Now final in @elife.bsky.social: #Synesthetes really do 'see' when reporting colors while reading (typeface gray) numbers: pupils change according to the perceived colors' brightness - if a synesthete sees a bright yellow, the pupils become smaller. elifesciences.org/articles/110...
We show that synesthesia is sensory and automatic in nature: the pupil scales with the brightness of experienced synesthetic colors. doi.org/10.7554/eLif... Now in its new dress @elife.bsky.social (convincing & valuable in round 1). If anyone wants to pick up the method, happy to share & explain!