Hemispace and information control by the two cerebral hemispheres: which interaction?

Area of Science:

• Neuroscience
• Cognitive Psychology
• Sensory Perception

Background:

• The cerebral hemispheres process information differently, with a known right hemisphere superiority for certain spatial tasks.
• Visual experience may influence how sensory information is processed across cerebral hemispheres and hemispace.

Purpose of the Study:

• To investigate how the spatial location of tactile stimuli affects information processing in the left and right cerebral hemispheres.
• To compare the effects of visual experience (blind vs. sighted subjects) on hemispheric lateralization in tactile discrimination.

Main Methods:

• Two experiments were conducted using an angle discrimination task.
• Subjects included both sighted and blind individuals, with performance measured using the left and right hands.
• Stimuli were presented in left, central, and right hemispace to assess spatial effects.

Main Results:

• Sighted subjects showed a left-hand (right hemisphere) advantage, more pronounced in the left hemispace.
• Blind subjects exhibited a left-hand advantage in the central and left hemispace, with no difference in the right hemispace.
• Hemispace effects were primarily driven by changes in the performance of the left hand (right hemisphere).

Conclusions:

• Hemispheric control of hemispace interacts with the dominant hemisphere's processing capabilities.
• Visual experience modulates the lateralization of tactile spatial processing.
• The right hemisphere's role in tactile spatial discrimination is influenced by both hemispace and prior sensory experience.