PMC

Newborns looked consistently longer at the displays that were congruent in number with the auditory sequences presented during familiarization, when the numbers to discriminate were separated by a ratio of 3:1 (4 vs. 12, 6 vs. 18), but not for a smaller ratio (4 vs. 8; ratio 2:1). Error bars represent standard errors.

Newborn infants were familiarized with auditory sequences containing a fixed number of syllables, and were then tested with images of the same or a different number of items (here 4 or 12). Auditory sequences were equated across numbers on extensive parameters (total duration), and visual arrays where equated on intensive parameters (size of each item, density of the array).