biopsychology 2 Flashcards
What is Localisation of Function?
Broca and Wernicke discovered that there were specific parts of the brain associated with different
Functions
If a certain area of the Brain get Damaged it will impair the Function of that area
What are the Hemispheres of the Brain?
We have a Left Hemisphere and a Right Hemisphere
- Left side of the Body is controlled by Right Hemisphere
- Right side of the Body is controlled by Left Hemisphere
What is the Cereberal Cortex?
The Outer Layer of Both Hemispheres
How is the Brain Divided?
Both Hemispheres are Divided into 4 ‘Lobes”
- Frontal Lobe
- Parietal Lobe
- Occipital Lobe
- Temporal Lobe
Each lobe is associated with a different function
What is the Frontal Lobe’s Function?
Contains the Motor Area
- Controls Voluntary movement in the Opposite Side of the Body
- Damage to this area may lead to the loss of Control over Fine Movements
What is the Parietal Lobe’s Function?
Contains the Somatosensory Area
- Is where Sensory Information is processed
- The amount of area devoted to a particular Body Part Denotes it Sensitivity (e.g. Hands are very sensitive = Large Area)
What is the Occipital Lobe’s Function?
Contains the Visual Area
- Information from the Right Visual Field goes to the Left Visual Cortex
- Information from the Left Visual Field goes to the Right Visual Cortex
What is the Temporal Lobe’s Function?
Contains the Auditory Area
- Damage to this area may cause Hearing Loss
- Damage to specific areas may cause specific consequences
What Happens if Wernicke’s Area suffers Damage?
Damage to Wernicke’s area can lead to an inability to comprehend Language
- Wernicke’s area is responsible for Language Comprehension
- Wernicke’s Aphasia can cause someone to speak in Gibberish (Neologisms)
What Happens if Broca’s Area suffers Damage?
Damage to Broca’s area can lead to an inability to produce Language
- Broca’s area is responsible for Language Production
- Broca’s Aphasia can cause someone to speak Very Slowly and Lack Fluency
Strength of Localisation of Function
Evidence from Brain Scans
- Petersen et al used Brain Scans to show that Wernicke’s area was Active during Listening Tasks and Broca’s area during Reading Tasks
- Buckner and Petersen found that Semantic and Episodic Memories reside in Different parts of the Prefrontal Cortex
- Therefore there is Scientific Evidence for the Brains Function
Limitations of Localisation of Function
Individual and Gender Differences
- Bavellier found Variation in both Left & Right Temporal Lobe, and Left Frontal & Occipital Lobes
- Harasty found Women’s Broca’s Area & Wernicke’s Area were Larger than Mens
Equipotentiality
- Plaza found that slow destruction of Broca’s Area by Brain Tumors can leave Speech relatively Intact
- This Suggests that its Function can Shift to Nearby Brain Areas
- Idea that the Localisation isn’t Permanent and can be in Different Areas
What is Hemispheric Lateralisation?
The idea that the 2 Halves of the Brain are Functionally Different and that each Hemisphere has Different Dominances
- The Left is Dominant for Language Tasks
- The Right is Dominant for Motor Tasks
What is Split Brain Research?
A Split Brain operation is the severing of Connections between the Left Hemisphere and the Right Hemisphere
- This is done by Cutting the Corpus Callosum
- This is often done to Treat Seizures
What was Sperry’s Split Brain Research?
- 11 People with Split Brains were studied by putting an image in their Right Visual Field (Processed by Left Hemisphere) and then putting an image in their Left Visual Field (Processed by Right Hemisphere)
- Found that when something was shown to the RVF the participant could Describe what was seen
- When something was in the LVF they could not Describe what was seen
- Participants could match and object out of sight in their Left Hand (Right Hemisphere)
Strength of Split Brain
Related to Increased Neural Capacity
- By using 1 Hemisphere to do a Task the other is Free to do another function
- Rogers et al Found that in a Chicken Brain Lateralisation is associated with Enhanced Ability to Perform 2 Tasks Simultaneously
Limitations of Split Brain
Associated Disadvantages
- Left Handed people are more likely to suffer from Allergies and Problems with Immune System
- Tonnessen et al found that Genetic processes for Lateralisation are also for Immune System Development
Gender Differences
- Females have Bilateral Brain Usage during Linguistic Tasks whereas Men have more Left Brain Only
- Females have Bilateral Brain Usage in Spatial Tasks whereas Men have more Right Brain Only
- Studies Suggests Women have a Thicker Corpus Callosum
what is Brain Plasticity?
The brains Ability to Change and Adapt because of Experience
What is an Example of Brain Plasticity?
Maguire et al
- The role of the Hippocampus is to facilitate Spatial Memory
- Black Cab drivers undergo Extensive Memory Training (‘The Knowledge’) which makes them an ideal Test Group
- 16 Right Handed Male Black Cab drivers and 50 Right Handed Non-Black Cab drivers given MRI scans
- Found Increased Grey Matter in Hippocampi of Taxi Drivers compared to controls
- Found Increased Volume in Posterior Hipocampi of Cab Drivers
Strengths of Brain Plasticity
Supportive Evidence
- Kempermann studied Rats to see whether Enriched Environments could Alter Neurones in the Brain
- Found that Rats housed in a Complex Environement Showed increased amount of Neurones in the Hippocampus
- Supports idea that Life Experiences can affect Brain Plasticity
Supportive Evidence
- Boyke taught a group of 60 Year Olds to Juggle and found increased Grey Matter in their Visual Cortex
- However this Reversed when they Stopped Juggling
Limitation of Brain Plasticity
Negative Plasticity
- 60-80% of Amputees develop ‘Phantom Limb Syndrome’ which is Painful and Unpleasant
- Ramachandran and Hirstien found that this was due to Cortical Reorganisation in the Somatosensory Cortex
What is Functional Recovery?
The Transfer of Functions from a Damaged Area of the brain after Trauma to other Undamaged Areas
What is Neuronal Unmasking in Functional Recovery?
Where the Brain is able to ‘Rewire’ itself and Create Alternative Pathways around Damaged Areas and Taking over Functions that were Lost
What are Stem Cells in Functional Recovery?
A Treatment that involves Functional Recovery as Stem Cells can Replace Dead / Dying cells in the Brain
- Stem Cells can also help the Regeneration of Damaged Cells or Link an Undamaged Brain Site with a Damaged one
