L14 - Studying the brain through lesions Flashcards
what is the principle of patient studies?
studying humans with brain damage to help understand normal brain functioning through reverse engineering
brain damage is often localised allowing to link specific parts of the brain to behavioural deficits
what are the causes for brain damage?
neurosurgery, strokes, traumatic head injuries, tumours, viral infections, neurodegenerative disorders
what are classic examples for the studies with brain damaged patients?
H.M.: Suffered memory loss after surgery to treat epilepsy
Phineas Gage: Survived a severe brain injury that affected his personality
what’s single dissociation?
patient is impaired on one task but normal on another indicating specific cognitive processes related to the damaged region
what’s double dissociation?
two complementary single dissociations
e.g., Broca’s aphasia (speech production impairment) vs. Wernicke’s aphasia (speech comprehension impairment)
what are the benefits of studying the brain in lesions?
provides insight into normal and abnormal brain function
helps in understanding and treating disorders
what are the issues of studying the brain in lesions?
patients with severe lesions are rare
variability in damage specificity and associated deficits
relies on single case studies
what are the principle of animal studies?
controlled lesions in animals to observe effects on behaviour
can create control groups for comparison
What are the 4 types of lesions?
Aspiration: Suction device removes brain regions.
Transection: Cutting of white matter bundles.
Neurochemical Lesions: Toxins targeting specific neurotransmitter systems.
Reversible Lesions: Temporary effects using pharmacological manipulations.
what are the benefits of using animal studies?
Overcomes the rarity and specificity issues of human studies.
Controlled environment allows for precise experimentation.
what are the issues of using animal studies?
Ethical and welfare concerns.
Limited inference from animal models to human behaviour and brain structure.
what is principle of Transcranial Magnetic Stimulation (TMS)
Magnetic induction creates a secondary electric current in the brain, interfering with neuronal activity (virtual lesion).
Can inhibit or induce activity in targeted brain regions.
what are the applications of TMS?
Clinical Use: Treating neurological disorders and mental health conditions (e.g., depression)
Research Use: Studying neural plasticity and specific brain functions
What are the benefits of TMS?
Brief and reversible, allowing group studies
High specificity for targeted brain regions
What are the issues of TMS?
Safety concerns (risk of seizure, mild discomfort).
Exclusions for certain conditions (e.g., epilepsy, pacemakers).
Limited to surface neurones, unable to target deeper brain structures.
