We’re all just animals, aren’t we?

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The question of when to use non-human animal studies as evidence for human behaviour is a tricky one. Because it remains unethical to lesion the brain of a live human to look for a correlation between brain damage and behaviour (at the moment!), animal studies are used in large numbers at the biological approach. However, many people are becoming more disturbed by this than previously as over the years we have come to realise that animals also suffer pain, fear and anxiety as we do, and maybe other ways should be sought to conduct animal studies.

In Psychology Sorted, this is part of the Biological extension: the British Psychological guidelines for working with animals (2012) state that researchers should: Replace animals with other alternatives. Reduce the number of animals used. Refine procedures to minimise suffering.  But isn’t how they are used a large part of the problem?  After all, observation under natural conditions should be no problem.  Xu et al. (2015) researched naturally-occurring depression in macaque monkeys by observing monkeys living at a research base in China in environmental conditions that closely resembled what they would experience in the wild, for nearly 3 years.  The monkeys were housed in colonies, usually of two males and 16-22 females, with offspring of under six months.

Instead of unnaturally separating baby chimpanzees from their mothers, as Bowlby and others have done, causing distress,  Stanton et al. (2015) ‘picked up poo’: they investigated the effect of maternal stress on the glucocorticoid levels of infant chimpanzees by examining and measuring faecal glucocorticoid metabolite (FGM) concentrations of mothers and babies in the wild.  Much less stress for the monkeys, though maybe not for the researchers! 

Bearing in mind that we are animals too, it is time empathy stretched to our non-human cousins, and these methods seem to be a first step on the way.  See Psychology Sorted for more examples of ethical animal research.

 

Research from Psychology Sorted: Poverty and childhood cognitive development – a biological approach.

This is the first in a series of posts using research directly from our new bookpoverty3349068_640 Psychology Sorted.  The study we’re looking at today is Luby et al. (2013) on how children’s brain development and therefore their cognitive development are affected by poverty. The researchers found that exposure to poverty in early childhood impacts cognitive development by school age. However, the effect is mediated positively by good caregiving and negatively by stressful life events.

This is highly relevant in light of reports from the UK, USA and  South-East Asia of the large, and in some cases growing, number of children living in poverty.  This research can be used as an example of both localization and neuroplasticity within the Biological Approach,  and to illustrate the influence of poverty/socio-economic status on cognitive development, for those studying the Developmental Psychology option.

This was a longitudinal study of 145 children from a sample of children already enrolled in a 10-year study of preschool depression who, prior to being scanned by MRI,  had undergone regular testing.  Once a year (for a duration of 3-6 years) the children had taken part in a series of tests aimed at measuring their cognitive, emotional and social aptitudes. The involvement of significant adults in their lives was also recorded (e.g. how close they were to their caregivers) as well as the occurrence of any negative and stressful events in their lives. Once this collection of information had been amassed, each child underwent two MRI scans – one of the whole brain and one of the hippocampus and amygdala only. This study can therefore also act as an example of the use of brain-imaging technology as a technique used to study the brain in relation to behaviour.

Both the hippocampus and the amygdala showed less white and grey matter in the MRI scans of the poorer children in this study, with a positive correlation between income/needs being met and brain volume. While both the hippocampus and amygdala showed less development in poverty-affected children the researchers found that in cases where the child experienced positive care there was less negative effect on the hippocampus. Difficult and stressful life events only affected the left hippocampus.

Of course, students and teachers need to evaluate the use of this research as well: how valid is the study as an illustration of both localization and neuroplasticity? This was a relatively small sample of pre-schoolchildren from the USA who exhibited symptoms of depression.  Moreover, attempting to measure complex variables (e.g. the nature of caregiving and behavioural responses) is beset with difficulties as these variables are not exact and may lack construct validity.  Nonetheless, there was triangulation of methods, with the background data from cognitive testing providing a rich backdrop for the results of the scans, and this research is supported by other studies, such as that by Duval et al. (2017). 

Encourage your student to find and read media and academic examples of evidence and counter-evidence, and to engage in critical thinking and evaluation. For example, some poor families often cannot afford pre-school kindergartens for their children, who may be raised to some extent in isolation as well as in poverty.  This could be a confounding variable. Are there others? The student who is thinking like this is well on the way to writing a good argumentative essay on the effects of poverty on childhood cognitive development.

Pheromones – are we looking the the wrong place?

pheromonesA pheromone is a chemical substance released  by a non-human mammal or an insect which affects the behaviour or physiology of others of its species. Most of the search for human pheromones has focused on their role in attracting members of the opposite sex, even though in animals and insects they have also been shown to affect the feeding behaviour of ants and baby rabbits are known to begin nursing when exposed to a specific pheromone from a lactating mother rabbit.  If you search for ‘pheromones’ on the web, it is quite likely that a picture like the one above will pop up, and you will be encouraged to buy ‘X perfume spray, which contains the highest possible concentrate of known human pheromones, to make you irresistible to the opposite sex.’ Wow!

Of course this statement is probably true, as the total numbers of known human pheromones is exactly zero. There are no known human pheromones, and Tristram Wyatt is one researcher who says that scientists are looking in the wrong place for them.  In his TED talk he points out that rather than thinking about sex, we should be thinking about breast feeding  and the secretions from those tiny little white bumps in the areolae around the nipples of both men and women. It is over nine years since the secretion from these glands in lactating women was shown to act on newborn babies, causing them to wake and suckle.  Research by Doucet et al. (2009) shows that this is true of  any newborn and any woman, which means, like a pheromone, this is action at species level, rather than individual level.

So, while the perfume spray may attract one or two members of the opposite sex, it is not because of the human pheromones in there. In fact this is not where the real action is at all. In his most recent article, Wyatt argues that we should go back to the beginning and focus on a possible human mammary pheromone, rather than wasting any more time thinking about attracting others through chemical secretions. Sounds like a plan!

Lifelong learning – old dogs and new tricks

dog-2183114_640You can’t teach an old dog new tricks – or so the saying goes.  Developmental psychologists like Piaget tended to assume that cognition and the corresponding brain development were complete by the age of about twenty.  However, recent research into brain neuroplasticity shows that adults, even older adults, can continue to learn throughout their lives, and improve their brains in the process.  Lisa Pauwels and her colleagues published a paper this month, describing the structural and functional brain changes that occur with practice of a new task.  They found that older adults may be a little slower than younger ones in attaining new skills, but they were equally capable of learning, and intensive practice led to modulation of GABA (gamma-amino butyric acid, the main inhibitory neurotransmitter) and an increase in neurons and connections  (neurogenesis) in the corresponding brain regions.

The brain doesn’t only respond to learning, as Sandrine Thuret describes in her TED talk (below).  When you eat and what you eat, exercise and sleep all increase neurogenesis in adults.

So, if some days you are struggling with your studies, remember,  it is never too late to grow some more brain!

Coming soon – ‘Psychology Sorted’, the book!

Hi Psychology teachers from all over the world! Yes, I know that summer is beckoning but wouldn’t you like a sneaky peak at a BRAND NEW RESOURCE that is due to be out around October 1st? Written by Laura Swash and Claire Neeson, this resource will solve all those pesky teaching dilemmas such as: ‘Which studies should I use for each topic and how can I re-use them to create less bulk for the students to learn?  How can I find a streamlined, easy, cross-referenced resource that’s user-friendly (for me and my students)?  What can I use for both teaching AND revision?’ Here is a sample for you to taste, to get the ‘flavour’ of what we’re doing. Add us to your school shopping list: #1 Order ‘Psychology Sorted’ next term.  Sorted!

Sample_Section 1_Bio. updated

Bio KS1 Fisher et al_2005

What is a ‘key study’?

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Key studies are studies that are the most useful for any Psychology course, because they provide the ‘key’ to understanding a concept or theory.  For example, Maguire’s famous ‘taxi driver’ study, Loftus and Palmer’s ‘car crash’ study or Rosenhan’s research into the validity of diagnosis on admission to mental hospitals.

Teachers and students can benefit by summarising these studies according to Background, Aim, Participants, Procedure, Results, Conclusion, Evaluation.  This can be done on 1-2 sides of paper and kept to be used for essays, revision and even for HL Paper 3 practice if you are an IB Diploma teacher or student.  Below is a short example of what this could look like, from the biological approach.

KEY STUDY: Caspi et al. (2003) Influence of Life Stress on Depression: Moderation by a Polymorphism in the 5-HTT Gene.

 Background

Looked at the relation between inherited short alleles on the 5HTT serotonin transporter gene and incidences of stress and subsequent depression.

Links to:

  • Abnormal Psychology: Genetic explanation for inherited predisposition to depression as a response to environmental stressors.

Aim

To investigate whether a functional change in the 5HTT gene is linked to a higher or lower risk of depression in an individual.

Participants

The researchers used an opportunity sample from a cohort of participants who were part of another longitudinal study. There were 847 participants of 26 years old and they were split into three groups, depending on the length of the alleles on their 5HTT transporter gene.

Group 1 – two short alleles

Group 2 – one short and one long allele

Group 3 – two long alleles

Procedure

  1. Stressful life events occurring after the 21st birthday and before the 26th birthday were assessed using a life-history calendar.
  2. Past-year depression was assessed using the Diagnostic Interview Schedule.
  3. A correlation was tested for between stressful life events and depression, between the length of the alleles and depression and an interaction between perceived stress and the length of the alleles.
  4. A further test was done to see if life events could predict an increase in depression over time among individuals with one or two short alleles.

Results

The participants with two short alleles in the 5HTT transporter gene reported more depression symptoms in response to stressful life events than either of the other two groups. Those participants with two long alleles reported fewer depression symptoms. Moreover, childhood maltreatment was predictive of depression in adulthood only in adults with either one or two short alleles.

Conclusion

While there is no direct relation between short alleles on the 5HTT gene and depression, there is a relationship between these and incidences of stress and subsequent depression. The long alleles seem to protect against suffering depression as a result of stress. The effects of the gene adaptation are dependent on environmental exposure to stress.

Evaluation of Caspi et al. (2003)

Strengths

  • This was a very large cohort of males and females and the age was controlled in order to isolate the variable of number of stressful life events between the ages of 21 and 26.
  • It was a natural experiment, with the naturally occurring IV being the length of the alleles. If the results are replicated this would suggest high reliability.

Limitations

  • Gene action is highly complex, and actions of other genes could not be controlled. While the stressful life events were standardised as employment, financial, housing, health and relationship, whether or not a participant experienced a certain event as stressful is highly personal.
  • The symptoms of depression were self-reported, although each participant was contacted in order to verify the symptoms; self-reporting can be unreliable.

Reference

Caspi, A., Sugden, K., Moffitt, T. E., Taylor, A., Craig, I. W., Harrington, H., … & Poulton, R. (2003). Influence of life stress on depression: moderation by a polymorphism in the 5-HTT gene. Science301(5631), pp. 386-389.

Overstimulation of newborn mice leads to deficits in cognition and attention

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This research could be a useful counter argument to the classic Rosenzweig, Bennett and Diamond study (1972) into enriched environment and neuroplasticity.   It suggests disco lights are out, but toys are in!

This study was based on earlier findings by Christakis et al. (2004) that young children’s excessive television watching led to later attention problems. Christakis, Ramirez and Ramirez (2012) subjected ten mice to overstimulation by flashing lights and noise for six hours a day for 42 days.  They then compared them with a control group on four different cognitive tests, and found that the experimental group subjected to the stimulation performed the tasks significantly worse than the control group in terms of memory and attention, exhibiting ‘increased activity and risk taking, diminished short term memory, and decreased cognitive function.’

The results suggest that overstimulation during periods of critical development can have unexpected negative effects on cognition.  However, this is a very small experimental study, and no measurements of brain changes were taken, so its reliability remains open to question.