Biological Area Flashcards
1
Q
What are the basic assumptions of the biological area?
A
- our behaviour is determined by our genetic makeup, neurological makeup and by biochemical reactions involving hormones
- strongly in favour of the nature side of the nature vs nurture debate, suggesting our behaviour is pre-determined
- suggests unusual behaviour can be considered a product of an illness with a physical cause
2
Q
What are the strengths of the biological area?
A
- mental disorders can be treated using drugs or surgery, which offers a potential cure for real world problems
- it tends to use highly objective methods of measurement, which makes research more reliable and replicable - a vital element of scientific research
- new technology is giving scientists different ways of investigating our body without harming the individual (PET, MRI, CAT) and give us an improved understanding of the physiognomy
3
Q
What are the weaknesses of the biological area?
A
- there is often only an association between a psychological event and a biological event - so we do not know the direction of the cause
- because it is so strongly in favour of nature, it is very reductionist, oversimplifying behaviour and rarely acknowledging the context within which behaviour occurs
- because physiological psychology often examines unusual and complex phenomena, sample sizes are often small and unrepresentative
- there are limits to our ability to interpret the objective methods of data collection, e.g. an MRI scanner can show us that an area of the brain is more active but can’t explain why
4
Q
What was the background to Sperry’s study?
A
- he began by looking at split brain in cats and monkeys and found that with training it was possible to teach a skill to one hemisphere while the other one remained unaware
- in humans, found that when an image was presented to the right visual field it was processed by the left, so they could say what they saw, but when it was presented to the left and processed by the right, they could only draw what they saw
5
Q
What was the aim of Sperry’s study?
A
- to investigate the effects of deconnection to show the difference in their functions
- also to show that the function of the corpus callosum is to communicate between the two hemispheres
6
Q
What method did Sperry use?
A
- quasi experiment
- tasks took place in a laboratory environment
- IV: whether or not the participants had split brain
7
Q
What participants did Sperry use?
A
- 11 split brain patients who already had corpus callosectomies as a treatment for severe epilepsy
- can be considered an opportunity sample
- at least one male and at least one female
8
Q
What procedure did Sperry use?
A
- used a tachistoscope to allow various sensory info to be presented to only one hemisphere at a time
- visual info was presented on a screen and tactile info was presented to one hand or both without the participant being able to see them
- visual info was projected for just 0.1 seconds so it was only presented to one field
- had to remain silent during the studies unless asked a question by the experimenter (to prevent info passing from the right to the left hemisphere)
9
Q
What visual investigations did Sperry conduct?
A
One visual field:
- participants would cover one eye and look at a fixation point
- an image was projected for 1/10 of a second either right or left of the fixation point
Both visual fields:
- two different images would be flashed simultaneously either side of the fixation point
- they would be asked to say and draw what they had seen
10
Q
What tactile investigations did Sperry conduct for one hand?
A
- the participant’s hand would be hidden from their view and they would be asked to find an object corresponding to the image they’d seen on the screen
- the object would be placed in their hand and they were asked to say or point to what they were holding
11
Q
What tactile investigations did Sperry conduct for both hands?
A
- participant’s hand would be hidden from view and they would be given a different object in each hand - once objects were taken away, they were asked to find them in a pile of objects or say what they were holding
- participant’s hands would be out of sight and the experimenter would place one hand in a position - they would have to move their other hand to a symmetrical position
- with hands out of sight, experimenter would touch a point on one of the fingers and then ask the participant to touch the same point with the tip of their thumb
12
Q
What tests of the right hemisphere were conducted by Sperry?
A
- the left visual field is presented with an object on the screen and the participant is asked to pick out a similar object by touch
- simple maths problems are presented to the left visual field and the participant is asked to sort objects by shape/size/texture using their left hand
- some geometric shapes would be projected to both visual fields and a picture of a nude would be presented to the left visual fields - they were later asked if they saw anything other than shapes
13
Q
What were the results of Sperry’s visual investigations?
A
- when they were shown an image to just one visual field they would only recognise it if it was shown to the same field again
- if it went to the RVF they could say what they’d seen, and if it went to the LVF they could draw what they’d seen
- when images were presented to both visual fields, they could say what had been presented to the RVF but were unaware they’d seen anything else
-> but if they were given a pen in their left hand and asked to draw with their eyes closed, they could draw what they saw in the LVF
14
Q
What were the results of Sperry’s tactile investigations?
A
- they could identify objects in their right hand by name
- they could find the object from an array when it was placed in the left hand
- unable to mirror their hand after it was placed in a position by the experimenter
- when they touched a target point on their hand they were unable to find the same point on the other hand
15
Q
What were the results of the tests of the right hemisphere Sperry conducted?
A
- they could pick out similar objects after the left eye was presented with it
- they were able to complete simple mathematical problems and could could use their left hand to sort objects
- when they saw geometric shapes they would giggle and look away at the nude woman but couldn’t explain what they were reacting to
16
Q
What was the conclusion of Sperry’s study?
A
- the brain consists of two hemispheres, each with its own consciousness, and without the corpus callosum information cannot be transferred between the two sides
- the left seems to be dominant
17
Q
What practical problems were faced in Sperry’s study?
A
- split brain is extremely rare so obtaining a sample is difficult
- presenting info to only one hemisphere is challenging (overcome by using apparatus to direct info to one visual field)
- difficult to assess the right hemisphere (overcome by using non-verbal responses to nude etc)
18
Q
Was Sperry’s study valid?
A
- low ecological validity: unusual apparatus and unfamiliar tasks (unusual to only see something in one visual field for 0.1secs)
- low population validity: only looking at people who had their brains artificially split due to epilepsy (not generalisable)
- high construct validity: many different tasks to test the roles of the hemispheres in different ways
19
Q
How does Sperry’s study contribute to the free will vs determinism debate?
A
Highly deterministic: does not account for individual differences (e.g. did all participants answer in the same amount of time?) and doesn’t allow for the effect of motivation
20
Q
How does Sperry’s study contribute to the reductionism vs. holism debate?
A
Highly reductionist as it ignores other potential explanations for the behaviour of split brain patients, e.g. their cognitive processes could have been affected by the operation
21
Q
How does Sperry’s study contribute to the individual vs situational debate?
A
- the brain has been affected by the operation, which is to some extent a situational variable
- however, the individual characteristic of having or not having a corpus callosum determines the behaviour
22
Q
What was the background to Casey’s study?
A
- Mischel conducted a “marshmallow test”, or delay of gratification test, in which children are given a marshmallow and told they can eat it now or wait and be given a second
- some can do this (high delayers) and some can’t (low delayers) –> it’s a test of self control
- Casey highlighted that low delayers can be taught “cooling techniques” to reduce the appeal
- Mischel suggested there is a “cool” system in the prefrontal cortex that manages thoughts helping us resist temptation, and a “hot” system related to emotions and desires in the ventral striatum which is associated with rewards
23
Q
What was the aim of Casey’s study?
A
to look at participants who were “low delayers” at age 4 and reported low self control in psychometric measures in their 20s-30s to see:
- if they would show more errors on a go/no-go task if the stimuli were “hot” than high delayers
- if they would show lower activity in their right prefrontal cortex whilst doing the go/no-go task
- if they would show increased activity in the ventral striatum than the high delayers
24
Q
What sample and method did Casey use?
A
- quasi experiment, as the IV was whether the participant was a low or high delayer
- sample was 59 participants who had taken part in 3 previous studies assessing ability to delay gratification and scored consistently across all three (all in Mischel’s original study)
- 27 low delayers and 32 high delayers
25
Q
What was Casey’s first procedure?
A
- pre-programmed laptops were sent to participants homes
- before the task, instructions would appear on the screen saying which face was the target stimulus
- each face would appear for 500 milliseconds with a one second break between them
- tested in four conditions:
1. cool (pressing when male neutral face appeared)
2. cool (pressing when female neutral face appeared)
3. hot (pressing when happy face appeared)
4. hot (pressing when fearful face appeared)
26
Q
What were the results for Casey’s first procedure?
A
- both groups performed well on “go” tasks and made more errors on “no-go” tasks
- both low and high delayers made similar numbers of errors on “cool” tasks but low delayers made more errors on the “hot task”, especially when the happy face was the no-go stimulus
- 15.7% errors on no-go happy trial for low delayers, whereas 11.2% errors for high delayers
27
Q
What was Casey’s second procedure?
A
- fMRI was used to examine neural correlates of delay gratification
- participants completed a similar “hot” go/no-go task as experiment one
- this time 2-14.5 seconds between each face
- 48 trials run for each facial expression (happy and fearful)
28
Q
What were the results of Casey’s second procedure?
A
- low delayers showed lower activity in the right inferior frontal gyrus (prefrontal cortex) than in high delayers on no-go trials
–> suggests this region plays an important role in withholding a response - low delayers showed higher activity in the ventral striatum, specifically when “happy” faces were the no-go stimulus
–> suggests that the rewarding nature of this “hot” stimulus made the region more active so it was harder to resist, leading to more errors
