title: The maturation of mismatch negativity networks in normal adolescence.
abstract: OBJECTIVE
  We investigated the neurophysiological mechanisms underpinning the generation of the mismatch negativity (MMN) and its development from adolescence to early adulthood.
  
  
  METHODS
  We used dynamic causal modelling (DCM) to study connectivity models for healthy adults and adolescents. MMN was elicited with an auditory oddball paradigm in two groups of healthy subjects with mean age 14 (n=52) and 26 (n=26). We tested models with different hierarchical complexities including up to five cortical nodes.
  
  
  RESULTS
  We showed that the network generating MMN consisted of 5 nodes that could modulate all intra- and internodal connections. The inversion of this model showed that adolescents had reduced backward connection from rIFG to rSTG (p<0.04) together with increased excitatory activity in rSTG (p<0.02). There was a reduced modulation of excitability in rSTG (p<0.02) and of forward connectivity from lA1 to lSTG (p<0.03).
  
  
  CONCLUSIONS
  The cortical network generating MMN continues to develop in adolescence up to adulthood. Cortical regions in the temporal and frontal lobes, involved in auditory processing, mature with increasing fronto-temporal connectivity together with increased sensitivity in the temporal regions for changes in sound stimuli.
  
  
  CONCLUSIONS
  This study may offer an explanation for the neurobiological maturation of the MMN in adolescence.
authors.affiliation: Clinical Neurophysiology, Karolinska University Hospital, Stockholm, Sweden. Electronic address: gerald.cooray@ki.se.
authors.forename: G K
authors.initials: GK
authors.lastname: Cooray
authors.affiliation: Queensland Brain Institute, The University of Queensland, St Lucia, QLD, Australia; ARC Centre of Excellence for Integrative Brain Function, The University of Queensland, St Lucia, QLD, Australia.
authors.forename: M I
authors.initials: MI
authors.lastname: Garrido
authors.affiliation: Clinical Neurophysiology, Karolinska University Hospital, Stockholm, Sweden.
authors.forename: T
authors.initials: T
authors.lastname: Brismar
authors.affiliation: Clinical Neurophysiology, Karolinska University Hospital, Stockholm, Sweden.
authors.forename: L
authors.initials: L
authors.lastname: Hyllienmark
mesh_terms: D000161:Acoustic Stimulation / Q000379:methods*; D000293:Adolescent; D000294:Adolescent Behavior / Q000502:physiology; D000328:Adult; D001307:Auditory Perception / Q000502:physiology; D002648:Child; D004569:Electroencephalography / Q000379:methods; D005072:Evoked Potentials, Auditory / Q000502:physiology*; D005260:Female; D005625:Frontal Lobe / Q000502:physiology*; D006801:Humans; D008297:Male; D009415:Nerve Net / Q000502:physiology*; D013702:Temporal Lobe / Q000502:physiology*; D055815:Young Adult
keywords: Dynamic causal modelling; EEG; ERP; Maturation adolescence; Mismatch negativity