NOT ON ALEVEL 8.3.1 olds and milner classic study

Question 1

what was the title of the health classic study

Answer 1

positive reinforcement of septal area and other regions of rat brain

Question 2

what was the aim of the health classic study

Answer 2

to investigate the pain and pleasure centres of a rat’s brain and see if over time, if they choose to self-stimulate. also to investigate whether electrical self-stimulation of the brain acts as a reward, a punishment or a neutral stimulus

Question 3

what was the procedure of the health classic study

Answer 3

participants : 15 hooded male rats, each with electrodes surgically inserted in the brain. the electrodes did not interfere with normal behaviours, each rat was placed in a skinner’s type box

method: the skinner’s box, when lever was pressed, delivered an alternating with electrical current to the brain
the box was live for 6-12 hours (acquisition time) and off for 1-2 hours (rest-time and test of extinction: to see if rat would keep pressing lever with no reward)
the time (%) the rat spent receiving the shock during acquisition time was measured

Question 4

what was the results of the health classic study

Answer 4

rats spent 75% of the time pressing the lever whilst it was live (acquisition time) and during this time their brain was being stimulated. rats only spent 25% of their extinction time pressing the lever suggesting that stimulation or the septal area of the brain acts as a desirable positive reward. comparing to other parts of the brain - if there was no response in some rats it indicated that pressing the lever delivered a punishment

mammillothalamic tract = the one rat stimulated here spent 71% lever pressing during acquisition and only 9% during extinction

rat n34 septal area stimulation lever pressed 7500 x over 12 hours, average of 742 responses per hour (almost 0 during extinction).
rat a-5 (mammillothalamic) gave 1250 response on average per hour, almost a response ever 2 seconds

Question 5

what was the conclusion of the health classic study

Answer 5

stimulation of the septal area of the brain leads to addictive type behaviour, rewarded by self-stimulated pleasure. the rats chose the behaviour solely to get the reward. this experiment was the first to identify the location or the brain’s reward centre.
as stimulation of all the other brain structures they tested had either neutral of punishing effects. this is evidence that the brain also contains punishment centres. they also concluded that their methodology could be used in future studies to clarify the mechanisms of reward and also help choose between competing theories of the effects of the reward on behaviour

Question 6

evaluate the health classic study, olds and milner in terms of generalisability

Answer 6

generalisability : biggest issue with the olds and milner study. as there is serious questions as to whether the structure and function of human and rat brains are sufficiently similar for the findings to generalise to humans as humans are so complex. but it is clear that there are reward centres in the human brain that parallel these in the rat brain, so not fundementally different so research with rats is useful (if treated w caution). also only male rats, not female = lacks generalisability

Question 7

evaluate the reliability, for olds and milner health classic study

Answer 7

reliability= because all rats share a common brain structure and because it was possible to repeat the same stimulation procedure in each ppt fat due to standardised procedure (stating which area was stimulated and the amount of voltages), the reliability is good also their findings were supported and extended by later research. eg olds 1958 reported experiments

Question 8

evaluate the validity of the olds and milner classic health study

Answer 8

the use of electrical stimulation of the brain is quite different to the kind of experiments that give rise to pleasure in everyday life = question over the validity = low ecological validity . the reputable lever pressing used as the outcome measure is simply a measure of reinforcement and may also lack a validity as a measure of pleasure = it is impossible to know whether the rats experienced subjective pleasure

Question 9

evaluate the replicability of the olds and milner classic health study

Answer 9

has been replicated many times and now know about reward pathway. 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 stare rather than stop doing so

Question 10

evaluate the reductionism in the classic health study olds and milner

Answer 10

pleasure = complex experience and may be too reductionist to look at pleasure in terms of bio alone

Question 11

evaluate the application of olds and milner health classic study

Answer 11

used to explain the addiction in humans

the idea is that behaviours ranging from drug taking to internet searching. the technique of brain stimulation is also used in humans to treats a range of conditions ranging from parkinson’s to depression

Question 12

evaluate the ethics of olds and milner classic health study

Answer 12

rats killed afterwards for brain analysis = unethical

but lengthy of time they were tested on was reduced = minimising harm to later rats

rats had food and water and kept in conditions under batesons cube