Biological Approaches to Human Behaviour Flashcards
Describe the use of one technique used to study the brain in relation to behaviour.
Brain: an organ of soft nervous tissue contained in the skull, functioning as the coordinating centre of sensation and intellectual and nervous activity.
Techniques to study behaviour: CAT scan, PET scan, MRI, fMRI, and EEG.
Within MRI, nuclei emit energy in response to a magnetic field in a large cylindrical apparatus.
Studies to use: Draganski et al. (2004) and Draganski et al. (2006)
(check neuroplasticity for studies)
Describe the study conducted by Draganski et al. in 2004.
AIM: A study done on neuroplasticity aiming to show whether a change in behaviour can really alter the brain structure.
**PARTICIPANTS: **
- 24 participants,
- random sampling design,
- self-selected sample. (remember by juggling being random)
**PROCEDURE: **
- confirmation of participants having no experience with juggling
- participants were randomly allocated into 2 groups (one control group= no juggling, one experimental group= juggling every day)
- 1st MRI scan completed before practice,
2nd MRI scan completed after 3 months of practice,
3rd MRI scan completed after both groups had done no practice for 3 months.
**RESULTS: **
- before conducting the study, the researchers found no significant difference between the brain structures of the two groups.
- after 3 months of practice, within the experimental group: the mid-temporal area increased in gray matter.
- after 3 months of no practice: mid-temporal are decreased however was still greater within the experimental group than in the control group.
**EVALUATION: **
- experimental design= cause+effect relationship can be established
- very small sample size= not reliable (study would must be replicated to establish its reliability)
- problems with the internal validity as participants were located mainly at home therefore confounding variables have not been limited.
(remember self-selected random sample by juggling being random)
Describe the study conducted by Draganski et al. in 2006.
AIM: A study done on neuroplasticity aiming to show whether a change in behaviour can really alter the brain structure.
**PARTICIPANTS: **
- 38 German medical students,
- contol participants: sex-and-age mached non-medical students
**PROCEDURE: **
- 1st MRI scan completed 3 months before the exam,
2nd MRI scan completed the first of second day after the exam,
3rd MRI scan completed 3 months after the exam.
- the same has been completed to the control group.
**RESULTS: **
Medical students:
- increase in posterior-parietal gray matter (associated with storage of short term visual memory),
- increase in posterior hippocampus gray matter,
- increase in inferior parietal gray matter,
- decrease of gray matter in the occipital-parietal lobe
- CONTRADICTION: 3 months after the exam, the students posterior hippocampus continued to grow.
**EVALUATION: **
Strengths:
- little bias,
- high ecological validity,
Weaknesses:
- impossible to replicate (individuals have different brain structures)
- limited control
- low population validity
What is the role of the mid-temporal lobe?
The mid temporal lobe is an area known for implication of coordination of movement and memory.
What is the role of the posterior-parietal lobe?
It is associated with storage of short term visual memory
Explain one example of neuroplasticity.
Explain how one study demonstrates neuroplasticity.
Neuroplasticity: is the ability of the brain to change over a period of time, due to the making and breaking of synaptic connections between neurons.
Studies to use: Draganski et al. 2004, Draganski et al. 2006.
Explain the effect of one neurotransmitter on behaviour.
Describe how one example illustrates the effect of neurotransmitters on human behaviour.
Neurotransmitters: chemical messengers which carry chemical signals from one neuron (nerve cell) to the next target cell. The next target cell can be another nerve cell, a muscle cell or a gland.
Seratonin:
- Serotonin plays a large role in regulating your mood, including your level of anxiety, happiness, and well-being.
- Sexual function. Taking medications that increase the level of serotonin (such as antidepressants) causes a decrease in libido and sexual function.
- Depression. Some scientists believe that low levels of serotonin cause depression, although there is considerable controversy over this matter.
Studies to use: Crocket et al. ; Rogers
Describe the study done by Crocket et al.
AIM: The aim of the study was to investigate the effect of seratonin, a neurotransmitter known for sustaining a stable mood and sleep cycle, on the chances of inflicting pain onto others.
**PARTICIPANTS: **
- 30 healthy participants
- double blind study
**PROCEDURE: **
- participants were divided into 2 groups: control group (placebo), experimental group (self-administered SSRI (selective seratonin reuptake inhibitor)
- introduced to the dillema of the “trolley problem”, both personal and impersonal scenarios
impersonal scenario: pull a lever directing a train onto another track.
personal scenario: push a man on the track for interference
- their responces were later recorded
**RESULTS: **
Experimental Group:
- less likely to inflict pain on other individuals (personal scenario) in comparison to the control group
- same responces in impersonal senarios
CONCLUSION:
Increased levels of seratonin may cause individuals to be more opposed to the idea of influencing harm onto others.
**EVALUATION: **
Strengths:
- little bias,
- experimental procedure: cause=effect has been established
- as a double blind study was completed, demand characteristics have been eliminated,
- high internal validity
Weaknesses:
- small participant number (decrease in reliability);
- low ecological validity,
- The citalopram intaked induced slight nausea (individuals might recongnise which condition they are in);
- low population validity.
Describe the study done by Rogers.
like ‘ro’mantic
AIM: Investigate the role that serotonin plays in perceiving emotional intimacy.
PARTICIPANTS:
- 40 healthy males
METHODOLOGY:
- Approximately half of the participants received a drink containing tryptophan, which increases levels of serotonin,
- the other half received a drink not containing tryptophan.
- Afterwards, participants were given photos of couples, and asked to rate how “intimate” and “romantic” the couples appeared.
RESULTS:
- Participants with lower serotonin levels (those that did not receive tryptophan) rated the couples as less intimate and romantic as those that received tryptophan
- lower seratonin=lower intimacy
CONCLUSION:
- Serotonin appears to play a role in how we judge the emotional closeness of people’s relationships.
- This has implications for the study of depression. Depressed people often report feelings of loneliness and social isolation. It could be that low levels of serotonin are a factor in how they perceive their relationships.
EVALUATION:
STRENGTHS:
- High construct validity: The study is based on the experimental method, demonstrating a causal relationship between levels of serotonin (the IV) and ratings of relationship intimacy (the DV)
Weaknesses:
- low ecological validity: Rating the emotional intimacy of couples in photographs is not something that people would ordinarily do.
- low population validity: small scale study which was conducted in one culture (the UK). (The findings should be replicated on a larger scale, with different samples)
Describe the study done by Fisher, Aron and Brown.
AIM: To investigate neural mechanisms of romantic love.
PARTICIPANTS:
- 17 “intensely in love” participants
- mean age of 21
- duration of being inlove = 7 months
METHOD:
- experiment
- repeated measures
PROCEDURE:
- all participants have been put into an fMRI scanner,
- every participant underwent 4 scans,
- each scan was repeated 6 times.
1) viewing a photograph of a person they love (30 seconds)
2) filler activity (40 seconds)
3) viewing a photograph of an emotionally neutral acquitance (30 seconds)
4) filler activity (20 seconds)
- brain responses to the picture of a loved one and to the picture of a neutral aquitence were compared.
RESULTS:
- there was a specific pattern of activation in the brain in response to the photographs of the loved ones.
- activation was especially prominent in dopamine-rich brain areas.
EVALUATION:
STRENGTHS:
- high construct validity (highly controlled)
WEAKNESSESS:
- small sample size (17 people)
- low ecological validity (unnatural situation)
- low population validity (around the same age, same place)
- low internal validity (confounding variables such as negative associations with relationship)
Explain one example of localization of function in the brain.
Outline how one study demonstrates localization of function in the brain.
Using one or more examples, explain localization of function.
Localization: phenomena stating that every behaviour is associated and controlled within a specific brain area.
Strict localization: the idea that functions of the brain can be mapped to certain parts of the brain.
Studies to use:
For: Brockas Aphasia, Wernikes Aphasia
Against: Karl Lashley
What is the frontal lobe responsible for?
Reasoning, planning, thinking and decision making.
What is the parietal lobe responsible for?
movement, orientation, recognition
What is the occipital responsible for?
visual processing
What is the temporal responsible for?
auditory information, memory and speech
