The Other Species Effect

Brief Description:

In this study, we are interested in learning more about the development of facial recognition in infants. We are using state of the art eye-tracking technology to gain insight into the scanning techniques employed by infants of different ages while they become familiar with pictures of both monkey faces and human faces.

Eligibility for study participation:

We are currently recruiting typically-developing 6-month-olds for this study.

  • Infants: 6 months old
  • Born within 2 weeks of due date

Participation Details:

This study involves one visit to the Labs. The session will last about 45 minutes and will be scheduled at a time that is convenient for you and your child. You will be with your child at all times.

Research Contact:

Eliza Congdon

Full Description:

Previous research with infants has shown that 6-month-olds are capable of discriminating between both human faces and monkey faces. In other words, if you show a 6-month-old two monkey or two human faces side by side, she will be able to tell them apart. However, by the age of 9 months, infants lose the ability to discriminate between the monkey (other-species) faces. This phenomenon, broadly known as perceptual narrowing, is the focus of the current study. We know that as babies develop, they begin to specialize in interpreting the faces that they see most often in their surroundings, while losing the ability to interpret the types of faces that they see less often, such as monkey faces. This developmental trajectory is the underlying hypothesis for why adults are much better are processing faces of their own race, gender, and species.

By using a Tobii eye-tracking system to record scanning and fixation patterns, we hope to gain insight as to why and exactly how younger infants are able to tell the difference between two monkey faces, and older infants are not. If 6-month olds employ more rudimentary looking patterns, while 9-month olds use more sophisticated, adult-like face scanning patterns, this will be reflected in the eye-tracking data. The results of this study will not only further our understanding of the typical development of facial recognition strategies, but will also provide an important baseline against which we can measure the behavior and looking patterns of children who show differences in facial recognition, such as children diagnosed with Autism Spectrum Disorders.

How can we tell if infants are discriminating between two faces? Infants consistently show a novelty preference, which means that they will look longer at something that is new, rather than something they have seen before. To test whether or not infants can discriminate between two faces, we familiarize them with a single face and then present them with that same face next to a new one of the same type (monkey or human). We can infer that infants who look longer at the new picture are not only remembering the first face, but they are successfully discriminating between the two (one is new and exciting, the other is old and boring). Conversely, if they look equally at the old and the new face, we can infer that they cannot discriminate between the two.