Friday, 27 May 2016

Higher Psychology - Research Section

With the Higher Psychology exam looming, it's worth checking the mandatory content in the Research unit, from SQA's course documents. This is what you're expected to know about:

  • The stages of the research process
  • Ethical issues in terms of current British Psychological Society guidance
  • Research methods which must include: field experiment, laboratory experiment, natural experiment, participant and non-participant observation, case study, interview, survey.
  • Descriptive statistics and their interpretation: mean, median, mode and range and their calculation from a set of data
It's a good idea to practise answering exam-type questions - if you have my N5 and Higher textbook, there are 3 practice sections on research on pages 392-393. Note that the 'stages of the research process' are essentially the same as what you will have done for your Assignment - planning, writing a hypothesis, sampling, gathering data, etc.

Remember that there are 20 marks for this section in the exam, meaning it's worth as much as the two social psychology topics combined. A good mark here will set you up to do well overall.




Approaches to Psychology - Summaries

What are the approaches in psychology? These are broad perspectives, which can be applied to many different topics.

For example, personality could be studied in terms of how the brain affects your personality (biological approach) or an explanation could focus more on your childhood, and unconscious thoughts/feelings (psychoanalytic approach). Memory is often studied in terms of taking in and processing information (cognitive approach) but we could also look at how neurons change structure and form connections when new memories are created (biological approach).

Sometimes one approach might be right and another wrong, but often they prove to be complimentary, and looking at a problem from more than one perspective can be very helpful.

Here are summaries of four key approaches in psychology from previous blog posts on this site:

The biological approach
The cognitive approach 
The psychoanalytic approach
The behaviourist approach

When writing about how an approach can be used to explain a topic, I'd recommend beginning with a brief summary of the approach itself. For example, with the cognitive approach, include a paragraph or two on schemas/faulty thinking. Then move on to the issue itself, e.g. how the approach explains dreams, or memory, or mental illness.

Image by Queen's University


Pre-exam tips: identifying the IV and DV.

Students sometimes have to look at an example research study and identify certain characteristics, such as finding the independent and dependent variable (IV & DV) in an experiment. Some of my students find this hard, so I would suggest the following strategies:

  • The IV is always the predicted cause and DV is always the effect. So if you could put it in a sentence like "---is causing --- to change" or "Does --- have an effect on ---?" then the first one in the sentence would be the IV, the second would be the DV.
  • Generally there are only two (or at least just a few) values/options of the IV, and the DV could have any value. For example, in a memory experiment on the spacing effect, the IV might be whether information was shown spaced out or 'massed' together. 2 options, 2 'conditions'. Everything else is kept constant, and the DV is measured - in a memory experiment, usually that will be proportion of items recalled on a test of some kind, and could be any number.
  • If you put the results in a bar graph, the IV is typically along the bottom, signifying the names of two (or more) bars, and the DV is shown up the y-axis, with the height of the bar indicating the score on the DV.

Source: http://bit.ly/1THPHz8
Other than that, just look at lots of examples. You could look at example studies on the BPS digest, such as these ones:

http://digest.bps.org.uk/2016/05/a-laughing-crowd-changes-how-your-brain.html
http://digest.bps.org.uk/2016/05/men-who-can-tell-good-story-are-seen-as.html
http://digest.bps.org.uk/2016/05/minimalist-anonymous-rooms-are-probably.html

They all have a pretty clear IV and DV (at least in my view!) Looking at example research and identifying variables is very good practice - and you can also learn about useful current studies while doing so.

Finally, remember that this only really applies to experiments - for things like case studies, there typically won't be a single pair of variables, so you would not be asked to identify an IV and DV.

Saturday, 2 April 2016

What is Sleep For? Oswald's Restoration Theory of Sleep

What is sleep for? In some ways it is a paradox - evolution is a race to survive, yet we have evolved to be unconscious of our surroundings for several hours a day!

We know that it must have had a benefit to have evolved. Even when there is an apparent adaptive pressure not to sleep, animals don't evolve to stop sleeping. For example, in some aquatic mammals such as dolphins, sleep occurs in one brain hemisphere at a time, so that they do not lose consciousness and drown!

Bottlenose dolphins sleep with
half their brain at a time. Image: Willy Volk

Restoration theory

So why do we sleep? It seems to make sense to assume that the body uses sleep to repair itself. Oswald (1966) was one of the first to suggest that sleep - especially slow-wave sleep - is important in allowing the body to rest and repair itself before the rigours of another day. This could include:
  • Repairing minor injuries
  • Removal of waste chemicals in the muscles
Adam & Oswald (1983) believed that REM sleep also played a key role - restoring the brain and nervous system. This could again include repair, as well as:
  • Replenishing neurotransmitters in the nervous system 
As evidence, they noted that damage to the nervous system was linked with longer REM sleep phases.

Exhausting the body

However, there is evidence against the idea that the body needs sleep in order to function. Horne (1978) reported that sleep deprivation did not interfere with participants’ ability to play sport, and it didn't make them physically ill, either.

So, a lack of sleep does not stop us from exercising. But what happens when people do a lot of sport, and tire themselves out?

This question was asked by Shapiro et al. (1981). In a sleep study of runners who had completed a 92km road race, it was found that their sleep lasted on average 90 minutes longer than normal over the next two nights. In particular, it was slow-wave sleep which increased in duration, rising from 25% to 45% of their total sleep. This support's Oswald's restoration theory.

Body... or brain?

However, Horne and Harley (1988) believe that repair of the body is not the main function of sleep. Instead, they suggest, extended exercise can lead to a heating of the brain, and it is this which results in longer sleep, not wear and tear to the body. In an experiment, they heated people's faces and heads using a hairdryer! 4 out of their 6 participants were then found to have a longer period of slow-wave sleep.

McGinty and Szymusiaka (1990) agree that sleep would have benefits to an overheated brain, including protecting it from damage, and facilitating immune defence. In other words, perhaps it is the brain which needs to rest and repair, and not the body. As Hobson (2005) put it, "Sleep is of the brain, by the brain and for the brain".

Memory consolidation

Memory researchers are increasingly arguing that sleep is not so much about repairing the brain, however, but allowing it to undergo key psychological reorganisation. This can include consolidating memories that are laid down temporarily during the day. As Rasch & Born (2013) argue, other functions could easily take place during quiet rest, without the need for the individual to lose consciousness - something which has an evolutionary cost due to the risk of predators.

Overall, the idea that the body sleeps in order to repair itself now looks overly-simplistic, and it is becoming evident that sleep plays a key role in the maintenance of cognitive functioning.

See also: REM sleep and creativity

References

Adam, K., & Oswald, I. (1983). Protein synthesis, bodily renewal and the sleep-wake cycle. Clinical Science, 65(6), 561-567.

Hobson, J. A. (2005). Sleep is of the brain, by the brain and for the brain. Nature, 437(7063), 1254-1256.

Horne, J.A. and Harley, L.J. (1989). Human SWS following slective head heating during wakefulness. In Sleep '88 by Horne, J.A. (ed.) New York: Gustav Fischer Verlag.

McGinty, D. and Szymusiaka, R. (1990). Keeping cool: a hypothesis about the mechanisms and functions of slow-wave sleep.  Trends in Neurosciences, 13(12), 480–487.

Oswald, I. (1966). Sleep. London: Pelican.

Rasch, B., & Born, J. (2013). About sleep's role in memory. Physiological Reviews, 93(2), 681-766.
Chicago

Shapiro, C.M., Bortz, R., Mitchell, D., Bartel, P. and Jooste, P. (1981). Slow-wave sleep: a recovery period after exercise. Science, 11(214/4526), 1253-1254.

Wednesday, 14 October 2015

Why Do We Sleep?

Sleep is a mysterious process - we spend a large proportion of our lives doing it, often having dreams which include vivid hallucinations. Why? What prompts our bodies and brain to go through this process on a daily basis?

Everyone sleeps. Image by PedroSimoes7

Role in other processes

Sleep can affect a number of areas of our waking lives, including:

 - Education: early risers get better school grades (Preckel et al., 2013)

 - Memory: sleep plays a major role in consolidating memories (Walker & Stickgold, 2004)

 - Creativity: people with later sleep cycles are more creative.

 - Mood: an afternoon nap can tune out negative emotions (Gujar et al., 2010)

 - Metal health: sleep problems are associated with stress and depression.

When people don't sleep, they lose the ability to concentrate on even the simplest of tasks, and begin to hallucinate and feel deeply paranoid (Lindzay et al., 1976). It is also so unpleasant that sleep deprivation is used as a form of torture.


What happens during sleep?

Activity in the brain changes over 5 sleep stages. The first four of these often just called stages 1-4, and during these, you fall into a progressively deeper sleep. In stage 5, 'REM sleep', the brain becomes more active again, and you begin to dream - something that Freud considered to be focused on 'wish fulfilment'.

Electrical activity in the brain changes over the sleep stages. One particular brain wave, the delta wave, has a very slow frequency and a high voltage, and is only normally found during deep sleep. There are no delta waves in stages 1 or 2. During the first stage, the brain’s activity is very similar to wakefulness with small rapid brain waves, but by stage 4, delta waves are dominating.

Because of this, stages 3-4 are often called delta sleep or slow-wave sleep (SWS), and it may be the case that these stages are especially important to allow the brain to consolidate episodic memories, and allow the brain to recover in order to store new memories the next day (Walker, 2009).


The evolution of sleep

The evolution of sleep is a puzzle, but we know that as it exists in animals as basic as the fruit fly, sleep must have served a useful function throughout our evolution.

All animals sleep; sloths sleep in the trees
for large parts of the day. Image by Brian Gratwicke.

On the surface, sleep might appear to be a waste of valuable hours in the day, as well as leaving animals vulnerable to attack. For this reason, sleep must be a valuable - perhaps essential - process, and must fulfil a function for which rest would not be enough.

One possibility is that sleep evolved because it helped our ancestors to repair damage to the body, giving them a survival advantage. However it would appear that resting would fulfil the same function, and sleep deprivation does not seem to cause much immediate physical harm to individuals.

Another suggestion is that sleep is essential for the nervous system. Resting does not cut the individual's nervous system off from external stimulation in the same way as sleep does, and this could be its key purpose (Cirelli and Tononi, 2008). It may well be that as organisms developed more complex brains, sleep evolved as a means of consolidating memories and restoring cognitive functions.

- More on theories of sleep and dreams to follow....

References

Cirelli C, Tononi G. Is sleep essential? PLoS Biol. 2008;6:1605–11.

Gujar, N., McDonald, S., Nishida, M., and Walker, M. (2010). A Role for REM Sleep in recalibrating the sensitivity of the human brain to specific emotions. Cerebral Cortex, 21(1), 115-123. doi: 10.1093/cercor/bhq064

Lindsey, G., Hall, C.S. and Thompson, R.F. (1978). Psychology (2nd Ed.) New York: Worth Publishers.

Preckel, F., Lipnevich, A., Boehme, K., Brandner, L., Georgi, K., K├Ânen, T., Mursin, K., and Roberts, R. (2013). Morningness-eveningness and educational outcomes: the lark has an advantage over the owl at high school. British Journal of Educational Psychology, 83(1), 114-134. doi: 10.1111/j.2044-8279.2011.02059.x

Walker, M.P. (2009). The role of slow wave sleep in memory processing. Journal of Clinical Sleep Medicine, 5(2 Suppl), S20.

Walker M.P. and Stickgold, R. (2004). Sleep-dependent learning and memory consolidation. Neuron, 30;44(1):121–33.

Monday, 28 September 2015

Introvert v's Extravert Personalities

An introvert is a person who prefers solitude or 1-to-1 interactions rather than busy social occasions, while an extravert is the opposite - they like to socialise, and don't particularly like to be alone.

Ambiverts

However, this is a very simplistic distinction - most people really fall on a scale from one extreme to the other, with few of us entirely introverted or extraverted. Sometimes researchers use the term 'ambivert' to mean someone who is more or less equally balanced between the two.

The following image illustrates this idea of a scale between two extremes:

Introversion v's extraversion. Source: here.

Biological basis

According to researcher Hans Eysenck (1967), some people have a less sensitive nervous system than others do, and therefore need more environmental input for the same end result. They therefore need more social interaction in order to feel stimulated causing them to be extraverted, while those with more sensitive nervous systems feel overwhelmed with too much input, and therefore avoid it i.e. they are introverted. This biological theory is supported by evidence suggesting that personality appears early in life, and that personality traits remain steady over the lifespan (McCrae & Costa, 1997).

Social factors

The work of McCrae and Costa (1997) suggests that personality factors including extraversion are universal, and therefore relatively little influenced by culture. The society that we live in does make a difference to whether traits are encouraged or even accepted, however; in her 2013 book 'Quiet', Susan Cain argues that society increasingly values the extravert, with introverts being misunderstood and undervalued.

From a teaching point of view, it is undoubtedly true that the typical classroom today - with discussions, debates, and a social-constructivist approach to learning in general - is more geared to the extravert than to the introvert.

References

Eysenck, H. J. (1967). The Biological Basis of Personality. Springfield, IL: Thomas Publishing.
McCrae, R.R. and Costa, P.T. Jr (1997). Personality trait structure as a human universal. American Psychologist, 52(5), 509-516.