Objective priming from pre-imagining inputs before binocular rivalry presentations does not predict individual differences in the subjective intensity of imagined experiences

Most people can imagine images that they experience within their mind's eye. However, there are marked individual differences, with some people reporting that they are unable to visualise (aphantasics), and others who report having imagined experiences that are as realistic as seeing (hyper-phantasics). The vividness of imagery is most often measured via subjective self-report. Chang and Pearson (2018), however, have suggested that a binocular rivalry (BR) protocol can be used as an objective measure. They found that pre-imagining a moving input could enhance performance on an objective probe detection task when probes are embedded in imagery consistent inputs, as opposed to imagery inconsistent inputs. To date, nobody has assessed if this type of objective imagery priming can be used to predict the vividness of different people's visualisations. Here, we report that imagery priming of objective sensitivity to probes within static BR inputs does not correlate with the ratings people use to describe the vividness of their visualisations (a between participants effect). However, objective priming of sensitivity to probes embedded in BR inputs was greater on trials when participants reported that their pre-imagined experience had been more vivid than average (a within participants effect). Overall, our data suggest that while imagery can prime objective sensitivity to probes during BR, there is currently no strong evidence that this effect can be used as a reliable objective method to predict the subjective vividness of different people's visualisations.