Contemporary study: Li et al Flashcards
Aim
Investigate the involvent of the posterior cingulate cortex in heroin dependence.
Aim to show the PCC is activated in a task that involves drug related cues
Procedure
What measures design was used
repeated measures
Procedure
sample size
29 total
14 experimental group
15 control group
Procedure
Describe features of participants in experimental group
Heroin-free
previously used heroin for 19-182 months
35 mean age
Procedure
Describe features of participants in control group
No history of drug dependence, head injury or psychiatric disorder
Participants in both groups smoked
Procedure
IV and DV
IV - Experimental group vs control group
DV - 1 dv was self reported measured of subjective craving
Procedure
What scanning technique was used and how many scans took place
fMRI scans
3 scans
Procedure
Describe scan 1
Each participant had a structural MRI scan to identify standard anatomical areas
Procedure
describe scan 2
fMRI scan took of participants resting state, fixing on a dot at the center of the screen.
Lasted 5 minutes
Procedure
Describe scan 3
2nd fMRI scan 490 seconds long.
48 images were shown, 24 relating to heroin (like syringe needles) 24 neutral.
Each image showed for 2 seconds in random order
Self reported craving scores 0-10 taken.
FIndings
Craving score findings
heroin user = higher subjective craving scores than control group.
avarage scores rose from 2.23 to 3.21
FIndings
findings of brain activation in cue induced tasks
researchers found heroin users had stronger functional connectivity between the Posterior Cingulate Cortex and insula, and between PCC and dorsal striatum
Conclusion
Findings show drug-related cues are powerful predictors of reward for heroin adicts, and that the PCC is linked to neural circuts invoved in drug cravings
Strength of study (reliability)
What is a strength of the study
It has a high degree of standardised instructions
Strength of study (reliability)
Evidence of this high degree of standardised instruction
All participants recieved the same heroin related and neutral images for the same amount of length (2 seconds)
Strength of study (reliability)
What do these standardised instructions mean for the study
The study had high reliability and could be easily replicable
Competing arguement of standardised instructions
What is a competing arguement for the standardised instructions
Some of the procedure was inadequate
Competing arguement of standardised instructions
Example of inadequate procedure
sample size was too small, only 14 heroin users participated
Competing arguement of standardised instructions
What does the low sample size mean
The chances of making Type 1 statistical errors increased, therefore differences in brain activity between the groups may not of been true
Weakness of study
What is a weakness of the study
The influence of nicotine could have been a potential confounding variable
Weakness of study
How can the use of nicotine been a confounding variable
Kohut 2017 found evidence that nicotine and heroin interact biochemically, this interaction could have potentially impacted the results of the experimental group
Strength of study (validity)
What is a strength of the study
Researchers created tight controls for the study
Strength of study (validity)
evidence of tight controls in the study
The control group was required to have no history of drug dependence and all participants couldn’t have any head trauma or psychological illness’
Strength of study (validity)
What do these tight controls mean for the study
Reduced possibility of confounding variables impacting the study, therefore greater internal validity
