Early development of brain responses to rapidly presented auditory stimulation: a magnetoencephalographic study.
BACKGROUND
The processing of rapidly presented stimuli has been shown to be a precursor for the perception of speech in infants, long before they learn to speak. However, the onset and early development of rapid temporal processing (RTP) skills is not yet well understood. The main goal of this study was to assess the development of RTP skills during the prenatal and early postnatal stages of life.


METHODS
Tone pairs were presented in two difficulties (long and short) and event-related magnetic fields were recorded using MEG. Pregnant women (22) (gestational ages between 29 and 38 weeks') participated in the fetal study and 15 returned for a neonatal follow-up study between 2 and 38 days after delivery or 38 and 44 weeks gestational age (GA).


RESULTS
In the postnatal follow-up study, a trend towards two peaks with increasing chronological and gestational age was observed in the longer tone pair. However, no such trend was evident in neonatal responses to the short tone pairs or in fetal recordings.


CONCLUSIONS
Neonates showed a gradual trend to successful processing of the longer tone pair with increasing age. By 22 days of chronological age, the infants processed this tone pair successfully, as indicated by two-peak waveforms. Therefore, the first 3 weeks of life could be critical for the development of RTP.


CONCLUSIONS
This study is a first approach towards the assessment of early RTP development. The results provide promising indications for future studies, which might lead to an early detection of deficits in speech perception and therefore prevent further language impairments.
Sheridan
Carolin
C
Department of Obstetrics and Gynecology, University of Arkansas for Medical Sciences, 4301 W. Markham # 518, Little Rock, AR 72205, USA. carolin.sheridan@gmail.com
Draganova
Rossitza
R
Ware
Maureen
M
Murphy
Pamela
P
Govindan
Rathinaswamy
R
Siegel
Eric R
ER
Eswaran
Hari
H
Preissl
Hubert
H
D000161:Acoustic Stimulation / Q000379:methods*; D001921:Brain / Q000196:embryology / Q000254:growth & development* / Q000502:physiology*; D005072:Evoked Potentials, Auditory / Q000502:physiology*; D005260:Female; D005333:Fetus / Q000502:physiology*; D005865:Gestational Age; D006801:Humans; D007223:Infant; D015225:Magnetoencephalography / Q000379:methods*; D011247:Pregnancy