According to the , the preferential looking technique is "an experimental method for assessing the perceptual capabilities of nonverbal individuals ". If the average infant looks longer at the second stimulus, this suggests that the infant can discriminate between the stimuli. This method has been used extensively in cognitive science and developmental psychology to assess the character of infant's perceptual systems, and, by extension, innate cognitive faculties. An investigator or examinor observes the infants behavior to determine which stimulus the infant fixates on.
Robert L. Fantz
Robert L. Fantz was a developmental psychologist who launched several studies on infant perception including the preferential looking paradigm. Fantz introduced this paradigm in 1961 while working at the Case Western Reserve University. The preferential looking paradigm is used in studies of infants regarding cognitive development and categorization. Fantz's study showed that infants looked at patterned images longer than uniform images. He later built upon his study in 1964 to include habituation situations. These situations exhibited an infants preference for new or unusual stimuli.
Summary of Findings
Conclusions have been drawn from preferential looking experiments about the knowledge that infants possess. For example, if infants discriminate between rule-following and rule-violating stimuli—say, by looking longer, on average, at the latter than the former—then it has sometimes been concluded that infants know the rule. Here is an example: 100 infants are shown an object that appears to teleport, violating the rule that objects move in continuous paths. Another 100 similar infants are shown an object that behaves in a nearly identical manner to the object from group 1, except that this object does not teleport. If the former stimulus induces longer looking times than the latter, then, so the argument goes, infants expect that objects obey the continuity rule, and are surprised when they violate this rule. Some researchers have suggested, of some such experiments, that infants have innate knowledge of those rules the violation of which they can perceptually discriminate. Common criticisms of this innateness thesis include that the infant has already acquired enough experience of non-teleporting objects to justify its surprise, and that teleporting objects are attention-grabbing for reasons other than expectancy violation. Findings from preferential looking experiments have suggested that humans innately possess sets of beliefs about how objects interact and about how animate beings interact.
The Preferential Looking Technique at Work
This study collected data using a preferential looking paradigm. The paradigm was analyzing looking behavior and pupil dilation to track children's recognition to different degrees of mismatching labels and objects in a picture. It was found evidence that there is a sensitivity to phonological mismatch among children. The study also provided support for the thesis that early comprehension and knowledge of root words are solid enough to convert subphonemic detail to what they are not familiar with. Preferential looking experiments have been cited in support of hypotheses regarding a wide range of inborn cognitive capacities, including:
