title: Asymmetric cortical adaptation effects during alternating auditory stimulation.
abstract: The present study investigates hemispheric asymmetries in the neural adaptation processes occurring during alternating auditory stimulation. Stimuli were two monaural pure tones having a frequency of 400 or 800 Hz and a duration of 500 ms. Electroencephalogram (EEG) was recorded from 14 volunteers during the presentation of the following stimulus sequences, lasting 12 s each: 1) evoked potentials (EP condition, control), 2) alternation of frequency and ear (FE condition), 3) alternation of frequency (F condition), and 4) alternation of ear (E condition). Main results showed that in the central area of the left hemisphere (around C3 site) the N100 response underwent adaptation in all patterns of alternation, whereas in the same area of the right hemisphere the tones presented at the right ear in the FE produced no adaptation. Moreover, the responses to right-ear stimuli showed a difference between hemispheres in the E condition, which produced less adaptation in the left hemisphere. These effects are discussed in terms of lateral symmetry as a product of hemispheric, pathway and ear asymmetries.
authors.affiliation: Department of Biomedical Sciences, G. d'Annunzio University of Chieti and Pescara, Chieti-Pescara, Italy. Alfredo.Brancucci@Unich.It
authors.forename: Alfredo
authors.initials: A
authors.lastname: Brancucci
authors.forename: Giulia
authors.initials: G
authors.lastname: Prete
authors.forename: Elisa
authors.initials: E
authors.lastname: Meraglia
authors.forename: Alberto
authors.initials: A
authors.lastname: di Domenico
authors.forename: Victor
authors.initials: V
authors.lastname: Lugli
authors.forename: Barbara
authors.initials: B
authors.lastname: Penolazzi
authors.forename: Luca
authors.initials: L
authors.lastname: Tommasi
mesh_terms: D000161:Acoustic Stimulation; D000222:Adaptation, Physiological; D001303:Auditory Cortex / Q000502:physiology*; D001307:Auditory Perception; D004569:Electroencephalography; D005260:Female; D006801:Humans; D008297:Male; D055815:Young Adult