Gender differences in a dichotic listening and movement task: lateralization or strategy?

Area of Science:

• Neuropsychology
• Cognitive Neuroscience
• Speech Perception Research

Background:

• Traditional dichotic listening (DL) procedures may underestimate left-hemisphere language lateralization in right-handed individuals.
• Confounding factors like attention, report order, and memory can obscure true cerebral differences in DL tasks.
• A novel DL adaptation was developed to mitigate these traditional limitations.

Purpose of the Study:

• To present an improved dichotic listening procedure for more accurate assessment of speech perception lateralization.
• To investigate the sensitivity of the adapted DL procedure in detecting cerebral lateralization for language.

Main Methods:

• Participants responded to auditory cues by moving to color-coded targets.
• Auditory cue conditions included monaural, dichotic-same, and dichotic-different presentations.
• The adapted DL procedure aimed to reduce attentional, order of report, and memory biases.

Main Results:

• Ninety-three percent of participants exhibited a right ear advantage (REA) for correct responses.
• A significant REA was observed across reaction time, movement time, and total response time.
• Error patterns suggest gender differences may stem from task strategy, not cerebral lateralization differences.

Conclusions:

• The adapted dichotic listening procedure demonstrates high sensitivity to speech perception lateralization.
• This method offers a more reliable assessment of language lateralization compared to traditional DL techniques.
• Findings contribute to understanding hemispheric specialization for language processing.