On perception of a partially occluded object in 6-month-olds

An Event Set x Event Set design used the occluded stick, solid stick, and divided stick stimulus events from Experiment 1 by Kellman and Spelke (1983). The design was analyzed using five different psychological models of the additive components of infant looking time in the nine cells of the design. Application of linear regression analysis to the data revealed that four of the models fit well. The best fitting model was shown to have two possible psychological interpretations. In one interpretation the infants represent the occluded stick as a solid stick but in the other the infants look longer in response to changes involving the divided stick. The fit of this model was greatly improved by assuming that some of the infants prefer looking at the novel stimulus but others prefer looking at the familiar stimulus. The implications of familiarity preference for the conduct and interpretation of other research are discussed.