Exploring the relationship between grapheme colour-picking consistency and mental imagery

Abstract

Previous research has indicated a potential link between mental imagery and synaesthesia. However, these findings are mainly based on imagery self-report measures and recruitment of self-selected synaesthetes. To avoid issues of self-selection and demand effects, we recruited participants from the general population, rather than synaesthetes specifically, and used colour-picking consistency tests for letters and numbers to assess a ‘synaesthete-like’ experience. Mental imagery ability and mental rotation ability were assessed using both self-report measures and behavioural assessments. Consistency in colour-picking for letters (but not numbers) was predicted by performance on the visual mental imagery task but not by a mental rotation task or self-report measures. Using the consistency score as a proxy measure of grapheme-colour synaesthesia, we provide more evidence for the suggestion that synaesthetic experience is associated with enhanced mental imagery, even when participants are naive to the research topic. This article is part of a discussion meeting issue ‘Bridging senses: novel insights from synaesthesia’.

What is the relationship between Aphantasia, Synaesthesia and Autism?

“…Another recent study also sought to eliminate the self-referral bias, again by screening for synaesthesia in the general population (rather than asking synaesthetes to come forward). Spiller, Harkry, McCullagh, Thoma, and Jonas (2019) found that scores in a test assumed to identify grapheme-colour synaesthetes (or synaesthesialike behaviour) did correlate with scores in a test assumed to tap mental imagery ('Animal Tails Test';Farah, Levine, & Calvanio, 1988). However, we suggest here that neither test may have met its intended goal: the test for grapheme-colour synaesthesia was successfully passed by 24% of their sample (instead of the known synaesthesia prevalence of 1-2%), and their test for mental imageryalthough widely accepted as suchcan be performed just as well by aphantasics (who have no imagery) as by controls (Milton et al, 2020;Zeman et al, 2010) 1 .…”

Investigating relationships between trait visual imagery and phenomenological control: the role of context effects

“…Notably, by using a double-blind procedure Brang & Ahn (2019) failed to replicate the higher VVIQ scores found among synesthetes in previous studies which directly recruited this special population (e.g., Barnett and Newell, 2008). Similarly, by screening participants from the general population (single-blind procedure), Spiller et al (2019) failed to find evidence that scores on a task used to identify grapheme-colour synaestheses were related to VVIQ scores. We therefore suggest that to reduce the risk of confounding demand characteristic effects, imagery extremes should preferably be recruited using a single-blind procedure as in Study 1 (e.g., identifying them from a pool of participants and subsequently relate their score to a measure of interest collected separately).…”

Bridging senses: novel insights from synaesthesia

“…Regardless of whether or not they were synaesthetic, all participants performed letter and number colour-picking consistency tests (see also [12,13] in this issue), and their mental imagery abilities were evaluated via self-report (Vividness of the Visual Imagery Questionnaire and Spontaneous Use of the Imagery Scale) and behavioural tests (Animal Tails and Mental Rotations). Colour-picking consistency was correlated with performance on the Animal Tails visual imagery test, but not with the Mental Rotations task or either self-report measure [16]. In regression models, there was a significant relationship between consistency in colour-picking for letters (but not for numbers) and scores on the Animal Tails test; higher colour-choice consistency predicted faster and more accurate performance in object imagery.…”

“…In regression models, there was a significant relationship between consistency in colour-picking for letters (but not for numbers) and scores on the Animal Tails test; higher colour-choice consistency predicted faster and more accurate performance in object imagery. Given the unselected nature of the sample, the authors argue that relationships between synaesthetic experience and imagery extend beyond synaesthesia and into the general population [16]. In general, a shift towards studies of naive participants for experimental studies could represent a valuable step forwards for synaesthesia research.…”

“…Spiller et al [16] investigated 70 adult individuals who were recruited to their study without reference to either synaesthesia or imagery, to ensure that they were naive to the goals of the research. Regardless of whether or not they were synaesthetic, all participants performed letter and number colour-picking consistency tests (see also [12,13] in this issue), and their mental imagery abilities were evaluated via self-report (Vividness of the Visual Imagery Questionnaire and Spontaneous Use of the Imagery Scale) and behavioural tests (Animal Tails and Mental Rotations).…”