Hemisphere differences in event-related potentials (ERPS) to monaural presentations of simple speech sounds

Percept Mot Skills. 1992 Jun;74(3 Pt 2):1043-54. doi: 10.2466/pms.1992.74.3c.1043.

Abstract

The aim of the present study was to compare ERPs over the left and right hemispheres to monaural consonant-vowel (CV) syllables. It was predicted that, if the contralateral auditory representation is stronger than the ipsilateral one, then ERPs over the left hemisphere should be larger for right-ear stimulus input. Furthermore, if the hemispheres differ in efficiency in processing of speech sounds, then ERPs recorded at any given site should vary as a function of the ear to which the sound is presented. Twelve right-handed subjects participated. The CV-syllables used were /Ba/ and /Pa/ with 15 presentations of each syllable to each ear in a randomized order. EEG was recorded from F3, Fz, and F4 with linked ears as reference. The results showed no significant asymmetry in the ERP-leads. N1- and N2-amplitudes were, however, larger at Fz than at F3 and F4, and N1-latency was shorter for right-ear presentations, which also interacted with the /Pa/-syllable presentations. P3-latency was longer to the /Pa/-syllable compared to the /Ba/-syllable, while N4-latency was longer to the /Ba/-syllable. N4-amplitude was more negative for the /Pa/-syllable presented to the left ear. The results are discussed in terms of phonemic differences between the unvoiced /Pa/ and voiced /Ba/, and early versus late stages of processing. The results are also seen in relation to ear differences in dichotic listening.

Publication types

  • Clinical Trial
  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Attention / physiology*
  • Dichotic Listening Tests
  • Dominance, Cerebral / physiology*
  • Electroencephalography* / instrumentation*
  • Evoked Potentials, Auditory / physiology
  • Frontal Lobe / physiology
  • Humans
  • Male
  • Phonetics
  • Reaction Time / physiology
  • Signal Processing, Computer-Assisted / instrumentation*
  • Speech Perception / physiology*