Biological Area Flashcards
what are the assumptions of the biological area
-all that is psychological is first physiological. The mind resides in the brain and so all thoughts, feelings and behaviours have a biological cause
-behaviour is due to biological factors such as genes, brain structure, and hormones
-therefore states that psychology should investigate the brain, neurochemistry, the nervous and endocrine system and genetics
what is an application of the biological area?
the advances in brain scanning techniques have helped to explain the cause and mechanisms involved in mental disorders and vulnerability to addiction
what is the background to Sperrys study?
-previous research using split-brain animals showed numerous behavioural effects
-sperry set out this to show that each hemisphere: posses an independent stream of conscience awareness and has its own chain of separate chain of memory’s that are inaccessible to each other
What is the aim of Sperry’s study?
to study the effects of a split brain in order to show that each hemisphere has a different function and therefore demonstrates lateralisation of functioning.
what does the left hemisphere control and process?
-controls the right hand and right visual field
-processes language
what does the right hemisphere control and process?
-controls the left hand and left visual field
-processes pictures /symbols, and emotion
what is the sample to Sperry’s study?
11 split brain patients who had a history of advanced epilepsy which could not be controlled by medication
what was the method to Sperry’s study?
-Quasi Experiment as IV of having a split brain is naturally occurring
-procedure to treat epilepsy
-considered a case study as studies a small group of people, and testing them multiple times over a period of time longitudinally collecting qualitative data
-DV is the performance on the visual and tactile task as this demonstrates there lateralization of functioning
what was the procedure to Sperry’s research?
-used a tachistoscope
-participants wore an eyepatch on one eye and sat in front of the screen with hand holds, and were asked to fixate on a black cross in the center of the screen
-all images, words, and objects were of the same difficulty a to identify and were flashed 0.1 seconds
-standardized so it is replicable so results on lateralization of functioning are more likely to be reliable
-allowed causality to be established between affect of split brain on lateralization of functioning and therefore allowed a more valid explanation of functioning
describe the visual test used in Sperry’s research.
-images were flashed on a 35mm transparency from a projector for 0.1 seconds to either the left or right visual field while other eye was covered
-ppts were shown a symbol of a ? to there LVF and were asked if they could name it, if they couldn’t they were asked to draw it with their left hand
-ppts were shown a $ to their RVF and were asked the same questions if they could name it they were not asked to draw it.
describe the tactile test used in Sperry’s research.
-objects were placed in either left or right hand
-ppts were given a key in their left hand and asked to name it if they couldn’t they were given a grab bag and asked to select the item in their left hand amongst other items
-ppts were given a tennis ball in their right hand and were given a grab bag and told to locate the item in their hand.
what were the findings in Sperry’s study?
when ppts were shown a ? in their LVF they could not identify seeing it however they could draw it with their left hand, after seeing it they could name it
-when pots were shown a $ to their RVF they could easily name it as it was processed by the left hemisphere which controls language
what were the conclusions of Sperry’s study?
there is lateralization of functioning, the left hemisphere is responsible for language and the left side of the body and the right hemisphere is responsible for the creative tasks and controls the left side of the body
- there is a lack of cross integration and the two hemispheres and they have there own stream of consciousness
What is lateralization of functioning?
The two half’s of the brain are functionally different and that each hemisphere has functional specialisations.
What is the function of the cerebellum?
Controls coordination, movement and balance
What is the function of the brain stem?
Helps regulate body functions, including your breathing and heart rate
What is the function of the frontal lobe?
Responsible for high cognitive functions like memory, emotions, impulses, control, problem solving and moral function
What is the role of the corpus callosum?
Allows information to be transmitted between each hemisphere
What is the function of the inferior frontal gyrus?
Processes speech and language.
What is the function of the ventral striatum?
Associative information from the amygdala and the prefrontal regions can influence motor output to guide behaviour
What is the background to Casey et al’s study?
Regions of the brain
What is delay gratification?
The ability to resist temptation in favour for a long term goal, which is essential for an individuals success, and depends on ones cognitive control
What is the Go/No-Go Task?
a cognitive control task that uses the brain in the same way as delaying gratification but is used for adults, as it is quite difficult to determine what would be alluring for each individual. Usually an image is flashed on the screen and the person is given an instruction of when to press the button (go) or not (no-go)
What is meant by “cool” features?
Focus on cognitive features such as weight and shape, these relate to cognitive control
What is meant by “hot” features?
Appealing features of the stimuli such as taste, these are relating to desires and emotions
What is a high delayer?
The ability to resist temptation for a long period of time
What is a low delayer?
Someone who is unable/ finds it difficult to resist temptation
What is the aim of Casey’s study?
To investigate if delay of gratification in childhood could predict impulse control abilities and sensitivity to alluring social cues at the behavioural and neural level at 40
What is the method to Casey’s study?
Was a quasi-experiment as the IV of weather the participant was a high or low delayer was naturally occurring, and so cannot be directly manipulated by the experimenter.
The DV was the performance on the impulse control cognitive go/no-go task in both experiments, Experiment 2 was the imaging results using an fMRI
What is a strength of using a longitudinal methodology?
You are able to build up detailed information over time and are able to have more accurate and reliable findings.
What was the sample for Casey’s study?
-562 4 year-olds from Stanford’s Bing Nursery
-117 of 135 were contacted and asked if they would like to take part in the study and 59 (23m and 36f) agreed
-Initially the sample was large which meant that it was likely to be representative of how everyone delays gratification and it being due to the ventral stratum and inferior frontal gyrus can be generalised and these results have population validity. However the sample is ethnocentric as it only samples children from a nursery in Stanford and so cannot explain the delay of gratification in other cultures as their society
What is the procedure for Casey’s study?
-Experiment 1- is experiment tested whether delay of gratification was a stable behavioural characteristic. Children defined as low delayers in childhood and as young adults were predicted to show less impulse control in the suppression of responses to “hot” relative to “cool” social cues. High delayers were predicted to find this much easier. A total of 160 trials were presented per run. Accuracy and response latency data (reaction times) were acquired in four runs representing each combination of stimulus sex (male, female) and trial type (go, no-go). High levels of control, such as each face being displayed for 500ms and there is always a determined interval between faces, ensures the tasks are standardised and the same for every participant with the same faces, number of trials and fMRI scanner. This means that the results about how participants delay gratification are more likely to be reliable. However the task itself lacks mundane realism as a person does not often press a button in response to images of faces to identify their sex. Therefore it is questionable if results are ecologically valid at explaining delay of gratification in a real world situation
-Experiment 2-fMRI scanner to examine the neural correlates of delay of gratification. It was predicted that low delayers would show diminished activity (less) in the right prefrontal cortex (inferior frontal gyrus) and amplified activity (more) in the ventral striatum compared to high delayers
What were the findings of Casey’s study?
-Experiment 1-completing the “go” trials there was no effect of delay group (high or low delayer) on reaction times. Completing the “no-go” trials overall low delayers made more false alarms and therefore were less accurate. This suggests that they had more difficultly using their inferior frontal gyrus to suppress their immediate response from their ventral striatum.
-Experiment 2- the two groups did not differ significantly in reaction times and therefore low and high delayers performed similarly for correct trials. Overall accuracy rates for the “hot” go/no-go task were uniformly high for “go” trials.
What were the conclusions of Casey’s study?
-Individuals at the age of 4 who had difficulty delaying gratification continue to show reduced self-control abilities and have more difficulty as an adult in suppressing responses to positive social cues than those who don’t.
-The capacity to resist temptation varies by context
What is the background to Blakemore and Cooper’s study?
- Hirsch and Spinelli (1970) reported that early visual experience can change neural organisation in kittens. They reared kittens with one eye
viewing vertical stripes, the other horizontal and found that out of 21 neurones with elongated receptive fields all were monocularly driven, and
in all but one case the orientation of the receptive field closely matched the pattern experienced by that eye. - Blakemore and Cooper therefore began a related project and this study is a preliminary report of their findings.
- Their approach is slightly different to that of Hirsch and Spinelli in that they allowed kittens normal binocular vision in an environment
consisting entirely of horizontal or vertical stripes. (Monocular vision is vision in which each eye is used separately whereas binocular vision is
vision in which both eyes are used together)
What is the Aim to Blakemore and Cooper’s study?
to investigate the development of the primary visual cortex (in cats) and to find out if some of its properties
such as orientation selectivity are innate (as suggested by Hubel and Wiesel) or learned.
What is the Sample to Blakemore and Cooper’s study?
- Kittens (studied from birth until this report was compiled) were randomly allocated to one of the two conditions.
- Two of the kittens (one reared in a horizontal and one in a vertical environment) were used to study neurophysical effects.
What is the Procedure to Blakemore and Cooper’s study?
- The kittens were housed from birth in a completely dark room.
- From the age of two weeks they were put into a special apparatus for an average of about five hours per day.
The kitten stood on a clear glass platform inside a tall cylinder the entire inner surface of which was covered
with high contrast black-and-white stripes, either vertical or horizontal. There were no corners to its
environment, no edges to its floor and the upper and lower limits to its world of stripes were a long way
away. It could not even see its body as it wore a wide black collar that restricted its visual field to a width of
about 130o (The kittens did not seem upset by the monotony of their surroundings and sat for long
periods inspecting the walls of the tube.) - This routine was stopped when the kittens were 5 months old (well beyond the ‘critical period’ in which
total visual deprivation causes physiological deficits, Hubel & Weisel, 1970). - The kittens were then taken for several hours each week from their dark cage to a small, well-lit room, furnished
with tables and chairs. - Their visual reactions were observed and recorded/noted.
- At 7.5 months, two of the kittens (one reared in the horizontal and one reared in the vertical environment) were anaesthetised so their
neurophysiology could be examined
What is the Method to Blakemore and Cooper’s study?
- This was a laboratory experiment which used an independent measures design.
- The independent variable (IV) was: whether the kittens were reared in a horizontal or a vertical environment.
- The dependent variable (DV) was their visuomotor behaviour once they were placed in an illuminated environment i.e. whether the horizontally
raised kittens could detect vertically aligned objects and/or if the vertically raised kittens could detect horizontally aligned objects.
What is the Findings to Blakemore and Cooper’s study?
*Regardless of whether the kittens had been exposed to vertical or horizontal stripes, they were initially extremely visually impaired:
-Their papillary reflexes were normal but they showed no visual placing when brought up to a table top and no startle response when an
object was thrust towards them.
-They guided themselves mainly by touch.
-They were frightened when they reached the edge of the surface they were standing on.
-They showed‘behavioural blindness’ in that the kittens raised in the horizontal environment could not detect vertically aligned objects and
vice versa.
-Only the eyes of the kitten brought up in vertical stripes followed a rod held vertically and only the eyes of the kitten reared in horizontal
stripes followed the rod if it was held horizontally i.e. both kittens remained blind to contours perpendicular to the stripes they had lived
with.
*The kittens quickly recovered from many of the deficiencies and within a total of about 10 hours of normal vision they showed startled
responses and visual placing and would jump with ease from a chair to the floor.
*However, some of their defects were permanent:
-They always followed moving objects with very clumsy, jerky head movements.
-They often tried to touch things moving on the other side of the room, well beyond their reach.
-The neurophysiological examination showed:
- No evidence of severe astigmatism, which might have explained the behavioural responses
What is the Conclusions to Blakemore and Cooper’s study?
- Visual experiences in the early life of kittens can modify their brains and have profound perceptual consequences.
- A kitten’s visual cortex may adjust itself during maturation to the nature of its visual experience.
- A kitten’s nervous system adapts to match the probability of occurrence of features of its visual input.
- Brain development is determined by the functional demands made upon it, rather than pre-programmed genetic factors.
- The environment can determine percep
What is the background to Maguire’s research?
- Research has shown increased hippocampal volume relative to brain and body size in small mammals and birds who show behaviour requiring
spatial memory e.g. food storing. - In some species, hippocampal volumes enlarge specifically during seasons when spatial ability is greatest.
- Research has also shown that there are differences in the structure of healthy human brains e.g. between males and females, musicians and
non-musicians.
What is the aim of Maguire’s research?
to show that the hippocampus in the human brain is the structure associated with spatial memory and navigation
What is the sample to Maguire’s research?
- The experimental group of 16 taxi drivers were all healthy, right-handed, male London taxi drivers, mean age 44 years (range 32-62 years), mean
time as a licensed London taxi driver (passed The Knowledge) 14.3 years (range 1.5-42 years). - The control group who did not drive taxis (50 for the VBM analysis, 16 for the pixel counting) were matched for health, handedness, sex, mean
age and age range
What is the procedure to Maguire’s research?
- The scans of the control group were selected from the structural MRI scan data base at the same unit where the taxi drivers were scanned.
- The MRI scans of all participants were analysed using:
(i)VBM (voxel-based morphometry) which is an automatic procedure that‘normalises’the scans to a template to eliminate overall brain size
as a variable and then identifies differences in grey matter density in different regions of the brain. The brains of the 16 taxi drivers were
compared to those of 50 non-taxi drivers to see if there were any differences in structure.
(ii)Pixel counting compared the volume of anterior, body and posterior cross-sections of the taxi drivers’hippocampi
with those of a previously age, gender and handedness-matched sample of 16 controls taken from the 50 used in the
VBM analysis. The images were analysed by one person experienced in the technique and blinded to whether the scan
was of a taxi driver or a control and the VBM findings. This procedure allowed the total hippocampal volume to be
calculated
What is the method to Maguire’s research?
- This was a quasi/natural experiment because the independent variable (IV) – whether the participant was a London taxi driver or a person who
did not drive taxis – was naturally varying and so could not be manipulated or controlled by the researchers. The dependent variable (DV) was
the volume of the hippocampi including their anterior, body and posterior regions; measured by analysing MRI scans of participants’brain using
the two techniques of VBM and pixel counting. - The study used an independent measures, matched participants design
What are the findings to Maguire’s research?
- Correlations showed a significant positive correlation between the length of time as a taxi driver and the right posterior hippocampal volume,
but a negative correlation for the anterior hippocampal volume.
-Pixel counting showed that although there was no significant difference in overall volume of the hippocampi between the two groups:
(i) Taxi drivers had a significantly greater posterior hippocampal volume than controls.
(ii) Controls had a significantly greater anterior right hippocampal volume than the taxi drivers.
(iii) A significantly greater hippocampal body volume on the right than the left in both the taxi drivers and the Controls.
-VBM analysis showed no significant differences between the brains of the two groups except:
(i) Taxi drivers had significantly increased grey matter volume in the right and left posterior hippocampi compared to controls.
(ii) In the controls there was a relatively greater grey matter volume in the right and left anterior hippocampi compared to taxi drivers.
What are the conclusions to Maguire’s research?
- There are regionally specific structural differences between the hippocampi of licensed London taxi drivers compared to those who do not
drive London taxis. - The professional dependence on navigational skills in licensed London taxi drivers is associated with a relative redistribution of grey matter in
the hippocampus. - It can be suggested that the changes in the arrangement of hippocampal grey matter are acquired i.e. due to nurture.
- Findings also indicate the possibility of local plasticity in the structure of a normal human brain which allows it to adapt in response to
prolonged environmental stimuli.
What are the strengths of the biological area?
- Use of laboratory experiments means it is scientific and brings academic reliability.
- Useful in leading to greater understanding of physiology and how it impacts behaviour.
-Use of sophisticated and specific equipment ( such as brain imaging techniques) are not open to subjective interpretation. - Emphasis on controlled and standardised methodology makes it easier to test for reliability.
what are the weaknesses of the biological area?
- Reductionist by the way of reducing the cause of complete behaviours to a physiological basis, ignoring other possible causes of behaviour.
- Deterministic by way of assuming biology is the cause of behaviour would imply individuals have no free will in how they behave.
- Biological characteristics are not possible to manipulate and therefore quasi experiments limit ability to eliminate extraneous variables
How does sperry link to the biological area
it shows through split brain patients, the way in which different abilities are localised within the two hemispheres of the brain and distinct areas control specific behaviours
how does casey link to the biological area
it involves trying to see wheather there is neutral basis to self-regulation, this is done through fMRI scans of people whohad taken part in delay grattification test
how does blackemore and cooper link to the biological area?
it focuses on neurons and also because it opens up the debate about whether biology affects behaviour or whether behaviour may affect biology
how does link maguire to the biological area
illustrates brain plasticity through different parts of the brain, the hippocampus,. it also uses different techniques, MRI scans to investigate it
