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Date May 2019 Marks available 2 Reference code 19M.3.HL.TZ1.4
Level Higher level Paper Paper 3 Time zone Time zone 1
Command term Outline Question number 4 Adapted from N/A

Question

To investigate the effects of the drug MDMA (ecstasy) on impulsive behaviour, investigators carried out a test on former users, current users and those who had never taken the drug. Impulsive behaviours were defined by the researchers as those done quickly, without fully considering the consequences. The participants in the study were asked which of the images (1 to 6) was identical to the original image on the left.

The time and accuracy of their responses were recorded. The results are based on 15 participants per group.

[Source: National Institute on Drug Abuse; National Institutes of Health; U.S. Department of Health and Human Services]

Calculate the difference in the number of former users of MDMA and those who have never used the drug making an error before a correct response.

[1]
a.

Outline the evidence that MDMA leads to impulsive behaviour.

[2]
b.

Explain the effect MDMA has on the metabolism in the brain. 

[3]
c.

Markscheme

6

a.

a. MDMA «former» users made quicker responses AND made more errors than those who never used drugs ✔

b. quick responses with errors suggest impulsive behaviour ✔

c. possible impulsive behaviour was reason for taking drug rather than a consequence
OR
drug users could always have shown impulsive behaviour
OR
study shows correlation, not causation ✔

b.

a. MDMA increases the release of serotonin ✔

b. occurs in synapses of brain cells ✔

c. MDMA binds to serotonin transporters so MDMA not removed from synapse ✔

d. MDMA also causes increased dopamine/norepinephrine secretion ✔

e. these neurotransmitters influence our mood/cause euphoria
OR
may lead to memory problems ✔

c.

Examiners report

This may have been the most successfully answered question on paper 3, and almost all candidates achieved this mark.

a.

While many students did achieve at least 1 mark here, few connected the data with impulsive behavior. In addition, this question showed that students still need guidance on how to make sure their writing is clear. Many lost a mark because they were unable to express that they were looking at number of errors and time taken to give an answer.

b.

This question was not answered well. Few candidates addressed synaptic transmission as the key element when explaining an effect on brain metabolism. Very few students achieved full marks on this question.

c.

Syllabus sections

Option A: Neurobiology and behaviour » Option A: Neurobiology and behaviour (Additional higher level topics) » A.4 Innate and learned behaviour
Option A: Neurobiology and behaviour » Option A: Neurobiology and behaviour (Additional higher level topics)
Option A: Neurobiology and behaviour

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