Biological Approach - Case Studies

Question 1

HM: Milner (1966)

Answer 1

Aim: To determine the extent of HM’s memory deficiency.
Procedure: HM was initially studied by Brenda Milner, administering a range of tests and measures such as personality and mood tests, depression questionnaires, and interviews with psychiatrists. His scores did not indicate depression, anxiety or psychosis and he communicated a good awareness of his condition (i.e. he did not ‘forget’ that he was suffering from anterograde amnesia). He completed a standard IQ test on which his score was normal, however his scores on the Wechsler Memory Scale test demonstrated his severe memory impairment. Milner noted that HM frequently forgot what had happened that day, thought he was younger than his actual age, forgot the names of people he had just met and commented that every day felt as if he was just waking up from a dream. Milner studied him (and later, Corkin) for over 50 years until his death.
Results: Concluded that the hippocampus wasn’t the site of memory storage, but the site where it turns short term to long term memories (confirmed by post-mortem analysis).
Conclusion: HM strongly affirms the idea of localization of function in the brain and the study asserts that the function of organization of memory is localized in the hippocampus

Question 2

Feinstein et al. (2011)

Answer 2

• Case study for localization of function -

Aim: To study role of amygala (in fear).
Participant: SM, a patient with bilateral amygdala damage due to a genetic condition
Procedure: This study followed prior studies that showed she had impairment in other fear-related behaviours, like fear conditioning and the ability to recognize fear in other people. The researchers tried to induce fear by taking her to a pet store (with snakes, spiders etc), a haunted house and showed her scary film clips to see if she would be afraid. They also gathered data on her life by using self-report questionnaires
and interviews.
Results: Biological fear impulse is affected by lesions on amygdala. She could still see situations as dangerous and could act on it.
Conclusion: the amygdala is a key part of the brain that is responsible for our ability to experience fear.

Question 3

Maguire et al. (2000)

Answer 3

• Quasi single-blind experiment for neuroplasticity -
  Aim: To investigate localisation of function linked to spatial navigation experience in London black cab taxi drivers
  Participants: 16 healthy, experienced taxi drivers from London
  Procedure: The participants were placed in an MRI scanner and their brains were scanned. The MRI measured the volume of grey matter in the hippocampus of each participant, and this was then compared to pre-existing scans of 50 healthy, right-handed males (the control group). Grey matter was measured using voxel-based morphemetry (VBM) which focuses on the density of grey matter and pixel counting.
  Results: The posterior hippocampi of the taxi drivers showed a greater volume of grey matter than that of the controls, who had increased grey matter in their anterior hippocampi compared to the taxi drivers. Maguire also carried out a correlational analysis which showed a positive correlation between volume of posterior hippocampal grey matter and length of time spent as a taxi driver
  Conclusion: The posterior hippocampus may be linked to spatial memory and navigation.

Question 4

Draganski (2004)

Answer 4

• Field experiment for neuroplasticity -

Aim: To investigate whether structural changes in the brain would occur in response to environmental demands (learning and then ceasing juggling).
Participants: A self-selected sample of 24 adults aged 20-24 years old (21 female; 3 male) with no prior experience of juggling.
Procedure: The participants were randomly allocated to 2 conditions: jugglers or non-jugglers. Each participant underwent an MRI scan. Those in the juggling condition were taught a 3-ball cascade juggling routine. They were asked to practice this routine and to notify the researchers when they had mastered it. At that point the jugglers had a second MRI scan. After this second scan they were told not to juggle anymore and then a third and final scan was carried out 3 months later. The non-jugglers also underwent 3 separate MRI scans at pre-determined intervals.
Results: No difference before the experiment. Second scan the jugglers had more grey matter in some areas, mostly mid-temporal area. Third scan differenced decreased but jugglers had denser gray matter.
Conclusion: Grey matter appears to increase in specific brain regions (neuroplasticity) in response to environmental demands (learning to juggle) and shrinks in the absence of that learning (stopping juggling) but not to its original state. Thus, this study provides evidence for both neuroplasticity and neural pruning (and neural networks as it is via these that the learning takes place).

Question 5

Harris & Fiske (2006)

Answer 5

• Localization of function -

Aim: To investigate the biological correlation of stereotypes and prejudice
Participants: 22 Princeton University undergraduates. The group was randomly allocated to two conditions - with 10 participants seeing images of people and 12 seeing images of objects.
Procedure: The researcher scanned the students while watching either pictures of different humans or objects,
Results: The medial prefrontal cortex was active when participants looked at humans but not when they looked at objects (normally activated when thinking about ourselves or other people). When people looked at pictures of people from extreme groups such as the homeless and addicts, the amygdala and insula was activated. These regions are related to ‘disgust’ and fear and also indicates that the extreme groups were objectified.

Question 6

Setiawan (2013)

Answer 6

• Case study for neurotransmission -

Aim: To determine the role of the brain’s reward pathway in addiction
Procedure: Participants were given a test to clasify them as high or low risk for addiciton. Half of the participants were given orange juice and lemon soda and the other half were given the same mixture with alcohol. Participants were put into an PET scan to measure brain activity.
Results: High risk participants who drank alcohol showed greater activity in the brain’s reward pathway than the other participants.

Question 7

Askari et al. (2012)

Answer 7

• Neurotransmission double-blind experiment -

Aim: To examine the efficacy and tolerability of granisetron when combined with an SSRI called fluvoxamine, for patients with moderate to severe OCD:
Procedure: Used YBOC (OCD scale) to measure participants thoughts about worry, questionnaire prior to treatment. The participants were then randomly allocated to the experimental or the control group. They either resieved an SSRI or a placebo for 8 weeks every 12 hours.
Results: The experimental group experienced a reduction in their symptomps in comparison to the placebo group.
Conclusion: People with OCD can achieve a faster and greater reduction in symptomps by combining fluvoxamine and granisterton, with no increase in adverse side effects.

Question 8

Antonova (2011)

Answer 8

• Double blind Experiment for neurotransmission -

Aim: To determine how blocking the acetylcholine receptors with scopolamine affects the spatial memory.
Procedure: 20 healthy male adults. They were injected with scopolamine (antagonist for acetylcholine) or a placebo before the experimental task. They were put into an fMRI while playing “arena task”. They were trained and knew the rules prior. Brain activity was measured for spatial memory.
Results: Participants injected with scopolamine demonstrated a significant reduction in the activation of the hippocampus compared to the control group.
Conclusion: Acetycholine plays a key role in the encoding of spatial memories in humans

Question 9

Prevot et al. (2019)

Answer 9

• Experiment on animals for inhibitory neutransmitter -

Aim: To investigate if using an agonist which activates the GABA receptor sites in the hippocampus would increase the inhibition of neural activity which would lead to improved memory function.
Procedure: A double blind experiment with pre-test/post-test design. The mice were either allocated to the placebo condition or the drug condition. They were given in an agonist and then placed alone in a maze. The task was to test spatial memory. The sample was mice that suffered from memory impairment as a result of chronic stress and older mice.
Results: Stressed and aged mice had improvement in the spatial working memory if given GABA.

Question 10

Porges et al. (2017)

Answer 10

• Lab experiment for Inhibitory neurotransmitter -

Aim: To see if GABA concentrations in the frontal cortex would exhibit superior cognitive function.
Procedure: 94 older adults without cognitive impairment were picked as a sample. Their GABA concentrations were measured, and then they were assessed for their cognitive functioning using the Montreal Cognitive Assessment.
Results: Greater frontal GABA concentrations were associated with superior cognitive performance. Gaba concentrations decreased with age.

Question 11

Schmitz et al. (2017)

Answer 11

• Correlational study for Inhibitory neutransmitter -

Aim: To see how levels of GABA affect the ability to suppress intrusive thoughts.
Procedure: Participants were given pairs of unrelated words to associate. In an fMRI, they were either asked to suppress or associate the words, based on if they recieve a green or red signal.
Results: Suppression limits hippocampal activity and therefore those with more GABA in hippocampi were better at suppression.

Question 12

Baumgartner et al (2008)

Answer 12

• Lab experiment for hormones -

Aim: to investigate the role oxytocin plays with trust in human relationships and interactions.
Procedure: Participants played the trust game (trustee, investor and banker). The 3 groups of participants were injected, either with high levels of oxytocin, low levels of oxytocin, or placebo.
Results: Participants with higher levels of oxytocin were more trusting and more likely to risk their money.
Conclusion: Oxytocin hormone plays a key role in the human behaviour of trust. However, this does not continue with non-human interactions (when played with a computer).

Question 13

Zak et al. (2009)

Answer 13

• A double blind experiment for hormones -

Aim: To investigate the role played by testosterone in prosocial behaviour.
Procedure: A sample of 25 young males. they played the ultimatum game after either being injected with testosterone or placebo.
Results: Participants injected with testosterone were less generous and were seen as more aggressive.
Conclusion: Testosterone has the opposite effect of oxytocin. It increases the action potential towards the amygdala in response to perceived threat and leads to aggression which leads to antisocial behaviour (generosity).

Question 14

Klinesmith (2006)

Answer 14

• Experiment for hormones -

Aim: To see if the presence of a gun increases aggressiveness and/or testosterone levels.
Procedure: Sample of 30 young males. Salive samples were collected to observe normal testosterone levels. The experimental group was given a gun to “assembly/dissemble” and the control given was given a toy to do the same. Afterward, they were given a class of water with 1 drop of hot sauce and were told it was prepared by the previous participant. They were asked to rate the taste and then decide how much hot sauce to use for the next participant. (Glass was weighed to check amount added).
Results: Participants who had been handling the gun showed a great increase in testosterone and added more sauce into the water. Positive correlation between hot sauce added and changes in testosterone level.
Conclusion: Aggression is increased by handling a gun, and the increase happens because of an increase in testosterone levels.

Question 15

Wedekind (1995)

Answer 15

• Test for pheremones and MHC -

Aim: To see whether the human body odors and female preferenced for them are dependent on a persons MHC - genes.
Procedure: 49 female participants and 44 male participants were tested to idenitfy MHC genes. The males had to wear a short for 2 days straight and then the females were asked to smell the shirts on the 3rd day and rate them 1-10 on pleasantness.
Results: Women preferred men with dissimilar immunge systems or MHC - genes to their own. Except for woman who used oral contraceptives.
Conclusion: Out attraction to toher people could be due to the smell of their genes and the more dissimilar the genes are to our own the more likely we are to be attracted to the scent.

Question 16

Doucet (2009)

Answer 16

• Experiment for pheremones -

Aim: To investigate the role of the secretion of the areolar gland (by the nipple) in suckling behaviour in3-day old infants.
Procedure: The babies were exposed nasally to different substances and their behaviour was observed. The substances were the secretion from the areolar glands, human milk, cow milk, formula milk, vanilla and a clean control.
Results: The infants only reacted to the substance from the areolar glands by starting suckling and increased breathing.
Conclusion: The secretion of the areolar glands causes infants to start suckling.

Question 17

Bouchard (1990)

Answer 17

Aim: to investigate the effect of genetic inheritance, shared environment, and unique
environment on a large number of psychological traits.
Procedure: Through advertisements researchers identified several hundred monozygotic twins that had either been raised together (MZT twins) or apart (MZA twins) through adoption. Subjects completed a large number of tests including IQ tests, physiological measurements, and questionnaires regarding things like political views, religiosity, aggression, etc. Results were then compared between the two different groups of twins in order to determine the concordance (from 0 to 1) in each group.
Results: For a large number of the psychological traits, the twins raised apart (MZA) were as similar to each other as the twins raised together (MZT). The highest heritability for a psychological trait is the heritability for IQ.
- A surprising result from this study was that the shared environment in a family has only a very small influence on the behavior of the twins in that family. Instead, it is genetic inheritance together with each twin’s unique environment that together influence the behavior of the individual.

Question 18

Turkheimer (2003)

Answer 18

Aim: To investigate the role of the environment, and in particular whether heritability of intelligence is equally high in all socio-economic classes.
Procedure: Turkheimer searched for archival data on twins from a wider range of families than had previously been included. In a sample from research from the 1970’s he found 320 twin pairs, many from poor families, who had taken IQ tests at age 7. Turkheimer performed correlational analysis on the twins data to examine whether identical (mono-zygotic) twins had more similar IQs than fraternal (di-zygotic) twins who share on average only 50% of their genes.
Results: Heritability of IQ among the twins who had grown up in wealthy families was, as expected, very high. The big surprise is among the poorest families. For the children who grew up poor, the IQ’s of monozygotic twins vary just as much as the IQ’s of dizygotic twins, meaning that heritability of IQ is close to 0. Meanwhile, the role of the environment was reversed - with both shared and non-shared environment being of great importance for the IQ in poor children, and not noticeably important at all for the wealthiest children.

Question 19

Sorensen et al (1990)

Answer 19

Aim: The role of genetics in behaviour or the question of the role of genetics in explaining behaviour.
Procedure: Sorensen et al (1992) studied 840 adult Danish adoptees. The study used the adoptees as probands. The height and current weight were measured to calculate BMI. In addition, school records were obtained to determine their height and weight at ages 7 - 13 years old. Data from both the birth parents and the adoptive family were obtained through questionnaires, asking for height and current weight, as well as the maximum weight. This data was used to calculate BMI.
In addition, adoptees were given a questionnaire in order to document environmental factors which may have played a role in obesity. This included the age of the child and parent at time of adoption, family income and smoking habits.
Results: The results showed the following correlations across the ages 7 - 13 years. (Higher correlation with biological family than adoptive family.)

Correlation: bio siblings > bio mom > bio dad > adoptive siblings > adoptive mom > adoptive dad.

When looking at the adult data, they found similar levels of correlation, both for current weight and for maximum weight. None of the environmental factors studied showed any significant correlation with BMI. This implies a potential genetic influence.

Question 20

Caspi et al. (2003)

Answer 20

Aim: To investigate whether a functional change in the 5-HTT gene is linked to a higher or lower risk of depression in an individual.

Participants: The researchers used a sample of participants who were part of another longitudinal study. There were 847 participants of mean age 26 years old, split into three groups, depending on the length of the alleles on their 5-HTT transporter gene.
- Group 1 - two short alleles
- Group 2 - one short and one long allele
- Group 3 - two long alleles

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.

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.

Question 21

Ronay & von Hippel (2010)

Answer 21

Aim: to investigate the hypothesis that physical risk-taking by young men increases in the presence of an attractive female; and that increased risk-taking in the presence of an attractive woman might be induced by elevated testosterone. / to investigate the potential role of evolutionary factors in male skateboarding behavior.

Participants: The sample was made up of 96 young adult Australian male skateboarders with a mean age of 21.58. Participants were recruited at skateboard parks.

Procedure: Tests were conducted between 2 and 6 pm. 43 participants were assigned to a male experimenter condition and 53 were assigned to a female experimenter condition. testing was conducted between 2:00pm and 6:00pm to control for variation in testosterone concentrations. skateboarders were asked to chose one easy trick and one difficult trick they had not yet mastered which they attempted 10 times each while being video-taped by the male or female experimenter (blind to the hypothesis). attractiveness of the female was established by 20 independent male raters. saliva samples were collected at the conclusion of the experiment to monitor testosterone levels.

Results: participants took greater risks on the difficult tricks in the presence of the female experimenter. as predicted, testosterone levels were significantly higher among men who skateboarded in front of the female experimenter. the analysis suggests that increased risk-taking in front of the female experimenter was partially mediated by increased testosterone levels.

Conclusion: young men take greater physical risks when in the presence of an attractive woman and that increases in circulating testosterone partially explain this effect. researchers also suggest that the prefrontal cortex, specifically the ventral medial prefrontal cortex (VMPFC) might play an intermediary role in these processes since the area is involved in decision making under risk. higher levels of testosterone might impair the functioning of the VMPFC, leading to higher risk-taking behavior which may hay an evolutionary origin to attract a beautiful mate.

Question 22

Cook (1989)

Answer 22

Aim: To test whether monkeys acquire fear responses by imitation of other monkeys // To see whether they’re more likely to learn a fear of dangerous objects than non-dangerous objects. (e.g. comparing fear-relevant and non-relevant stimuli).

Method: There were 2 lab experiments.

Procedure:

• Lab 1: 22 lab rhesus monkeys (aged 4-11) observed a 32 yr old wild monkey with fear of snakes. They watched a video tape of model monkey showing the fear, then watched a video where the fear response was spliced (edited) with flowers instead (so it appeared the monkey was afraid of flowers)

-Lab 2: Procedure repeated with 20 rhesus monkeys, observers watched video of lab reared monkey taught to fear crocodiles, then watched vid where fear response spliced with toy rabbit.

Then, the time it took to reach for food in presence of fear stim to measure fear in observers after observing models. (toy snake, toy croc, toy rabbit, flowers).

Results: In both experiments, time taken to reach for food increased after watching tape where fear stim was dangerous (increased from 9 TO 27 in presence of TOY SNAKE.) BUT it did not increase when fear stim was not dangerous (flower and toy rabbit).

Conclusion: Fear response can be acquired by social learning, but only to objects that are potentially dangerous.

Question 23

Öhman (1975)

Answer 23

Aim: To investigate the preparedness explanation of phobia acquisition using different images, electric shocks and GSR.

Procedure: Shown pictures of houses, snakes, spiders and faces of people. 1/2 the participants received an electric shock when shown a picture of a house or face. Other half received a shock when shown snake or spider. Used GSR.

Results: Both groups showed fear with electric shock, measured by skin reaction called galvanic skin response (GSR). Higher GSR when shocked when shown snakes and spiders compared to other group.

Conclusion: May be more biologically prepared or ready to develop phobias for animals such as snakes and spiders (may threaten survival).

Question 24

Weissman et al (2005)

Answer 24

• Family studies in genetics, longitudinal study

Aim: To study the potential genetic nature of Major Depressive Disorder.
Procedure: Took place over 20 years with a sample of 161 grandchildren and their parents and grandparents, looking at both high and low risk families for depression. The original sample (now grandparents) was selected from a clinic and the non-depressed patients were selected from the same communicty. The original sample of parents and children were interviewed multiple times during this period. These children now have children of their own, allowing the study of the third generation. Data was collected from clinicians. To increase credibility, triangulation was used. Children were evaluated by 2 clinicians, inter-rater reliability.
Results: High rates of psychiatric disorders in the grandchildren with two generations of major depression. Children had an increased risk of any disorder if depression was observed in both the grandparents and the parents, compared to the children where their parents were not depression. Also, the severity of a parent’s depression was correlated with an increased rate of mood disorders in the children. However, if a parent was depressed with no history of depression in the grandparents, there was no significant effect of parental depression on the grandchildren.