core studies- bio

Question 1

background to Casey?

Answer 1

ppts at 4 years old- marshmallow test
tested ability to resist temptation by not eating the marshmallows
looked at hot cues and cold cues
based on Metcalfe and Mitchell- Suggested that the inferior frontal gyrus is associated with deciding whether to resist or not (so it would be MORE active in high delayers)

Question 2

research methods of casey?

Answer 2

Longitudinal- over 40 years
Main experiment was in 2011
Quasi experiment

Question 3

Casey: experiment 1aim?

Answer 3

If people who were low delayers at 4 years old would be the same at 40 years

Question 4

Casey: experiment 1 sample?

Answer 4

59 ppts, 27 low delayers, 32 high delayers

Question 5

how many ppts took part at 4 years old in Casey?

Answer 5

562 participants

Question 6

how was delay of gratification measured in casaey experiemtn1?

Answer 6

self-control was measured by a Go/No-Go Task

Question 7

procedure of casey experiment 1?

Answer 7

ppts push a button when they see a certain stimuli, and not push a button when a different one.
It had “hot” and “cool” stimuli:
“Hot” = rewarding stimulus happy face
“Cool” = neutral or fearful faces

Question 8

what was the point of the hot and cold cues in the GO/NO GO task?

Answer 8

Casey wanted to see if the low delayers would make more errors in the task with “hot” stimuli because the brain couldn’t control the response to the hot cue

Question 9

results of experiment 1 of casey?

Answer 9

those who delayed gratification as children showed greater ability to suppress impulse control as an adult
no-go trials - low delayers performed less well that high delayers on the hot tasks. Their mean false alarm rate for the hot task was 12.2% and 9.96% for the cool task.

Question 10

Casey: experiment 2 sample?

Answer 10

27/59 ppts in study 1 1 male was excluded due to poor task performance
26: 15 high delayers and 11 low delayers

Question 11

Casey: experiment 2 aim?

Answer 11

To investigate regions of the brain that they predicted would be implicated in self-control. (ventral striatum and inferior frontal gyrus

Question 12

procedure of experiment 2 of casey?

Answer 12

Using an fMRI scanner to look at the physiognomy of the brain (how it works)
Repeated Measures as go/no go task again but in a scanner instead.
Instead of 1sec delay there was a 2-14.5 sec delay between presentation of faces

Question 13

materials in casey?

Answer 13

Laptop sent to the participants home with the test on. A screen appeared before each test indicating which stimulus was the target. Face shown for 500ms followed by a 1 second interval.

Question 14

experiement 2 results?

Answer 14

Low delayers had higher activity in the ventral striatum, suggesting this is a reward related region and harder to resist
low delayers had lower activity in the inferior frontal gyrus than high delayers showing that this is involved in withholding a response

Question 15

background of sperry?

Answer 15

brain has 2 hemispheres joined by the corpus collosum. hemisphere deconnection involves cutting the corpus collosum

Question 16

aim of sperry?

Answer 16

to investigate psychological effects of hemispheric deconnection
how the LH and RH work in split brain patients

Question 17

research methods of Sperry?

Answer 17

quasi experiment
controlled observation
snapshot study

Question 18

IV of sperry?

Answer 18

presence of absence of split brain

Question 19

DV of sperry?

Answer 19

participants performance on various visual and tactile tasks

Question 20

sample of sperry?

Answer 20

11 white memorial Centre patients who had split brain operation following epileptic seizures

Question 21

materials in sperry?

Answer 21

tachitoscope, a device that displays visual stimuli, back projected onto a screen

Question 22

procedure of sperry?

Answer 22

participants focused on cross on middle of screen, one eye covered. images flashed on one screen for 0.1 second. images flashed to LVF and RVF then asked to write or say what they saw.

Question 23

what were the tactile tasks in sperry?

Answer 23

ppts asked to select object belowe the screen to match what they see on the screen

Question 24

results of sperry?

Answer 24

images shown to LVF can’t be named but can be drawn or picked out of a bag of other objects with the left hand only. Images shown to RVF can be named + described.
Object placed in RH can be described in speech and writing. LH = wild guesses

Question 25

conclusions of sperry?

Answer 25

LEFT hemisphere= speech and writing can communicate the experiences of the RIGHT half of the body-
RIGHT hemisphere is MUTE but can show NON-VERBAL knowledge and understanding of LEFT half of the BODY.
In split brain patients: -Information received by one hemisphere is not accessible by the other.

Question 26

background of Maguire?

Answer 26

hippocampus is important for spatial memory and navigation.
Hippocampal volume enlarges for example in birds and small mammals who do food storing and have to travel long distances.
Black cab drivers have to have detailed knowledge about over 320 streets in London to gain their taxi license in the knowledge test.

Question 27

Aim of Maguire?

Answer 27

investigate the role of hippocampus in navigational skills and how this changes when exposed to extensive navigational experience.
also If there is a correlation between length of taxi driving experience and measures of grey matter volume

Question 28

sample of maguire?

Answer 28

16 licensed taxi drivers who were right-handed and varied in age. All had psychological and medical tests
Control group of 50 people who didn’t drive taxis from same MRI unit as taxi drivers.
Matched for health, sex, handness, mean age and age range.

Question 29

research methods of Maguire?

Answer 29

quasi experiment

Question 30

what is the experimental design of Maguire?

Answer 30

independent measures

Question 31

what are the IV’s and DV’s of Maguire?

Answer 31

IV’s- taxi driver or not, which was naturally occurring and not manipulated by the researcher on the study.
DV- volume of the hippocampi measured by MRI scans of ppts brains.

Question 32

what was the procedure in maguire?

Answer 32

participants placed in a structural MRI scanner. 2 techniques were used: VBM (voxel-based morphometry) and pixel counting
hippocampus volume was adjusted to account for diff sizes between ppts brains, so data was comparable.

Question 33

what is VBM in maguire?

Answer 33

voxel-based morphometry is the difference in density of grey matter more grey matter meant more neuron connection.

Question 34

what is the pixel counting in maguire?

Answer 34

to calculate hippocampal volume, pixels were counted on photographic slices made from the MRI scan. person counting the pixels were blind to the condition the ppts were in. pixels counted for anterior, posterior and body of hippocampus.

Question 35

results of maguire?

Answer 35

taxi drivers had an increased amount of grey matter in their posterior right and left hippocampus compared to control group.
drivers have greater posterior hippocampi than control.
correlations showed positive correlation between length of time as a taxi driver and right posterior hippocampal volume. negative correlation for anterior hippocampi
results were significant at p<0.05 r=0.6

Question 36

conclusions of Maguire?

Answer 36

are regionally specific structural differences between hippocampi of licensed London taxi drivers compared to normal people.
dependence on navigational skills is associated with the increased grey matter

Question 37

DV’s of Blakemore and cooper

Answer 37

DV’s: Behaviour differences: comparisons between the V & H raised cats: as well as comparing to normal cats
Neurophysiological differences: i.e. cells in the visual cortex were tested to see how they responded to lines of different orientations.

Question 38

aim of Blakemore and cooper?

Answer 38

to investigate…
1. the physiological and behavioural effects of restricted early visual experience on the development of visual cortex cells in cats.
2. to consider whether brain plasticity occurs due to nurture rather than nature.

Question 39

IV’s of Blakemore and cooper

Answer 39

IV’s: kittens were raised in ether a horizontal or vertical environment

Question 40

background for Blakemore and cooper?

Answer 40

Hubel and Wiesel- found there are columns of cells that respond to one particular orientation of a line. if an eye sees a line slanted at 45º, only one of these columns will respond to signal.
Hirsch and Spinelli kittens with one eye experiencing one orientation. They found that each eye ‘preferred’ the orientation of stripe that it had been exposed to suggesting that the neurones in the visual cortex have developed according to the exposed environment.

Question 41

method of Blakemore and cooper

Answer 41

lab experiment
Independent measures

Question 42

materials used in Blakemore and cooper

Answer 42

Special cylinder was constructed.
Glass clear platform.
Surface of the cylinder was covered with contrasting black and white stripes (different widths).
Kitten wore a black collar to prevent it from seeing its body.

Question 43

procedure of Blakemore and cooper?

Answer 43

First two weeks kittens in a completely dark room. At two weeks they were placed in the cylinder for an average of five hours a day. Rest of the time they were in the dark room. At 5 months the visual deprivation had stopped as the cats visual systems were fully developed past the critical period.

Question 44

what happened after the visual deprivation stopped in Blakemore and cooper?

Answer 44

For several hours a week the cats were taken from the dark room and placed in another room. This one was well-lit and had chairs and tables and given artificial lenses to ensure any visual difficulties were not due to astigmatism which causes blurred vision.

Question 45

what was the behavioural assessment in Blakemore and cooper?

Answer 45

Behavioural assessment:
Cats initial responses to the new visual world were observed.
Further observations were made over the following weeks, as they learned to ‘see’ the new environment.

Question 46

what was the neurophysiological assessment in Blakemore and cooper?

Answer 46

Neurophysiological assessment:
At 7.5 weeks the cats were temporarily paralysed. The responses of individual ‘units’ (the columns of neurons in their visual cortex) were tested using an electrode inserted into the micropipette that measures the electrical firing of each individual neuron. The cats eyes were shown lines of all possible orientations

Question 47

what are the behavioural results of Blakemore and cooper?

Answer 47

-rod was presented horizontally to two kittens only the horizontally raised kitten would respond to the rod.
-Temporary deficit- the visual placing reflex was not shown immediately (cats reach out their legs when a surface is nearby

Question 48

what are the neurophysiological results of Blakemore and cooper?

Answer 48

H cats- the cells in the visual cortex did not respond to lines within 20º of the vertical orientation and only 12 of the 52 neurons responded within 45º of the vertical orientation. In other words, vertical lines were not seen. Similar response in V cats but to horizontal or near horizontal lines.

Question 49

conclusions of Blakemore and cooper?

Answer 49

Nature (the brain) is modified by nurture (experience) so that the biological system fits the demand of the environment.
The unused parts of the innate nervous system don’t simply degenerate but they adapt to match the actual visual experience.
Both of these conclusions demonstrate brain plasticity.