Development of auditory event-related potentials in young children and relations to word-level reading abilities at age 8 years

Abstract

A relationship between brain responses at birth and later emerging language and reading skills have been shown, but questions remains whether changes in brain responses after birth continue to predict the mastery of language-related skills such as reading development. To determine whether developmental changes in the brain-based perceptual skills are systematically related to differences in word-level reading proficiency at age 8 years, brain event-related potentials (ERPs) to speech and non-speech stimuli were recorded annually at the ages of 1 through 8 years in a sample of 109 typically developing children. Two measures of word-level reading (one that requires decoding of real words and one of pseudowords) were administered at age 8 years. Growth curve analysis, using the hierarchical linear models, related reading performance (average versus low) to the longitudinal maturation in the ERP waveform peak and latencies. Maturational changes (e.g. slope, acceleration and cubic growth) in N1 amplitude from ages 1 to 4 were related to proficiency in decoding pseudoword stimuli only, with children who were less proficient in decoding pseudowords evidencing more steeply negative declines in amplitude with age, particularly at the frontal and parietal recording sites in response to both speech and non-speech stimuli. In contrast, proficient in decoding real words was related to developmental changes in N2 amplitudes from ages 4 to 8 only at the parietal recording site and only in response to non-speech stimuli. The early development of biologically-based differences in the perception and processing of auditory information contributes to later group differences in reading proficiencies at school age.

Figure 1

Group averaged auditory ERPs recorded from six scalp electrodes, over left and right frontal, temporal, and parietal regions of 1- through 4-year-old infants and children in response to speech (solid line) and nonspeech (dashed line) syllables. ERPs are averaged across consonant sounds. Waveform duration includes an initial 75 ms prestimulus baseline period followed by the 925 ms ERP. Time calibration markers occur at 50 ms intervals. Central calibration marker is 2.5 µV.

Figure 2

Group averaged auditory ERPs recorded from six scalp electrodes over left and right frontal, temporal, and parietal regions of children from 5 through 8 years of age in response to speech (solid line) and nonspeech (dashed line) syllables. ERPs are averaged across consonant sounds Waveform duration includes an initial 75 ms prestimulus baseline period followed by the 925 ms ERP. Time calibration markers occur at 50 ms intervals. Central calibration marker is 2.5 µV.

Figure 3

Top: N1 amplitude by WJ-R word attack groups for frontal recording site, speech stimuli condition. Bottom: N1 amplitude by WJ-R Word Attack groups for frontal recording site, nonspeech stimuli condition.

Figure 4

Top: N1 amplitude by WJ-R Word Attack groups for temporal recording site, speech stimuli condition. Bottom: N1 amplitude by, WJ-R Word Attack groups for temporal recording site, nonspeech stimuli condition.

Figure 5

Top: N1 amplitude by WJ-R Word Attack groups for parietal recording site, speech stimuli condition. Bottom: N1 amplitude by WJ-R Word Attack groups for parietal recording site, nonspeech stimuli condition.

Figure 6

Top: N2 amplitude by WRAT-R Reading groups for parietal recording site, speech stimuli condition. Bottom: N2 amplitude by WRAT-R Reading groups for parietal recording site, nonspeech stimuli condition.