essay studies outline + evaluation

Rogers and kesner (2003) outline + evaluation (for animal model essay)

aim: test the role of acetylcholine on the formation of spatial memory

procedure:

30 rats were put in a maze woith food in a corner and became familiar with it / no longer scared of the environmennt)

injected directly in the hippocampus with either: (randomly allocated)

scopolamine (antagonist for acetylcholine receptors)

saline solution

so that injection did not cause a variable in memory

tested the errors made by the rats in the first 5 trials to find the food in the corner of the maze

Findings:

participants in the experimental conditions took longfer to find food/ higher erros made=> suggests that acetylcholine may play a role in the formation of spatial memory

Strenghts:

Highly standardize => replicable / reliable

high internal validity=> lots of control (es. placebo) / true experiment

cause and effect relationship established

can help treatments of dementia / alzheimer

Limitations:

reductionsit approach

confounding variable of injection (may have increased adrenaline)

difference between how acetylcholine works in humans rats

human brain is more complex than rats

antonova et al (2011) outline + evaluation

Aim:

test the hippocampus activity in the brain after scopolamine injection (to test role of acetylcholine in the formation of spatial memory)

Procedure:

20 helathy male adults

conducted complex virtuality game in an fMRI

randomly allocated in these two condition:

injected with scopolamine

injected with scopolamine solution

double blind

counter balanced

participants were in an arena and had to became familiar with the environment, than they had to reach a pole. after screeen would go blank for 30 seconds and put in a diffrent initial place, and had to find the pole again.

for 6 trials

Findings:

significantly lower activity in the brain of participants in the experimental condition. Took slightly longer/ made more mistakes. Thus acetylcholine play a role in the brain and thus in the formation of memory.

Strenghts:

Highly controlled (standardized procedure/ double blind (no research bias)/ counter balanced ( no practise effect)

Limitations:

small sample size (low population validity)

participants felt stress due to injection=> externous variable

limitations of using animal models (brain and behaviour essay)

brain more complex in humans than in rats

acetylcholine may play a different role in rats than in humans (assumption of the contrary in teh experiments)

reductionsit approach

can we generalize from rats to humans

drugs that works in rat do not work in humans.

cases et al (1995) outline + evaluation

Aim:

study the genetic origins of depression

Procedure:

transgenic mouse used

gene that produces MAOA (enzyme that breaks down serotonin and adrenaline) was removed in rats

Findings:

male offsprings without that gene were more aggressive

high levels of serotonin/ adrenaline in all the offsprings

strenghts:

cause and effect relationship was established

standardize procedure

limitations:

can explain human behaviour.

reductionist

low ecological validity as it was done in a lab

Caspi et al (2002) outline + evaluation

Aim:

test if the MAOA gene had an effect on aggressive behaviour

Procedure:

26 years old longitudinal study

1000 kids from new zealand

genotype of the boys were studies

36% of the boys were maltreated ( either rejected by their mother/ physically / sexually abuused)

Findings:

if the boy had MAOA gene and maltreated => higher chance to bully when was younger / criminal / antisocial behaviour)

if the boy did NOT have MAOA gene and maltreated=> did not develop this behaviour.

strenghts:

longitudinal study

big sample size

limitations:

correlational in nature ( no cause and effect relationship)

reductionist

winslow outline + evaluation

aim: test role of vasopressin in rats in the likelyhood of developing of monogamous relationship

procedure:

rats injected with either:

saline solution

antagonist for vasopressin solution

rats put in a cage with a femal in heat

after mating, put in a cage with three rooms:

one with the previous sexual partener

one with another female

findings:

rats injected with antagonist spend equal time with their previous mate and the other female

rats injected with the placebo conditions stayed only with their sexiual partner

strenghts:

high controlled true experiments => high ecological validity

can we extend the findings to human?=> than yap about Walum study

Walum outline + evaluation

aim: test if the level of vasopressin would predict the level of marital satisfatcion

procedure:

500 mens