Auditory event-related potentials (ERPs) and mismatch negativity (MMN) in healthy children and those with attention-deficit or tourette/tic symptoms

Abstract

The study compares 5 auditory event-related potential (ERP) components (P1 to P3) after 3 tones differing in pitch and rarity, and contrasts the mismatch negativity (MMN) between them in 12 children with attention-deficit hyperactivity disorder (ADHD; mean 10.2 years of age), 12 healthy controls pairwise matched for age (controls), and 10 with Chronic Tic or Tourette Syndrome (TS). Topographic recordings were derived from 19 scalp electrodes. Four major effects are reported. (a) Shorter latencies in ADHD patients were evident as early as 100 ms. (b) Both ADHD and TS groups showed very large P2 components where the maxima were shifted anteriorly. The differences in the later potentials were of a topographical nature. (c) Frontal MMN was non-significantly larger in the ADHD group but normalized data showed a left rather than a right frontal bias as in control subjects. Maxima for TS were usually posterior. (d) ADHD patients did not show the usual right-biased P3 asymmetry nor the frontal versus parietal P3 latency difference. From these results it is suggested that ADHD patients process perceptual information faster from an early stage (N1). Further, along with the TS group, ADHD patients showed an unusually marked inhibitory phase in processing (P2), interpreted as a reduction of the normal controls on further processing. Later indices of stimulus processing (N2-P3) showed a frontal impairment in TS and a right hemisphere impairment in ADHD patients. These are interpreted in terms of the difficulties in sustaining attention experienced by both ADHD and TS patients.

Cognitive switching processes in young people with attention-deficit/hyperactivity disorder

“…Activity of the neurotransmitter dopamine facilitates switches between the inputs that are in control of the output of various cortical and subcortical nuclei in the brain (Oades, 1985). Activity in these frontal and parietal loci is reduced in adolescents with ADHD when switches are required (Smith, Taylor, Brammer, Toone, & Rubia, 2006), especially on the right side (Oades, Dittmann-Balcar, Schepker, & Eggers, 1996), and it is widely accepted that dopamine is suboptimally active in ADHD patients (Oades, 2002;Oades, 2006). …”

Avaliação eletrofisiológica do sistema auditivo em indivíduos com gagueira desenvolvimental persistente

“…Regarding LLAEP amplitude components, a difference was and state of attention and represents the activity of the supratemporal auditory cortex [26][27][28] .…”

Potenciais evocados auditivos de longa latência na síndrome de Asperger: estudo de dois casos

“…Thus, these findings indicate a possible central auditory processing dysfunction, suggesting deficits in attention and sound discrimination.Impairment in these skills could be observed in the necessity to repeat the instructions for the tests and in the difficulty that these individuals had in perceiving the rare stimulus. [28][29][30] In addition, limitations and other important observations regarding the electrophysiological evaluation in children with Asperger Syndrome were noted.The presence of the child's therapist is required to favour a familiar environment, since the interaction between them is already established. The therapist favoured the patient interaction and collaboration in accomplishing the task proposed, the audiological and electrophysiological assessment.…”