Frequency asymmetries in vision: The action asymmetry hypothesis

Area of Science:

• Cognitive Neuroscience
• Perception
• Human Motor Control

Background:

• Established research indicates specialized processing of visual and auditory frequencies by the left and right cerebral hemispheres.
• The underlying cause of this hemispheric specialization remains largely unknown.
• The action asymmetry hypothesis proposes a link between hand dominance and perceptual frequency specialization.

Purpose of the Study:

• To investigate whether hemispheric asymmetries in visual perception are linked to asymmetries in performing high- and low-frequency actions with dominant and non-dominant hands.
• To test the action asymmetry hypothesis by examining visual frequency perception in relation to handedness.

Main Methods:

• Two large-scale, preregistered online studies were conducted.
• Participants (right and left-handers) judged low- and high-frequency shapes presented in either the left or right visual hemifield.
• A third experiment utilized dichotic listening to assess language laterality.

Main Results:

• The typical hemispheric asymmetry for visual frequencies observed in right-handers was significantly reduced in left-handers.
• Hemispheric asymmetries for high-spatial-frequency stimuli were reversed between strong right- and left-handers.
• Dichotic listening results indicated that language laterality differences do not explain the observed perceptual reversals.

Conclusions:

• The findings provide initial support for the action asymmetry hypothesis.
• Frequency asymmetries in visual perception may be influenced by frequency asymmetries in motor actions associated with hand dominance.
• This research offers a novel explanation for hemispheric specialization in sensory processing.