Biological Area Flashcards
1
Q
What’s the background to Sperry’s study
A
- brain has left and right hemisphere joined by commisures which allow communication
- some functions happen on both sides (lateralisation)
- others only happen in the left ( language in the brocas and wernikes areas, localisation)
- sperry wanted to show each hemispher had an independent stream of consciousness
2
Q
What’s Sperry’s design
A
- quasi experiment
- IV = having a split brain or not
- DV = p’s performance on visual or tactile tasks
3
Q
What was the sample in Sperry’s study
A
- 11 patients who had undergone hemispher deconnection surgery by cutting through the cerebral commisures
4
Q
What was Sperry’s procedure
A
- in a visual test the p’s centre there gaze on a fixed point in the centre of a tachistoscope, this allows an image to be flashed up for 1/10th of a second
- anything presented to the left of the screen will be processed by left visual field and passed to the right hemisphere and vice versa
- p’s had a visual stimuli presented to either visual field, this would then appear again on either visual field and they would be asked if they had seen it before
- in a split brain p’s where the left and right sides are no longer connected if the image was flashed again on the left side they would be able to recall it
- for tactile tasks there is a gap below the screen where p’s can place there hands and not see them
- objects were placed in either the left or right hands, objects in the right would be processed by left hemisphere and vice versa
- they were asked to say or draw the object and state whether they had already held it
5
Q
What were the findings in Sperry’s study
A
- images seen in one visual field were only recognised if presented to the same visual field
- images presented in the left visual field were not identifies because there is no language in the right hemisphere
6
Q
What did Sperry conclude
A
- people with split brains have two separate visual worlds
- the two hemispheres don’t exchange information
- have two separate independent streams do consciousness
- there is lateralisation for language because p’s could only describe what they had seen or held if it was processed in left hemisphere
7
Q
What was the background in Casey’s study
A
- delayed gratification = ability to resist temptation to gain a greater reward, using cognitive control
- cool features (size) is an effective delay strategy rather than hot
- inferior frontal gurus is involved with cognitive control
- ventral striatum involved with immediate choices
- investigating the link between childhood delay gratification performance and adult self control
8
Q
What was Casey’s design
A
- quasi experiment
- IV = whether the participant was a high or low delayer
- DV exp 1 = performance on the impulse control task
- DV exp 2 = performance on impulse control task and results of FMRI ( functioning magnetic resonance imaging) scan
- independent/repeated design
- longitudinal study
9
Q
what was the sample in Casey’s study
A
- 562x 4 yo from Stanford’s Bing nursery school, completed a delay gratification task in 1960s
- 155 of these completes self control scales in their 20s and 135 again in their 30s
- 117 who were below or above average in original task at age 4 were asked to take part in the current study
- 59 took part in exp 1
- 27 of these took part in exp 2
10
Q
what was Casey’s procedure
A
- experiment 1
p’s were shown neutral faces for 500 milliseconds, and told to press a button for a target stimulus - p’s were told which gender was the target (go) and the no response target (no go)
- 160 trials were presented per run in a psuedo randomised order, with 120 go targets and 40 no go.
- the first condition was the cool version as there was little emotional involvement
- the second condition was identical to the first exept the faces were either fearful or happy ( hot version)
- took place in their own homes
- experiement 2
completed a hot version similar to condition 2 - 2 runs with 48 trails per run
- p’s completed the task whilst having an FMRI scan
11
Q
what was the results in Casey’s study
A
- exp 1 = p’s were highly accurate in there responses to go trials for both cool and hot (99.8%)
- low delayers were less accurate than high delayers
- low delayers performed significantly worse on the no go hot trials than cool ( low delayers are worse at using cognitive control
- exp 2 = little difference between accuracy of low and high delayers
- right inferior angular gyrus was involved in not accurately pressing the button
12
Q
what did Casey’s conclude
A
- the ability to resist temptation is a stable characteristic that can be predicted from childhood
- cognitive control is influenced by hot features as low delayers perform worse
13
Q
what was the background to Blakemore and coopers study
A
- cats and humans have similar lobes in the cerebral cortex and have gyrencephalic brain surfaces ( convolutions)
- brain plasticity = lasting change to the brain
- hirsch and spinelli shown early visual experiences can change neural organisation in kittens
- blakemore and cooper wanted to investigate the development of primary visual cortex in cats and find out if some properties were innate or learnt
14
Q
what was the design in Blakemore and coopers study
A
- laboratory experiment
- independent measures design
- IV = whether the kitten saw horizontal or vertical stripes
- DV = visual behaviour when placed in normal environment
15
Q
what was the sample in Blakemore and coopers study
A
- kittens studied from birth until the report was compiled
16
Q
what was the procedure in Blakemore and coopers study
A
- the kittens were housed from birth in a completely dark room
- after 2 weeks they were placed in a special apparatus for 5 hours a day
- they stood in a cylinder ( 2m across and 46cm wide) that had either horizontal or vertical stripes
- the kitten wore a wide collar that restricted its visual field
- continued until they were 5 months old
- then taken to a well lit room for several hours a week with tables and chairs
- the observer noted the visual reactions of kittens
- at age 7.5 months, the visual systems within the brains were examined, a micro electrode was inserted into visual cortex
17
Q
what did Blakemore and cooper find
A
- initially all the kittens were extremely visually imapired
- showed no startle response or evidence of visual placing
- showed behavioural blindness in that the kittens raised in vertical stripes showed no recognition of horizontally aligned objects and vice versa
- after 10 hours they showed startle response and visual placing
- when following objects head movement were jerky and kittens would often reach for things that were well out of reach
- none of the kittens showed any signs of astigmatism
75% of the cells in the kittens were binocular and functioning normally
18
Q
what did Blakemore and cooper conclude
A
- early visual experiences can have profound consequences in visual development
- brain development is determined by demands made upon it rather than genetic factors
19
Q
what was the background to Maguire’s study
A
- the hippocampus is in loves with behaviours that satisfy needs, plays a part in laying down new memory traces
- research shows increase in the volume of the hippocampus in animals that require spatial memory
- maguire wanted to see whether the role of the hippocampus in humans was similar to non humans
- if this area had brain plasticity from environmental stimulation
20
Q
what was the design in Maguire’s study
A
- quasi experiment
- matched p’s design
- IV = whether or not the p’s was a London taxi driver
- DV = volume of hippocampus
21
Q
what was the sample in Maguire’s study
A
- 16 right handed male London taxi drivers who had passed the ‘knowledge’
- control group was 50 non taxi drivers
22
Q
what was the procedure in Maguire’s study
A
- the brains of taxi drivers were scanned using MRI (magnetic resonance imaging) scan
- the control group had already had scans
- the MRI scans were analysed by, voxel based morphometry ( identifies differences in grey matter density) and pixel counting (compared the volume of anterior, body and posterior cross sections of the hippocampi
23
Q
what did Maguire find
A
- the VBN analysis showed that taxi drivers has significantly increased grey matter in the right and left posterior hippocampi
- taxi drivers had significantly greater posterior hippocampi volume
- positive correlations between length of time being a taxi driver and volume of right posterior hippocampi
24
Q
what did Maguire conclude
A
- there are structural differences in the hippocampi of taxi drivers and non taxi drivers
brain plasticity occurs as a result of prolonged environmental stimuli
25
What is the biological explanation
- the way we behave is a consequence of physical factors, eg genes and hormones, neurotransmitter levels and brain structure
- faulty hypothalamus has been linked to anorexia
26
What are the strengths and weaknesses of the biological area
+ has practical applications, If we know what physical factors cause mental disorders we can create treatments for them
+ research is scientific establishing a cause and effect
- reductionist because it reduces behaviour down to one single biological factor and ignores environmental factors
- research can lack ecological validity
