title: Influence of the serotonin transporter promoter gene and shyness on children's cerebral responses to facial expressions.
abstract: BACKGROUND
  Childhood shyness can predate social anxiety disorder and may be associated with biased discrimination of facial expressions of emotions.
  
  
  OBJECTIVE
  To determine whether childhood shyness, or the serotonin transporter promoter polymorphism genotype, can predict participants' visual event-related potentials in response to expressions of children of similar ages.
  
  
  METHODS
  Study group drawn from an inception cohort of 149 subjects characterized 1 year before the present study by their degree of shyness.
  
  
  METHODS
  Third- and fourth-grade schoolchildren.
  
  
  METHODS
  Forty-nine of the inception cohort children, randomly selected.
  
  
  METHODS
  Latencies and amplitudes of the N400 waveform in response to happy, neutral, and angry expressions.
  
  
  RESULTS
  Shyness predicted significantly smaller N400 amplitudes in response to anger (at Pz: P < or = .04) and to a neutral expression (at Pz: P < or = .047). Shyness was significantly different across the 3 genotypes, the SS genotype being associated with higher shyness levels (analysis of variance: F(2,42) = 4.47, P < or = .02; Tukey honestly significant difference, SS vs LL, P < or = .01). An analysis of covariance showed that neither the type of expression nor the genotype per se influenced the N400 amplitudes, but a significant expression X genotype interaction was found (F(4,72) = 3.57, P < or = .01), sustained by the difference in amplitude of the SS and S carrier subjects compared with the LL subjects when exposed to the anger expression (Tukey honestly significant difference, P < or = .02).
  
  
  CONCLUSIONS
  Children who manifest higher levels of shyness or have 1 or 2 copies of the short allele of the serotonin transporter promoter gene appear to have a different pattern of processing affective stimuli of interpersonal hostility.
authors.affiliation: Department of Psychology, Vita-Salute San Raffaele University at the Department of Neuropsychiatric Sciences, Istituto Scientifico San Raffaele, Milan, Italy. marco.battaglia@hsr.it
authors.forename: Marco
authors.initials: M
authors.lastname: Battaglia
authors.forename: Anna
authors.initials: A
authors.lastname: Ogliari
authors.forename: Annalisa
authors.initials: A
authors.lastname: Zanoni
authors.forename: Alessandra
authors.initials: A
authors.lastname: Citterio
authors.forename: Uberto
authors.initials: U
authors.lastname: Pozzoli
authors.forename: Roberto
authors.initials: R
authors.lastname: Giorda
authors.forename: Cesare
authors.initials: C
authors.lastname: Maffei
authors.forename: Cecilia
authors.initials: C
authors.lastname: Marino
mesh_terms: D000339:Affect / Q000502:physiology; D000786:Anger / Q000502:physiology; D001921:Brain / Q000502:physiology*; D002648:Child; D002652:Child Behavior / Q000502:physiology*; D015331:Cohort Studies; D005071:Evoked Potentials / Q000235:genetics / Q000502:physiology*; D005149:Facial Expression; D005260:Female; D020022:Genetic Predisposition to Disease; D014644:Genetic Variation / Q000502:physiology; D005838:Genotype; D006791:Hostility; D006801:Humans; D007266:Inhibition, Psychological; D008297:Male; D008562:Membrane Glycoproteins / Q000235:genetics*; D026901:Membrane Transport Proteins / Q000235:genetics*; D009419:Nerve Tissue Proteins / Q000235:genetics*; D010698:Phobic Disorders / Q000175:diagnosis / Q000235:genetics; D011110:Polymorphism, Genetic / Q000502:physiology; D011401:Promoter Regions, Genetic / Q000235:genetics*; D050486:Serotonin Plasma Membrane Transport Proteins; D012792:Shyness; D014796:Visual Perception / Q000502:physiology
chemical_list: D008562:Membrane Glycoproteins; D026901:Membrane Transport Proteins; D009419:Nerve Tissue Proteins; C493230:SLC6A4 protein, human; D050486:Serotonin Plasma Membrane Transport Proteins