Biological Approach Flashcards

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1
Q

Localization of a function

A

Theory that certain parts of the brain correspond to certain functions and reflect that behaviour, emotion, and thoughts originate in specific regions of the brain

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2
Q

Weak localization

A

The idea that several parts of the brain are responsible for the same function, but only one of these areas is dominant

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3
Q

Role of amygdala

A

Triggers fear. When perceiving things that are threatening, the amygdala helps activate a process that results in the release of stress hormones.

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4
Q

Role of prefrontal cortex in decision making

A

Is located in the frontal lobe and is responsible for executive functions such as decision making, planning, self-regulation, and social behaviour

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5
Q

Grafman et al. (1996)

A

Aim: impact of brain injuries on behaviour/aggression
Procedure:
- viet war veterans who had suffered head injuries that resulted in damage to areas of the brain, which included the prefrontal cortex
- was compared to a control group
- participants measured aggression on self-reported scales and questionnaires
Findings:
- veterans who had damage to the PFC had higher levels of reported violence and aggressions than the controls or veterans with damage to other parts of the brain
Conclusion:
- damage to the PFC lessens decision making and self-regulation, and increases aggressive behaviour that no damage or damage to other areas of the brain

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6
Q

Neuroplasticity

A

The brains ability to adapt by forming new connections as a result of genetics, experience, learning, or following an injury.

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7
Q

Neural networks

A

Created when activity is repeated, causing the brain to stimulate and neurone to connect to one another as new things are learned.

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8
Q

Grey matter

A

The branching of neutrons in the brain and can result in changes to brain structure

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9
Q

Neural pruning

A

The activity is not practiced, leads to a decrease in number of neural connections

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10
Q

Maguire et al. (2000)

A

Aim: investigate whether neuroplasticity occurs in London cab drivers, who must memorize thousands of street names, landmarks, restaurants, and hotels to earn a cab license
Procedure:
- right handed male taxi drivers
- a control group: healthy right handed male subjects who did not drive a taxi
- MRI was used to measure the variables and then compared between the 2 groups
Findings:
- taxi drivers had increased grey matter volume in the posterior hippocampus, compared to the control group. On the other hand, the controls subjects had increased grey matter in the anterior hippocampus.
Conclusion:
- the hippocampus is the region of the brain associated with memory, and the posterior is believed to be related to spacial memory and navigation. experienced cap drivers develop a “mental map” of London and this causes an increase in the posterior of the hippocampus and the development of neural networks.

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11
Q

Draganski et al. (2004)

A

Aim: to investigate whether structural changes in the brain would occur in response to practicing a simple juggling routine
Procedure:
- sample was randomly divided into 2 groups: jugglers and non-jugglers
- jugglers spent 3 months learning to juggle with 3 balls followed by 3 months in which they stopped practicing
- participants in the control group never practiced juggling for the 6 months
- 3 brain scans (MRI) were performed in both groups before the experiment, 3 months in, and after 6 months
Findings:
- after 3 months, jugglers had significantly more grey matter in the mid-temporal area of the cortex, which is responsible for the coordination of movement
- after 6 months, the group that stopped practicing saw a decrease in the grey matter but they still had more than non-jugglers
Conclusion:
- grey matter grows in the brain in response to environmental demands in the absence of stimulation (neural pruning). This shows the cause-and-effect relationship between learning and brain structure.

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12
Q

Brain imaging techniques

A

Allows for non-invasive methods to study the brain (classified at tools to measure variables)

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13
Q

MRI - principal of work

A

When placed in external magnetic field, some atomic nuclei (hydrogen) can emit energy. these pulses of energy can be detected and be used to produce a 3D image of brain structure. Can also be used to investigate which parts of the brain are involved in specific thoughts and behaviour.
Strengths:
- allows for research triangulation
Limitations:
- produce a static image and is therefore correlational

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14
Q

Neurotransmitters

A

Chemical messengers that send messages along neural pathways. the nervous system is a system of neutrons.
1. When the axon of 1 neuron approaches another neuron, a synapse is formed. neurotransmitters are released into the synaptic gap connecting the 2 neurons.
2. They then bind to a specific receptor sites of the postsynaptic neutron, creating an electrical signal called the action potential, which passes the signal further.
3. The signal continues to spread until reuptake - the neurotransmitters are pulled back into the axon that released it - occurs

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15
Q

Neurotransmitter associations

A

Low levels of serotonin and dysfunction in this part of the brain could help explain violence and impulsive behaviour. High levels have been associated with prosocial behaviour.

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16
Q

Passamonti et al. (2012)

A

Aim: test the effects of reduced levels of serotonin within the prefrontal cortex
Procedure:
- randomized, double blind study
- healthy participants consumed a drink that lacked tryptophan (an amino acid that helps build serotonin in the brain) or a placebo that would not alter tryptophan levels.
- participants were then put in a fMRI and their brain activity was measured while they were seeing images of happy, angry, or neutral faces.
Findings:
- the group low in serotonin had reduced PFC activity when viewing angry faces (but not others)
- they also showed weaker communication between the amygdala and PFC
Conclusion:
- low serotonin levels disrupt the function of PFC and its ability to regulate stress/fear triggered by the amygdala
- this might increase emotional levels and increase the chances of a highly emotional reaction to the threat.

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17
Q

Inhibitory neurotransmitters

A

Stop the impulse, preventing it from crossing, producing a calming effect on the brain, decreasing the likelihood that the postsynaptic neuron will fire an action potential.

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18
Q

Example of inhibitory neurotransmitter

A

Serotonin. Low levels have been correlated with impulsive behaviour and violence, high levels have been associated with promoting prosocial behaviour. Adequate amounts of serotonin are necessary for a stable mood and to balance excessive excitatory (stimulating) neurotransmitters, such as dopamine from firing in the brain.

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19
Q

Agonist

A

Act by enhancing the action of neurotransmitters, by producing the same effect as whatever molecule normally binds to a receptor.
- neurotransmitters are endogenous agonists: the brains natural chemical that binds to receptor sites, leading to an action potential.
- drugs can also play the same role and are called exogenous agonists: they bind to receptors, causing the neuron to fire, or they inhibit reuptake, thus increasing its concentration in the synapse.
- citalopram is an example of an SSI (selective serotonin reuptake inhibitor) and an indirect agonist for serotonin. by inhibiting reuptake of serotonin, this increases the levels of serotonin in the synapse.

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20
Q

Crockett et al. (2010)

A

Aim: to investigate the effect of high levels of serotonin on prosocial behaviour
Procedure:
- repeated measures, double blind
- condition 1: participants were given a dose of citalopram
- condition 2: given a placebo
- in each condition, participants were given moral dilemmas based on the class trolley problem, in which they must decide if they do nothing or kill 1 individual to save 5 people tied to a train track.
- in the impersonal scenarios, participants had to decide if they killed 1 person by pulling a lever that diverts the train to the one individual.
Findings:
- in the impersonal scenario, participants were not affected by the citalopram (high serotonin)
- in the personal scenario, citalopram made participants less likely to interfere and push the man onto the tracks
Conclusion:
- citalopram and high levels of serotonin may cause people to be more opposed to the idea of inflicting harm on someone (prosocial), even if it means it would have saved more people.

21
Q

Hormones

A

Chemical messengers that are released into the bloodstream and regulate relatively slow processes such as growth and metabolism.
- They are released by glands in the endocrine system
- Hormones can only produce reactions in certain cells

22
Q

Target cells

A

Have appropriate receptor sites for the hormone. When a hormone binds to a target cell, it either increases or decreases its function.

23
Q

Oxytocin

A

Love hormone. Oxytocin I produced in the hypothalamus and is released by the pituitary gland and plays a role in social bonding

24
Q

Scheele et al (2012)

A

Aim: to investigate the role of oxytocin in promoting fidelity in humans
Procedure:
- heterosexual men, some single and others in a stable relationship
- independent measures design, double-blind
- either oxytocin or a placebo were administered to the participants and then asked to engage in 2 tasks:
1. participants stood at one of the of the room and were told to approach an attractive woman and stop at a distance that made them feel slightly uncomfortable
2. participants were then shown a series of photos and were asked to pull on the joystick when they saw a picture they liked. Included were photos of attractive women, landscapes, and other random objects
Findings:
- oxytocin caused men to keep a greater distance from the attractive female, but only if the man was in a stable relationship
- oxytocin caused men in a relationship to like and pull the joystick slower only on pictures of attractive women.
Conclusion:
- oxytocin causes men in a relationship to keep a greater distance from attractive women who are not their partner. Therefore, staying true to their current relationships.

25
Q

Pheromones

A

Chemical messengers that communicate information from one member of a species to another.

26
Q

Pheromones in animals

A

Pheromones are processed in a different part of the brain than ordinary smells. It is processes in the vomeronasal organ (VNO) and is connected to a special region called the accessory olfactory bulb.

27
Q

Examples of pheromones

A

Androstadienone (AND) and estratetraenol (EST). AND is a compound that is present at much higher concentrations in male sweat and has been linked with improved mood and focus in women. Thereby, influencing behaviour.

28
Q

Wedekind et al. (1995)

A

Aim: investigate the influence of MHC genes on females’ ratings of attractiveness of male sweat odour. Dissimilar MHC in parents produces a stronger immune system in the offspring and may be encoded by body odour.
Procedure:
- half female, half male participants
- females were asked to report if they used contraceptives
- men were asked to wear a cotton shirt for 2 nights. The shirts were then given to female participants who were asked to rate the odour of the 7 t-shirts on a scale of 0 to 10 on intensity, pleasantness, and sexiness.
- one of the shirts was a control, 3 were of men with similar immune systems, and 3 with dissimilar immune systems (best in terms of genes)
Findings:
- women who did not take the oral contraceptives rated the odour of MHC dissimilar as more pleasant, which would produce a stronger immune system in their offspring.
Conclusion:
- suggest that gene compatibility is transmitted via smell and is an example of pheromones in humans

29
Q

Genes

A

Sequences of DNA that are found in the chromosome of cells. They provide the blueprint and function of the human body, which could include behaviour.

30
Q

Monoamine oxidase A (MAOA) gene

A

Produces an enzyme that affects neurotransmission. Low expressions of the gene (MAOA-L) have even correlated with reduced activity in the PFC and its ability to reduce emotion and anger generated in the amygdala. The could result in aggressive behaviour and anti-social behaviour.

31
Q

Caspi et al (2002)

A

Aim: Test the effects of the MAOA genotype and increased response to abuse exposure.
Procedure:
- Followed over 1,000 children in New Zealand over 25 years and took measures every few years.
- Focus was on why some children who are maltreated grow up to develop antisocial behaviour (violent/property offending), whereas others do not.
- Participants were divided into those with high and low MAOA gene expression.
Findings:
- A low expression of MAOA gene increases the impacts of maltreatment and is 3 times more likely to develop antisocial problems with conduct, compared to those with MAOA-H.
Conclusion:
- Low expression of the MAOA gene increases the impacts of maltreatment and environmental insults.

32
Q

Twin and kinship studies

A

Used to determine heritability - the extent to which variations in behaviour can be attributed to genetic factors. This is based on the principle of genetic similarity. Twin studies compare similarities in behaviour between MZ and DZ twins. Comparing similarities in behaviours between these 2 allows researchers to see the extent to which these variations are based on genetics.

33
Q

Bouchard and Mcgue (1981)

A

Aim: estimate the heritability of IQ
Procedure:
- meta-analysis, which combines the results of multiple scientific studies, included hundreds of twin studies that looked into heritability and intelligence. Participants included fraternal and identical twins, siblings, parents, and their offspring.
- median correlations were calculated between IQ scores of the various pairs.
Findings:
- identical twins reared together had the highest IQ correlation, next were identical twins reared apart, then fraternal twins reared together, and last were siblings reared together.
- using the Falconer model, the heritability coefficient was 54%.
Conclusion: study demonstrates that intelligence is inherited to a considerable extent.

34
Q

Evolution

A
  • survival of the fittest: those with favourable characteristics are better able to survive and reproduce.
  • natural selection: organisms that are better adapted, pass on their genes and help strengthen the gene pool.
35
Q

Buss (1989)

A

Aim: identify cross-cultural and/or differences in attraction
Procedure:
- 10,000 participants across 33 countries
- answered questionnaire in which they had to rate each of the 18 characteristics (intelligence, good finance, etc.) on how important they are in choosing a mate.
Findings:
- men preferred younger women
- women preferred men who were older and higher social status
Conclusion:
- women and men seek traits which are likely to help procreate healthy offspring
- supports ideas of evolution and the importance of finding a fit partner who can help procreate healthy offspring.

36
Q

Localization study

A

Grafman et al

37
Q

Neuroplasticity study

A

Maguire et al

38
Q

Neural networks study

A

Maguire et al

39
Q

Neural pruning study

A

Draganski et al

40
Q

Techniques used to study the brain (MRI) study

A

Grafman et al

41
Q

Neurotransmitters study

A

Passamonti et al

42
Q

Inhibitory neurotransmitters study

A

Passamonti et al

43
Q

Agonists study

A

Crockett et al

44
Q

Hormones and behaviour study

A

Scheele et al.

45
Q

Pheromones and behaviour study

A

Wedekind et al.

46
Q

Genes and behaviour study

A

Caspi et al

47
Q

Genetic Similarities / twin study

A

Bouchard and McGue

48
Q

Evolutionary explanations for behaviour study

A

Buss