The benefit of prior visual experience on estimating angle size


Our visual system provides us with useful information about the world around us. An important step in identifying an object is establishing it's size, including the size of angles which bound two lines with a common end point (Chen & Kuai, 2018). The current study looked to determine how accurately we perceive angles of different sizes. Participants (N = 30) estimated the size of an angle between two connecting lines when the availability of a reference angle was manipulated. In Task 1, participants were presented with seventeen testing angles ranging between 5 degrees to 85 degrees in five degree increments. Task 2 differed from Task 1 in that participants first viewed a reference angle with known size before estimating the size of the testing angle. The size of the reference angle differed from the testing angle by a maximum of 5 degrees. We found that participants' estimates were fairly accurate across the two tasks, demonstrating minimal errors (average absolute error = 4 degrees). That said, participants were significantly more accurate in their estimates in Task 2 compared to Task 1, suggesting that prior visual experience enhanced response accuracy. Future work will look to determine how the perception of angle size is influenced by reaching with distorted visual feedback (e.g., a cursor that is rotated 30 degrees relative to hand motion).

Acknowledgments: Acknowledgements: supported by Natural Sciences and Engineering Research Council of Canada [EKC].