biological psych Flashcards
biological assumptions
all behaviour has a physiological origin, all thoughts, feelings, have a biological basis
phsyioloigcal differences are due to genetics, and we inherit genetics from parents.
Blakemoor and cooper background, aim, sample
background- cats have similar brain structure to humans, the ways its brain is encoded is based on environmental stimuli.
aim- investigate development of primary visual cortex in cats, and find out if properties like oriental selectivity are innate or learned.
sample- Kittens studied from birth, randomly allocated to one of two conditions,
2 chosen from opposing conditions to study for neurophysical effects.
Blakemoor and cooper research method iv and dv
research method- lab experiment
iv- vertical or horzontal environment
dv-visuomotor behaviour in light environment
Blakemoor and cooper procedure
kittens housed in dark room
spent five hours day in tall cylinder with either horizontal lines or vertical lines
could only see their bodies, collar restricted view to 130 degrees, no corners
ended at 5 months
kittens then taken from dark room to a small, well lit, furnished room for several hours a day where their visuomotor behaviour was recorded/
after 7.5 months, 2 kittens were chosen, anasthetised to examine neurophysiology
Blakemoor and cooper results and concludiond
results
Behavioural blindness- cats in horizontal environment could not detect vertical objects and vice versa
both sets of kittens were blind to perpendicular
if played with rod and shaked it vertically, horizontal group couldn;t identify it.
physical blindness-
kittens in horizontal enviornment had no neurons in vertical orientation and vice vera
conclusions-visual experiences in early life of kittens can modify brains and have important perceptual consequences
Blakemoor and cooper issues and debates
nature and nurutre- environment you are in, alters and modfies brain regions, which then impacts behaviour
holism- biology and situation
determinism- predetermined by the environment they are in
ethics- distress- seperating cats from mothers, altering brains for purpose of research is unethical
psych as a science- high controls, standardised, lab, objective,cause and effect
practical applications-
Sperry background, aim and sample and sampling method
hemisphere deconnection involves cutting through the connection between two hemispheres of the brain (corpus collosum), treatment for severe epilepsy. Wanted to see how patients response and behaviour would vary from a “normal brain”
laterlisation of function- carry out different task - left=lang right=pictures
contralateral control= brain cross wired, rh control lefts side and lh controls right side
aim-record psychological effects of hemisphere deconnection in pateints with severe epilepsy and understand how RH and LH work in normal individuals.
sample- 11 split brain patients,male and female in most cases operation reduced severity and freq of seizures
sampling method- opportunity
Sperry experimental design, research method IV and DV
quasi experiment
independent measures (assumed normal brain task can already do the tasks)
iv- whether individuals had a split brain or not
dv- performance on visual and tactile tasks
Sperry apparatus and general procedure
materials- tachistoscope, projects visual stimuli onto screen. Projected on to right or left side. Small gap underneath screen, meaning pps can handle various objects they were presented with.
procedure- one eye covered, look at fixed point in center of projection screen, Visual stimuli present on on side for 0.1 second. Could only process imagine in visual field it was placed in.
Sperry one visual field and findings
sat at table with one eye covered
look at fixation point in center of transculecent screen
image shown for 0.1 to either side
would be asked to say what they saw, draw it , or point/select it from grab bag.
finding-right visual field can describe object (linked to LH which is language)
if shown in left visual field, cant describe object but can point at it with their left hand (as connected to RH)
if image/ word is shown to RVF, would only recognise if shown again to RVF but not LVF as hemispheres are not connected.
Sperry both visual fields and findings
pps look at fixation point, 2 images flash simutaneously (dollar sign and question mark)
asked to say what they had seen or given pen with his left hand and draw what saw (either with eyes closed or hand out sight)
findings-
if pps asked to draw with left hand, they would draw image from LVF
if asked to say what they saw, they would say the image from RVF
Sperry one hand task and findings
FIND- pps hands hidden from view, would be asked to find object that they had seen on screen
SAY- object placed in one hand or other, unable to see what holding, asked to say what they are given
POINT/SELECT- object placed in one hand or other, without being able to see what it is, asked to point what they have been given
findings- if item in right hand, can be said and written with right hand
if item in left hand, can’t be said but can be selected again by same hand
Sperry both hands task
pps cant see their hands
given two diff objects, one each hand
pps asked find object by touch or say what they held
findings- evidence of laterlisation of function, hemispheres worked independtly to find objects
sperry qualitative finding and conclusion
nude picture shown to left visual field, caused pps to blush/giggle but could not say they had seen it
conclusions- supports argument for laterilisation of function, two independent streams of functions
sperry issues and debates
nature/individual- affect on brain regions impact behaviour
deterministic
reductionism
scientific- deduction (evidence for lateralisation of function), controlled environment, standardised
ethics- no protection from harm could lead to discrimination , or be frustating when they cant do task, but confidentiality, r2w etc
ssc- could lead to discrimination, see split brain patients as less able
practical apps- develop understasnding of why split brain patients study,help with the rehabilitation of brain damaged patients, accomodate everyday life to ensure they are able
maguire background
hippocampus is a major structure in limbic system
when spatial ability is required, hippocampus volume is enlarged
past research has not shown whether differences in brain structure can have plastic change in response to environment, the role of hippocampus in humans, whether human brain responds to experiences in same away as other mammals and birds
maguire aim
to investigate the differences in the brains of london taxi drivers and non taxi drivers
investigate differences in volume of hippocampis
investigating possible plasticity in brain
maguires sample and type of experimental design
matched pairs design
experimental group- london taxi drivers
16 male taxi drivers
all healthy and right handed
mean age 44 yrs
been taxi driver for 14.3 yrs
control group-
16 male non taxi drivers
all right handed
mean age 44
no medical, neurological or psychological health problems
why was maguire quasi
cant change how long someone has been a taxi driver for
maguire iv and how was dv measured
iv- taxi driver or not
dv- 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.
what was maguires correlational analysis
size of hippocampus of taxi drivers and length of time in their profession
maguire procedure
-scans of control group selected from MRI scan data base
-MRI scans all analsyed using
1) VBM- automatic procedure that identifies differences in grey matter density in different regions of the brain.
2) Pixel countring- compared volume of anterior, body and posterior cross sections of taxi drivers hippocampi with 16 controls.
images were then analysed by one experienced expert without knowing who was taxi driver or control group
this allowed total hippocampus volume to be calculated
maguire results
VBM analysis showed no significant differences between brains of two groups apart from
- taxi drivers had significantly increase grey matter volume in right and left posterior hippocampi
-in the controls there was relatively greater grey matter volume in right and left anterior hippocampi
pixel counting showed no significant differences in overall volume of hippocampi but
- taxi drivers had significantly grater posterior hippocampi volume than controls
-controls had greater anterior right hippocampal volume than taxi drivers and a significantly greater hippocampal body volume on right than left.
defintions of anterior, posterior, body
anterior- front
posterior- bacl
body-centre
