Neural coding of formant‐exaggerated speech in the infant brain

Abstract

Speech scientists have long proposed that formant exaggeration in infant-directed speech plays an important role in language acquisition. This event-related potential (ERP) study investigated neural coding of formant-exaggerated speech in 6-12-monthold infants. Two synthetic ⁄ i ⁄ vowels were presented in alternating blocks to test the effects of formant exaggeration. ERP waveform analysis showed significantly enhanced N250 for formant exaggeration, which was more prominent in the right hemisphere than the left. Time-frequency analysis indicated increased neural synchronization for processing formantexaggerated speech in the delta band at frontal-central-parietal electrode sites as well as in the theta band at frontal-central sites. Minimum norm estimates further revealed a bilateral temporal-parietal-frontal neural network in the infant brain sensitive to formant exaggeration. Collectively, these results provide the first evidence that formant expansion in infant-directed speech enhances neural activities for phonetic encoding and language learning.

Relative distance and gaze in the use of entity-referring spatial demonstratives: An event-related potential study

“…A midline parietaloccipital group (MPO) included POz and Oz. Similar regional groupings for electrodes were applied in previous studies (Rao et al, 2010;Zhang et al, 2011).…”

“…The same system was used in previous auditory ERP studies (Rao et al, 2010;Zhang et al, 2011). The sampling rate was 512 Hz, and the bandpass was between 0.016 and 200 Hz.…”

“…A modified two-tailed point-to-point t-test procedure similar to Bonferroni correction was conducted on the regional electrode groupings in order to consider the temporal evolution of significant differences between the congruent and incongruent conditions (Guthrie & Buchwald, 1991;Zhang et al, 2011). By this method, the temporal evolution of an ERP is considered by the following factors: sample size (N ¼ 14 subjects), number of sampling points, and an auto-correction value.…”

“…The minimum average number of accepted trials was 50 for any of the spatial configurations in the study. Weighted averaging was applied to calculate the grand average in order to avoid strong influences from individual subjects with relatively fewer trials (Zhang et al, 2011).…”

Estratégias de percepção da língua materna: do nascimento até um ano de vida

“…It has been verified that 7,5-month-olds have a facility for recognizing words from the segmentation of the utterance since these words are located at the beginning or at the end of the sentence next to its pause 28 .…”