neural and hormonal

Question 1

what are the neural mechanism for the explanation of aggression

Answer 1

serotonin
agression
limbic system

Question 2

what is the limbic system

Answer 2

• the limbic system is a set of neural structures located in the brain and it consiss of the
  amydala
  hypothalmus
  hippocampus

Question 3

what is serotonin

Answer 3

• an inhibitory neurotransmiter reducing neural activity that is important in controlling /calming agressive impulses
  serotonin the orbito frontal cortex controls /dampen aggressive impulses coming from areas in the limbic system lie the amygdala, maintaning a stable calm mood

Question 4

what is testosterone

Answer 4

androgen (male sex hormone)
found in high levels in males and thought to resposnsible for increased agression n x8 higher in men than females

• excessive levels of testosterone in the of reduces the activity in the ofc meaning it is less able to regulate aggressive impulses from the limbic system, eg from the amgydala with reduced executive function the individual is more prone to emotional aggessive outburts

high levels of this also increases the activity of the amygdala resulting in more aggressive impulses

high levels of testosterone can reduce the activity of serotonin limiting its ability to calm aggressive impulses

Question 5

what is the role of the limbic system

Answer 5

• collection of structures in the brain and its role is too process emotion responses such as aggression

Question 6

what is the role of the amygdala

Answer 6

• has been identified as being linked to the production of agressive behaviours
  (Gospic) FMRIS shows increased activity during aggressive responses

Question 7

what is the role of the hypothalmus

Answer 7

• intergrating and expressing emotional responses it can trigger aggressive behaviour as part of the fight or flight resposne

Question 8

where is the limbic system located and why is this important

Answer 8

the limbic system communicate with the orbito frontal cortex (external layer of the brain) which controls executive function such as decision making which attempts to control agression produced by the limbic system

Question 9

evaluation of the limbic system

Answer 9

• egger and flynn (1963) demonstrated that electrically stimulating an area of the hypothalmus would cause cats to show aggression towards a rat. They also showed that stimulating different parts of the amygdala would either increase or suppress aggressive behaviour
  this suggests the hypothalmus has a role in producing agressive behvauour and ifferent areas of the amygdala have separate toles in regulating aggression , study conducted on ats unable to to generalise

Question 10

evaluating limbic system human example

Answer 10

sumer (2007) conducted a case study on a 14 yr old that showed extreme aggressive behaviours and epiletpic fits
mri san revealed tumor pressing on her amygdala
after removal of the tumor her aggression levels became normal
this suggests that the tumor was stimulating the amygdala which casued agressive behaviour - supporting the theory that the amgydala is linked to agression

• case study possible other factors beyond the tumor unable to generalise
  eg the fact she suffered from fits

Question 11

what is the serotonin deficiency hypothesis

Answer 11

suggests lower than normal levels of serotonin in the ofc results in less self control over the limbic system aggressive impulses
this is show by lower levels of 5-HIAA biproduct of serotonin breakdown in the spinal fluid of more aggressive people suggesting people w aggression have lower levels of serotonin the the brain

Question 12

serotonin evaluations

Answer 12

• passamonti (2012) tryptophan inn food is needed by the body to produce serotonin.

this study used a technique called acute tryotophan depletion which meant avoiding foods which had tryptophan in it

researhers measured the brain using an fmri in response to seeing angry faes

the results showed redued commication between the orbitofrontal cortex and the amgydala
pps also scored highly on a aggression questionnare
this demonstrates that a lack of serotonin reduces the ability for the orbito frontal cortex to reduce aggressive impulses from the amygdala

study was double blind placebo , randomised the use of such careful scientific measurements suggests these findings have high internal validity
however the use of a questionnare could be seen as not truly measuring aggression levels

Question 13

testosterone evals

Answer 13

• Wagner (1980) measured aggression inby how often they bit a target it was found that males bit more frequently than females however this sex difference disappeared after castration and dropped to the same level of female mice
  the sex difference in biting frequency was also restored when the mice were injected with testosterone. Injections of testosterone into females also increased the female mie bite frequency this suggets that the level of the hormone testosterone in ie is directly linked to to the expression of aggressive behaviour

Question 14

general evalutions

Answer 14

biological explanations for aggression have socially sensitive implications or the people it studies.
self fufilling prophecy - if this is their biological make up they might act to align with it
if aggressive criminality is found to be linked to limbic abormalities and predicitve of vulnerability of commiting a crime this could lead to suspicion and discrimation towards people even before they have committed a crime

biologically reductionist - neural mechanisms could be just a predisposition whilst whether the person acts on that is determined by other factors such as psychological factors - slt