title: Autism diagnosis differentiates neurophysiological responses to faces in adults with tuberous sclerosis complex.
abstract: BACKGROUND
  Autism spectrum disorder (ASD) is a common and highly heritable neurodevelopmental disorder that is likely to be the outcome of complex aetiological mechanisms. One strategy to provide insight is to study ASD within tuberous sclerosis complex (TSC), a rare disorder with a high incidence of ASD, but for which the genetic cause is determined. Individuals with ASD consistently demonstrate face processing impairments, but these have not been examined in adults with TSC using event-related potentials (ERPs) that are able to capture distinct temporal stages of processing.
  
  
  METHODS
  For adults with TSC (n = 14), 6 of which had a diagnosis of ASD, and control adults (n = 13) passively viewed upright and inverted human faces with direct or averted gaze, with concurrent EEG recording. Amplitude and latency of the P1 and N170 ERPs were measured.
  
  
  RESULTS
  Individuals with TSC + ASD exhibited longer N170 latencies to faces compared to typical adults. Typical adults and adults with TSC-only exhibited longer N170 latency to inverted versus upright faces, whereas individuals with TSC + ASD did not show latency differences according to face orientation. In addition, individuals with TSC + ASD showed increased N170 latency to averted compared to direct gaze, which was not demonstrated in typical adults. A reduced lateralization was shown for the TSC + ASD groups on P1 and N170 amplitude.
  
  
  CONCLUSIONS
  The findings suggest that individuals with TSC + ASD may have similar electrophysiological abnormalities to idiopathic ASD and are suggestive of developmental delay. Identifying brain-based markers of ASD that are similar in TSC and idiopathic cases is likely to help elucidate the risk pathways to ASD.
authors.affiliation: MRC Social, Genetic and Developmental Psychiatry Centre, Institute of Psychiatry, King's College London, De Crespigny Park, London, SE5 8AF UK ; Child and Adolescent Psychiatry, Institute of Psychiatry, King's College London, London, UK.
authors.forename: Charlotte
authors.initials: C
authors.lastname: Tye
authors.affiliation: Dipartimento di Psicologia dello Sviluppo e della Socializzazione, Università di Padova, Padova, Italy ; Centre for Brain and Cognitive Development, Birkbeck, University of London, London, UK.
authors.forename: Teresa
authors.initials: T
authors.lastname: Farroni
authors.affiliation: Centre for Brain and Cognitive Development, Birkbeck, University of London, London, UK.
authors.forename: Ágnes
authors.initials: Á
authors.lastname: Volein
authors.affiliation: Institute of Cognitive Neuroscience, University College London, London, UK.
authors.forename: Evelyne
authors.initials: E
authors.lastname: Mercure
authors.affiliation: Centre for Brain and Cognitive Development, Birkbeck, University of London, London, UK.
authors.forename: Leslie
authors.initials: L
authors.lastname: Tucker
authors.affiliation: Centre for Brain and Cognitive Development, Birkbeck, University of London, London, UK.
authors.forename: Mark H
authors.initials: MH
authors.lastname: Johnson
authors.affiliation: MRC Social, Genetic and Developmental Psychiatry Centre, Institute of Psychiatry, King's College London, De Crespigny Park, London, SE5 8AF UK ; Child and Adolescent Psychiatry, Institute of Psychiatry, King's College London, London, UK.
authors.forename: Patrick F
authors.initials: PF
authors.lastname: Bolton
keywords: Autism spectrum disorder; ERP; Face; Gaze; Tuberous sclerosis complex