Brain asymmetry in directing attention during dichotic listening test: An fNIRS study


Eskicioglu E., Taslica S., Narin B., GÜDÜCÜ Ç., Oniz A., Ozgoren M.

LATERALITY, vol.24, no.4, pp.377-392, 2019 (SSCI) identifier identifier identifier

  • Publication Type: Article / Article
  • Volume: 24 Issue: 4
  • Publication Date: 2019
  • Doi Number: 10.1080/1357650x.2018.1527847
  • Journal Name: LATERALITY
  • Journal Indexes: Social Sciences Citation Index (SSCI), Scopus
  • Page Numbers: pp.377-392
  • Keywords: Brain asymmetry, dichotic listening, fNIRS, auditory task performance, NEAR-INFRARED SPECTROSCOPY, RIGHT AUDITORY CORTICES, RIGHT EAR ADVANTAGE, ACTIVATION, CORTEX, STIMULI, INHIBITION, LANGUAGE, SPEECH, SOUNDS
  • Dokuz Eylül University Affiliated: Yes

Abstract

In a classical dichotic listening paradigm, besides auditory brain asymmetry, cognitive functions such as attention and conflict resolution play a major role. The aim of this study is to reveal the possible haemodynamic mechanisms of higher attentional performance in prefrontal cortex during dichotic listening test. Twenty-six healthy participants underwent a dichotic listening task in three sessions; non-forced attention, attention focused to right ear, and attention focused to left ear. In each session, haemodynamic activity of prefrontal brain area was recorded using functional near-infrared spectroscopy (fNIRS). Effects of focused attention and performance level of the task on oxy-, deoxy-, and total haemoglobin levels were investigated. Oxy- and total haemoglobin levels in right prefrontal regions during forced-right and forced-left sessions were significantly higher than levels of the non-forced session. This might be an indicator of inhibition and orienting attentional functions of right inferior frontal gyrus. High performers had significantly higher deoxyhaemoglobin levels in the forced-left session compared to the non-forced session, while low performers' deoxyhaemoglobin levels did not differ among these sessions. Observing this difference only in the forced-left session but not in the forced-right session might suggest conflict resolution in top-down and bottom-up processes during the forced-left session for right-handed participants.