Biological Approach

Question 1

1. Techniques used to study the brain
2. Neuroplasticity
3. Neural networks
4. Neural pruning

Answer 1

Maguire et al.
A - Investigate difference in brain structure of London taxi drivers & the average brain
S - 16 right-handed male taxi drivers. Average experience of 14.3 years. Control group: 50 healthy right-handed male subjects who don’t drive a taxi
T - Quasi experiment; correlational study (driving experience/grey matter volume)
P - MRI scans compared b/w drivers & non-drivers. Correlated the results.
R - Taxi drivers had increased grey matter vol in posterior hippocampus compared to control. Control had increased grey matter vol in anterior hippocampus. Positive correlation observed for PH, negative correlation for AH.
C - Redistribution of grey matter occured in hippocampus of taxi drivers, from AH to PH.

Question 2

1. Neurotransmitters
2. Agonist/antagonist effect on neurotransmitter
3. Excitatory/inhibitory neurons

Answer 2

Crockett et al.
A - Investigate effect of serotonin on prosocial behaviour
S - 30 healthy volunteers
T - Experiment; repeated measures design; double-blind study
P - In cond 1, participants given dose of citalopram (SSRI). In cond 2, participtants given placebo. Trolley problem presented. 2 scenarios: impersonal (interfering & killing 1 person instead of 5), personal (interfering & pushing a man on the tracks to slow down trolley). Death of 1 person inevitable.
R - participant responses unaffected by citalopram in impersonal scenario. In personal, citalopram made participants less likely to interfere.
C - citalopram reduces acceptability of personal harm & promotes prosocial behaviour. Increased levels of serotonin may have resulted in people being more opposed to idea of inflicting harm

Question 3

Localization

Answer 3

Gazzaniga & Sperry
A - Investigate how 2 hemispheres function independently when correlation b/w them is severed.
S - 4 patients who underwent novel epilepsy treatment (involving cutting the corpus callosum)
T - in-depth case study
P - showed visual stimuli to either far left/right for 1/10 seconds. Optic nerves from right eye connected to left hemisphere, allowed researchers to present stimuli to a single hemisphere. Sensual stimuli also offered.
R - (1) when pic of spoon shown to left eye, no response from participants. Still capable of picking up a spoon with left hand - language production localized in left hemisphere. (2) pencil flashed to right hem, participants able to pick out object - right hem capable of simple speech. (3) 4 plastic letters in a pile behind a curtain, participant able to spell love but not name thw word.
C - Localization of language is not strict. Both language production & comprehension mostly located in left hem. Right hem can perform simple tasks.

Question 4

Hormones

Answer 4

Scheele et al
A - Investigate role of oxytocin in promoting fidelity in humans
S - 86 heterosexual men, some single some in stable relationship
T - experiment; independent measures design, double blind study
P - either oxytocin/placebo administered intranasally. task 1, stop distance paradigm (participant stood at one end of room, attractive female confederate stood opposite. instructed to slowly approach female & stop at distance that makes them uncomfy.
Task 2, approach/avoidance task (positioned in front of screen, shown 4 stimuli pics - positive social pics, positive non-social pics, negative spcial pics, negative non-social pics), if participant liked pic, pull the joystick, increasing pic size.
R - first task showed that oxytocin caused men to keep greater distance but only if in a stable relationship. second task showed that only group of pics affected by oxytocin & relationship status was positive social grp.
C - oxytocin causes men in a relationship to keep greater distance from attractive women - promoting fidelity. this effect of oxytocin is highly specific & selective to a specific stimuli: attractive women

Question 5

Pheromones

Answer 5

Lundstrom & Olsson
A - Investigate effect of androstadienone on the mood of women in presence of men.
S - 37 heterosexual women, mean age 25, with normal menstrual cycle.
T - experiment, 2 x 2 experimental design
P - Female participant’s mood studied in a 2 x 2 design. Assessed after being exposed to androstandienone or control, in presence of either male (age 30) or female (age 28) experimenter. Multiple questionnaires carried out - one measuring mood.
R - Androstandienone increased women’s mood in presence of male experimenter, but not female.
C - Androstandienone may serve function of signalling sexual attractiveness, supporting its role as a pheromone.

Question 6

Genes
Genetic similarities
Twin & Kinship studies

Answer 6

Bouchard & McGue
A - Investigate estimate of heritability of IQ.
S - 111 twin studies that looked into heratability of intelligence. Included MZ and DZ twins (reared together & apart), siblings (reared together & apart), parents & their offspring
T - meta-analysis
P - Researchers selected studies based on number of criteria, cleaned the data & calculated median correlations b/w IQ scores
R - Heratability coefficients estimated using Falconer model. 54%.
C - Intelligence inheritable to an extent. No perfect heritability though, even for MZ twins - shows that environment plays a role.

Question 7

Evolutionary explanation

Answer 7

Curtis, Aunger & Rabie
A - If disgust is a product of evolution: disgust should be stronger in response to stimuli associated with disease; disgust responses should be similar cross-culturally; disgust should be more pronounced in females (protective mechanism); disgust should become weaker with age (reproductive potential declines)
S - survey of 77000 people from 165 countries
T - correlational study
P - Participants asked series of demographic questions (age & country of origin). Asked to rate 20 pics for disgust from 1 to 5. Pics were similar pairs of digitally manipulated stimuli - one of the pics in pair was disease-salient & other was less salient
R - Ratings of disease-salient stimuli higher than less salient. Results consistent across cultures. More pronounced in sub-sample of females. Ratings declined with age.
C - Supported evolutionary explanation of disgust - biologically based responsese to disease-salient stimuli, reducing risk of disease.