How many letters does the top answer for “the ability to form mental images of things or events” have?

The most common answer is imagery (7 letters).

Crossword clue: the ability to form mental images of things or events

2 answers found in Letterora's clue database (Wikidata facts, Open Trivia DB, WordNet and Webster definitions — all licensed sources).

imagery 7 letters wn-def

the ability to form mental images of things or events

imaging 7 letters wn-def

the ability to form mental images of things or events