Gredebäck, G., & von Hofsten, C. (2004) Infants’ evolving representation of moving objects between 6 and 12 months of age. Infancy, 6(2), 165-184

Infants’ ability to track temporarily occluded objects that moved on circular trajecto- ries was investigated in 20 infants using a longitudinal design. They were first seen at 6 months and then every 2nd month until the end of their 1st year. Infants were pre- sented with occlusion events covering 20% of the target’s trajectory (effective occlu- sion interval ranged from 500–4,000 msec). Gaze was measured using an ASL 504 infrared eye-tracking system. Results effectively demonstrate that infants from 6 months of age can represent the spatiotemporal dynamics of occluded objects. In- fants at all ages tested were able to predict, under certain conditions, when and where the object would reappear after occlusion, moving gaze accurately to the position where the object was going to appear and scaling their timing to occlusion duration. The average rate of predictive gaze crossings increased with occlusion duration. These results are discussed as a 2-factor process. Successful predictions are depend- ent on strong representations, which are themselves dependent on the richness of in- formation available during encoding and graded representations.