Aphantasics recalled significantly fewer object details than controls, and showed a reliance on verbal strategies; showed equally high spatial accuracy as controls, and draw fewer false objects than controls

Quantifying Aphantasia through drawing: Those without visual imagery show deficits in object but not spatial memory. Wilma A. Bainbridge, Zoë Pounder, Alison F. Eardley, Chris I. Baker. bioRxiv, Dec 2019. https://doi.org/10.1101/865576

Abstract: Congenital aphantasia is a recently identified experience defined by the inability to form voluntary visual imagery, with intact semantic memory and vision. Although understanding aphantasia promises insights into the nature of visual imagery, as a new focus of study, research is limited and has largely focused on small samples and subjective report. The current large-scale online study of aphantasics (N=63) and controls required participants to draw real-world scenes from memory, and copy them during a matched perceptual condition. Drawings were objectively quantified by 2,700 online scorers for object and spatial details. Aphantasics recalled significantly fewer object details than controls, and showed a reliance on verbal strategies. However, aphantasics showed equally high spatial accuracy as controls, and made significantly fewer memory errors, with no differences between groups in the perceptual condition. This object-specific memory impairment in aphantasics provides evidence for separate systems in memory that support object versus spatial details.


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Aphantasics draw fewer false objects than controls

Finally, we quantified the amount of error in participants’ drawings from memory by group. AMT workers (N=5 per drawing) viewed a drawing and its corresponding image and wrote down all objects in the drawin gs that were not pre sent in the or iginal image (essentially quantifying false object memories). Significantly more memory drawings by controls contained false objects than drawings by aphantasics (control: 12 drawings, aphantasic: 3 drawings; ...); examples can be seen in Fig. 5. Similarly, significantly more objects drawn by controls were false alarms than those drawn by aphantasics ... This indicates that control participants were making more memory errors, even after controlling for the fewer number of objects drawn overall by aphantasics. Interestingly, all aphantasic errors (se e Fig. 5) were transpositions from another image and drawn in the cor rect location as the original object (a tree from the bedroom to the living room, a window from the kit chen to the l ivi ng room, and a ceiling fan from the kitchen to the bedroom). In contrast, seve ral fa lse memories from controls were objects that did no t exist across any image but instead appeared to be filled in based on the scene category (e.g., a piano in the living room, a dresser in the bedroom, logs in the living room). No perception drawings by participants from either group contained false objects.