title: Unreliable evoked responses in autism.
abstract: Autism has been described as a disorder of general neural processing, but the particular processing characteristics that might be abnormal in autism have mostly remained obscure. Here, we present evidence of one such characteristic: poor evoked response reliability. We compared cortical response amplitude and reliability (consistency across trials) in visual, auditory, and somatosensory cortices of high-functioning individuals with autism and controls. Mean response amplitudes were statistically indistinguishable across groups, yet trial-by-trial response reliability was significantly weaker in autism, yielding smaller signal-to-noise ratios in all sensory systems. Response reliability differences were evident only in evoked cortical responses and not in ongoing resting-state activity. These findings reveal that abnormally unreliable cortical responses, even to elementary nonsocial sensory stimuli, may represent a fundamental physiological alteration of neural processing in autism. The results motivate a critical expansion of autism research to determine whether (and how) basic neural processing properties such as reliability, plasticity, and adaptation/habituation are altered in autism.
authors.affiliation: Department of Psychology, Baker Hall, Carnegie Mellon University, Pittsburgh, PA 15213, USA. ilan@cns.nyu.edu
authors.forename: Ilan
authors.initials: I
authors.lastname: Dinstein
authors.forename: David J
authors.initials: DJ
authors.lastname: Heeger
authors.forename: Lauren
authors.initials: L
authors.lastname: Lorenzi
authors.forename: Nancy J
authors.initials: NJ
authors.lastname: Minshew
authors.forename: Rafael
authors.initials: R
authors.lastname: Malach
authors.forename: Marlene
authors.initials: M
authors.lastname: Behrmann
mesh_terms: D000328:Adult; D000344:Afferent Pathways / Q000098:blood supply / Q000473:pathology; D001321:Autistic Disorder / Q000473:pathology* / Q000503:physiopathology*; D001931:Brain Mapping; D002540:Cerebral Cortex / Q000098:blood supply* / Q000473:pathology*; D005071:Evoked Potentials / Q000502:physiology*; D005260:Female; D007839:Functional Laterality; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008297:Male; D010100:Oxygen; D010812:Physical Stimulation; D011569:Psychiatric Status Rating Scales; D015203:Reproducibility of Results; D017603:Signal Detection, Psychological; D059629:Signal-To-Noise Ratio; D013997:Time Factors; D055815:Young Adult
chemical_list: D010100:Oxygen