Biopsychology - Lateralisation Flashcards
Intro to hemispheric lateralisation
Idea that the two halves of the brain have different functions
Left hemisphere: dominant for language
Right hemisphere: dominant for visual and motor tasks
Corpus callosum
Bundle of nerve fibres connecting the two hemispheres
Facilitates communication between left and right sides
Split-brain patients
Individuals who have undergone commissuritomy
Procedure severs the corpus callosum
Used as a treatment for severe epilepsy
Provides unique opportunity to study hemispheric specialisation
Sperry and gazzaniga’s split-brain research
Pioneering studies on split-brain patients
Aimed to examine hemispheric lateralisation
Used various tasks to test each hemisphere separately
Images presented to felt or right visual field
Left visual field = processed by right hemisphere
Right visual field = processed by left hemisphere
Left field/right hemisphere: cannot describe verbally
Right field/left hemisphere: can describe verbally
Tactile test
Objects placed in left or right hand
● Left hand → processed by right
hemisphere
● Right hand → processed by left
hemisphere
● Results:
● Left hand: Can’t describe, but can identify similar object
● Right hand: Can describe and identify
Drawing task
Pictures presented to left or right visual field
● Patients asked to draw what they saw
● Results:
● Left hand (right hemisphere): Clearer, better drawings
● Right hand (left hemisphere): Less clear drawings
Summary of findings
● Left hemisphere: Superior in language tasks
● Right hemisphere: Superior in visual-spatial tasks/facial recognition
● Each hemisphere has unique capabilities
Implications and applications of split-brain research
● Better understanding of brain function
● Insights into language processing
● Potential for targeted therapies
● Challenges “dominant hemisphere” misconceptions
