title: Mismatch response (MMR) in neonates: Beyond refractoriness.
abstract: In the adult auditory system, deviant detection and updating the representation of the environment is reflected by the event-related potential (ERP) component termed the mismatch negativity (MMN). MMN is elicited when a rare-pitch deviant stimulus is presented amongst frequent standard pitch stimuli. The same stimuli also elicit a similar discriminative ERP component in sleeping newborn infants (termed the mismatch response: MMR). Both the MMN and the MMR can be confounded by responses generated by differential refractoriness of frequency-selective neural populations. Employing a stimulus paradigm designed to minimize this confounding effect, newborns were presented with sequences of pure tones under two conditions: In the oddball block, rare deviant tones (500Hz; 10%) were delivered amongst frequent standards (700Hz; 90%). In the control block, a comparison tone (500Hz) was presented with the same probability as the deviant (10%) along with the four contextual tones (700Hz, 980Hz, 1372Hz, 1920.8Hz; 22.5% each). The significant difference found between the response elicited by the deviant and the comparison tone showed that the response elicited by the deviant in the oddball sequences cannot be fully explained by frequency-specific refractoriness of the neural generators. This shows that neonates process sounds in a context-dependent manner as well as strengthens the correspondence between the adult MMN and the infant MMR.
authors.affiliation: Institute of Cognitive Neuroscience and Psychology, Research Centre for Natural Sciences, Hungarian Academy of Sciences, Budapest, Hungary. Electronic address: haden.gabor@ttk.mta.hu.
authors.forename: Gábor P
authors.initials: GP
authors.lastname: Háden
authors.affiliation: Institute of Cognitive Neuroscience and Psychology, Research Centre for Natural Sciences, Hungarian Academy of Sciences, Budapest, Hungary; Department of Cognitive Science, Central European University, Budapest, Hungary.
authors.forename: Renáta
authors.initials: R
authors.lastname: Németh
authors.affiliation: Department of Obstetrics-Gynaecology and Perinatal Intensive Care Unit, Military Hospital, Budapest, Hungary.
authors.forename: Miklós
authors.initials: M
authors.lastname: Török
authors.affiliation: Institute of Cognitive Neuroscience and Psychology, Research Centre for Natural Sciences, Hungarian Academy of Sciences, Budapest, Hungary; Institute of Psychology, University of Szeged, Szeged, Hungary.
authors.forename: István
authors.initials: I
authors.lastname: Winkler
mesh_terms: D000161:Acoustic Stimulation; D002657:Child Development / Q000502:physiology*; D004569:Electroencephalography; D005072:Evoked Potentials, Auditory / Q000502:physiology*; D005260:Female; D006801:Humans; D007231:Infant, Newborn; D008297:Male
keywords: ERP; MMN; MMR; Neonate; Oddball; Refractoriness