Lateralization and Language Flashcards
What hemisphere are language centers in
Left hemisphere
Describe what happens a key is shown to the right visual field and the left visual field in a split brain patient
Left: visual info about the key is sent to right hemisphere, and cannot cross over to the left hemisphere language center leading to an inability to verbalize what they see
Right: visual info about the key is sent to the left hemisphere, leading to an ability to verbalize what they see
What type of fibers are in the corpus callosum
Mostly inhibitory
What occurs across our brain due to the inhibitory nature of the corpus callosum fibers
Leads to one hemisphere competing with the other for the type of processing that occurs
What happens when a split brain patient is shown a different object in each visual field (spoon and pencil) and asked to use both hands to pick up the object seen
Right and left hands see different things to pick up and therefore cannot agree to pick up one thing. This leads to picking up a different object or one hand preventing the other from performing the task
What hemisphere dominates in a visual field task “competition” in split brain patients
Left hemisphere, even if the response isn’t verbal
What is dichotic presentation
When one ear hears one sound while the other hears another, different sound
What ear has an advantage in dichotic presentation and why?
Information presented to the right is the sound that gets repeated as it crosses straight over to the left hemisphere language center
- Opposed to sound in the left ear that crosses over to the right then back over to the left which takes more time
What demographic of people may have a left ear advantage in dichotic presentation
Left handed people, about 50%
What effect does being a musician (well trained in auditory processing) have on the brain
Leads to a highly asymmetrical brain, with larger planum temporale on the left side
What side of the brain has the larger auditory cortex (both primary and secondary)
Left hemisphere
Tachistoscope test
Test where stimuli are very briefly exposed in either the left or right visual field
Planum temporale
A brain area in the superior temporal lobe adjacent to the primary auditory area that is larger in the left hemisphere than the right in most adults
Prosody
Perception of emotions in a person’s tone of voice
What hemisphere is responsible for prosody
Right hemisphere
Wada test
An anesthetic (sodium amytal) is injected into the carotid to anesthetize one hemisphere at a time
Fusiform gyrus
Brain region at the temporo-occipital junction associated with face recognition
When presenting a composite face (celebrity and participants face) to a participant, what occurs when the left hemisphere in anesthetized?
Participants are able to recognize themselves in the composite even with the left hemisphere asleep
When presenting a composite face to a participant, what occurs when the right hemisphere in anesthetized?
Participants are unable to recognize themselves and usually see the celebrity in the composite
Bilateral destruction of the Fusiform gyrus leads to what condition
Prosopagnosia (aka face blindness) where they lose the ability to recognize faces
What happens when a split brain patient is asked to perform a visuospatial task with both hands (duplicating a pattern on blocks)
The split brain patient can duplicate the pattern with their left hand (right hemisphere), but is unable to do so with their right hand (left hemisphere)
Hemisphere superior at visuospatial tasks
Right hemisphere
Split brain patients and asymmetrical tasks
Split brain patients are much better at reconstructing asymmetrical patterns/carrying out conflicting motor programs
- Spatial representations of movements are isolated to each hemisphere
Propose an evolutional theory for the lateralization of language and perception
Right and left hemispheres change from being both allocated for perceptual groupings due to a mutation. The left hemisphere begins to accommodate the development of language. This organization was maintained because the corpus callosum connects the two hemispheres with no extra cost
Which hemisphere has an advantage at interpreting Gestalt images
Both hemispheres can see illusory shapes, but when outlines disturb the Gestalt image only the right hemisphere can still see the illusion
- Left hemisphere no longer perceives the image as a whole