biological area Flashcards
what is behaviour due to according to the biological area?
physical causes, including brain structure, hormones, genes, chemicals etc
‘Everything that is psychological is first physiological’
what is the brain?
an organ composed of neurons
can be divided into areas, each responsible for a certain function or behaviour
although the general structure of the brain remains the same, the amount of neurons in an area may change in response to environmental factors
what are hormones?
chemicals made by glands in the body. They send messages around the body and so can trigger changes in the body
eg pineal gland produces melatonin to regulate sleep patterns
what are genes?
made up of DNA + are inherited from our parents. Each gene has a function
Genes can be ‘switched’ on/off based on environmental triggers
eg there is a gene linked with increased risk of developing schizophrenia. Having it is not a guarantee of developing schizophrenia and some environmental factors such as drug use have been linked to the switching on of the gene
methodology of the biological area?
biological psychology is interested in how physical aspects affect our behaviour
previously, case studies were conducted on people with injuries which may affect behaviour eg Phineas Gage
Nowadays, more scientific methods can be used such as varying types of brains cans to show which areas of the brain are most active when completing certain tasks
what is the lateralisation of brain function?
the idea that the hemispheres have specialised and different functions
what does the right hemisphere of the brain do?
intuition
creativity
emotion
controls the left side of the body
what does the left hemisphere of the brain do?
perception
planning
language
controls the right side of the body
what is Broca’s area?
Broca (1861) conducted a case study of a man who could only say the word ‘tan’
an autopsy showed damage to a lower section of the left frontal lobe. this led to the suggestion that this area is responsible for language production
known as broca’s area
what is wernicke’s area?
Wernicke worked with patients whose speech was fluent but disordered ie they were saying words but not in context
autopsies showed damage to the top of the left hemisphere which is responsible for the fluency of language
known as wernicke’s area
what is the corpus callosum?
a bundle of nerves found in the centre of the brain
it connects the hemispheres, allowing info to pass between them
what are split brain patients?
the severing of the corpus callosum used to be a treatment for epilepsy in patients who could not be treated with medication
patients who received this procedure referred to as ‘Split-Brain Patients’
aims of Sperry?
to investigate the functions of hemispheres in the brain
he also wanted to investigate the effects of hemisphere deconnection in split brain patients
sample for sperry?
11 split brain patients
1 male patient had the surgery 5.5 years b4 the study
1 female patient had the surgery 4 years b4 the study
the remaining 9 were reported to have had surgery ‘shortly before’ the study
how were the visual tests set up in sperry?
pts sat in front of a projector screen with one eye covered. in the middle of the screen was a point pts were asked to focus on
visual stimuli in the form of an image or word would appear on one side of the fixation point for 1/10th of a second
images were presented using a tachistoscope
how did the visual tests where one image was displayed go in sperry?
if the image was displayed to the right visual field, pts could say what they had seem
if the image was displayed to the left, pts could not say what they had seen
however, pts could pick out a matching object from an array with their left hand.
what hemisphere is responsible for language?
left
what hemisphere are the left hand and left visual field linked to ?
the right
how did the visual tests where two images were displayed go in sperry?
when two images were displayed at the same time to both visual fields, pts could only say what they had seen in the right visual field
if pts were asked to draw what they had seen using their left hand, pts drew the image displayed to their left visual field
how did the pinup image visual test go in sperry?
when the image of a nude pinup was presented to the left visual field, pts would giggle and blush, but were unable to explain why they were embarrassed (right hemisphere not responsible for language)
same image presented to right, pts would explain why they were embarrassed
what was the set up of the tactile tests in sperry?
pts sat in front of screen w/ gap between screen and table. this gap was big enough for pts to place their arms through to reach objects, but pts could not see their arms, only the screen in front
how did the tactile test of finding an object go in sperry?
if pts originally picked up the object w their left hand and placed it back into the array, they were unable to retrieve it w their right hand.
however, they could find the object again w their left hand
the same was true vice versa (w right hand as original)
how did the tactile test of naming an object go in sperry?
pts holding an object in left hand could not say what they were holding
if in right hand, they could name the object they were holding
conclusions of sperry?
provided evidence for the lateralisation of brain function
issues w sharing of info between hemispheres are not a day to day issue for split brain patients as in the real world info is presented for more than 1/10th of a second, and u can hold objects with both hands
strengths of sperry?
quasi makes it ethical to investigate split brain patients by using people who have already had the surgery
ethics, ps gave consent
provides evidence for lateralisation of brain function eg language is in left hemisphere
weaknesses of sperry?
lacks ecological validity as visual stimuli only flashed for 1/10th second + ps only used one eye, these limits to visual stimuli not true to real world
less validity as assumed that non-split patients could complete the tasks without problems
only 11 people in sample, lacks population validity (+all ps splitbrained)
quasi = not manipulating IV so open to confounding variables
what is instant gratification?
unable to resist the temptation of an immediate reward
what is delayed gratification?
resisting the temptation of an immediate reward in order to get a later rewards
what is the inferior frontal gyrus?
an area in the Front Lobe found in both hemispheres
responsible for interpretation of facial expression and generating an appropriate emotional response
plays a role in response inhibition and avoiding risky behaviour
known as the Cool system as it does not excite us
what is the Ventral Striatum?
an area in the Limbic System
it is associated with immediate choices and rewards
also responsible for behaviour in social interactions
known as the Hot system as it involves desires and emotions
what was the Marshmallow Test?
children sat in room w one marshmallow in front of them and told they can eat it but that if they wait until the researcher returned, they could have 2 marshmallows.
researcher left room for 15 mins. 2/3 of ps had eaten marshmallow
people who cannot delay gratification were labelled Low-Delayer whilst those who could were labelled High Delayer
what system was more active in Low Delayers and High Delayers?
Hot System more in Low Delayers
Cold System in High Delayers
what are Go/NoGOo tests?
for adults
involve pushing a button when you see on type of stimuli but not pushing the button when you see a different stimuli
aims of Casey?
to investigate whether a delay of gratification in childhood can predict delay gratification in adulthood
they looked into impulse control abilities + reaction to social cues
DV of first Casey Experiment?
performance on an impulse control task measured in reaction time + accuracy
DV of second Casey experiment?
activity in brain regions measured from fMRI data
sample of Casey in late 60s/ early 70s?
marshmallow test with 562 four year olds from Stanford Uni nursery
sample of Casey 1993?
155 of original ps who were now in their 20s completed a self control scale
sample of Casey 2003
135 of original ps who were now in 30s completed self control scale
sample of 2011ish Casey?
117 of these Ps who were either above or below average in their responses were contacted and asked to take part
59 responded and agreed to take part (23 males/36 females)
how were ps classified in Casey 1 ?
ps classified as high delayers or low delayers based on performance in Delay of Gratification task and self reports
32 High-Delayers (12 Males/ 20 Females)
27 Low-Delayers (11 Males/ 16 Females)
how were trials presented in Casey 1?
using pre programmed laptops sent to ps homes
the Go stimuli changed between trials (Happy/Fearful/Males/Female)
each stimuli shown for 0,5 seconds with a 1 second break between stimuli
was a total of 160 trials per run. these trials were presented in a pseudo randomised order (120 Go/40 NoGo)
what was the Hot Go/No Go task in Casey 1?
ps asked to click when they saw a happy face and not click when shown a fearful face and vice versa. This task aimed to target the hot system by showing different emotions for ps to react to
Cool Go/NoGo task in Casey1?
ps asked to click when they saw a male face and not click when shown a female face and vice versa
Results of Experiment 1 Casey?
no difference in reaction times between High Delayers and Low Delayers
Both groups accurate on the ‘Go’ trials
Low Delayers made more errors on the Hot task than on the Cool task
sample of Casey 2?
27 participants from Exp 1 agreed to take part
15 high delayers and 11 low delayers, allocated based on previous performance
before data was analysed, results from 1 participant was removed due to their poor performance, this means the data of only 26 ps was taken to account
equipment in Casey2?
the data was collected using an fMRI scanner, showing the flow of blood to active regions of the brain so that we can see which regions are active for certain tasks
within the scanner there was a screen to display the task and a Neuroscan 5 button pad for ps to respond to the stimuli
what was the task in Casey2?
ps only completed Hot Go/NoGo task
each picture shown for 0.5 seconds and the gaps between each of the pictures ranged from 2 seconds to 14.5 seconds
they completed this task whilst inside the fMRI scanner so the data about which regions were activated could be collected
results of Casey 2?
differences between groups in NoGo accuracy were consistent with Exp , with low delayers being more likely to wrongly click
low delayers showed lower levels of activity in their Inferior Frontal Gyrus when shown NoGo stimuli
Low Delayers also showed increased activity in the Ventral Striatum when shown the NoGo stimuli
conclusions of Casey
the ability to delay gratification seems to be a trait that is stable over a lifetime and has a biological cause
the ability to resist temptation varies by context. the more tempting the stimuli, the more predictive the individual differences
strengths of Casey?
quantitative data eg how many errors = easy to analyse and compare
ethics, gave consent
quasi allows you to study natural differences
weaknesses of Casey?
longitudinal study = lots of people withdrew
quasi = IV not being directly manipulated so harder to establish cause and effect
all kids from Stanford Uni nursery for Marshmallow test = ethnocentric
similarities between casey and sperry?
both quasi
ethics
independent measures
both lack ecological validity
differences between casey and sperry
casey longitudinal, sperry snapshot
sperry lower population validity as smaller sample size than casey’s marshmallow test sample
sperry’s brains different bc of a surgery (human cause), caseys different naturally
strengths of the biological area?
improves understanding: explains the extent to which our behaviour is affected by physical factors such as genes, hormones and the structure of the brain
builds credibility, as it tends to use scientific and objective methodology to investigate biological causes of behaviours, eg uses of fMRI in Casey
tends to use scientific and objective methodology in controlled conditions to investigate behaviour - higher replicability to test reliability
weaknesses of the biological area?
ability to study the brain directly is still limited and so other methodology must be used, eg in Sperry data was gathered based on whether ps could complete the tasks– not entirely valid
reductionist to ignore the influence of nurture
results can be somewhat open to interpretation, eg in Casey’s study the activity shown in the Ventral Striatum doesn’t necessarily clearly indicate whether it was encouraging or discouraging behaviour
how does casey change our understanding of individual diversity?
advances knowledge
sperry = lateralisation of hemispheres
casey = specific areas eg ventral striatum / inferior frontal gyrus
how does casey change our understanding of social diversity?
both have male and female ps
casey - socioeconomic bias, all from stanford uni nursery
sperry - all have epilepsy/surgery - American healthcare is expensive so there might be socioeconomic bias
how does casey change our understanding of cultural diversity?
both ethnocentric (both american)
