Enhanced articulatory speed in ambidexters

Area of Science:

• Neuroscience
• Cognitive Psychology
• Speech Science

Background:

• Speech lateralization, the brain's organization for language, is typically asymmetric.
• Incomplete or atypical lateralization has been hypothesized to correlate with motor control differences, including speech rate.
• Previous research has not fully explored the relationship between handedness, speech articulation speed, and lateralization patterns.

Purpose of the Study:

• To investigate the relationship between speech lateralization and articulatory speed in young adults.
• To compare speech production speed across individuals with varying degrees of handedness (strongly left, strongly right, and ambidextrous).
• To examine whether observed differences in motor tasks extend to speech tasks.

Main Methods:

• Two studies were conducted with normal, young adult participants.
• Speech production speed was measured under various conditions.
• Speech lateralization was assessed using dichotic listening scores.
• Manual movement tasks were also evaluated in the second study.

Main Results:

• Contrary to expectations, ambidextrous subjects demonstrated faster speech production than strongly left- or right-handed subjects.
• No significant differences in speech lateralization were found between handedness groups based on dichotic listening scores.
• Ambidextrous individuals also showed superior performance in certain manual movement tasks.

Conclusions:

• Incomplete speech lateralization is not directly related to reduced articulatory speed.
• Ambidexterity may be associated with enhanced motor control, manifesting in faster speech and manual task performance.
• Handedness, particularly ambidexterity, presents a complex interplay with motor speed and brain lateralization.