Topic 3 Bio - Classical & Contemporary studies

Question 1

What is a classical study for topic 3 bio?

Answer 1

Raine et al (1997)

Question 2

What is the aim for Raine et al (1997) study?

Answer 2

• Use brain scanning technology to identify brain differences between murderers who pleaded not guilty by reason of insanity (NGRI) & a control group of non-murderers

Question 3

What is the procedure for Raine et al (1997) study?

Answer 3

• 41 murderers (NGRI) - 39 males & 2 females
• Murderers matched to non murderers (control group) on sex, age & ethnicity -> 6 non murderers were schizophrenic
• Each Pp did a PET scan -> completed a practice task then a visual task -> increasing brain activity for 32 min

Question 4

What are the findings for Raine et al (1997) study?

Answer 4

• Murderers less activity in the Prefrontal Cortex compared to non-murderers
• Murderers high activity in the occipital lobe
• Murderers lower control in subcortical regions than the control group (corpus callosum, left amygdala, left medial temporal lobe, hippocampus)
• Murderers high activity in right amygdala, right medial temporal lobe & right thalamus

Question 5

What is the conclusion for Raine et al (1997) study?

Answer 5

Murderers (NGRI) have different brain activity compared to non-murderers -> murderers had abnormal activity in areas of the brain involved with violent behaviour (lack of fear, lack of self control & high aggression)

Question 6

What is a contemporary study for Bio?

Answer 6

Li et al. (2013)

Question 7

What is the aim of Li et al (2013)?

Answer 7

• To find the role of the Posterior Cingulate Cortex (PCC) in heroin addiction
• To see if the PCC is activated more in heroin addicts compared to healthy controls -> if so, sign of brain dysfunction in addiction

Question 8

What is the procedure of Li et al (2013)?

Answer 8

• Repeated Measures Design - Lab exp
• Compared 2 groups -> all participants smoked
  Exp group: 14 male heroin users
  Control group: 15 male healthy
• All participants underwent:
  Scan 1: Structural MRI scan to identify standard anatomical areas
  Scan 2: Resting state fMRI scan performed - it was taken as participant fixated their gaze in the centre of the screen - 5 min
  Scan 3: cue reactivity trial involved another fMRI scan to test cue-reactivity. Heroin related & neutral images shown -> each image shown for 2 seconds with a gap of 4-12 sec
  Before & after cue activity run.
  Self report from 0-10 to assess craving.

Question 9

What are the findings for Li et al. (2013)?

Answer 9

• Heroin users had higher subjective craving scores than control group after (but not before) cue induced craving
• Interactions between PCC & dorsal striatum & insula associated with heroin dependence
• These areas involved in addiction, dysfunction of organisation is an adaptation of long term heroin use.

Question 10

What are the findings for Li et al. (2013)?

Answer 10

• Heroin users had higher subjective craving scores than control group after (but not before) cue induced craving
• Interactions between PCC & dorsal striatum & insula associated with heroin dependence
• These areas involved in addiction, dysfunction of organisation is an adaptation of long term heroin use.

Question 11

What are the strengths?

Answer 11

Standardisation:

• Highly controlled procedure -> each pp saw same heroin-related & neutral images -> all shown for 2 sec
• fMRI scan same procedure -> resting-state scan took 5 min to complete - identical for all pps
• Highly scientific - Replicated -> Reliable - controlled confounding variables -> high internal validity

Confounding Variables:

• Nicotine may influenced study -> all pps were smokers
• Ignore potential interaction between heroin & nicotine -> occuring in exp group
• EVIDENCE heroin & nicotine reacting -> (Kohut. 2017)

Ethics: Approved by ethics committee

Question 12

What are the Weaknesses for Li et al (2013)?

Answer 12

Confounding Variables:

• Nicotine may influenced study -> all pps were smokers
• Ignore potential interaction between heroin & nicotine -> occuring in exp group
• EVIDENCE heroin & nicotine reacting -> (Kohut. 2017)

Sample: Small sample - only males
- can’t be generalised to population -> possibility of making Type I statistical error, e.g. finding a significant result when none existed -> unreliable results

Ethics:
Pps weren’t checked after study -> went home after treatments