Infants Understanding of Continuity of Objects

In the article “Infants’ Physical World” by Rene´e Baillargeon, evidence shows that from a young age, infants understand the general principles of continuity, which are that objects exist continuously in time and space but cannot exist at the same point in time (Spelke 1994). This article suggests that infants form “event categories” that contain knowledge to help them identify what variables should be included in the physical representation of objects. When infants watch an event, they use basic information about what they see and what they will expect to see. The event categories consist of containment, occlusion and covering events. Results suggest that “infants do not generalize variables from occlusion to containment or covering events, but learn separately about each event category” as they grow older (Baillargeon). Infants at 2.5 months old already have expectations about these event categories, and by 7.5 months old they have learned about height and transparency as occlusion variables.

The article “Limits to Infants’ Knowledge of Objects: The Case of Magical Appearance” by Karen Wynn and Wen-Chi Chiang also suggests that infants have the knowledge that objects exist continuously, cannot be in the same space at the same time and that objects are solid and have boundaries. The study included examining how 8 month olds respond to the magical appearance or disappearance of an object as an unexpected event. Baillargeon states that infants this age are learning about occlusion variables and how occluded objects still exist when hidden. This coincides with Wynn and Chiang’s finding because they show that 8 month olds are not surprised when an object “discontinuously appears” but are surprised when an object “discontinuously disappears”(Wynn & Chiang). With respect to Baillargeon’s findings, infants 8 months of age have learned about occlusion variables and how objects still exist after they disappear. Since infants track objects and update their locations, it would make sense that the infant is curious when the object has suddenly disappeared. To support Wynn and Chiang’s finding that infants are not surprised when an object appears, infants do not pay attention to a scene where there is no object to focus on. When one appears, the infant is not surprised due to “object centered attentional processes” that require an object to be present in order to engage attention or to “provide the bases of a mental representation” (Wynn & Chiang). “The appearance of a new object creates no conflict because processes specify information only about tracked objects” (Wynn & Chiang). Because of more limited reasoning capacities, infants cannot identify a magical appearance as a violation of continuity because the capacity to reason about an object’s immediate past may not be fully developed at 8 months of age. However, infants may have the same understanding of object continuity as adults.

One question to ask about these finding is since infants are surprised at the magical disappearance of an object, wouldn’t they be just as surprised to see a new stimulus that was not there before since both are in violation of the continuity principle? Since they can detect expected appearances and disappearances, it would seem that unexpected appearances do cause surprise like unexpected disappearances. If infants have limited reasoning capacities but possibly the same understanding of object continuity as adults, one would expect these two events to produce the same effect. Another question about Wynn and Chiang’s findings is that infants can “determine the correct results of simple additions and subtractions of small numbers of physical objects, and are surprised when the resulting number of objects that is shown to them is incorrect.” If infants have numerical knowledge, wouldn’t this apply to knowledge of numbers of objects as well?