Auditory change detection in fragile X syndrome males: a brain potential study

Clin Neurophysiol. 2012 Jul;123(7):1309-18. doi: 10.1016/j.clinph.2011.11.039. Epub 2011 Dec 20.


Objective: The present study investigated involuntary change detection in a two-tone pre-attentive auditory discrimination paradigm in order to better understand the information processing mechanisms underlying attention deficits in fragile X syndrome (FXS) males.

Methods: Sixteen males with the FXS full mutation and 20 age-matched control participants (mean age 29 years) were presented with series of auditory stimuli consisting of standard and deviant tones while watching a silent movie.

Results: Brain potentials recorded to the tones showed that N1 and P2, sensory evoked potentials, were significantly enhanced in FXS compared to age-matched control participants. In contrast to controls, the N1 to standard tones failed to show long-term habituation to stimulus repetition in FXS. Additionally, both mismatch negativity and P3a generation, reflecting automatic change detection and the involuntary switch of attention, respectively, were significantly attenuated in FXS males.

Conclusions: The current study demonstrates that auditory stimulus discrimination in the FXS brain is already compromised during the pre-attentive stages of information processing. Furthermore, the apparent pre-attentive information processing deficiencies in FXS coincide with a weakness in the involuntary engagement of attentional resources.

Significance: The stimulus-driven information processing deficiencies in FXS might compromise information processing in several domains and, thus, present a key-deficit in FXS neurocognition.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acoustic Stimulation
  • Adolescent
  • Adult
  • Attention Deficit Disorder with Hyperactivity / physiopathology
  • Auditory Threshold / physiology*
  • Brain / physiopathology*
  • Brain Mapping
  • Case-Control Studies
  • Electroencephalography*
  • Evoked Potentials, Auditory / physiology*
  • Fragile X Syndrome / physiopathology*
  • Humans
  • Male
  • Middle Aged
  • Pitch Discrimination / physiology
  • Reaction Time / physiology
  • Young Adult