1. What’s your pleasure? Olds and Milner (1954)
Matt Jarvis
Hodder & Stoughton © 2016

2. Positive reinforcement produced by electrical stimulation (Olds and Milner, 1954)
Generalisability
This is probably the biggest issue with the Olds & Milner study. For obvious ethical reasons the study was conducted on non-human participants, in this case rats. There is however a serious question as to whether the structure and function of human and rat brains are sufficiently similar for Olds and Milner’s findings to generalise to humans.
Hodder & Stoughton © 2016

3. Positive reinforcement produced by electrical stimulation (Olds and Milner, 1954)
Reliability and validity of procedures
Because all members of a species share a common brain structure, and because it was possible to repeat the same stimulation procedure in each participant rat, the reliability of Olds and Milner’s procedure is good. However, the use of electrical stimulation of the brain is quite different to the kind of experiences that give rise to pleasure in everyday life (presumably for both humans and rats). This means that there is a question over the validity of the procedure. The repetitive lever pressing used as the outcome measure is simply a measure of reinforcement and may also lack validity as a measure of pleasure — it is impossible to know whether the rats experienced subjective pleasure in the way we do when something nice happens.
Hodder & Stoughton © 2016

4. Positive reinforcement produced by electrical stimulation (Olds and Milner, 1954)
Replicability
A gold standard for a good scientific study is that it can be replicated, and that independent replications produce similar findings. The Olds and Milner study has been replicated many times, and we now know a lot about the strength of the pleasure-seeking tendency. Wise (2002) found that rats were so motivated to seek pleasure through electrical stimulation that they would press a lever thousands of times and were willing to starve rather than stop doing so.
Hodder & Stoughton © 2016

5. Positive reinforcement produced by electrical stimulation (Olds and Milner, 1954)
Biological reductionism
The central idea underlying the Olds and Milner study is that the experience of pleasure can be understood in terms of activation of key areas of the brain. All scientific research is reductionist in that it focuses on one aspect of a phenomenon. However, in this case reductionism is a criticism of the study. Pleasure — at least in humans — is a complex experience involving cognitive, emotional and social aspects. It may be too reductionist to look at pleasure in terms of biology alone.
Hodder & Stoughton © 2016

6. Positive reinforcement produced by electrical stimulation (Olds and Milner, 1954)
Practical applications
The Olds and Milner studies have been used to explain the phenomenon of addiction in humans. The idea is that behaviours ranging from drug taking to internet searching involve the repetitive stimulation of neural pathways. The technique of brain stimulation is also used in humans to treat a range of conditions ranging from Parkinson’s to chronic pain and depression.
Hodder & Stoughton © 2016