WANG ET AL (2005)- using FMRI's to measure stress

Question 1

What was the aim of Wang et al (2005) study?

Answer 1

• To investigate whether FMRI’s could accuratley measure cerberal blood flow changes in response to mild to moderate stress.

Question 2

What methods were used in Wang et al (2005) study?

Answer 2

• Design- lab experiment
• Method- used arterial spin labelling (ASL)
• Experimental task- complete a arithemtic stressful task whilst undergoing a FMRI scan
• Comparison- brain activity during rest vs during stress
• Controls- the procedure took place between 3 and 5pom to control for any cortisol fluctuation throughout the day/ objective measures

Question 3

Describe the sample?

Answer 3

• 32 american ppts
• 23- in the experimental group
• 7 - in the control group
• Average age (23)

Question 4

Summarise the procedure?

Answer 4

• MRI’S: ppts were given four 8 minute MRI’s. (first and last for baseline tests/ second and third during the tasks)
• (high-stress condition)- asked to do a mental arithmetic task (subtract 13 from a 4 digit number) awnsering aloud, restarting if any errors were made, gven prompts to speed up.
• (low stress condition)- asked to count backwards from 1000 to control for autitory and verbal activation
• Data collection- self-report measures for stress and anxiety on a 1-9 scale, saliva samples, heart rate.
• Control group- asked to do no tasks but same data was collected from them

Question 5

What were the results of Wang et al (2005) study?

Answer 5

• found increased cerebral blood flow (CBF) in the ventral right prefrontal cortex (RPFC) during stress.
• RPFC- linked to sadness, fear, increased vigilence
• Positive correlation between cerebal blood flow in the RPFC and subjective ratings of stress

Question 6

What was the conclusion of Wang et al (2005) study?

Answer 6

It is possible to use FMRI scans to monitor the effects of stress on brain blood flow.

Question 7

Name 1 strength and 1 weakness of the study?

Answer 7

Strength- FMRI’s provides real-time, measurable data on brain activity, reduces researcher bias and mitigates the subjectivity of the self-report methods.
Weakness- low ecological validity- the artifical setting of the lab and being inside a scanner may cause unnatural stress that may not occur in real-life settings