Proceedings of the Annual Meeting of the Cognitive Science Society

Prior work has demonstrated structured individual differences in mental representations of colors. Do similar differences exist in other low-level domains? We investigated representations of line orientation using triadic comparisons of Gabor patches varying in orientation angle (0-360–é). When we embedded similarity judgments into personalized 2D spaces, own embeddings predicted judgments better than others' embeddings (p<.001), but no better than orientation (p=0.69), suggesting participants represented similarity by orientation, with some variation. When Gabor patches also varied in contrast (high vs. low), own embeddings predicted judgments better than others' (p<.001) and orientation (p<.001), but not better than contrast (p=.08). When instructed to judge similarity by orientation, participants clustered based on similarity judgments made by orientation angle (n = 13) or by contrast (n = 21). This evidence suggests individual differences in mental representations of line orientation; participants may differ in their ability to make judgments based on one stimulus dimension versus another.