Dr. salzano is showing infants pictures of their parents and of strangers. he wants to know if the babies will consistently look at their parents rather than look at the two pictures equally. dr. salzano is using the technique.
1. conservation
2. preferential looking
3. habituation
4. object permanence

2. preferential looking

Explanation:

Based on American Psychological Association, the preferential looking technique is a technique that is used to test the visual capability of those who can't use words or who rely on nonverbal communication.

Such as infants or animals , it tests whether infants are capable of distinguishing between different stimuli for example if they state at the picture of their parents more than they do with a picture of a stranger that means they can discriminate different stimuli. This can means their perceptual system is developing well.