Left and right brain Flashcards
What are the two types of facial expressions? And which pathways do these include?
•spontaneous expressions
- issued by the basal ganglia nuclei
•voluntary smiles
-initiated in the motor cortex, most likely in the left hemisphere
Explain the dissociation in expression production shown for right hemisphere damage
- effects motor areas involved in generating voluntary expressions
- when smiles spontaneously: action is natural and symmetrical so basal ganglia in intact
- when asked to produce a smile his LH can command the right side of his face but the RH can’t pass this command on so only the right side smiles
Explain the dissociation in expression production shown for Parkinson’s disease.
- involves loss of dopamine producing cells in the substantia nigra (part of basal ganglia)
- basal ganglia is damaged so can’t spontaneous smile
- they can still smile voluntarily
Local vs global:
Explain the lateralisation effects observed in the Navon paradigm for split brain and unilateral brain damage patients.
- LH more efficient at identifying local targets
- RH more efficient at identifying global targets
Categorical vs coordinate information:
Understand kosslyn’s paradigm
- left hemisphere is more efficient at the categorical information task
- right hemisphere is more efficient at the coordinate information task
Causal reasoning:
Explain the matching and maximising strategies and evaluate their potential for error
- matching: participants try to work out how often they get each shape and guess that shape just that often- high error rates
- maximising: working out that circles occur more than diamond and just guessing circles all the time- 80% hit rate
What is the difference in Sylvian fissure?
- in the right hemisphere the sylvian fissure is steeper than in the left hemisphere
- LH is longer than RH
What is the difference in planum temporal and why is it thought to precede language use?
- located in the superior temporal lobe
- larger in the LH than in RH
- this size difference is found in pre-linguistic human infant as well as apes- so it’s size is not a consequence of language use
What is the Wernicke-Geschwind model of repeating spoken language?
- the auditory cortex professes the sound structure and wernicke’s area is involved in accessing meaning
- activation then travels to Broca’s area through a bundle of axons called the actuate fasciculus
- Broca’s area accesses the speech representation of the word and instructs the motor cortex to execute action
What is the Wernicke-Geschwind model of repeating written language?
- the visual code of the written word is converted into a phonological code
- this phonological representation is interpreted in the wernickes area and then the rest of the pathway is the same
What are the symptoms for brocas’s aphasia?
Slow speech output, difficulty finding words, paraphasic errors, telegraphic speech, difficulty mainly with productions rather than comprehension, agrammatism (sentence structure- the leopard was killed by the lion)
How did Penfield use electrical stimulation of the brain?
- the patient is bought out of anaesthesia once the skull has been opened
- brain tissue is electrically stimulates the patient can report the corresponding experience
- there are no pain receptors in the CNS so these shocks can’t be felt
- this allows a functional map to be created and relates to what was known from brain damage data
How does semantic priming work?
Refer to folder
What are the symptoms for Wernicke’s Aphasia?
Problems understanding spoken or written language, communication cut off, phonemic paraphasia (wrong speech sound), semantic paraphasia (substituting words related in meaning happens in deep dyslexia), difficulty connecting to meaning
What are the symptoms for conduction aphasia?
Problems with repeating heard words, comprehension (Wernickes area) and speech production (Broca’s area) is okay
