ENVIRONMENTS & BRAIN DEVELOPMENT

AIM:

environments & brain development

RESEARCH METHODS:

- true experiment
- justified animal experiment

PROCEDURE:

rats placed in different cages for 30-60 days
male rats chosen from different litters (control of gender & genetics)
randomly allocated 2 conditions:
1. enriched condition - 10-12 rats with a variety of toys (inc. maze training)
2. deprived condition = alone in a cage with no toys and just food/water
post mortem analysis was conducted after euthanising the rats

RESULTS:

EC rats developed heavier, thicker brain cortex (7-10% heavier, 20% more
synapses)
EC rats’ frontal lobes were heavier and had more acetylcholine receptors
experiment was ran multiple times and showed the same results

CONCLUSION:

childhood environments can affect brain development
this experiment could support the results from natural experiments on
children suffering from neglect (e.g Perry and Pollard 1997)

CHILDHOOD MALTREATMENT

AIM:

investigate the neurobiological impact in childhood maltreatment

PROCEDURE:

case studies 1
two groups of participants from london
20 kids who had been exposed to family violence
control group of 23 kids w/ no exposure to family violence
fMRI scans
kids were shown a series of pairs of faces : angry (threatening), sad (non-
threatening) and neutral

RESULTS:

atypical stress response hypothalamic pituitary adrenal (HPA) axis
associated to childhood maltreatment
mixed findings in children: some show elevated cortisol (regulates stress
responses), others show suppression
adults with maltreatment history show increased stress response if they
have depression, and reduced cortisol level if they have ptsd

CONCLUSIONS:

the violence exposure group had higher activation in their right amygdala
when angry faces, but not sad faces, were shown together with neutral
faces
this shows they are more responsive to threats specifically (not just any
faces)
violence creates a neurological risk factor for a hyper responsive amygdala
evidence that early stress links to atypical HPA functioning

MRI & CRIMINAL BRAINS

AIM:

understand brain abnormalities and the role they may have in committing
crimes from violent offenders to non-violent antisocial individuals

PROCEDURE/METHODS:

.

RESULTS:

case studies 2
murderers have reduced grey matter in their pfcs
vmpfc - controlled emotions and decision making
dorsolateral pfc - controlling our behaviour

CONCLUSIONS:

patterns indicate impairment across a range of emotions in cognitive
systems
these together reduce essential checks and balances in executive function,
moral judgement and behavioural controls
reduced grey matter in murderers may have affected their ability to control
emotions, decision-making, moral judgement, etc

TESTOSTERONE IN MASCULINE BEHAVIOURS

AIM:

testosterone in masculine behaviours

METHODS/PROCEDURES AND RESULTS:

group
1
normal roosters as
control group

METHODS/PROCEDURES AND RESULTS:

group :
2.

condition :
castrated (testes
removed) roosters

results :
reduced comb and wattle size; loss of
masculine behaviours (crowing,
aggression, sexual behaviour)

METHODS/PROCEDURES AND RESULTS:

group
3.

condition :
testes removed and
reimplanted

results :
normal comb and wattle size; restoration of
masculine behaviours

METHODS/PROCEDURES AND RESULTS:

group :
4.

condition :
testes removed and
transplanted into other
roosters

results :
normal comb and wattle size; restoration of
masculine behaviours

CONCLUSION:

testisticular secretions are necessary for the normal expression of
aggressive behaviour
testes produce a substance (later identified as testosterone) that is
necessary for the development of masculine characteristics and behaviour
this substance acts through the bloodstream, affecting distant target organs

TESTOSTERONE UNDER CONDITIONS

AIM:

testosterone under conditions

PROCEDURE:

researchers asked a group of men to play w/ a gun or toy for 15 minutes
they then gave them a cup of water they thought they were going to give to
another person
they could put as much hot sauce in the water as they wanted

RESULTS:

the gun group had a bigger increase in testosterone
they also added more hot sauce to the water
data analysis showed the increase in testosterone was the reason they
added more hot sauce

SENSE OF BELONGING

AIM:

investigate the effect of discrimination on acculturative stress

STUDY TYPE:

correlational

PARTICIPANTS:

889 latinos (mexican, chicano, cuban, etc)
around half born outside US, half born in the US

PROCEDURE:

questionnaires
measured by :
- perceived discrimination
case studies 4
- acculturative distress
- psychological distress

RESULTS:

discrimination had less of an effect on the integrated latinos as they had
lower levels of acculturative and psychological distress
integration into mainstream culture was measured by their use of english
language

TESTOSTERONE AND AMYGDALA

AIM:

investigated the relationship between perceiving a social threat,
testosterone, and the amygdala

METHODS/PROCEDURES:

54 healthy female participants were given either testosterone or a placebo
(they held the solution under their tongue for 60s before swallowing it)
fmri scanned their brains as they viewed angry or happy faces
asked to approach (make larger) or avoid (make smaller) the faces using a
joystick to move

RESULTS:

testosterone group had the highest amygdala activation when approaching
the angry faces
the testosterone administration increases amygdala responses in healthy
women during threat approach and decreases it during threat avoidance

CONCLUSIONS:

testosterone biases the amygdala toward social threat approach

TESTOSTERONE IN CRIMINALS

AIM:

investigate whether violent crimes were linked to testosterone levels

METHODOLOGY:

single sample measurement of free testosterone in saliva of 89 male prison
inmates

RESULTS:

inmates w/ higher free testosterone were found to be more likely to be
convicted of violent crimes
those w/ higher levels of testosterone received longer punishments

CONCLUSION:

higher testosterone levels = higher aggression levels

TESTOSTERONE AND AGGRESSION

AIM:

the affect of testosterone on aggression with rats

METHODOLOGY:

identified the alpha rats (strongest/largest)
split into 4 groups: 1. castration 2. castration, implanting testosterone
tubes 3. castration, implanting empty tubes 4. “sham” castration,
implanting empty tubes (no castration)

RESULTS:

group 1 & 3 showed less aggressive behaviours, group 2 & 4 continued to
display same level of aggression. when rats from 1 or 3 were put with 2 and
4, 2 and 4 took the alpha role

CONCLUSION:

testosterone increases dominance and aggression

CONFORMITY

AIM:

to investigate the extent to which social pressure from a majority group
could influence a person to conform

METHOD/PROCEDURE:

50 American male college students took a vision test : match the length of a
line to 3 comparison lines.
1 real participant seated amongst 6 - 7 actors who gave wrong answers on
certain trials
18 trials in total → actors gave incorrect answers on 12 “critical trials”
control: a group of participants answered without actors to measure the
baseline accuracy

RESULTS:

about 75% conformed at least once to the wrong majority
on avg, participants conformed to the incorrect answer about 37% of the
time on critical trials
in the control group (no actors), error rate was less than 1%

CONCLUSION:

demonstrated the power of normative social influence (conforming to be
accepted by a group)
people often conform to the majority, even when the answer is clearly
wrong

RELEVANCY:

supports conformity research in the sociocultural approach and
demonstrates normative social influence which is useful for discussing
culture, ethics and methodology in evaluating research.

COMPLIANCE AND OBEDIENCE

AIM:

case studies 7
investigate the extent to which ordinary people would obey an authority
figure when instructed to perform actions conflicting with their personal
conscience

METHOD/PROCEDURE:

RESULTS:

100% of participants went up to at least 300 volts
65% obeyed fully, delivering the maximum 450 volts despite apparent
distress
participants showed visible tension: sweating, trembling, nervous laughter

CONCLUSION:

ordinary people are likely to follow orders from authority figures, even when
it results in harming others
obedience is strongly influenced by situational factors (authority, setting,
perceived legitimacy)
demonstrates the power of authority in shaping behaviour

RELEVANCY:

supports research into obedience and authority (sociocultural approach);
useful when evaluating ethics in psychological research
shows importance of situational over dispositional factors in explaining
behaviour