2.1 Localisation Flashcards
What is localisation of function?
tempting to assume that every behaviour has its specific place in the brain and is associated with a certain brain area
This idea is known as localization of function
What are the 4 main parts of the brain + another important system?
- nervous system
- cortex
- limbic system
- cerebllum
What is the role of the cortex?
Associated with high-order functions e.g abstract thought/voluntary action
What 4 sections is the cortex divided into?
frontal lobes
parietal lobe
temporal lobes
occipital lobe
What is the role of the frontal lobes?
associated with reasoning, planning, thinking and decision-making, voluntary action, complex emotions
What is the role of the parietal lobe?
associated with movement, orientation, perception and recognition.
What is the function of the occipital lobe?
visual processing.
What is the function of the temporal lobes?
processing auditory information, memory and speech
What two main sections is the brain divided into?
Deep furrow along cortex that divides it into left and right hemispheres
What is the structure called that connects the two hemispheres?
structure of neurons that connects these two hemispheres is known as the corpus callosum
What is the cerebellum associated with?
Associated with coordination of movement and balance
What is the limbic system associated with?
May be referred to as “emotional brain”
What is the limbic system composed of? 4
- thalamus
- hypothalamus
- amygdala
- hippocampus
what is the thalamus associated with?
mostly sensory functions, nerves from almost all sensory organs reach here as a final location before connected to cortex
what is the hypothalamus involved in?
involved in emotion, thirst and hunger
What is the amygdala involved in?
involved in memory, emotion and fear
What is the hippocampus involved in?
involved in learning, memory and transferring short-term memory to a more permanent store, spatial orientation
What are the functions of the brain stem?
Main function to regulate basic vital processes e.g breathing/heartbeat
Connects brain to spinal cord
What studies were the main backbone to support strict localisation?
studies performed with patients with brain damage
Some of these studies showed that a person with damage to a very specific brain area may demonstrate a very specific malfunction in behaviour
What studies were done or what theories support the idea of strict localisation?
- Paul Broca 1861 (Tan)
- Carl Wernicke 1878
- WIlder Penfield
What case study did Paul Broca carry out? What condition did he discover?
Patient called Tan - could only pronounce syllable Tan and could not speak/write however could understand what was being said to him
Broca’s Aphasia - loss of articulated speech
What were Broca’s main findings in relation to localisation?
Asserted that speech articulation is controlled by left frontal lobe
Broca’s findings suggested that other functions can also be mapped onto specific brain areas
What are symptoms of Wernicke’s aphasia?
People with Wernicke’s aphasia have a general impairment of language comprehension, while at the same time speech production is intact, cannot understand speech
What is wernicke’s area?
Wernicke’s area was discovered by Carl Wernicke in 1874
Area located in the temporal lobe of the dominant hemisphere (which is the left hemisphere for most individuals)
Area responsible for the comprehension of written and spoken language
What method was used by both broca and wernicke?
studying a patient with a naturally occurring brain lesion and conducting brain autopsy after the patient’s death
What is the drawback of studying a patient with a brain lesion?
A naturally occurring brain lesion is rarely neat or confined to a specific area (hard to prove strict localisation)
What did Wilder Penfield achieve?
He mapped brain functions on a larger scale - created cortical homunculus
How did WP map brian functions?
Used method of neural stimulation
Part of his work involved treating patients with severe epilepsy by destroying nerve cells that initiated the seizures
Before conducting the surgery he would stimulate various parts of the brain while the patient was still conscious, and observe the effects this stimulation had on behaviour
What is an example of research opposing strict localisation?
Karl Lashely 1929
What was the aim of Karl Lashley’s experiment?
To pinpoint where memory is localised in the cortex
What were the results of Karl Lashley’s experiment?
Research failed - concluded that memory was distributed rather than localised
Conclusion supported by:
what were the 2 main principles/ findings to come out of Karl Lashley’s research?
- Principle of Mass Action - memory of maze depended on percentage of cortex destroyed not on the location of the lesion
- equipotentiality 0 one part of cortex can overtake functions of another part of cortex
WHat was Lashley’s conclusion?
- memory is not localised (widely distributed across cortex)
- other parts may take over function of missing part
