Auditory N1, N2, and MMN to Pure-Tone and Consonant–Vowel Stimuli in Developmental Dyslexia and Benign Rolandic Epilepsy: A Progressive Insight Into the Underlying Disruptive Neurophysiology

David Tomé,1,2 Ilídio Pereira,3 Maria Celeste Vieira,4 Ana Paula Soares,5 Fernando Barbosa6 1Department of Audiology, Center for Rehabilitation Research (CiR), School of Health (E2S), Polytechnic Institute of Porto, Porto, Portugal; 2Serviço de Neurologia do Hospital de São João, EPE, Porto, Portugal; 3Department of Biomathematics, Biostatistics and Bioinformatics, School of Health (E2S), Polytechnic Institute of Porto, Porto, Portugal; 4Clínica de Dislexia, Matosinhos, Portugal; 5Department of Basic Psychology, School of Psychology, University of Minho, Braga, Portugal; 6Laboratory of Neuropsychophysiology, Faculty of Psychology and Educational Sciences, University of Porto, Porto, PortugalCorrespondence: David Tomé, School of Health (E2S), Rua Dr. António Bernardino de Almeida, 400, Porto, 4200-072, Portugal, Tel +351 222 061 000, Email [email protected]: Benign rolandic epilepsy or benign epilepsy in childhood with centrotemporal spikes (BECTS) and developmental dyslexia (DD) are two of the most studied disorders in childhood. Despite decades of research, the neurophysiological mechanisms underpinning these disorders are largely unknown. Here, we use auditory event-related potentials (AERPs) to shed light on these issues, since several authors have reported the existence of language and learning impairments. AERPs reflect the activation of different neuronal populations and are suggested to contribute to the evaluation of auditory discrimination (N1), attention allocation and phonological categorization (N2), and echoic memory (mismatch negativity (MMN]).Patients and Methods: This study aims to investigate and document AERP changes in a group of children with BECTS and another group with DD. AERPs were recorded to pure-tones and consonant–vowel (CV) stimuli in an auditory oddball paradigm in eight children with BECTS, seven with DD, and 11 gender- and age-matched controls.Results: The results revealed perceptual deficits for pure-tone and CV stimuli (pre-attentional and auditory discrimination) in DD, related to N1 reduced amplitude (p< 0.05; Fz: 2.57 μV, Cz: 2.75 μV). The BECTS group revealed no significant results for N1; however, there was an increase in N2b latency.Conclusion: The findings in the DD group support the anchor-deficit hypothesis as an explanation for neurolinguistic deficits. The increased N2b latency in the BECTS group could be related to a potential lack of inhibitory mechanisms of pyramidal neurons, as justified by the process of epileptogenesis.Keywords: N1, N2b, auditory processing, developmental dyslexia, BECTS