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Updated: Apr 21, 2026
Infant Auditory Processing and Event-related Brain Oscillations
Published on: July 1, 2015
Low-level prenatal lead exposure alters auditory recognition memory in 2-month-old infants: an event-related
Fengji Geng1, Xiaoqin Mai, Jianying Zhan
1a Center for Human Growth and Development , University of Michigan , Ann Arbor , Michigan.
Insights
Prenatal lead exposure can impact infant auditory recognition memory. Even low lead levels (≥2.00 μ g/dL) in cord blood were linked to poorer memory in 2-month-old infants.
Area of Science:
- Neuroscience
- Developmental Psychology
- Environmental Health
Background:
- Prenatal exposure to environmental toxins, such as lead, is a significant public health concern.
- Low-level lead exposure has been associated with adverse neurodevelopmental outcomes in children.
- Auditory recognition memory is a critical developmental milestone in early infancy.
Purpose of the Study:
- To investigate the effects of low-level prenatal lead exposure on auditory recognition memory in 2-month-old infants.
- To determine the threshold of cord-blood lead concentration associated with impaired auditory recognition memory.
Main Methods:
- Utilized event-related potentials (ERPs) to measure brain activity in response to auditory stimuli.
- Categorized 2-month-old infants into four groups based on cord-blood lead concentrations.
- Compared ERP component amplitudes (P2, P750, LSW) elicited by familiar (mother's) and unfamiliar (stranger's) voices.
Main Results:
- Infants with cord-blood lead levels <2.00 μ g/dL exhibited normal auditory recognition memory, showing expected differences in ERP amplitudes.
- Infants with cord-blood lead levels ≥2.00 μ g/dL did not show these expected differences in one or more ERP components.
- Electrophysiological evidence indicated poorer auditory recognition memory in infants with prenatal lead exposure at or above 2.00 μ g/dL.
Conclusions:
- Prenatal lead exposure at levels ≥2.00 μ g/dL is associated with impaired auditory recognition memory in 2-month-old infants.
- ERPs provide a sensitive measure for detecting subtle neurodevelopmental effects of low-level lead exposure.
- These findings highlight the importance of minimizing lead exposure during pregnancy to protect infant neurodevelopment.
Abstract:
This study used event-related potentials (ERPs) to assess effects of low-level prenatal lead exposure on auditory recognition memory in 2-month-old infants. Infants were divided into four groups according to cord-blood lead concentration: (1) <2.00 μ g/dL, (2) 2.00-2.99 μ g/dL, (3) 3.0-3.7 μ g/dL, and (4) ≥3.7 μ g/dL. The first group showed the normally expected differences in P2, P750, and late slow wave (LSW) amplitudes elicited by mothers' and strangers' voices. These differences were not observed for one or more ERP components in the other groups. Thus, there was electrophysiological evidence of poorer auditory recognition memory at 2 months with cord-blood lead ≥2.00 μ g/dL.
