Toolkit 3 - Research with clinical and non-typical populations Flashcards
Why are studies with clinical populations important for our understanding of cognition?
Observing neural activity with EEG, MEG, fMRI can only provide CORRELATIONAL evidence.
Observing neural activity cannot teach us whether a stimulus CAUSES a given physiological activity
What do individuals with brain lesions help us to understand?
- the functional contribution of individual brain areas to the cognitive system
- the functional connectivity of brain areas with one another
What is single dissociation?
The loss or impairment of a brain function can be related to a single physical difference in the brain
What is double dissociation?
A situation in which a single dissociation can be demonstrated in one person and the opposite type of single dissociation can be demonstrated for another person.
What is triple dissociation?
A situation in which a single dissociation of related brain processes can be demonstrated in 3 different individuals indicating independence of subprocesses.
What dissociation are Broca and Wernicke’s area?
Broca - single dissociation: language production related to the frontal lobe.
Wernicke - single dissociation: language comprehension related to the temporal lobe.
How does a stroke cause brain damage?
Strokes result in (sudden) focal lesions combined with sudden loss of function that help us understand brain- behaviour connections
What is hemispatial neglect?
A neuropsychological condition after damage (stroke) to one hemisphere of the brain (motor & sensory cortex affected).
A deficit in attention to and awareness of one side of the field of vision/body, commonly contralateral to the damaged hemisphere (left more often than right).
How do tumours cause brain damage?
Tumor removal also results in (surgical) focal brain lesions when removed
Compared to strokes, the lesion caused by a tumor grows slower, giving the brain time to relocate functions due to brain plasticity. While these lesions still help us understand brain-behaviour connections, the evidence is not as strong as with stroke lesions.
What is the lesioning technique?
Removing part of the brain either surgically or by injection of chemical substances that locally break down tissue.
Used to treat neurological dysfunctions in humans (similar to tumor removal).
How does trauma cause brain damage?
Different from stroke and tumor removal, these injuries are not usually focal but concern large brain areas (to different degrees).
Hard to localise and quantify damage.
Brain injury from trauma can also come, with a secondary stroke due to internal bleeding (hemorrhagic stroke).
Explain the case of Phineas Gage
First proof of localisation of function
In 1848, an incident changed our understanding of the relation between mind and brain.
Iron through cheek and skull.
Remained conscious but showed personality changes.
The areas injured were responsible for his rational decision-making.
What is meant by neurodegeneration?
Neurodegeneration is the progressive loss of structure or function of neurons, which ultimately involve cell death.
How is Alzheimer disease caused?
Alzheimer’s disease is caused by abnormal buildup of proteins in and around brain cells resulting in loss of neurons and synapses.
Alzheimer’s disease affects the cerebral cortex and certain subcortical structures, resulting in gross atrophy of the temporal lobe, parietal lobe, and parts of the frontal cortex and cingulate gyrus.
How is Parkinson’s disease caused?
Death of dopaminergic neurons in the midbrain.
This results in dopamine deficiency impairing synaptic transmission relying on dopamine.
The cause of this selective cell death is unknown.
