P300 auditory event-related potentials and the effects of contralateral competition in children with learning disabilities

Abstract

Subject: White noise contralateral stimulation effects on Auditory P300 in children with Learning Disorder compared to children with Academic Difficulties (due to stimulation/sociocultural and educational problems) and to children in typical development of the academic skills. Aim: To compare the latencies and amplitudes of P300 auditory event-related potencials in children with learning disabilities in two assessment conditions: with and without white noise contralateral stimulation. Study design: observational cross-sectional survey to be developed at the Centre of Research and Studies in Rehabilitation (CEPRE) - Faculty of Medical Sciences of the University of Campinas. Material and method: 40 children ranging from 9 to 15 years of age, both genders, will undergo the P300 assessment. The children will be divided into 3 groups: LDG - 10 children with Learning Disorder as per interdisciplinar diagnosis, according to DSM-IV criteria; ADG - 15 children with academic difficulties (due to educational problems); and CG - 15 children in typical development and without learning/academic issues. All subjects must be normal hearing in order to be included in the study. Children with hearing impairments, attention defict hyperactive disorder or any other genetic neural or psychologic disease will be excluded. To elicit the P300 all subjects will be submetted to the same auditory discrimination task - to identify and to count the target stimuli. Surface electrodes will be placed on the vertex and on the rigth and left mastoid. The target acoustic stimuli ( 2KHz tone bursts) and frequent stimuli (1KHz tone bursts) of 70 dB nHL intensity will be presented randomly in an oddball paradigm through TDH-39 headphones. The equipment used will be the Interacoustics EP25 and the test will be repeated using contralateral white noise stimuli of 70 dB nHL. Data analisys will compare the P300 latency and amplitude values in both assessment conditions in order to verify if the P300 responses will be supressed due to white noise contralateral stimulation. After that, the suppresion values will be compared between the groups. Hypothesis: The suppression values of P300 latencies and amplitudes of LDG group will be smaller (or absent) when compared to the other groups. Expected outcomes: It is expected that the outcomes of this study will provide information to the understanding of the sound processing in children with Learning Disorder and help to base proper individualized diagnosis and treatment plans. (AU)