Essays (Mine) Flashcards
What is LTP? Cite 3 lines of evidence to show LTP is an important neural mechanism in memory
What is LTP?
Synaptic mechanism of learning and memory, Elicitied by levels of stimulation that mimic normal neural activity, Hebb’s postulate for learning: – Co-occurrence of firing in pre and post-synaptic cells is necessary for learning and memory
Three lines of evidence:
- the effects are greatest in brain areas involved in learning and memory
- learning can produce LTP-like changes
- drugs that impact learning often have parallel effects on LTP
Describe a study to test how language is processed in the L and R hemispheres of the brain. Mention 3 different methods you could use to test lateralization of language in the brain. What is one advantage and one disadvantage to each of these 3 methods?
Three methods to test lateralization: 1. Sodium amytal test - anesthetize one hemisphere and check for lanuage function 2. Dichotic listening - report more digits heard by the dominant half 3. Functional brain imaging - fMRI or PEt used to see which half is active when doing a language test
Describe the ground-breaking study of Myers and Sperry on split-brain cats.
Myers & Sperry (1953) - 4 groups of cats: 1. corpus callosum severed 2. optic chiasm severed 3. corpus callosum and optic chiasm severed 4. intact controls Blindfolded one eye, performed visual discrimination task Each hemisphere learned independently Split brain cats with one eye patch: - learned task as well as controls - no memory or saving demonstrated when the patch was transferred - intact cats or those with intact corpus callosum or optic chiasm - similar to findings with split brain monkeys
Describe the Wernicke-Geschwind model. Cite several lines of evidence that contradict that model.
Evidence that contradict the model: • Surgery that destroys only Broca’s area has no lasting effects on speech (Hecaen & Angelergues, 1964) • Removal of much of Wernicke’s area does not have any lasting effects on speech • Some argue that failure to support the model is due to pathology-related reorganization • Damage limited to identified areas has little lasting effect on language • Brain damage in other areas can produce aphasia • Pure aphasias are rare
Explain what is happening in the brain of schizophrenic individuals. Next, describe how antipsychotic drugs affect the brain. Draw a diagram of the pre and post synaptic neuron in your answer.
What happens in the brain: – Schizophrenia affects frontal and temporal lobe structures of brain – Appears that interference with the normal development of susceptible individuals may lead to development of the disorder – Slightly smaller prefrontal cortex, temporal cortex, hippocampus, and amygdala – Larger than normal ventricle How antipsychotics affect the brain: – Side effects of antipsychotic drugs suggests role for dopamine – Drugs work by decreasing DA levels, disorder is a consequence of DA overactivity – Reserpine depletes brain of DA and other monoamines by making vesicles leaky – Amphetamine and cocaine are DA agonists and produce psychosis – Chlorpromazine antagonizes DA activity by binding and blocking DA receptors In general, the higher affinity a drug has for DA receptors, the more effective it is in treating schizophrenia
