Mental imagery "Extremes"
Visual mental imagery is the mental simulation of visual sensory information. In the past few years, it has come to light that many people have a "blind mind's eye" (aphantasia; Zeman et al., 2020), or the absence of visual mental imagery. A more widely explored phenomenon is extremely vivid visual imagery, now called "hyperphantasia". Not a lot is known about the behavioral and neural differences between people with aphantasia and hyperphantasia, or people with mental imagery extremes and "typical" mental imagery. In my research, I am currently exploring behavioral differences across the mental imagery spectrum. I am also investigating new techniques for classifying individuals who believe they have aphantasia or hyperphantasia -- moving away from the VVIQ as a "diagnostic" tool (see McKelvie, 1995). This research is ongoing and updates will be posted to my website in time!
Previous studies have proposed a link between modal imagery vividness and hallucination proneness in pathology (Aleman et al., 2000; Aleman & de Haan, 2004). Exploring the relationship between visual imagery and anomalous perception in normative samples (in the absence of pathology) will provide much-needed insight about top-down factors that contribute to hallucinatory experience. My research therefore focuses on inducing pseudo-hallucinatory experiences using visual noise (pareidolia) and visual flicker (Ganzflicker) paradigms. Currently, I am interested in individual differences in the likelihood to experience vivid and complex pseudo-hallucinations in people with different visual imagery abilities, such as aphantasia.
A breakdown of the likelihood to experience NO pseudo-hallucinations across different imagery vividness ratings from 0 (complete aphantasia) to 10 (extremely vivid imagery), shown in gray. A logistic regression line in blue indicates the probability of seeing PH: about 60% probability for aphants and about 90% probability for people with vivid imagery. Blue shading around the line shows the 95% confidence intervals. Individual data points (blue dots, jittered) indicate the distribution of individuals who saw pseudo-hallucinations (above the bars) and those who did not see pseudo-hallucinations (underneath the bars). In summary, individuals who report having even a little bit of visual imagery are just as likely to see pseudo-hallucinations in Ganzflicker as those with moderate and vivid imagery. Individuals with complete aphantasia, on the other hand, are much less likely to experience pseudo-hallucinations at all. N=1,810.