Abnormal Attention in Autism Shown by Steady-State Visual Evoked Potentials

Matthew Belmonte

Autism 4(3):269-285 (September 2000)

Address for correspondence: mkb4@Cornell.edu

ABSTRACT: This study examined brain electrical responses as a physiological measure of speed and specificity of attentional shifting in eight adult males with autism. Subjects were required to shift attention between rapidly flashed targets alternating between left and right visual hemifields. When targets were separated by less than 700ms, steady-state brain electrical response in both hemispheres was augmented and background EEG decreased for rightward shifts as compared to leftward shifts. At longer separations, persons with autism showed no modulation of background EEG, and high variability in steady-state response. These results contrast with those in normal controls, where in each hemisphere separately steady-state response increased and background EEG decreased for shifts directed contralaterally to that hemisphere. Group differences were significant at p<0.04 for the steady state response and p<0.0001 for the background EEG. Lack of hemispherically independent modulation in autism may reflect the operation of a nonspecific mechanism of sensory gating.

A PDF reprint of this article is available. Due to restrictions imposed by Sage Publications, this electronic reprint must be used `as you would an offprint of the article.' I therefore must collect readers' email addresses as a prerequisite to making the article available electronically, just as I would have to receive a postal address before sending a hardcopied offprint. I will not release these addresses to any third parties, except as may be required by law.

To receive a password that will enable you to download a reprint, enter your email address here:

(requires password)
Download raw experimental data
(600 MB .tar.gz file, same password)
The raw data are in NeuroScan multiplexed (not SynAmps block) .CNT format. The accompanying C programs provide some documentation as to how these files are to be read. I haven’t the time to provide support for these very old data which were collected in 1993-1994; you’re on your own to sort it out from what’s there.


  1. Bosa CA. As relações entre autismo, comportado social e função executiva. Psicologia: Reflexão e Crítica 14(2):281-287 (2001).
  2. Allen G, Courchesne E. Differential effects of developmental cerebellar abnormality on cognitive and motor functions in the cerebellum: an fMRI study of autism. American Journal of Psychiatry 160(2):262-273 (February 2003).
  3. Raymaekers R, van der Meere J, Roeyers H. Event-rate manipulation and its effect on arousal modulation and response inhibition in adults with high functioning autism. Journal of Clinical and Experimental Neuropsychology 26(1):74-82 (February 2004).
  4. Baron-Cohen S. The cognitive neuroscience of autism. Journal of Neurology, Neurosurgery, and Psychiatry 75(7):945-948 (July 2004).
  5. Teder-Sälejärvi WA, Pierce KL, Courchesne E, Hillyard SA. Auditory spatial localization and attention deficits in autistic adults. Cognitive Brain Research 23(2-3):221-234 (May 2005).
  6. Kleinhans N, Akshoomoff NA, Delis DC. Executive functions in autism and Asperger's disorder: flexibility, fluency, and inhibition. Developmental Neuropsychology 27(3):379-401 (2005).
  7. Haist F, Adamo M, Westerfield M, Courchesne E, Townsend J. The functional neuroanatomy of spatial attention in autism spectrum disorder. Developmental Neuropsychology 27(3):425-458 (2005).
  8. Lyons V, Fitzgerald M. Asperger syndrome — a gift or a curse? New York: Nova Science Publishers (1 December 2005), p 18.
  9. Bird GP, Catmur CD, Silani G, Frith CD, Frith U. Attention does not modulate neural responses to social stimuli in autism spectrum disorders. NeuroImage 31(4):1614-1624 (15 July 2006).
  10. Levy F. Theories of autism. Australian and New Zealand Journal of Psychiatry 41(11):859-868 (November 2007).
  11. Sánchez-Marín FJ, Padilla-Medina JA. A psychophysical test of the visual pathway of children with autism. Journal of Autism and Developmental Disorders 38(7):1270-1277 (August 2008).
  12. Smith H, Milne E. Reduced change blindness suggests enhanced attention to detail in individuals with autism. Journal of Child Psychology and Psychiatry 50(3):300-306 (March 2009).
  13. Sokhadze E, Baruth J, Tasman A, Sears L, Mathai G, El-Baz A, Casanova MF. Event-related potential study of novelty processing abnormalities in autism. Applied Psychophysiology and Biofeedback 34(1):37-51 (March 2009).
  14. Sokhadze EM, El-Baz A, Baruth J, Mathai G, Sears L, Casanova MF. Effects of low frequency repetitive transcranial magnetic stimulation (rTMS) on gamma frequency oscillations and event-related potentials during processing of illusory figures in autism. Journal of Autism and Developmental Disorders 39(4):619-634 (April 2009).
  15. Simmons DR, Robertson AE, McKay LS, Toal E, McAleer P, Pollick FE. Vision in autism spectrum disorders. Vision Research 49(22):2705-2739 (10 November 2009).
  16. Bloemen OJN, Deeley Q, Sundram F, Daly EM, Barker GJ, Jones DK, van Amelsvoort TAMJ, Schmitz N, Robertson D, Murphy KC, Murphy DGM. White matter integrity in Asperger syndrome: a preliminary diffusion tensor magnetic resonance imaging study in adults. Autism Research 3(5):203-213 (October 2010).


  1. Belmonte MK, Yurgelun-Todd DA. Anatomic dissociation of selective and suppressive processes in visual attention. NeuroImage 19(1):180-189 (May 2003).
  2. Belmonte MK, Yurgelun-Todd DA. Functional anatomy of impaired selective attention and compensatory processing in autism. Cognitive Brain Research 17(3):651-664 (October 2003).
  3. Belmonte MK, Cook EH, Anderson GM, Rubenstein JL, Greenough WT, Beckel-Mitchener A, Courchesne E, Boulanger LM, Powell SB, Levitt PR, Perry EK, Jiang YH, DeLorey TM, Tierney E. Autism as a disorder of neural information processing: directions for research and targets for therapy. Molecular Psychiatry 9(7):646-663 (July 2004). Unabridged edition at http://www.cureautismnow.org/conferences/summitmeetings/
  4. Belmonte MK, Allen G, Beckel-Mitchener A, Boulanger LM, Carper RA, Webb SJ. Autism and abnormal development of brain connectivity. Journal of Neuroscience 24(42):9228-9231 (20 October 2004).
  5. Baron-Cohen S, Belmonte MK. Autism: a window onto the development of the social and the analytic brain. Annual Review of Neuroscience 28:109-126 (2005).
  6. Bonneh YS, Belmonte MK, Pei F, Iversen PE, Kenet T, Akshoomoff NA, Adini Y, Simon HJ, Moore CI, Houde JF, Merzenich MM. Cross-modal extinction in a boy with severely autistic behaviour and high verbal intelligence. Cognitive Neuropsychology 25(5):635-652 (2008).
  7. Baron-Cohen S, Golan O, Chakrabarti B, Belmonte MK. Social cognition and autism spectrum conditions. In: Social Cognition and Developmental Psychopathology (C Sharp, P Fonagy, I Goodyer, eds.), pp 29-56. Oxford: Oxford University Press (4 September 2008).
  8. Belmonte MK. What’s the story behind ‘theory of mind’ and autism? Journal of Consciousness Studies 16(6-8):118-139 (June-August 2009).