Short‐ and long‐term auditory recognition memory in 14‐month‐old human infants: Electrophysiological correlates

Two studies were conducted over a 2‐week period in an attempt to determine whether familiar and novel sounds would evoke different auditory event‐related potentials (ERPs) from a group of 14‐month‐old infants. Nine infants were presented with one of two bisyllabic nonsense syllables, consonant‐vowel‐consonant‐vowel (CVCV) over a 2‐day training period. On the third day, auditory ERPs were recorded from over the left and right hemisphere frontal, temporal, and parietal scalp regions of these infants while they listened to this familiar CVCV nonsense syllable as well as a novel CVCV syllable. An ERP component that peaked approximately 370 ms following speech onset discriminated familiar from novel speech sound sequences following the 2 days of training. This component was centered over the left and right frontal regions. Similar findings were noted at these sites when these same infants were tested after 1 week, as was an additional left hemisphere response that occurred approximately 200 ms later in time and centered over temporal and parietal regions that also discriminated familiar from novel CVCVs. These data were interpreted as providing evidence for long‐term memory in young infants.