The Nelson Lab
Quantity Perception During the First Year
In this study, we are interested in how babies learn to differentiate quantities, what brain areas are involved in quantity perception, and how this perception becomes more precise over the first year of life. To learn more about this, we will measure brain activity and eye movements while babies examine images of different quantities (e.g., 8 dots, 16 dots). We are interested in how far away two quantities need to be for infants to detect that they are different, and how that changes during development (e.g., can they differentiate 8 from 16? 8 from 10?).
Eligibility for Participation
We are currently enrolling typically developing infants between 5- and 10-months-old for this study.
Infants: 5- to 10-months-old
- Born within 2 weeks of due date
This study involves one visit to the lab. The session will generally last about 45 minutes and will be scheduled at a time that is convenient for you and your child. Parents will be with their child at all times.
Jennifer Wagner, Ph.D and Laura Edwards. You can also call Jen or Laura at 857-218-5213.
Research with humans and non-human animals has found a shared ability to quickly compare quantities using a ratio-based system. For example, when adults are presented with an image of 8 dots next to an image of 16 dots, they are faster to point to the side with ‘more’ than if they were to compare 8 vs. 12 or 8 vs. 10. Traditional looking-time studies with infants show that 6-month-olds can successfully differentiate dot arrays in a 1:2 ratio (e.g., 4 vs. 8; 8 vs. 16) but not a 2:3 ratio (e.g., 4 vs. 6, 8 vs. 12), while 9-month-olds can succeed in a 2:3 ratio but not a 4:5 ratio. Our present work will use eye-tracking in one set of studies and near-infrared spectroscopy in a second set of studies to examine whether more sensitive methods can show successful differentiation between quantities before these differences are detected in looking time studies.
With a better understanding of the neural and behavioral development of quantity processing during the first year, we hope to better evaluate how early quantity processing might predict later numerical achievement, such as learning to count during the preschool years, or more complex abilities such as addition and subtraction in early grade school.