Event-related potentials in autistic and healthy children on an auditory choice reaction time task

Abstract

Event-related potentials (ERPs) were recorded from midline (Fz, Cz, Pz) and lateral sites (F3, F4, P3, P4) in autistic children (n = 7) and age-matched controls (n = 9) on an auditory choice reaction time task. Subjects were asked to press a button to an infrequent target (500 Hz, P = 0.14) and to ignore higher pitched infrequent (2000 Hz, P = 0.14) and frequent (1000 Hz) non-targets. Autistic subjects made twice as many errors of omission as controls and showed a higher criterion (beta) for targets. Maximum ERP peak amplitudes showed a more varied scalp distribution in the autistic group. N1 latencies were consistently shorter in the autistic group and in 3 subjects the target P3 latencies were markedly longer than for the controls. Compared to controls, the N1 amplitude of the autistic response was larger to the rare stimuli (particularly to non-targets). The amplitude of the P3 component was smaller in the autistic group (particularly to the target). The stimuli were also presented in a passive condition requiring no response. After subtraction of the waveform obtained in the passive condition from that obtained in the active condition or subtraction of the waveform elicited by the rare non-target from that elicited by the target, N1 target amplitude was larger in control than in autistic children. Autistic subjects showed more early negativity to the rare non-target at left frontal and a larger P3 to the target at right parietal sites. ERPs of autistic children are more responsive to stimulus features (e.g. high/rare non-target tone) and less responsive to their associations or meaningfulness (e.g. target P3). Attention-related ERPs of autistic children show signs of precocious (right dominance for P3) and delayed development (P3 not maximal at parietal sites).

Event Related Potentials in the Understanding of Autism Spectrum Disorders: An Analytical Review

“…Children with autism had significantly shorter latencies of the P1, N1, P2 and P3 components (Martineau et al 1984). In an ACRT task with high functioning children, Oades et al found a shorter N1 latency with normal performance in autism compared to age matched controls (Oades et al 1988(Oades et al , 1990. Finally, Ferri et al (2003), in a study comparing children with autism with age-matched controls, found similar shorter latency of N1 in a standard oddball paradigm, with normal reaction times and accuracies (Ferri et al 2003).…”

“…Developmentally, the P300 appears in the third to fourth years of life. Its amplitude increases with low stimulus probability, and its latency increases with task difficulty (McCarthy and Donchin 1976;Oades et al 1988).…”

“…ERP responses to frequent, target, and novel stimuli are recorded. A specific oddball paradigm known as the "Auditory Choice Reaction Time" (ACRT) has been used by several researchers in order to assess response to novelty as well as auditory attention (Oades et al 1988(Oades et al , 1990). …”

Event-related potentials in clinical research: Guidelines for eliciting, recording, and quantifying mismatch negativity, P300, and N400

“…They have smaller and later P300s than healthy children. Oades et al (1988) reported that the P300 elicited by targets in an auditory choice reaction time task was smaller in amplitude and more anterior in distribution in autistic children than in healthy controls. However, P3a to rare nontargets was not reduced.…”

Cortical auditory system maturational abnormalities in children with autism disorder: an MEG investigation

“…Age-related 24 changes in evoked components provide indirect measures of auditory system maturation and reflect changes that occur during 25 development. We use magnetoencephalography (MEG) to investigate maturational changes in cortical auditory systems in left (LH) and 26 right (RH) hemispheres in children with autism disorder (AD) and Controls. We recorded auditory evoked responses over left and right 27 temporal lobes in 17 Control and 15 AD children in the age range 8-16 years and measured M100 latency as a function of age, subject 28 group and hemisphere.…”