The current study aims to investigate in infants the discrimination of the number set 1 versus 3. This number set has not been studied before within the field of early number discrimination. Participants were 16 full term 8-month-olds. They were assessed for their number discrimination ability with a computerized habituation task in combination with an eye tracking device as an accurate measure for looking time in infants. The stimuli (dots) were controlled for continuous variables. Attention was given to different approaches to analyse data retrieved from the habituation paradigm. The main results showed that 8-month-olds discriminated 1 from 3 dots by looking longer at a novel number after habituation to another number. This supports smal...