studies Flashcards
Passamonti et al
-30 healthy participants
-Drank a tryptophan lacking drink, or placebo (different days)
-Low tryptophan = low serotonin
-But we can’t measure serotonin in the brain of living participants
Randomized order (some T→P, others P→T)
-Double-blind procedure.
-Viewed images of different types of faces (sad, angry, neutral)
-The participants were put in fMRIs and their brain activity was measured (to observe the activation of different areas
-The results showed that there was reduced activity in the frontal lobe during the low serotonin conditions when the participant was viewing the angry face. Moreover, communication between the amygdala and the frontal lobe was weaker in this condition.
Feinstein et al. 2012
Case study:
S.M has a rare genetic condition
Damage to both amygdalae (localized damaged)
bilateral lesions in her amygdalae
which
Previous studies show reduction in fear conditioning and recognizing fear
This case study tested ability to experience fear
Three tests
Pet Store
Haunted House
Scary Film Clips
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Took her to an exotic pet store
Observed and took notes of her reactions to the snakes and spiders
She says she doesn’t like them and “tries to avoid them”
Her reactions in the shop showed otherwise
She was intrigued, curious, touched the snakes, even said “this is so cool.”
She didn’t display any fear.
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Took her to a “haunted house”
An old sanitorium turned into a haunted house once per year.
5 other female volunteers joined.
Researchers followed and took notes of their behaviour.
The volunteers were scared and shrieking, whereas SM displayed no fear.
She even scared one of the “monsters” by mistake.
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Conclusion:
This case study suggests that the amygdala might play an important role in the experiences of fear in scary and threatening situations. If we have damage to this area of the brain, perhaps we won’t be able to experience fear.
Radke et al. (2015)
Technique used to study the brain in Radke et al. (2015)
fMRI
Aim: to investigate relationships between perceiving a social threat, testosterone, and the amygdala
-54 healthy females
- half given small dose of testosterone
- half given placebo
- laid in fMRI and shown pics of “happy” or “angry” faces
- “Approach” or “avoid” faces as instructed to by researchers using joystick
- Group with testosterone had more activation in amygdala when approaching angry faces and was higher approaching happy face
- In situations involving social threat, people are more motivated to defend themselves, thus test increases activation of amygdala
Goetz et al., 2016
16 healthy young men
- doses of testosterone on one day, placebo the next
- both conditions, showed images of various types of face (neutral, angry, sad)
- Results showed that: when participants were injected with testosterone they showed increased reactivity of the amygdala and the hypothamulus when they ere viewing images of the angry faces
Iowa Gambling
- Four decks of cards
- Two have high short-term reward, long-term losses
- Two have low short-term rewards, better long term gains
- 100 trials
- Participants select
- After about 20 to 30 trials most people (adults) find a pattern and play the safe option.
Radke et al. (2015)
pg 88
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Technique used to study the brain in Radke et al. (2015)
fMRI
Aim: to investigate relationships between perceiving a social threat, testosterone, and the amygdala
-54 healthy females
- half given small dose of testosterone
- half given placebo
- laid in fMRI and shown pics of “happy” or “angry” faces
- “Approach” or “avoid” faces as instructed to by researchers using joystick
- Group with testosterone had more activation in amygdala when approaching angry faces when they were told to do so and that activation was higher than when approaching happy faces
- In situations involving social threat, people are more motivated to defend themselves, thus test increases activation of amygdala
- motivated to defend ourselves against that threat, testosterone levels play an important function in increasing the activation of our amygdala which will result in more emotional and physical readiness to react aggressively.
- activation of amygdala may help us prepare physically prepared for the confrontation by triggering the release of adrenaline
- tesotertone may be to help prepare for that confrontation
Goetz et al., 2016
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16 healthy young men
- doses of testosterone on one day, placebo the next
- both conditions, showed images of various types of face (neutral, angry, sad)
- Results showed that: when participants were injected with testosterone they showed increased reactivity of the amygdala and the hypothamulus when they ere viewing images of the angry faces
- Testosterone was not shown to have the same influence when observing other types of emotional faces
- Activation of the hypothalamus also suggests that the body will release adrenaline as the hypothalamus triggers the adrenal glads during the fight/flight response
Cohen et al (1996)
They wanted to compare Northern and Southern white males, so these were their participants.
The scenario involved the participants walking down a hallway and getting bumbled and insulted (being called an a**hole).
Control groups didn’t receive an insult.
In the first experiment, the researchers had observers pretending to do homework, but they were really sitting in a place where they could see the participants’ faces after they were bumped and insulted.
They rated their facial expressions and emotional reaction.
They found that Northern participants were more amused by the bump, and southerners were angrier.
Procedure 2:
Another procedure in the experiment involved giving a scenario ending task.
Where a man makes another man’s fiancés uncomfortable with multiple passes.
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Participates then had to write the end of the story. 75% of bumped
Southerners ended the scenario with violence, whereas only 20% on non-bumped and insulted Southerners did. This same variation was not seen in Northern participants (41% and 55%).
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This provides some evidence for the fact that Southern white males are more prone to responding to threats and insults with aggression, especially when they’ve been insulted. This could be explained by the culture of honour.
Bechara et al
Iowa Gambling Task
-Four decks of cards
-Two have high short-term reward, long-term losses
-Two have low short-term rewards, better long term gains
-100 trials
-Participants select
-After about 20 to 30 trials most people (adults) find a pattern and play the safe option.
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Bechara et al
-Compared 8 people with vmPFC lesions and 17 healthy controls
Gave them the Iowa Gamlbing Task
Participants with vmPFC lesions more likely to take the risk; didn’t identify the pattern
-Healthy controls slowly learned to avoid the decks of cards with high rewards but bigger long-term punishments, and opted instead for the low immediate reward with longer long-term gains.
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Suggests –>
System 1 & System 2
Meyer-Lindenberg et al. (2008)
Meyer-Lindenberg et al. (2008) showed this in their study that compared the brain activity of two groups of healthy participants.
One group had high expressing MAOA gene (MAOA-H), whereas another group had the variant that has low expression of the MAOA gene, which is the type correlated with aggressive behaviour (MAOA-L).
When viewing angry and fearful faces in an fMRI, the MAOA-L group had significantly increased activity in their amygdala, and reduced activity in their ventromedial prefrontal cortex.
Baker & Raine(2007)
Over 1000 MZ and DZ twins and triplets studied.
Antisocial behavior measured through self-report, teachers, and caregiver questionnaires.
Compared DZ & MZ twins antisocial ratings to create correlations
Overall results showed heritability was around 50%
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Aim
To investigate the extent to which anti social behavior can be attributed to genes (heritability of behavior)
Type of Experiment
Twin study
Participants
1,210 twins in California, USA
Procedure
Child, teachers, caregiver filled out questionnaires to test the child’s personality, behavior and social skills (anti-social behavior)
Results
Heritability of anti-social behavior always came to around 50%
Strengths Data triangulation (from child, teachers and caregivers) - reduces the effect of individual bias
Limitations
1) Cannot establish a causational relationship
Grove et al. (2007)
Studied 32 sets of MZ twins that were separate shortly after birth
Antisocial behavior measured w/ interviews and questionnaires.
Heritability 41% for children and 28% for adults.
This shows that genes play a role, but less as you get older.
Bandura et al
-Bandura (1961) conducted a controlled experiment study to investigate if social behaviors (i.e., aggression) can be acquired by observation and imitation.
-Bandura, Ross, and Ross (1961) tested 36 boys and 36 girls from the Stanford University Nursery School aged between 3 to 6 years old.
-The researchers pre-tested the children for how aggressive they were by observing the children in the nursery and judged their aggressive behavior on four 5-point rating scales.
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24 children (12 boys and 12 girls) watched a male or female model behaving aggressively towards a toy called a ‘Bobo doll’. The adults attacked the Bobo doll in a distinctive manner - they used a hammer in some cases, and in others threw the doll in the air and shouted “Pow, Boom.”
Another 24 children (12 boys and 12 girls) were exposed to a non-aggressive model who played in a quiet and subdued manner for 10 minutes (playing with a tinker toy set and ignoring the bobo-doll).
All the children (including the control group) were subjected to ‘mild aggression arousal.’ Each child was (separately) taken to a room with relatively attractive toys.
• The next room contained some aggressive toys and some non-aggressive toys. The non-aggressive toys included a tea set, crayons, three bears and plastic farm animals.
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Children who observed the aggressive model made far more imitative aggressive responses than those who were in the non-aggressive or control groups.
- There was more partial and non-imitative aggression among those children who had observed aggressive behavior, although the difference for non-imitative aggression was small.
- The girls in the aggressive model condition also showed more physical aggressive responses if the model was male, but more verbal aggressive responses if the model was female. However, the exception to this general pattern was the observation of how often they punched Bobo, and in this case the effects of gender were reversed.
- Boys were more likely to imitate same-sex models than girls. The evidence for girls imitating same-sex models is not strong.
Bobo doll experiment demonstrated that children are able to learn social behavior such as aggression through the process of observation learning, through watching the behavior of another person.
