Auditory Evoked Brain Potentials as a Function of Interstimulus Interval in Adults with Down's Syndrome

Abstract

Auditory-evoked potentials (AEP) to repeated binaural tone pips of several interstimulus intervals (ISIs) ≥1 s were recorded from the vertex of young adults with Down's syndrome (DS; trisomy 21) and normal young adults. The following results were obtained: (1) AEP amplitudes, as well as one latency measure, of both experimental groups increased with the lengthening of ISI. (2) AEP peak latencies of the DS group were longer than AEP peak latencies of the normal group for all the ISIs employed. (3) AEP amplitudes of the DS group tended to be larger than AEP amplitudes of the normal group. These findings are discussed in relationship to issues of attention.

Nous avons comparé les potentiels auditifs tardifs en fonction de trois valeurs de ISI (1, 4 et 8 s) chez de jeunes adultes normaux et de jeunes adultes atteints de syndrome de Down (SD). Nous avons observé: 1) que l'amplitude ainsi que la mesure de la latence des potentiels augmentaient avec la valeur de ISI chez les deux groupes de sujets; 2) que ces augmentations étaient plus fortes chez les sujets atteints de SD. Nous pensons qu'il s'agit d'un trouble de l'inhibition et de l'attention.

Key Words:

• Auditory-evoked potentials/auditory-evoked responses
• Vertex potentials
• Long-latency components
• Recovery functions
• Interstimulus intervals
• Down's syndrome
• trisomy 21