Hyperphantasia
Hyperphantasia is the condition of having extremely vivid mental imagery. It is the opposite condition to aphantasia, where mental visual imagery is not present. The experience of hyperphantasia is more common than aphantasia and has been described as being "as vivid as real seeing". Hyperphantasia constitutes all five senses within vivid mental imagery, although literature on the subject is dominated by "visual" mental imagery research, with a lack of research on the other four senses.
Research into hyperphantasia is most commonly completed by self-report questionnaires, such as the Vividness of Visual Imagery Questionnaire (VVIQ), developed by David Marks in 1973, which evaluates the vividness of an individual's mental imagery out of a score of 80. Individuals scoring from 75 to 80 are deemed hyperphantasics and are estimated to constitute around 2.5% of the population.