The Two Eyes of the Blind Mind: Object vs. Spatial Aphantasia?
Individual variability in imagery experiences has long attracted the interest of philosophers, educators, and psychologists. Since Aristotle’s time, it was assumed that imagery is a universal ability, so everyone possesses it. Galton first measured the vividness of subjective imagery experiences, and discovered that some individuals reported zero imagination. Recent research has coined the term “aphantasia” — an inability to form mental imagery, or having a “blind mind’s eye” (Zeman, Dewar, & Della Sala, 2015). We argue that there may be more than one type of aphantasia. Substantial behavioral and neuropsychological evidence has demonstrated a distinction between visual-object imagery (mental visualization of pictorial properties such as color, shape, brightness, and texture) and visual-spatial imagery (mental visualization of spatial locations, relations, and transformations). Notably, visual imagery is not a unitary ability, so individuals who excel in object imagery do not necessarily excel in spatial imagery, and vice versa. Here we argue that the commonly described “aphantasia” is not a general imagery deficit but rather a visual-object deficit of imagery (as aphantasic people are often identified by low scores on the Vividness of Visual Imagery Questionnaire, which assesses object imagery only). We hypothesize that “spatial aphantasia” (the inability to imagine spatial properties and relationships) can be a separate type of imagery deficit. Individuals with spatial aphantasia may not necessarily have a deficit in object imagery. We discuss future research directions examining how spatial aphantasia may manifest behaviorally and neurologically, and how object and spatial aphantasia may be related.