Sunday, 26 January 2014

Reitman (1974) - displacement or decay in STM?

We all know that information can leave our memories in a matter of seconds -even just walking from one room to the next, it can be easy to foget what you came for. 

Why is information forgotten from so easily from short-term memory (STM)?  Two prominent theories are:
So which is correct?  Judith Reitman explains that it is hard to measure decay without giving a distraction task which also potentially leads to displacement - e.g. asking participants to count backwards for a few seconds.

To address this problem, Reitman used a task involving tones.  As these didn't use verbal memory, it distracted attention from the target items without displacment.  Previous studies had shown that participants were not able to do the task at the same time as rehearsing the target words.

Early versions of her tone-distraction studies showed STM lasting longer than expected - could it be that there is no STM decay at all, and STM forgetting is just due to displacement?

Tones provide distraction without verbal displacement.

Ultimately, Reitman concluded that both play a role - displacement is important, but even with a tone-only task, decay still occurs.

Reference

Reitman, J.S. (1974). Without surreptitious rehearsal, information in short-term memory decays. Journal of Verbal Learning and Verbal Behaviour, 13, 365-377.

Wednesday, 29 May 2013

Write-ups: The Abstract

What is an 'abstract'? This is a very common question among people studying Psychology for the first time.

An abstract is a summary of a research write up, which is usually read before the main document. Searching sites such as Google Scholar allows you to read the abstract of a study, when often the full text is only available if your institution subscribes to the particular journal if you pay a one off charge.

In printed journals, an abstract appears at the beginning of every article. It is therefore a way to let readers know enough about a study to decide whether it will be useful to them to read on.

Psychology Journals - image source: http://bit.ly/11xDy4g

When writing an astract, it is important to remember that it is a summary of the whole report, so it doesn't just include aim and background, but things like results and conclusions too. Here is an example from the well-known Loftus and Palmer study of eyewitness testimony:

Two experiments are reported in which subjects viewed films of automobiled accidents and then answered questions about events occurring in the films. The question, “About how fast were the cars going when they smashed into each other?” elicited higher estimates of speed than questions which used the verbs collided, bumped, contacted, or hit in place of smashed. On a retest one week later, those subjects who received the verb smashed were more likely to say “yes” to the question, “Did you see any broken glass?”, even though broken glass was not present in the film. These results are consistent with the view that the questions asked subsequent to an event can cause a reconstruction in one's memory of that event.

As can be seen, the abstract gives an overview of the experiment/experiments in the report and certain key details. Things you might include in an abstract include: aim, background, method, sample, hypotheses, procedure, findings, conclusions. However, it should be short - not more than 150-200 words. Overall it should be understandable as a stand-alone piece.

As a student, the exact details of what you must include may depend on the marking scheme used by your institution or exam board, so that should be checked carefully. For submission to publication, refer to previous examples to get an idea of the house style of the particular journal.

The abstract always goes at the start of your write up. However, because it is an overview, it is often a good idea to write it last.

Thursday, 2 May 2013

What is depression?

Depression is a common and very severe psychological disorder.  It is an emotional state of great sadness and apprehension, feelings of worthlessness and guilt, social withdrawal, and loss of the usual drive and motivation (Davison and Neale, 2001).

Most of us will probably have an ample amount of sadness in our lives, though probably not to a degree that warrants the diagnosis of depression. However there are moves to broaden the clinical definition.

Depressed by Sander van der Wel

In the UK 10% of people will be diagnosed with depression at some point in their lives, and internationally this rate varies from 3% in Japan to 17% in the USA.


What are the symptoms?

A formal diagnosis of depressive disorder requires the presence of five of the following symptoms for at least two weeks, one of which must be either depressed mood or loss of interest and pleasure:

  • Sad, depressed mood.
  • Loss of interest and pleasure in usual activities.
  • Difficulties in sleeping.
  • Poor appetite and weight loss, or increased appetite and weight gain.
  • Loss of energy.
  • Feelings of worthlessness and guilt.
  • Difficulty in concentrating.
  • Recurrent thoughts of death or suicide.

Why do people get depressed?

The current biological model of depression suggests that the disorder relates to a malfunction of the neurotransmitter seratonin. This chemical is used by brain cells to communicate, and helps to controls mood, appetite and sleep. Chemical anti-depressant thereapies (e.g. Prozac) therefore try to boost levels of seratonin.

However, this explanation does not account for the varying worldwide prevalence of depression, nor can it explain why this neurotransmitter is faulty in the first place.

An alternative cognitive view is that some people develop faulty thinking styles, sets of negative 'schemas' about themselves, the world and the future (Beck, 1976). These are self-reinforcing and lead to negative mood and loss of motivation.

The answer may lie in a combination of the two approaches, as both drug and cognitive therapies have been found to be effective for depression. Reconciling the different approaches in psychology is an important challenge, not least in mental health.


References

Beck, A. (1976). Cognitive therapy and the emotional disorders. New York: International Universities Press.
Davidson, G. and Neale, S. (2001). Abnormal Psychology (8th Ed.) New York: Wiley.

Thursday, 7 March 2013

The huge problems with the new system of psychiatric diagnosis

The American Psychiatric Association publishes a manual for diagnosing mental disorders, called the DSM. This year they are publishing the 5th edition ("DSM-5") - in principle, an updated and more accurate version.

In practice, its revisions have been met with widespread dismay and alarm. In fact, I have yet to read anything positive about it.

Dr Doom! Image by JD Hancock.

Among the concerns that have been raised are the following:
Perhaps the most damning verdict comes from Prof. Allen Frances who chaired the previous review of DSM. He states: "DSM 5 remains a reckless and poorly written document that will worsen diagnostic inflation, increase inappropriate treatment, create stigma, and cause confusion among clinicians and the public" (source here).

What is your view of the state of psychiatric diagnosis? Are you worried about mental illness being over-diagnosed, or about the treatments used?

This post is part of #BlogFlash2013 - 30 days of flash blogging - using 
the prompt 'health' http://bit.ly/Y2BMEc

Wednesday, 6 March 2013

My top 5 brilliant psychology books for everyone

The following books are fantastic for anyone with an interest in psychology:

Fascinating, easy-to-read psychology books...

Nature via Nurture: Genes, experience and what makes us human by Matt Ridley

An expert on making evolutionary theory accessible, here Ridley tackles the nature-nurture debate, trying to find answers to the extent to which we are ruled by our genes. The key idea which he explains here is that the genome is not detailed enough to be a complete masterplan, but instead interacts with the environment to make us who we are. He shows how some of the great thinkers in psychology have contributed, each in their own way, to our understanding of human nature. 

Help! by Oliver Burkeman

Self-help books get a bad name, but how to distinguish the good from the bad (without having to read them all)? This book humourously runs through a vast range, current and classic. It debunks the likes of 'paraliminal' CDs and psycho-cybernetics, finds useful insights from some of the older titles in the genre, and gives intriguing summaries of many research findings. In a few cases he concludes, refreshingly, that he simply can't decide whether a technique works or not. It's light-hearted but well-researched throughout.

The Brain that Changes Itself by Norman Doidge

For years the structure of the brain has been viewed as static once we reach adulthood - no new neurons or functional change. Doidge elegantly summarises how the new field of neuroplasticity is changing that view, and how it applies to areas such as addiction and stroke recovery.

The Man Who Mistook his Wife for a Hat by Oliver Sacks

A classic - essays about mysterious neurological conditions, each fascinating and very readable. From the title case of visual agnosia to tales of memory loss to autistic savants. Curiously, Sacks himself suffers from a rare neurological condition called prosopagnosia, meaning that he is unable to recognise faces.

50 Psychology Classics by Tom Butler-Bowden

This book deserves its place in my list due to its massive scope, and it's a book I wish had been around when I was first studying psychology. By summarising both classic and contemporary works, it opens up a real magic box of research in neat, 4-page summaries and clearly shows why each is relevant to real life. I loved the 'in a nutshell' 1-sentence summaries for each one too, and the links to related chapters.

What have I missed? Share your favourites in the comments. 

This post is part of #BlogFlash2013 - 30 days of flash blogging - using 
the prompt 'books' http://bit.ly/Y2BMEc

Tuesday, 5 March 2013

Lost innocence: what do addiction, anorexia and Milgram's electric shocks have in common?

I recently heard several recovering substance abusers giving a talk about how they had become addicts.

All said that they had begun taking smaller amounts and/or 'safer' substances. At the start, none thought they were the kind of person who could take heroin. I asked if there was a moment at which they were aware that they were moving on from 'softer' drugs to heavier stuff but each said that there wasn't - they took a range of substances and it happened gradually.

Drugs such as cocaine can lie on the border between perceptions
of soft/hard drugs.  Image by Foxtongue.

Gradual change in behaviour

This gradual change in behaviour and attitude reminded me of other areas of psychology where behaviour and attitudes gradually shift:
  • The staged electric shocks of the famous Milgram experiment - where participants began by giving a low level of shocks - 15V - to a stranger. Nobody thinks they would give the maximum 450V shock to a complete stranger, yet in Milgram's original study, 65% did (Milgram, 1963). Add in peer pressure, and that amount rose to over 90% (Milgram, 1974).
  • Eating disorders. With extreme dieting as with addiction, people are compelled to do 'just a bit more'. None would expect, at the start, that they would ever be willing to starve themselves to death.  But the horrible truth is that many do - anorexia nervosa is the most deadly of psychological disorders.
In every case, the person starts as an innocent, unwilling to comtemplete the extreme behaviour, but becomes gradually sucked in by degrees.

Similarities

There is a tendency in psychology to divide things up into areas - developmental psychology, social psychology, etc. Perhaps we should focus more on the similarities, and work towards theories that apply to a multitude of situations.

There could be many more examples of people's behaviour gradually shifting - people getting used to abuse, becoming indocrinated in cults, breaking laws... Please post your thoughts in the comments.

References

Milgram, S. (1963). Behavioural study of obedience. The Journal of Abnormal and Social Psychology, 67(4), 371-378.

Milgram, S. (1974). Obedience to Authority: An Experimental View. New York: Harper and Row.

This post is part of #BlogFlash2013 - 30 days of flash blogging - using
the prompt 'innocence' http://bit.ly/Y2BMEc

Monday, 4 March 2013

Modifying our brains - can we make a cyborg?

With the recent developments in bionic eyes and bionic limbs hitting the news, an old question becomes ever more relevant - will we ever create true 'cyborgs' - part human, part robot?

In some ways we already are - if people's synthetic limbs can be connected to their brains in order to feel sensation. The US military has used controls wired to an insect brain to get a beetle to fly around with a tiny spy camera attached. They can actually control its movements remotely by stimulating its brain!

But still, these developments somehow feels like useful add-ons. Is there a line which will someday be crossed, requiring us to redefine what it means to be human?

How far will technology go? Image by The PIX-JOCKEY

What next?

One thing is for certain: this research is only going to go in on direction - it's going to get better and more sophisticated. Systems are going to become more sensitive, and increasingly miniaturised too. With further developments in creating artificial brain cells, it may one day be possible to have parts of the brain bionically replaced as well.

How will it feel to have synthetic brain parts?

In some ways, we already think with more than one 'brain' - our brains contain a primitive 'reptilian brain' composed of the brainstem and the thalamus which is responsible for basic bodily functions and basic emotions, and an evolutionarily newer 'thinking brain' - the neocortex - which is responsible for our more complicated perceptions and thoughts.

Perhaps these parts of the brain could be linked to Freud's ego and id - conscious and unconscious mind (Freud, 1910).

However, to 'think' with artificial brain parts? In some respects our mind can be reduced to the activity of a huge number of brain cells, each fairly simple. But for all our sophisticated modern neuroscience, the question of how this network leads to conscious thought - the 'mind-body problem' - has yet to be answered satisfactorily. It would certainly be interesting to know if people 'felt' different after having a synthetic brain system connected up.

Will it catch on?

At the moment, the new technology described above is helping people with visual or physical impairments. But if the technology became good enough, would it start to have a general appeal? Would we see athletes opt for bionic replacement body parts, for example?

And in terms of bionic brain parts, what would be the implications for personal safety and privacy if our brains had the same vulnerability to hackers as our computers currently have? Food for thought. Clearly there are a lot of questions - please post your thoughts in the comments!

Reference

Freud, S. (1910).  The origin and development of psychoanalysis. (Translated by H.W. Chase). American Journal of Psychology, 21, 181-218.

This post is part of #BlogFlash2013 - 30 days of 
flash blogging - using the prompt 'technology' http://bit.ly/Y2BMEc