Individual cases such as Phineas Gage has led to the investigation of such a relationship between brain and behaviour, and our development in technology has allowed techniques to be developed to further try and prove this. Controversially, scientists have purposely damaged selected parts of non-human animal’s brains to see what effect this would have. In this experimental group, a clearly defined part of the brain would be given an experimental lesion and the effect of behaviour observed. A control group of the same sex and age received sham lesions (cutting of skin and anaesthetic to mimic the experimental group) and the results were compared (Toates,2007). Obviously this raises ethical questions but has proven informative about synaptic functions and how the brain can create new neural pathways after such trauma to maintain its function.
It has also helped our understanding that damage to specific regions may not be as important as are the functions of the rest of the brain that is revealed after damage, also illustrating its adaptive capabilities.
In the past few decades there have been major advances and technological breakthroughs for non-invasive techniques in the form of capturing scans and imaging of the human brain. Most notably the Positron Emission Tomography (PET) scan that allows images of brain activity in subjects to be viewed by means of injecting a tracer that will be visible on a scan showing where blood flow is heading within the brain displaying which part is active.
Doing this has enabled researchers to map parts of the brain such as auditory and motor functions while participants perform different tasks; this enables researchers to hypothesise the relationship between brain functions. Medically speaking, this type of scan can benefit physicians to map motor functions before and after a major surgery to fix a defect in the brain. It can also be of benefit in understanding the effect of major trauma by showing parts of the brain with lower activity when compared to a control group; whilst also monitoring any improvement in brain functions after trauma through accident or surgery.
With regards to behaviour it has also been useful in control experiments using violent criminals as participants to see whether there are differences in that of a control group for comparison. It has shown that regions of the brain, notably the frontal lobes that exert control on actions, indeed appear to be underactive in violent criminals therefore affecting their behaviour and impulses (Raine, Buchsbaum and LaCasse as cited in Toates, 2007).
This essay has highlighted what difficulties are faced when using a single case of accidental brain trauma to establish a correlation between physiology and psychological behaviour, but has also shown what can be learned from it. Understanding this kind of brain trauma has encouraged other types of controlled testing to help establish a connection between brain and behaviour. The non-invasive technique of a PET scan would have proved extremely useful in the case of Phineas Gage because even to this day there is debate and conjecture surrounding the accounts and details of the study. However, without such cases occurring it may never have triggered our curiosity to understand and push for the development of modern day techniques that have taken our understanding to new levels. It is certain, though, that debate will still surround the issue of biology explaining our behaviour for some time.
Word Count 1042
References
Macmillan, M.B. (1986) ‘a wonderful journey through skull and brains: The
Travels of Mr Gage’s tamping iron’, Brain and Cognition, vol.5, pp.67–107.
Miell, D., Pheonix, A., Thomas, K., Toates,F. (2002) Mapping Psychology (2nd Edition 2007), Milton Keynes, The Open University.
Raine, A., Buchsbaum, M. and LaCasse, L. (1997) ‘Brain abnormalities in
Murderers indicated by positron emission tomography’, Biological
Psychiatry, vol.42, pp.495–508.
Toates, F. (2001) Biological Psychology: An Integrative Approach, Harlow,
Pearson Educational.
Wall, P.D. (1993) ‘Pain
Figure 1 (Historical Diagram (uncited) obtained from Internet, 2009)
Self-Reflection
I did enjoy this assignment, but because of personal issues I did fall behind on my studies and the first part of the assignment was more rushed than I would have preferred. I am still finding referencing difficult.
Part II
Question 1
- The two variables shown are “Nutritional Rating of Packed Lunch” and “Mean Response Time per Slide in Milliseconds.
- (ii) Negative.
- (iii) Medium.
- (iv) Speed of responding in a distraction task in the afternoon is a fair predictor of the nutritional quality of a child’s packed lunch.
- (i) Positive – There appears to be over +0.9 relatable correlation i.e. as one of the variables increase so does the other.
- If known, the parents may have deviated from their normal pattern of behaviour. Parents who would not normally provide a packed lunch high in nutritional value may have done so for an impression of the norm resulting in all the children participating with similar lunches.
- A very high negative value – this would imply a correlation between the two variables. However this is still not proof of causation. There are also many other factors that may have confounded the results I.e. rates of metabolism, the Hawthorne effect (extra willing to perform better in test environments) and the test itself was out of the children’s normal daily routine. It should also be noted that another set of variables exist in the form of actual correct responses to questions.
- I would expect the negative correlation between the two variables to significantly increase to very strong (-0.8 at least). The two children had a detrimental effect on the means test and the results, because all the other participants showed a negative correlation i.e. as on variable increased the other decrease. Without child 7 and 8 included in the results there is now a very strong positive correlation between nutritional value and a very strong negative correlation between the nutritional value of the lunches and response times.
Question 2
- (iv) the different stages of the experiment
- (v) the time spent reading the narrative during stage 1
- (iv) Between participants because some participants read the blatant change newspaper report and some read the subtle change.
- (ii) The length of time spent on the distraction task and, (iii) the number of inaccurate changes made in the two newspaper reports.
- (ii) Not all the questions asked during stage 3 were relevant to the investigation and, (v) the gender of the participants.
- I would try to make the number of male and female participants equal within each group. I would avoid questions that incur introspective opinion as everybody is different, therefore limiting questions to those that would avoid individual differences. The time of day is important to avoid confounding the results – David’s stage 1 was conducted in the evening and Emily’s stage 1 was conducted in the morning resulting in his participants waiting only half the time before initiating the final stage.
I would also highlight that the education, experience and age of participants are very important. David’s group seemed to consist of mainly male work colleagues and Emily’s group of young female mothers. Before conducting experiments it is important to have an established baseline for comparison – this experiment doesn’t seem to have established an unbiased group of participants.
- The design was flawed. The results could be rather inflammatory because not only have they showed the effect of misinformation on memory, but also the results could show a difference in gender comparison. As previously mentioned there is a lot more I believe they could have done to plan prior and during the experimental process.
Question 3
My experiment will consist of 10 participants. All participants will be of a relatively similar age group. Since this design is intended to focus on participants’ ability to study in order to see if vocal background music can be disruptive to study I have selected an age range of 18-21 year old students.
The chosen 10 will consist of equal gender – 5 males and 5 females. Prior to starting the experimental process I will ensure the participants are of relatively equal behaviour and intelligence by simple personality and IQ method testing.
The situation will involve each participant being tested within three different scenarios over 3 days. In each scenario at a given time they will all be invited into an isolated room and without interruption will be asked to read a group of 30 random unrelated words taken from the English dictionary. They will each be given 5 minutes to do this. After a one hour break, they will be asked to return and complete a test to see how many words they can remember.
The dependant variables will show the results of this test by measuring the number of correct answers, the time taken to answer and also how many words placed in correct order compared to the list they originally studied and memorised from.
The independent variable in each scenario will be:
One reading session with vocal music – This will be two popular current songs easily recognisable to the participant age range, the songs will be identical for all 10 participants.
One reading session with non-vocal music – this will be a classical instrumental piece of music that will be recognisable by participants.
One reading session with no music at all.
Music will be played at what is considered to be background level by a small portable CD player and the door will be monitored to prevent any disruption while the participants are in the experiment.
Confounding Variables
Practise Effects – The same words are not able to be used in every scenario due to memory of the participant i.e. familiarity may confound results. To counterbalance this each participant will be given 30 unrelated words that are different from other scenarios over the 3 days of testing. The information will be presented to the participant using the same format, printing style and typeface, conferring with other participants will also be made difficult by this.
Experimenter effects – this will be minimised by having no-one else in the room with participants. Experiment assistants will be given the envelope each day in random order and will not be aware of which set of words have been issued to the participant. The participant will remain anonymous and will be identified by an assigned number on the envelope. Once the assistant has left the room the participant will open the envelope and will begin when signalled to do so by indicator placed in the room. When signalled to end after five minutes the participant will seal the words back in the envelope and return in one hour to complete the test. The experiment assistant will then attach the answers provided to the envelope and return to me – thus allowing for double blind testing.
Differences in participants over time – Although testing will be done over three days, the test itself is relatively short. This will avoid fatigue and boredom. Setting the time every day at noon for the experiment will help establish routine and hopefully behaviour of the 10 participants over the time period. There are also enough participants to reduce individual differences. The random allocation of the independent variable will also help reduce this.
Figure 1: Front and lateral view of the cranium, representing the direction in which the iron traversed its cavity. (Wikipedia 2010)