neurobiology Flashcards
Describe the advatnage of fMRI over CT and MRI scans Explain what has happened in the brain in order to recover from the stroke (3)
- fMRI provides information on brain function wherea MRI and CT scan provide images which show structure
- neuroplasticity
- undamaged axons frow new nerve endings to connect damaged neurones
With reference to the homonculi shown above, identify what they show amd describe and explain the major differences between two images representing the homoculi (4)
- sensroy homonculus shows relatice senseitivity of different parts of the body and motor homonculus shows the motor control of different parts of the body
- area for hand is greater in motor cortex- fine motor control
- area for face is greater in motor cortex - because of the fine motor control needed for facia lexpressions/chewing/swallowing/vocalisation
- areas devoted to tongue/lips/genitals greater in motor cortex - due to large number of sensroy receptors
- no area in motor cortex for teeth, gums, genitals- no motor control of teeth, gums and genitals
A stroke affecting Wernike’s area has a different affect to a stroke affecting Broca’s area. Using your knowledge of these areas of the cerebral cortex describe the effect of each type of stroke (2)
- Stroke in Broca’s area - patient cannot produce speech
- Stroke in Wernike’s area - patient does not understand speech
What are the advantages to the meerkat colony of this dominance hierarchy (2)
- reduces aggression
- dominant males and females have fitter offspring , improving the survival/advantageous alleles passed
Explain the reasons for large size male lions (1)
- males fight for sexual access to females
- sexual selection has favoured evolution of larger males
What is the advantage to the study of uing meerkats ‘habituateed’ to close observation and handling (1)
- they are used to being handled and show natural behaviour
How can the investigation between weight gain and rate of play between meerkats be improved
- repeat investigation with more individuals
- use data from individuals of same age/same gender
The brain can be studies in several ways. Outlime the differences in the information provided by an EEG and CT (2)
- EEG -measures electrical activity of the brain
- CT- gives brain images
Suggest why children who are not exposed to languge druing the critical period are likely to never develop speech (4)
- druing critical period synapses are formed and strengthened
- if speech/language areas of the brain are not stimulated
- there is more pruning of unused synapses
- after critical period - brain is hard wired and more difficult to form new synapses for language
Suggest how the fMRI images and graph would differ for a feral child (1)
- less grey matter activity/darker scan and fewer synapses
State one factor which could be involved in causing this effect in feral children or those exposed to psychological trauma at an early age (1)
- high cotrisol levels
- epigenetic changes to the brain in critical period/increases methlyation
- maternal influence during pregnancy
Which area of the brain is involved in learning (1)
- hippocampus / temporal lobe
State two factors that shoudl be controlled when thirty female rats were placed in three groups and number of errors made when going through the maze was recorded (2)
- age/gender of rat
- length of time left in the mze
- mass of rat
- same maze
- same reward
Use the information provided to conclude the learning patterns exhibited by each group of rats
Group 1 -rewarded every time they completed the maze
Group 2 -places in the maze every day and only rewarded from day 10 onwards
Group 3 - never rewarded (4)
- group 1 - rewardede every time -operant conditioning as there is a steady decrease in errors
- group 2 - latenet learning until day 10
- then operant conditioning becasue reward is given
- group 3 latenet learniing only as no reward is given
Explain why a PET scans would be suitable for investigating activity levels within the brain whereas an MRI scan would not (2)
- MRI scans show structural anatomy of the brain and PET scans show areas of the brain which are functioning at a particular time
- MRI wouldn’t show active areas of the brain as language is an active process
Suggest and explain how the PET scans of a deaf person activley using british sign language would compare of that od a hearing person (5)
- brocas areas is the same as both as both produce language
- increased use of motor cortex in BSL and more activity in that area in scan
- BSL involves more movement than speech alone
- increaed use of occipital love for vision in BSL
- decreased use of the auditory cortex in BSL/ less activity in that area
- no link to sound and ear / no sound detected
Suggest two medical details that would be needed when interpreting PET scans from patients with hearing problems (2)
- ages when became deaf
- reason for deafness
- level of deafness
Explain why PET cans of adults with total hearing loss have revealed activation of regions of the cortex related to hearing (3)
- deaf people may exhibity neuroplasticity /brain adapted to form new connections as there is no auditory stimuli bieng recieved
- auditory cortex involved in interprtation of BSL
- new connections / different connections to hearing between auditory cortex and brocas/ wernickes area