Draganski (MRI, Localization, Neuroplasticity) Aim
To see if learning a new skill would have an effect on the brains of participants (in this case juggling)
Draganski (MRI, Localization, Neuroplasticity) Method
24 volunteers between the age of 20-24 21 females and 4 males All participants were non jugglers at the start of the study Each participants had an MRI scan at the start of the study to serve as a base rate for grey matter and brain structure
Draganski (MRI, Localization, Neuroplasticity) Procedure
The participants were separated into two conditions (the jugglers and non jugglers)
Those that were in the juggling condition were taught a three ball cascade juggling routine
They were asked to practice the routine and notify the researchers when they have mastered the skill at that point the researchers conducted a second MRI scan on the jugglers
After the second MRI scan the researchers told the participants to stop practicing the juggling routine
After three months a final third MRI scan was conducted on participants in the juggling condition
The non juggler condition served as a control group for the duration of the study
To analyze the MRI scans, researchers used a voxel-based morphometry (VBM) to determine any significant differences in neural density (grey matter) in the brains of non-jugglers and jugglers
Draganski (MRI, Localization, Neuroplasticity) Results
From the baseline scans at the start of the study there were no significant regional differences in grey matter between the two conditions
However, at the end of the first part of the study, jugglers showed a significantly larger amount of grey matter in the mid-temporal area in both hemispheres - an area associated with visual memory -
Three months after the jugglers stop juggling, MRI scans showed that the amount of grey matter in the mid-temporal area in both hemispheres had decreased
There was no change in the non juggler condition for the duration of the study
Draganski (MRI, Localization, Neuroplasticity) Evaluation
Strengths
There was a pre-test, post-test design to show the differences in neural density over time
The study was a lab experiment, providing a cause and effect relationship
There was a control group (the non jugglers) that served as a control group (help ensure the internal validity)
Limitations
The sample size was very small (data may not be reliable) The study has potential problems with internal validity as the participants were in their home environments for the majority of the study
The study will need to be replicated to establish its reliability
Maguire (MRI, Localization, Neuroplasticity) Aim
To investigate whether changes could be detected in the brains of London taxi drivers and to further investigate the role of the hippocampus in spatial memory.
Maguire (MRI, Localization, Neuroplasticity) Method
16 right handed male taxi drivers
50 right handed males who did not drive taxis
The participants must have had completed the "knowledge" test and held their license for at least 1.5 years
There was a variety of ages to show that age is not a confounding variable
The data from the MRI was measured using two different techniques: voxel-based morphometry (VBM) and pixel counting
Voxel-based morphometry (VBM) was used in this study to measure the density of grey matter in the brain.
Pixel counting consists of counting the pixels in the images provided by the MRI scans in order to calculate the area of the hippocampus.
Single-blinded study - researchers looked at MRI scans of both the participants and control group without knowing which belonged to what group.
Maguire (MRI, Localization, Neuroplasticity) Procedure
MRI scans were used to observe the structure of the hippocampus.
Maguire (MRI, Localization, Neuroplasticity) Results
There were two key findings of the study:
First, pixel counting revealed that the posterior hippocampi of taxi drivers were significantly larger relative to those of control subjects and the anterior hippocampus were significantly smaller.
VBM showed that the volume of the right posterior hippocampus correlated with the amount of time spent as a taxi driver.
No differences were observed in other parts of the brain.
Maguire argues that this demonstrates that the hippocampus may change in response to environmental demands.
Conclusion: It appears that the posterior hippocampus is involved when previously learned spatial information is used, whereas the anterior hippocampal region may be more involved during the encoding of new environmental layouts.
Maguire (MRI, Localization, Neuroplasticity) Evaluation
Strengths
The brain scans were coded so that analysis could be done blindly - that is, the researchers did not know which brain scan belonged to which participant in order to avoid researcher bias.
You cannot argue that the MRI has low ecological validity because the participants were not asked to do anything while in the scanner. They simply had their brain anatomy measured.
The study is ethically sound as the MRI does not pose any health risks to the participants and all gave consent.
Limitations
The study was a quasi-experiment, so no cause and effect relationship can be established. The researchers were unable to manipulate the independent variable; it was naturally occurring.
Although the study appears to have sampling bias, it is a reality that the vast majority of London cabbies (Taxi Drivers) are male. However, it still does make it difficult to generalize the findings
Fisher, Aron and Brown (Neurotransmission) Aim
to investigate neural mechanisms associated with the attraction system
Fisher, Aron and Brown (Neurotransmission) Method
10 women and 7 men between 18-26 years of age who were in love.
Fisher, Aron and Brown (Neurotransmission) Procedure
To determine duration, intensity and nature of the participant's romantic love, the researcher interviewed participants and asked them to complete questionnaire: "Passionate Love Scale (PLS)"
They were placed in fMRI scanner, showed picture of beloved, then asked to count backwards, then show picture of acquaintance. Repeat 6 times
Fisher, Aron and Brown (Neurotransmission) Results
fMRI results showed different parts of the brain were activated when participants viewed photos of beloveds vs. acquaintances. When showed picture of beloved, the right ventral tegmental area (VTA) activated. This is dopamine rich area of brain and part of the brain's reward system.
Fisher, Aron and Brown (Neurotransmission) Conclusion
The results indicate the possibility of brain circuits dedicated to attraction are same circuits associated with addiction. Dopamine increases with anticipation of reward (not just getting a reward). We anticipate reward so our brains are wired to drive us towards attaining those rewards. This is evolutionary explanations of human behavior; if we don't reproduce, our genes won't be passed on
Fisher, Aron, and Brown (Neurotransmission) Evaluation
Strengths
This is a highly controlled clinical method of obtaining data and Fisher and her colleagues checked objectivity at every stage of the procedure.
Identification of the reward center of the brain support to the idea that human beings may have an evolved brain system which ensures that they become ‘hooked’ on an individual, which increases the possibility of them reproducing.
The standardized procedure means that the study is replicable, which increases its reliability.
Limitation
The small sample size of 17 participants means that the results are not very meaningful and may not be robust in terms of statistical analysis.
The sample comprised relatively young students from the same university, which also limits generalizability.
Additionally, it is overly reductionist to use brain scans to determine how romantic love is experienced: there may be a range of other factors involved, such as similarity, same upbringing, shared ideals, cultural influences. So little is really known about the brain that there may be other explanations for the activation of the reward centers during the fMRI scan – perhaps the participants were simply excited to be in a brain scanner for the first time and this stimulated the dopamine-rich areas.
Scanning participants’ brains is clearly an artificial task, which means that the results are low in ecological validity.
Use of fMRI scans is also an expensive way to collect data, which is possibly why the sample is so small.
Crockett (Neurotransmission) Aim
to investigate the effects of serotonin on prosocial behavior
Crockett (Neurotransmission) Method
Lab Experiment
30 healthy participants (~15 males and females, 25 years old) were tested for any mental or physical health problems before being selected for the experiment.
Crockett (Neurotransmission) Procedure
In the experimental group, participants were given a dose of citalopram, an SSRI.
In the control group, participants were given a placebo.
After taking the drug, participants were given a series of moral dilemmas (the personal or impersonal trolley problem), which made them choose between a utilitarian outcome (saving 5 people) and aversive harmful actions (letting 1 person be killed)
Crockett (Neurotransmission) Results
Responses to the impersonal version were unaffected by citalopram.
Participants with SSRIs in the personal scenario were much less likely to push the man off the bridge than participants in the placebo conditions.
Crockett (Neurotransmission) Conclusion
Serotonin reduces the acceptability of personal harm and therefore promotes prosocial behavior (behavior intended to help others)
Crockett (Neurotransmission) Evaluation
Strengths
Double-blind design
Repeated measures design (comparing one to themself)
All healthy, similar participants
Construct validity (operationalized well, although they didn't measure serotonin)
Limitations
No brain scan to show that the brain was actually active, so can't really show cause and effect
Low population validity and volunteer sampling
Healthy adults shouldn't be taking SSRIs
Low ecological validity as trolley problems are not real, also in a lab
Testing effect, repeated measures
History bias
McGaugh and Cahill (Hormones) Aim
To investigate the role of adrenaline and the amygdala in the creation of emotional memories.
McGaugh and Cahill (Hormones) Procedure
Participants were divided into two groups. Each group saw 12 slides which were accompanied by a very different story.
In the first condition, the participant heard a rather boring story about a woman and her son who paid a visit to the son’s father in a hospital where they witnessed the staff in a disaster preparation drill of a simulated accident victim.
In the second condition, the participant heard a story where the boy was involved in a car accident where his feet were severed. He was quickly brought to the hospital where the surgeons reattached the injured limbs. Then he stayed in the hospital for some weeks and went home with his mother.
After viewing the slides, the participants were asked how emotional they found the story on a scale of 1 - 10.
Two weeks after participating in the experiment the participants were asked to come back and their memory for specific details of the story were tested.
The test was a recognition task that consisted of a series of questions about the slides with three options for them to choose from.
The researchers then did a follow-up study. The above procedure was repeated, but this time the participants in the "traumatic story" condition were injected with either a beta-blocker called propranolol or a placebo. Beta-blockers are used to slow down heart rates. It was used in the study since it prevents the activation of the amygdala.
McGaugh and Cahill (Hormones) Results
In the original version of the experiment, the researchers found that the participants who had heard the more emotionally arousing story demonstrated better recall of specific details of the story. They could also recall more details from the slides.
In the follow-up study, they found that those that had received the beta-blocker did no better than the group that had heard the "mundane" story. They, therefore, concluded that the amygdala plays a significant role in the creation of memories linked to emotional arousal.
McGaugh and Cahill (Hormones) Evaluation
Strengths
The fact that the researchers could block adrenaline in an experimental design gives rise to a cause-and-effect relationship between adrenaline and activation of the amygdala to create emotional significance of the story.
The study can be easily replicated because of its standardized procedure, allowing other researchers to test the reliability of the results.
Limitations
The study is artificial in nature and highly controlled. Therefore, there is a concern about ecological validity.
As the recognition task only had three options, it is possible that this is not a valid test of memory.
Newcomer (Hormones) Aim
To investigate whether high levels of the stress hormone cortisol interfere with verbal declarative memory.
Newcomer (Hormones) Method
Lab experiment
All participants were employees or students in university
All participants were given a clinical interview with a physician. They were excluded from the sample if they had any medical issues that could alter their hormonal levels, especially cortisol, such as pregnancy or mental illness.
Newcomer (Hormones) Procedure
The researchers carried out a double blind laboratory experiment in which the participants were matched for age and gender to one of three conditions:
Condition 1 – High level of cortisol: The participants in the high-level cortisol group were given a tablet containing 160 mg of cortisol on each day of the four-day experiment. This dose of cortisol produces blood levels similar to those seen in people experiencing a major stress event.
Condition 2 – Low level of cortisol: The participants in the low level of cortisol group were given a tablet containing 40 mg of cortisol per day. This dose is similar to the amount of cortisol circulating in the bloodstream of people undergoing minor surgical procedures such as having stitches removed.
Condition 3 – Placebo group: The participants in this condition were given placebo tablets - that is, a tablet that looked like the other tablets but with no active ingredient. This was done in order to have a control group.
All participants were asked to listen to and recall a prose paragraph. Each day they were given a different piece of prose with the same level of difficulty. They were tested three times.
Newcomer (Hormones) Results
The results indicated that high cortisol levels impaired performance in the memory task since the participants who received the highest level of cortisol also showed the worst performance in verbal declarative memory.
The researchers were also able to verify that the effect was not permanent; the performance of participants in the high cortisol condition returned to normal after they stopped taking the hormone tablet.
According to the researchers, these results demonstrate a clear link between levels of cortisol and remembering. It appears that high levels of cortisol interfered with the recall of the prose passage.
There was no statistical difference between the low dose and placebo groups on any day of testing and the researchers claimed that paragraph performance increased over time for the placebo and low dose groups because of practice effects or procedural learning
Newcomer (Hormones) Evaluation
Strengths
Since this study was experimental, the researchers could establish a clear cause and effect relationship between the IV and the DV.
The researchers carried out a baseline test in order to eliminate the possible confounding variable of individual differences between groups.
Limitations
The experiment ran over several days and the participants were not in the lab the whole time, so the researchers did not have full control over extraneous variables - for example, individual stressors in the lives of the participants. In spite of this, there was a clear relationship between the amount of cortisol ingested and the performance on the memory test.
Different texts were used for days 1 and 4. However, the researchers counterbalanced the use of the texts to act as a control that the difficulty of the text did not play a role in recall.
Memorizing a piece of prose is perhaps not the most authentic memory experience. Although it may explain student exam stress, the ability to generalize the results to other situations may be limited.
There are ethical considerations in the study. The participants ingested cortisol which affected their memory negatively. However, the participants had signed an informed consent form and the damage was not permanent.
Zhou et al (Pheromones) Aim
Investigate the role of androstadienone and estratetraenol in conveying gender information
Zhou et al (Pheromones) Method
Lab experiment with 96 participants (24 heterosexual men, 24 heterosexual women, 24 gay men and 24 lesbian women.)
Zhou et al (Pheromones) Procedure
Participants were asked to watch stick figures walking on a screen and to determine their gender. While carrying out the task, the participants were exposed to the smell of cloves. In the first condition, the cloves were mixed with androstadienone. In the second condition, the cloves were mixed with estratetraenol. In the control condition, only cloves were used.
Zhou et al (Pheromones) results
Smelling androstadienone biased heterosexual females and gay males, but not heterosexual males, toward perceiving the walkers as more masculine. By contrast, smelling estratetraenol biases heterosexual males and lesbian women toward perceiving the walkers as more feminine.
Zhou et al (Pheromones) Conclusion
The researchers concluded that pheromones influence communication of gender information in a sex-specific manner.
Zhou et al (Pheromones) Evaluation
Strengths
The IV was manipulated, allowing the researchers to establish a cause and effect relationship between the exposed pheromone (IV) and the rating of the stick figure (DV).
Limitations
Low reliability - Hare et al failed to replicate the study with a similar method and procedure.
Low mundane realism - The dose of AND and EST used in this study was significantly higher than humans naturally secrete. This means that although Zhou's study determined a significant effect, it is unlikely that this represents actual human behavior.
Caspi (Genes) Aim
To determine whether there is evidence for a gene-environment interaction for a mutation of the serotonin transporter gene (5-HTT).
Caspi (Genes) Method
Quasi-experiment
~850 New Zealand 26-year-olds.
All were members of a cohort that had been assessed for mental health on an every-other-year basis until they were 21.
They were divided into three groups based on their 5-HTT alleles:
Group 1: two short alleles
Group 2: one short and one long allele
Group 3: two long alleles.
The mutation of the 5-HTT gene has the shorter alleles.
Caspi (Genes) Procedure
The participants were asked to fill in a "Stressful life events" questionnaire which asked them about the frequency of 14 different events - including financial, employment, health, and relationship stressors - between the ages of 21 and 26. They were also assessed for depression.
Caspi (Genes) Results
People who had inherited one or more short versions of the allele demonstrated more symptoms of depression and suicidal ideation in response to stressful life events. The effect was strongest for those with three or more stressful life events. Simply inheriting the gene was not enough to lead to depression, but the genes' interaction with stressful life events increased one's likelihood of developing depression.
Caspi (Genes) Evaluation
Strengths
Acknowledges the interaction between both biological and environmental factors in depression (gene-environment interaction). This is a more holistic approach, not reductionistic.
High reliability - Longitudinal study, assessed from age 3
Population validity (Generalizability) - High sample size
Limitations
Correlational = no cause and effect relationship can be established
It may be the salience of the negative life events which plays a role in depression - that is, those that recalled them more easily may have a tendency towards depression. Those who are more resilient may not recall negative life events as easily.
Risch et al. carried out a meta-analysis of attempted replications and found that the results were not able to be replicated (low reliability).
McDermott (Genes) Aim
To investigate whether the MAOA gene predicts aggressive behavior when provoked.
McDermott (Genes) Method
Laboratory quasi-experiment (participants were not randomly allocated to conditions thus not a true experiment)
78 male subjects (a mix of MAOA-H and MAOA-L) MAOA-L is the variant (hypothesize to be more aggressive)
McDermott (Genes) Procedure
Participants did a simulation in which they were asked to administer hot sauce to fictional opponents who they were told don't like hot sauce (this was the supposed aggressive behavior)
In each round they were told that their opponent had taken a portion of their earnings/money
They could then punish their opponent by administering hot sauce The money taken was 0%, then 20%, then 80% in each round (3 rounds)
McDermott (Genes) Results
Individuals with MAOA-L were significantly more likely to administer the hot sauce compared to MAOA-H when 80% of their earnings were taken
When it was only 20% taken the difference between MAOA-H and MAOA-L was minimal
Evidence of a gene-environment interaction Individuals with MAOA-L (genetic variation) are more likely to demonstrate aggressive behavior when provoked through the environment
McDermott (Genes) Evaluation
Strengths
Shows gene-environment interaction between aggression and being provoked
Limitations
Quasi-experiment = no cause and effect relationship established
Low mundane realism (generalizability). Giving someone really spicy hot sauce is not exactly the same as committing a violent crime against them in a real world setting.
Low construct validity (internal validity). Is this really measuring aggressive behavior?
Kendler et al (Genetic Similarity, Twin Study) Aim
Kendler and his team wanted to investigate three questions in their study:
Past studies suggest a 35 - 45% heritability of major depression. Would this be true in a large Swedish sample?
Are there significant gender differences in the heritability of major depression?
Is there evidence that genetic and environmental factors in major depression differ over time?
Kendler et al (Genetic Similarity, Twin Study) Method
~15,500 complete twin pairs listed in the national Swedish Twin Registry. The twins were born between 1886 and 1958.
Only twins whose zygosity could be verified were used in the study.
Kendler et al (Genetic Similarity, Twin Study) Procedure
In order to gather their data, the researchers used a team of trained interviewers to carry out telephone interviews. Interviews were carried out between 1998 and 2003.
The interviewers assessed lifetime major depression by using modified DSM-IV criteria. ~8000 twins met the criteria for a diagnosis of major depression at some point in their life - and ~300 twins voluntarily discussed a history of antidepressant treatment.
In addition to this information, the interviewers also asked questions about the twins "shared environment" - that is, when they were living in the same household - and their "individual-specific environment" - that is, adult personal life events that may make members of the twin pair more susceptible to depression.
Kendler et al (Genetic Similarity, Twin Study) Results
The results indicate that the concordance rates for major depression were significantly higher in women than men. In addition, the correlations were significantly higher in monozygotic than in dizygotic twins. They also found no correlation between the number of years that the twins had lived together and lifetime major depression. The estimated heritability of major depression was 0.38, in line with previous research. There were also no significant differences seen in the roles of genetic and environmental factors in major depression in the three cohorts spanning birth years 1900-1958. Even when they split the entire cohort into pre and post World War II, there was no significant difference. This study suggests both that the heritability of major depression is higher in women than in men and that some genetic risk factors for major depression are sex-specific. In addition, the study confirms the level of heritability of major depression found in other studies, strengthening the reliability of European twin studies.
Kendler et al (Genetic Similarity, Twin Study) Evaluation
Strengths
The study appears to confirm previous research, strengthening the reliability of the findings
Very large sample size taken from a single population (~15,500)
Limitations
Correlational = no cause and effect relationship can be determined
No particular genes were isolated and tested in the study
Information about life-events and depressive symptoms was self-reported
Making a clinical diagnosis by telephone may be considered of questionable validity
Weissman et al (Genetic Similarity, Kinship Study) Aim
To study the potential genetic nature of Major Depressive Disorder.
Weissman et al (Genetic Similarity, Kinship Study) Method
Longitudinal family study with a sample
161 grandchildren and their parents and grandparents
The study took place over a twenty year period, looking at families at high and low risk for depression.
Weissman et al (Genetic Similarity, Kinship Study) Procedure
The original sample of depressed patients (now, the grandparents) was selected from an outpatient clinic with a specialization in the treatment of mood disorders. The non-depressed participants were selected from the same local community. The original sample of parents and children were interviewed four times during this period. The children are now adults and have children of their own - allowing for study of the third generation.
Weissman et al (Genetic Similarity, Kinship Study) Results
Data was collected from clinicians, blind to past diagnosis of depression or to data collected in previous interviews. In order to establish credibility, data triangulation was used. Children were evaluated by two experienced clinicians - with one being a child psychiatrist and the other a psychologist. The inter-rater reliability of their diagnoses were 0.82 for MDD, 0.65 for anxiety disorders and 0.94 for alcohol dependency. The researchers found high rates of psychiatric disorders in the grandchildren with two generations of major depression.
By 12-years-old, 59.2% of the grandchildren were already showing signs of a psychiatric disorder - most commonly anxiety disorders. Children had an increased risk of any disorder if depression was observed in both the grandparents and the parents, compared to children where their parents were not depressed.
In addition, the severity of a parent's depression was correlated with an increased rate of a mood disorder in the children.
Weissman et al (Genetic Similarity, Kinship Study) Evaluation
The study is longitudinal, increasing the reliability of the data. The association between parental MDD and child diagnosis is moderated by grandparental MDD status. The amount of time that a child spent with a health grandparent may be a confounding variable in the study. The use of researcher triangulation increases the credibility of the findings. A sample of 161 children is a large sample; however, more research would need to be carried out to confirm the reliability of the findings. Although family (kinship) studies indicate a potential genetic link to behavior, there is no actual genotype studied.
Curtis et al. (Evolution) Aim
To investigate the evolutionary origin of the disgust reaction.
Curtis et al. (Evolution) Hypothesis 1
Disgust should be felt more strongly when faced with disease-salient stimulus as opposed to similar stimulus with less salience.
Curtis et al. (Evolution) Hypothesis 2
Disgust should operate in a similar way across cultures.
Curtis et al. (Evolution) Hypothesis 3
Disgust should be more pronounced in females since they have to protect their babies in addition to themselves.
Curtis et al. (Evolution) Hypothesis 4
Disgust should become weaker as the individuals reproductive potential declines with age.
Curtis et al. (Evolution) Hypothesis 5
Disgust should be stronger in contact with strangers than close relatives because strangers potentially carry novel pathogens.
Curtis et al. (Evolution) Method
A survey was placed on the BBC Science website.
~40,000 participants across 165 countries, all ages and both sexes.
Curtis et al. (Evolution) Procedure
Participants were asked a set of demographic questions regarding their age, sex, country, etc. They were then asked to rate 20 photographs for disgust on a scale of 1-5.
Of the 20 photographs, 7 pairs were paired for disease salience vs less disease salience.
Last question asked: "With whom would you like to share a toothbrush?" This was to test the 5th hypothesis.
Curtis et al. (Evolution) Results
Found that the disgust reaction was more strongly elicited for those images of the pairs that evoked a health threat. They also found that the disgust reaction also decreased with ages and was higher in women than men.
Curtis et al. (Evolution) Evaluation
Strengths
Applicable
Generalizable
Cost/time effective
Limitations
Correlational
No control over variables
Online study
Wedekind (Evolution) Aim
To determine whether one's MHC would affect mate choice
Wedekind (Evolution) Method
49 female and 44 male students from a Swiss university.
Each participant was “typed” for their MHC, and a wide variance of MHC was included in the sample.
It was noted if the women were taking oral contraceptives.
Wedekind (Evolution) Procedure
The men were asked to wear a T-shirt for two nights and to keep the T-shirt in an open plastic bag during the day. They were given perfume-free detergent to wash clothes, bed clothes, and perfume-free soap for showering. They were asked not to use any deodorants or perfumes, to refrain from smoking tobacco or drinking alcohol, to avoid all spicy foods and to not engage in any sexual activity.
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Two days later, the women were asked to rank the smell of 7 t-shirts, each in a cardboard box with a “smelling hole.” The women were tested whenever possible in the second week after the beginning of menstruation, as women appear to be most odor-sensitive at this time and were also asked to use a nose spray for the 14 days before the experiment to regenerate the mucous membrane and prevent colds or flu. 3 of the 7 boxes contained T-shirts from men with MHC similar to the woman's own; 3 contained T-shirts from MHC dissimilar men; and 1 contained an unworn T-shirt as a control. Alone in a room, every woman scored the odors of the T-shirts for intensity (range 0-10) and for pleasantness and sexiness (range 0-10, 5 = neutral).
Wedekind (Evolution) Results
Women scored male body odors as more pleasant when they differed from their own MHC than when they were more similar. This difference in odor assessment was reversed when the women rating the odors were taking oral contraceptives.
Wedekind (Evolution) Conclusion
MHC may influence mate choice, showing how we have evolved to detect MHC-dissimilar scents as more attractive to produce a healthier child.
Wedekind (Evolution) Evaluation
Strengths
Double-blind study, since neither the researcher nor the participant knew what shirt they were exposed to, reducing demand characteristics
Met ethical standards as consent was obtained from all participants and they were debriefed
Limitations
Reductionist – over-simplifies the behavior of human mate selection by bringing it down to the MHC, ignoring cognitive and socio-cultural factors
Population validity – Participants were similar in age and culture (Swiss university students)
Bransford and Johnson (Schema Theory) Aim
To determine if schema activation would result in better understanding and recall of an ambiguous text.
Bransford and Johnson (Schema Theory) Method
Lab experiment (true experiment)
52 participants
Bransford and Johnson (Schema Theory) Procedure
3 conditions all tested at the same time:
Topic before group: told 'the passage you are about to hear is about washing clothes'
Topic after group: Told 'the passage you are about to hear is about washing clothes
No topic group: Told nothing
Recall of Ideas (18 ideas total could be recalled) - All participants asked to rank comprehension of paragraph on scale of 1-7
Bransford and Johnson (Schema Theory) Results
The researchers concluded that prior knowledge of a situation does not guarantee its usefulness for comprehension. in order for prior knowledge to aid comprehension, it must become an activated semantic context
Bransford and Johnson (Schema Theory) Evaluation
Strengths
The study is simplistic and is easily replicated. This allows researchers to determine the reliability of the findings.
The task is highly controlled, leading to high internal validity. This means that a cause and effect relationship can be determined.
The findings of the study have been applied to education, helping students to improve reading skills and retention of information.
Limitations
The task is rather artificial, lacking ecological validity.
The study used an independent samples design; participant variability with regard to experience with washing clothes may be a confounding variable.
A repeated measures design would not be possible as the text could not be reused.
It is not possible to know that an actual "laundry schema" was active while listening to the text. There should be other reasons for the rate of recall - e.g. good memory skills.
Anderson & Pichert (Schema Theory) Aim
To examine the stages of memory which are affected by schematic activation
Anderson & Pichert (Schema Theory) Method
Lab experiment (True experiment)
39 introductory ED psych students
Anderson & Pichert (Schema Theory) Procedure
All participants read a story with 72 ideas all initially given one of two conditions/roles before they read the story: Robber condition and homebuyer condition
2 minutes to read the story then a 12 minute vocab test (both a distraction task and a way to check/control their language proficiency)
Then told to write down/recalls as much as they can remember of the story 5 minute filler/distraction task (spatial puzzle test)
Recall a 2nd time which 1/2 of each condition were told to keep the same perspective and other 1/2 were told to recall from opposite perspective
Anderson & Pichert (Schema Theory) Results
Burglar information was better recalled than homebuyer information. This may be because students do not have a well developed homebuyer schema = it is likely that the schema influenced encoding. The group that had the burglar perspective recalled more burglar information, and the group that had the homebuyer perspective recalled more homebuyer information = it is likely that the schema influenced retrieval.
Participants who changed their perspective recalled an additional 7.1% of the information relevant to their new perspective. The group that did not change perspective recalled 2.9% less information relevant to their perspective.
Anderson & Pichert (Schema Theory) Evaluation
Strengths
The task is highly controlled, leading to high internal validity. This means that a cause and effect relationship can be determined.
Limitations
However, due to its artificial nature, it has low ecological validity.
Possible expectancy effect - it is possible that when asked to redo the task from the other perspective, they did not write down details from the first recall of the story because they did not think that they were relevant. This means we do not know if they were forgotten or simply excluded.
Fatigue effects may have played a role in the amount of detail recalled. - it is assumed that the homebuyer details were recalled less frequently because students do not have the schema for home buying as they do for burglaries. It could be, however, that the story was written in such a way that the burglary ideas were more engaging than the homebuyer details - and this could be the reason for the higher recall rates.
Glanzer and Cunitz (Multistore Model) Aim
To investigate the serial position effect with and without interference from a filler activity
Glanzer and Cunitz (Multistore Model) Method
Lab experiment with repeated measures design
46 enlisted army men
Glanzer and Cunitz (Multistore Model) Procedure
A series of 15 words read out to participants followed by free recall task.
There were three conditions:
A free-recall task immediately after hearing the words on the list
A filler activity (counting backwards from a random number for 10 seconds), then free recall
The same filler activity but for 30 seconds
Each participant was given 15 lists, 5 for each of the 3 conditions.
The order of the conditions was random. The independent variable is introduction of a filler task between the stimulus and the recall. The dependent variable was the proportion of words correctly recalled, separately for each of the 15 positions of the word on the list - this means there were 15 DV's.
Glanzer and Cunitz (Multistore Model) Results
In the condition without the filler task, both aspects of the serial position effects could be seen: the primacy and the recency effect.
In the condition with the filler task, the primacy effect stayed, but the recency effect disappeared - more so in the 30-second condition than the 10-second condition.
Glanzer and Cunitz (Multistore Model) Evaluation
Strengths
The design of the study was a lab experiment (true experiment) which help suggest a cause and effect relationship.
High in internal validity due to its artificial setting and controlled variables
Limitations
Lacks ecological validity as this memorization of the items does not present everyday ways of utilizing memory unless they were memorizing phone numbers, shopping lists etc. (mundane realism)
Questions internal validity - A study by Cole and Scriber shows that children without schooling do not show the primacy effect
Warrington and Shallice (Working Memory Model) Aim
To investigate how the damage done to patient KF’s brain affected his short-term memory
Warrington and Shallice (Working Memory Model) Method
Longitudinal case study of patient KF, who suffered from brain damage due to a motorcycle accident
Warrington and Shallice (Working Memory Model) Procedure
Multiple procedures to investigate KF’s memory: free recall tasks, the Peterson procedure, proactive interference tasks and missing scan tasks.
Warrington and Shallice (Working Memory Model) Results
He quickly forgot numbers and words when they were presented to him orally, but he was able to remember these words or numbers when presented to him visually. KF's impairment was mainly for verbal information - his memory for visual information was largely unaffected.
Warrington and Shallice (Working Memory Model) Conclusion
This supports Baddeley's theory that there are separate STM components for visual information (visuospatial sketchpad) and verbal information (the phonological loop).
Warrington and Shallice (Working Memory Model) Evaluation
Strengths
Longitudinal case study, over time Warrington and Shallice were able to be more precise in their findings.
Limitations
Cannot be replicated due to being a case study (unethical)
Cannot completely generalize findings through a singular patient