Dynamic behavior of the auditory N100 elicited by a baby's cry

We compared auditory N100 responses in female adults to two non-attended human sound stimuli. An infant's cry represented an unfamiliar, emotionally colored sound and the Finnish word "hei" (meaning "hi") a familiar and emotionally neutral sound. Both sounds elicited clear N100 responses over auditory areas in both hemispheres. However, the dynamic behavior of the N100 response following the first few repetitions of the sounds was significantly different. We observed faster habituation and longer response latencies, particularly over the ipsilateral hemisphere, during the first and second repetitions of the cry stimulus. This pattern may reflect an altered arousal level and slower, bilateral processing during the unfamiliar emotionally loaded cry as compared to the emotionally neutral word "hei" .