect shows "evidence for dual coding and context availability," their conclusion being that no single theory can claim the effect exclusively.
Jessen et al. (2000)

"You do not have a single mental notepad. You have two, a verbal channel and a visual channel, and the secret to durable learning is to write the same idea on both."

The Big Idea

You do not have one mental notepad, you have two. Dual Coding Theory says human cognition runs on two cooperating systems, one specialized for language and one for mental imagery, and that an idea written into both is remembered far better than an idea written into only one. That is why concrete words beat abstract ones, why instructing someone to picture an idea can double recall, and why a meaningful diagram beside a paragraph helps the lesson stick. The detailed mechanism is genuinely contested today, and honest brain imaging supports a two component story without crowning a winner. But the durable, practical insight has survived every critique: combining words and relevant pictures helps almost everyone learn. The lever is the material, not your supposed "type." You are not a "visual learner," and that is good news, because the strategy that actually works is available to all of us.


Next Episode Preview

Episode 26: The Picture Superiority Effect : We saw that a picture can be coded twice, as an image and as a word, while a word is usually coded just once. So what happens when we put pictures head to head against words in a memory test? The answer is almost unfair. Next time we explore why your brain is, quite simply, a machine built for images.

What is The Knowledge Architects: Building Wisdom in the Information Age?

The Knowledge Architects is a free, science-based podcast exploring how we learn, remember, and organize knowledge. Each episode translates peer-reviewed research from cognitive science, neuroscience, and psychology into practical insights—helping you understand how your mind works and how to work with it more effectively. Brought to you by ElysFlow.