Behavioral and Neural Signatures of Visual Imagery Vividness Extremes: Aphantasia versus Hyperphantasia.
Level 4 - case-series / case-control
Cross-sectional case-control study comparing groups defined by extreme and average imagery vividness
PubMed 34296179 · doi:10.1093/texcom/tgab035
What was done
Researchers conducted a neuropsychological and functional magnetic resonance imaging (fMRI) study comparing three groups defined by visual imagery vividness: aphantasia (n = 24), hyperphantasia (n = 25), and midrange imagery controls (n = 20). Assessments included standard memory tests, measures of autobiographical memory, imagination, face recognition, autistic spectrum traits, the Revised NEO Personality Inventory (NEO-PI-R), resting-state fMRI, and an active task-based fMRI paradigm comparing visualization of famous faces and places with perception.
What was found
Standard memory test performance was equivalent across all groups. However, autobiographical memory and imagination scores showed a stepwise pattern: hyperphantasia performed best, followed by controls, and aphantasia scored lowest (no numerical test scores reported in abstract). Participants with aphantasia reported higher rates of face recognition difficulties and autistic spectrum traits, alongside reduced extraversion on the NEO-PI-R, whereas hyperphantasic participants showed increased openness. Resting-state fMRI demonstrated stronger functional connectivity between prefrontal cortices and the visual network in hyperphantasia compared to aphantasia. Task fMRI showed greater anterior parietal activation during visualization versus perception in both hyperphantasic and control participants relative to aphantasic participants.
Why it matters
This study provides initial neuroimaging and behavioral evidence that subjective extremes of visual imagery (aphantasia and hyperphantasia) correspond to measurable differences in frontoparietal-visual connectivity, autobiographical memory recall, and specific personality dimensions.
Limits
The abstract reports no numerical estimates, effect sizes, or confidence intervals. The sample size is modest (total n = 69 across three arms). Phenotype grouping relies on subjective vividness classification, and the cross-sectional design cannot establish causal relationships between brain connectivity patterns and imagery capacity.