Athanasios Bourganos¹, Dirk B. Walther¹; ¹University of Toronto

Canonicalness is a psychological variable that represents viewing preference around a three-dimensional object. Object perspectives with higher canonicalness are perceptually privileged when compared to perspectives with lower canonicalness. Various methods have attempted to quantify canonicalness around objects, employing Likert ratings, best/worst view selection, and Thurstonian Case V scaling. Canonical field approximation (CFA) is an updated, robust method for measuring the canonicalness of a set of discrete perspectives around an object. Using CFA measurements, two-dimensional interpolation facilitates generation of an approximate canonical field around an object. We deployed the CFA methodology on two sets of participants (exploratory and replication) to 1. Validate the CFA method, 2. Attempt replication of observations from past canonicalness research, and 3. Generate and test behavioral hypotheses. Results suggest CFA is a valid method for measuring canonicalness, with high Spearman correlation between canonicalness scores and ordinal perspective ranks and high agreement between participants (within and between samples). Observations from past canonicalness rating studies, relating to observer agreement and rating variance, were replicated. Alongside validation of CFA, two behavioral predictions were generated and tested. Decision time for choosing the more canonical perspective in the 2-alternative forced choice task that underlies CFA is negatively correlated with the absolute difference between the canonicalness ratings of the two perspectives. This is true for both a participant’s individual canonicalness ratings and the mean sample canonicalness ratings for predicting decision time, with almost equivalent model parameter estimates. We also predicted and observed an affordance effect on canonicalness, where right- and left-handed participants preferred opposite, mirror-image perspectives of graspable objects with one handle, with the handle oriented towards their dominant hand. This effect was overlooked in past research that employed lower resolution canonicalness rating methods. Ultimately, CFA is a robust canonicalness rating method that provides insights into object perception processes and behavior arising therefrom.

Acknowledgements: This work was supported by NSERC Discovery Grant (RGPIN-2020-04097) to DBW.