תאריך:
ה', 07/06/201812:30-14:00
מיקום:
Wechsler
Subjective representation: the case of numerical perception:
In this talk, I will present a short overview of the topics that we pursue in my lab. Namely, we are interested in the way our subjective experience is built. I will then focus on the case of numerical perception. In the field of numerical cognition, the dominant view suggests that numerical perception is governed exclusively by an innate ‘number sense’. This view was recently challenged by studies that demonstrated the central role of physical properties in numerical tasks. However, these studies were limited in two main aspects. First, they demonstrated the influence of physical properties only in comparison tasks and not in enumeration tasks. Second, they did not suggest a mechanism through which physical properties contribute to numerical perception.
We addressed these caveats guided by the notion that human cognition is shaped by the physical world. We tried to find a link between the physical properties of numerical arrays, their numerosity and their perceived numerosity. Methodologically, we tackled this in an exhaustive manner. We used mathematical theorem and a computational model that simulates the correlation between numerosity and the shape of convex hull (the smallest polygon containing all dots). The results of the simulation showed that shape of convex hull is a strong predictor of numerosity. Convex hull predictability changed with increasing numerosity, creating qualitatively different ranges corresponding to the behavioral enumeration curve. We then tested the hypothesis that shape of convex hull predicts perceived numerosity in two behavioral experiments that support the simulated results. Taken together, our results suggest that convex hull serves as a heuristic in enumeration, tapping on a general expertise mechanism that allows reduction of information with minimal error cost.