Behavioral and Neural Signatures of Visual Imagery Vividness Extremes: Aphantasia versus Hyperphantasia

Abstract

Although Galton recognized in the 1880s that some individuals lack visual imagery, this phenomenon was mostly neglected over the following century. We recently coined the terms “aphantasia” and “hyperphantasia” to describe visual imagery vividness extremes, unlocking a sustained surge of public interest. Aphantasia is associated with subjective impairment of face recognition and autobiographical memory. Here we report the first systematic, wide-ranging neuropsychological and brain imaging study of people with aphantasia (n = 24), hyperphantasia (n = 25), and midrange imagery vividness (n = 20). Despite equivalent performance on standard memory tests, marked group differences were measured in autobiographical memory and imagination, participants with hyperphantasia outperforming controls who outperformed participants with aphantasia. Face recognition difficulties and autistic spectrum traits were reported more commonly in aphantasia. The Revised NEO Personality Inventory highlighted reduced extraversion in the aphantasia group and increased openness in the hyperphantasia group. Resting state fMRI revealed stronger connectivity between prefrontal cortices and the visual network among hyperphantasic than aphantasic participants. In an active fMRI paradigm, there was greater anterior parietal activation among hyperphantasic and control than aphantasic participants when comparing visualization of famous faces and places with perception. These behavioral and neural signatures of visual imagery vividness extremes validate and illuminate this significant but neglected dimension of individual difference.

What is the Link Between Mental Imagery and Sensory Sensitivity? Insights from Aphantasia

“…Our intention was to characterise the sensory imagery deficits and sensory sensitivities experienced by people with aphantasia, and in doing so, examine how imagery and sensory sensitivity may be linked. Until now, aphantasia has been characterised by an absence of visual imagery (e.g., Milton et al, 2021 ; Zeman et al, 2015 , 2016 , 2020 ). But in Experiment 1 we found that aphantasic individuals report significantly weaker imagery compared to controls within all of the sense domains we tested (visual, olfactory, tactile, gustatory, bodily sensation, feeling, movement).…”

“…Sensory sensitivities are not only variable within the general population ( Horder et al, 2014 ; Robertson & Simmons, 2013 ) but are particularly characteristic of individuals with autism spectrum conditions (henceforth autism) ( American Psychiatric Association, 2013 ) or non-clinical autistic traits ( Ben-Sasson et al, 2009 ; Bogdashina, 2003 ; Horder et al, 2014 ; Robertson & Simmons, 2013 , 2015 ; Simmons et al, 2009 ). Importantly, higher autistic traits are also found in people with aphantasia ( Dance et al, 2021 ; Milton et al, 2021 ). These facts could potentially link imagery, aphantasia, and sensory sensitivities via the medium of autism.…”

“…People with aphantasia report either a complete lack of visual mental imagery, or imagery that is only dim, vague or fleeting (e.g., Keogh & Pearson, 2018 ; Zeman et al, 2015 ). Aphantasia has until now been defined exclusively as an absence of visual imagery ( Milton et al, 2021 ; Zeman et al, 2015 , 2016 , 2020 ) but of course mental imagery itself can encompass other modalities too, including auditory, olfactory, gustatory, tactile, motor, and bodily imagery. For us to investigate the nature of aphantasia (and subsequently, to investigate how imagery and sensation are themselves linked) an important initial question is whether the imagery impairment seen in aphantasia also extends to other sense domains.…”

Romance Scams: Romantic Imagery and Transcranial Direct Current Stimulation

“…There are large individual differences in mental imagery ability, ranging from aphantasia to hyperphantasia (7). Using revised NEO Personality Inventory, it has been shown that aphantasia is related to reduced extraversion whereas hyperphantaisa is linked to increased openness (12). Correspondingly, individual differences in mental imagery ability might be associated with social competence.…”

Visual imagery vividness declines across the lifespan

“…The dilemma of representativity also refers to the lack of research in the developmental stages. Most of the papers in the topic are engaged in undergraduate or adult participants (for recent examples, see: (Keogh & Pearson, 2014); Keogh et al, 2021;Milton et al, 2021;(Wicken et al, 2021), which sampling, however, ignores the potential effects in other age groups, including children and the elderly community. In aphantasia research, therefore, it is not easy to find even partial answers to our original question about imagery vividness across the lifespan.…”