Newborns discriminate novel from harmonic sounds: a study using magnetoencephalography.
OBJECTIVE
We investigated whether newborns respond differently to novel and deviant sounds during quiet sleep.


METHODS
Twelve healthy neonates were presented with a three-stimulus oddball paradigm, consisting of frequent standard (76%), infrequent deviant (12%), and infrequent novel stimuli (12%). The standards and deviants were counterbalanced between the newborns and consisted of 500 and 750 Hz tones with two upper harmonics. The novel stimuli contained animal, human, and mechanical sounds. All stimuli had a duration of 300 ms and the stimulus onset asynchrony was 1s. Evoked magnetic responses during quiet sleep were recorded and averaged offline.


RESULTS
Two deflections peaking at 345 and 615 ms after stimulus onset were observed in the evoked responses of most of the newborns. The first deflection was larger to novel and deviant stimuli than to the standard and, furthermore, larger to novel than to deviant stimuli. The second deflection was larger to novel and deviant stimuli than to standards, but did not differ between the novels and deviants.


CONCLUSIONS
The two deflections found in the present study reflect different mechanisms of auditory change detection and discriminative processes.


CONCLUSIONS
The early brain indicators of novelty detection may be crucial in assessing the normal and abnormal cortical function in newborns. Further, studying evoked magnetic fields to complex auditory stimulation in healthy newborns is needed for studying the newborns at-risk for cognitive or language problems.
Sambeth
Anke
A
Cognitive Brain Research Unit, Department of Psychology, University of Helsinki, P.O. Box 9, FIN-00014 Helsinki, Finland. anke.sambeth@cbru.helsinki.fi
Huotilainen
Minna
M
Kushnerenko
Elena
E
Fellman
Vineta
V
Pihko
Elina
E
D000161:Acoustic Stimulation / Q000379:methods; D000704:Analysis of Variance; D001307:Auditory Perception / Q000502:physiology*; D001931:Brain Mapping; D004307:Dose-Response Relationship, Radiation; D004569:Electroencephalography / Q000379:methods; D005072:Evoked Potentials, Auditory / Q000502:physiology*; D005260:Female; D006801:Humans; D007231:Infant, Newborn; D015225:Magnetoencephalography; D008297:Male; D012890:Sleep / Q000502:physiology; D013016:Sound