Describe two different methods you could use to test whether a 9 month old infant can engage in conceptual categorization.
While there could be other methods for testing whether a 9-month-old infant can engage in conceptual categorization, non-nutritive sucking and the habituation paradigm are more common. The first method, non-nutritive sucking, employs a physical capability common in most infants. This can be done by, for instance, allowing the infants to look at a silent color film alongside a pacifier for them to suck while monitoring their sucking rate and focusing on the movie. According to the ninth slide of the lecture notes (Week 2), synchrony between regions of the brain supports evolution of more systematic abilities of solving problems as well as voluntary behavior control. Therefore, if the children are able to suck the pacifier at a certain rate while watching the movie, it indicates that they are able to control and manage their sensory environment. On the other hand, the habituation paradigm entails availing an event (a stimulus) to the infants. This can be a sound or a picture that the infant has to attend to through turning to it or simply looking at it, or just do anything that maintains the continuity of the event. After sometime, the infants could learn to stop responding to repetitions of the same event which means they are able to habituate.
What types of evidence have led researchers to believe that infants may believe in the continued existence of hidden objects even though they fail to search for them?
The major evidence is drawn from Piaget’s results of object permanence as illustrated in this video (https://www.youtube.com/watch?v=TRF27F2bn-A). For instance, in the video, Myer finds a hidden toy while 10-month-old Simon searches for a hidden object in the wrong place. Regardless, these examples show that infants believe in the existence of these objects even if they fail to find them. Piaget, in a similar experiment found the same evidence and results. He realized that infants 8 months and below did not search for a toy while those above the age of eight searched for the toy. Simple object permanence and complex object permanence are, therefore, the types of evidence that make researchers believe that infants believe in the continued existence of hidden objects.