Aphantasia and the Mind's Eye: Exploring Visual Imagery with Dr Joel Pearson

American Psychological Association's Speaking of Psychology features Dr Joel Pearson, a leading cognitive neuroscientist, discussing aphantasia, the inability to visualize mental images. The interview covers how common it is, how researchers measure inner experiences, and what differences in imagination mean for memory, emotions, reading, and creativity. Pearson explains lab tools that quantify imagery, including binocular rivalry, skin conductance, and pupil responses, and surveys brain structure and excitability as they relate to mental imagery. The conversation also explores hyperphantasia, multisensory imagery, dreaming, and potential interventions. The episode highlights imagery's role in emotion and cognition and what studying aphantasia reveals about human consciousness and the mind's eye.

Introduction and Context

The Speaking of Psychology episode introduces Dr Joel Pearson, a professor at the University of New South Wales, who is a leading figure in the study of aphantasia—the inability to visualize mental images. The host explains that aphantasia is distinct from creativity or other imaginative processes, focusing specifically on the absence of visual mental imagery and occasionally other senses. The discussion situates aphantasia within a broader spectrum of mental visualization, where some people picture vivid images and others experience little to none, impacting everyday cognition and emotion.

What is Aphantasia and How Early Was It Recognized?

Pearson traces the concept back to Francis Galton in the 1880s, who noted that some colleagues could not conjure mental images. The term aphantasia was formalized in 2015, helping scientists and the public understand individual differences in mental imagery. The conversation emphasizes that aphantasia is about the voluntary creation of the mental image, not just a lack of creativity, and that people can differ widely in how they experience thoughts, memories, and future simulations without images.

How Common Is Aphantasia and How Do We Measure It?

Estimates based on the vividness of visual imagery questionnaire (VVIQ) place the prevalence around 4–8 percent, though the measure is imperfect. Pearson also notes a metacognition issue: responses reflect both actual imagery strength and individuals' criteria for rating imagery, which can inflate or obscure true prevalence. Some people may have never considered mental imagery to be more than a metaphor, skewing self-reports until they are shown examples of conscious visual imagery.

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"it's really the inability to visualize, typically visual mental imagery" - Dr Joel Pearson

Three Methods for Measuring Mental Imagery

Pearson outlines three complementary techniques developed over the years to assess imagery beyond questionnaires: binocular rivalry, skin-conductance during emotional imagery, and pupil responses during imagined brightness. In binocular rivalry, imagining a pattern biases perception toward the imagined stimulus when the rival images are presented; this demonstrates sensory-strength of imagery. Emotional imagery uses skin conductance as a proxy for emotional engagement when participants read scenarios. Pupillometry shows that imagining bright objects constricts the pupil, paralleling actual visual brightness, providing an index of visual imagery even in people who report little or no conscious imagery. A crucial control in the pupil task is the set-size effect, which shows that imagery load modulates the pupil similarly in both people with and without imagery, suggesting participants are indeed attempting the task even if their subjective experience differs. Pearson notes that these methods corroborate self-reports and help disentangle imagination from mere effort.

Brain Basis and Neural Correlates

The conversation moves to neurobiology, where studies link the size of the visual cortex to imagery strength, with genetic components influencing visual cortex size. Baseline cortical excitability—measured by TMS and TDCS—modulates imagery strength, though effects are modest. More recent work demonstrates that mental images can be decoded from visual cortex activity even in people who report no conscious imagery, raising questions about unconscious imagery. These findings fuel the debate about two possible types of aphantasia: true aphantasia with zero imagery and a variant where representations remain unconscious but detectable in brain data.

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"the content of their mental imagery, their visual imagery, was biasing the way they saw this visual illusion" - Dr Joel Pearson

Dreams, Reading, and Memory

Pearson discusses dreaming: questionnaire data suggest that people with aphantasia vary, with some reporting fewer or less vivid dreams. Reading fiction may be less emotionally vivid for some individuals with aphantasia because imagery contributes to emotional engagement. In memory, aphantasia correlates with fewer details in episodic recollections, though not a complete absence of details. Some reports describe face-specific imagery differences, hinting at links to prosopagnosia, though evidence is preliminary.

Hyperphantasia and Multisensory Imagery

The episode also covers the other end of the spectrum, hyperphantasia, where some people experience extremely vivid imagery. The researcher notes that while aphantasia is easier to define as a threshold, hyperphantasia lacks a clean cutoff and may be better understood via false-memory tendencies and related phenomena. Importantly, imagery can involve multiple senses, and researchers find multisensory aphantasia is a real but varied phenomenon, with some people lacking imagery across all senses and others only in specific modalities.

Creativity, Interventions, and Training

The discussion challenges the assumption that aphantasia blocks creativity. Some studies show no clear difference in divergent thinking or other standard creativity measures between those with and without imagery. The host and Pearson discuss potential interventions, including brain stimulation and brief imagery training, and an image-streaming technique borrowed from photography that encourages people to describe their visual details aloud before attempting them from memory. Psychedelic experiences are also discussed as a potential gateway to imagery changes, though evidence remains preliminary and not universal. The overarching idea is that imagery is malleable and that training might reveal residual capabilities in some individuals.

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"imagery seems to sit there in the middle, and it's almost like imagery as this virtual reality simulator that can amplify emotions" - Dr Joel Pearson

Broader Implications for Consciousness and Cognitive Diversity

Pearson frames aphantasia as a window into cognitive diversity and the structure of conscious experience. Studying how inner representations shape perception, emotion, and decision making can reveal the inner workings of the brain's feedback systems, crucial in visual perception and broader consciousness research. The interview closes with reflections on how understanding variations in mental imagery can illuminate the nature of thought, imagination, and the internal life of the mind.

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"anytime your thoughts take on the format of a depictive picture in your brain, that will nudge you and change the way you think" - Dr Joel Pearson

Conclusion

The episode leaves listeners with an appreciation for a spectrum of mental imagery, from complete absence to extraordinarily vivid scenes. It highlights the value of multiple measurement approaches, the relevance to memory and emotion, and the potential for interventions that may enhance or reveal imagery in different individuals. The broader takeaway is that how we think, and the format of our inner thoughts, can shape our experiences of the world in meaningful ways.