Unit 3: Health psychology – substance

misuse

The use of humans in drug research

The specification requires that you can:

‘Describe and evaluate two research methods using humans to study the effects of drugs’

…and that you can: ‘Evaluate, including relative strengths

and weaknesses, research methods using humans (including issues of reliability and validity)

This unit is synoptic, which means that you may be asked to describe and evaluate, drawing on other methods within the application and the five approaches studied at AS level

Therefore, the LOs for this session are:

1. Explain how humans are used in research into the effects of drugs (two methods)

2. Describe the features of an interview as a research method for investigating the effects of drugs, using Blattler’s study as an example, and identify relevant evaluation* points for this method

3. Describe the findings of Scott’s study (PET scanning) and identify relevant evaluation* points

These can be structured, semi-structured or unstructured …

They usually collect qualitative data, but sometimes a combination of both is gathered

The type of data which the researcher wants to gather will determine the type of questions asked – they can be closed or open-ended questions (or a combination of both)

Qualitative data is concerned with attitudes, opinions and comment; quantitative data involves numbers (scores, percentages, scales)

Recap Interviews …

Interviews …

Data is likely to be valid because interviews are in-depth, so different issues can be explored; also, participants can use their own wording

Interviews enable researchers to access participants thoughts and/or feelings•

Interviews …

Participant responses may be influenced by the characteristics/appearance of the interviewer, which would impact on reliability

Analysis of data can be subjective; generally, themes are used, which are generated from the researcher; these may be informed by preconceived ideas

As with any self-report method of research, participants may lie/exaggerate when responding

These are used to provide researchers with a picture of what happens in the brain when people take drugs

A radioactive tracer is mixed with a glucose solution and injected

Glucose is taken up by the body and the tracer travels along with it

The progress of the tracer, which provides small positively charged positrons, allows researchers to identify areas of the brain which are activated by different substances

RECAP: Positron emission tomography (PET) scans …

This study used PET scanning to investigate the effects of nicotine on the brain.

Nicotine stimulates the brain to produce OPIOIDS- this increases positive emotions and reduces pain (like Heroin)

PET scans are able to show opioid receptor activity in the brain Ppts were 6 healthy male smokers who did not smoke for 10 hours

prior to the scan. The participants first smoked a low-nicotine cigarette and then a

‘normal’ one, while in a PET scanner. The scan picked up differences in opioid flow between the 2

conditions. Ppts were also asked to describe how they felt. Findings showed that after the ‘normal’ cigarette there was increased

opioid activity in the brain; that participants said they had less cravings, they felt more relaxed and less alert.

The scan showed that brain regions for memory, emotion and pleasure were less active. Thus the scan and self report findings match.

These findings suggest that nicotine binds to opioid receptors in the same way that morphine and heroin do

Scott et al (2004) page 119 Brain

It is high in validity – scan pictures show a live brain actively processing substances

The same participants were used in both conditions (repeated measures), so this minimises the chance of participant variables affecting the results

The study took place in unfamiliar surroundings, which may have affected the findings

The task may have been unnatural – the brand of cigarette smoked in the study may not have been the same as the participant’s usual brand

Both of these issues may have implications for the validity of the findings

Scott et al (2004) - evaluation

Evaluation of PET scanning …

It is considered to be quite ethical, compared to methods such as lesioning, never the less a radio active substance is being injected into the body

It is reliable - easy to replicate and the same results would be expected if the scan were to be repeated

Evaluation of PET scanning …

Although more ethical than other methods, it may still be distressing for participants to have an radioactive tracer injected

It can be difficult to pinpoint an exact area of the brain, so findings can be limited; pictures are of large areas of the brain, but the area affected may be very small