Lecture 9 - brain laterality and split brains & memory and the hippocampus Flashcards
What are some function that are lateralized to the left hemisphere of the brain?
Function lateralized to the left hemisphere include language and speech production
What are some function that are lateralized to the right hemisphere of the brain?
Functions lateralized to the right hemisphere include tone of voice (prosody), face perception, and perceptual grouping.
How are movement, sensation and vision organized in terms of lateralization?
Movement, sensation and vision are contralateral functions.
The left hemisphere controls the right side of the body and the right side of vision, while the right hemisphere controls the left side of the body and the left side of vision
Who described the Broca’s area and what is its function?
Paul Broca described Broca’s area in 1861.
It is located in the left frontal lobe and is responsible for speech production
How is language lateralized in right-handed and left-handed people?
In right-handed people, 95% have language functions in the left hemisphere. In left-handed people, 70% have language functions in the left hemisphere.
What is the difference between contralateral and ipsilateral functions?
Contralateral functions are controlled by the opposite side of the brain, whereas ipsilateral functions are controlled by the same side of the brain
How is vision organized in terms of contralateral functions?
Each side of visual space is mapped to the contralateral vision cortex. The left side of vision is processed by the right hemisphere, and the right side of vision is processed by the left hemisphere
What is the role of the corpus callosum?
The corpus callosum connects the left and right hemispheres of the brain, allowing for the transfer of information between them
How can stimuli be selectively presented to one hemisphere in the laboratory?
Stimuli can be presented very briefly to the left or right side of the screen (less than 200ms) to ensure that they are processed by the contralateral hemisphere without the person having time to move their eyes
What is a “split-brain” procedure and why is it performed?
A “split-brain” procedure involves severing the corpus callosum to stop seizure activity from spreading between hemispheres in severe epilepsy cases.
What did Sperry and Gazzaniga’s split-brain experiments reveal?
The experiments revealed much about the lateralization of brain function. For instance, the left hemisphere can verbally report what it has seen, while the right hemisphere can only show it (e.g. via the left hand)
What are the main functions of the hippocampus?
The hippocampus is involved in forming new episodic memories and spatial navigation
Who was patient H.M and what was significant about his case?
Patient H.M (Henry Molaison) had his hippocampus removed to treat epilepsy, which cured his epilepsy but caused severe memory loss, preventing him from forming new memories while retaining the ability to recall events from before the surgery
What are the different components of long-term memory, and how are they affected by hippocampal damage?
Declarative memory: conscious recollection of facts and events
- episodic memory: memory of past events or “episodes”
- semantic memory: facts and basic knowledge
Procedural memory: skills that are not for conscious recall, such as riding a bike
Hippocampal damage affects the ability to form new declarative memories (both episodic and semantic), but procedural memory can still function)
How does short-term memory differ from long-term memory, and how was this evident in patient H.M?
short-term memory:
- lasts several seconds and involves the temporary holding of information, such as remembering a phone number long enough to dial it
Long-term memory:
- involves the storage of information for extended periods
Patients H.M could “mentally rehearse” to remember things for short periods but could not form new long-term memories
