Discuss two effects of the environment on physiological processes
We have already seen that changes in the environment can have an effect on our physiology, and as a result our behaviour (we saw two examples in the 'Hormones' section, for example). We also know that we have a role in shaping the environments that we occupy. The relationship between the environment and our physiology is therefore often said to be 'bidirectional'.
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Focus on Command Term - DiscussOffer a considered and balanced review that includes a range of arguments, factors or hypotheses. Opinions or conclusions should be presented clearly and supported by evidence.
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Study 1 - Curtiss (1977) Genie: A Psycholinguistic Study of a Modern-Day "Wild Child."
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The case study of Genie is one of the most famous, and tragic, stories in Psychology. Remarkably, however, despite its fame and the huge amount of work that has been done on the case (or related work that has been inspired by it), conclusions about exactly what Genie shows us about human development are controversial and hotly contested.
Watch the documentary on the left, and make notes about the key details of the case. Make sure you tailor your notes to the command term and to the question, so you need some evaluation of both the study and the conclusions drawn (as this is a 'discuss' question). Another documentary is here, if you're really keen. |
Assignment 1 - Genie timelineThe case and research procedures for the case of Genie can be nicely summarised in a timeline. Use the Timetoast program (or another one if you prefer, to create a timeline of the key stages in Genie's story and in the research.
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Study 2 - Bremner et al (2003): MRI and PET study of deficits in hippocampal structure and function in women with childhood sexual abuse and post-traumatic stress disorder
What is PTSD?
Post-traumatic stress disorder is an anxiety disorder that can arise from exposure to severe environmental stressors. Someone with PTSD will often relive the traumatic event through nightmares and flashbacks, and may experience feelings of isolation, irritability and guilt. They may also have problems sleeping, such as insomnia, and find concentrating difficult. These symptoms are often severe and persistent enough to have a significant impact on the person’s day-to-day life.
Environmental stressors and PTSD
An environmental stressor is any event that threatens to disrupt the body's normal balance and starts stress responses such as excretion of stress hormones or activation of the 'fear sensor' in the brain, the amygdala. Stressors can be acute (an assault or accident) or chronic (worry, anticipation of violence, stress etc). The body responds to these stressors with a "flight or flight" response to emergency, activating the sympathetic nervous system by releasing cortisol (e.g. glucocorticoids - link back to the Hormones page). Another frequent symptom of PTSD is memory problems and it is hypothesised that very high levels of stress hormones can cause atrophy of the hippocampus, as this area of the brain is essential for the formation of new memories (we know this already, of course, given the results of Sapolsky's study in the previous section).
Environmental stressors and PTSD
An environmental stressor is any event that threatens to disrupt the body's normal balance and starts stress responses such as excretion of stress hormones or activation of the 'fear sensor' in the brain, the amygdala. Stressors can be acute (an assault or accident) or chronic (worry, anticipation of violence, stress etc). The body responds to these stressors with a "flight or flight" response to emergency, activating the sympathetic nervous system by releasing cortisol (e.g. glucocorticoids - link back to the Hormones page). Another frequent symptom of PTSD is memory problems and it is hypothesised that very high levels of stress hormones can cause atrophy of the hippocampus, as this area of the brain is essential for the formation of new memories (we know this already, of course, given the results of Sapolsky's study in the previous section).
PTSD in historyWhat we would now call PTSD first began to be recognised after World War 1, when it was termed 'shell shock'. The Poet Siegfried Sassoon wrote a poem called 'Survivors' which summarises the effects of Shell Shock.
No doubt they’ll soon get well; the shock and strain Have caused their stammering, disconnected talk. Of course they’re ‘longing to go out again,’-- These boys with old, scared faces, learning to walk. They’ll soon forget their haunted nights; their cowed Subjection to the ghosts of friends who died,-- Their dreams that drip with murder; and they’ll be proud Of glorious war that shatter’d all their pride... Men who went out to battle, grim and glad; Children, with eyes that hate you, broken and mad. |
It's not only soldiers...Although PTSD is often associated with the military, it is important to remember that it is a condition which is seen in a number of other areas as well, such as the victims of abuse, accidents or people who are regularly exposed to very stressful conditions in their work (such as paramedics). Bremner et al's study illustrates this clearly...
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Bremner et al's study...
Here is the abstract from the Bremner et al (2003) study:
Objective: Animal studies have suggested that early stress is associated with alterations in the hippocampus, a brain area that plays a critical role in learning and memory. The purpose of this study was to measure both hippocampal structure and function in women with and without early childhood sexual abuse and the diagnosis of posttraumatic stress disorder (PTSD). Method: Thirty-three women participated in this study, including women with early childhood sexual abuse and PTSD (N=10), women with abuse without PTSD (N=12), and women without abuse or PTSD (N=11). Hippocampal volume was measured with magnetic resonance imaging in all subjects, and hippocampal function during the performance of hippocampal-based verbal declarative memory tasks was measured by using positron emission tomography in abused women with and without PTSD. Results: A failure of hippocampal activation and 16% smaller volume of the hippocampus were seen in women with abuse and PTSD compared to women with abuse without PTSD. Women with abuse and PTSD had a 19% smaller hippocampal volume relative to women without abuse or PTSD. Conclusions: These results are consistent with deficits in hippocampal function and structure in abuse-related PTSD. Assignment 3 - Summarising researchRead the abstract above, and the full study if you want to, and the produce a summary of the Bremner et al study in your own words. Include your interpretations and conclusions, and make sure you relate what you write to the key idea of environmental effects on physiological processes.
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Although the stressors which are often referred to in this video are not the same as the women studied by Bremner et al (2003) you can see the same classic PTSD pattern in the experiences described by the soldiers. A powerful video on therapy for PTSD (used on soldiers but originally developed for rape victims) can be seen here.
Bremner et al's full study can be read here.
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Chickens, eggs and psychological research - The direction of causalityWe have already seen (for example in the 'Neurotransmission' section) that it can be difficult to be certain of what causes what in Psychology. There can be a 'chicken and egg' type problem when we try to interpret some of the results obtained in psychological studies.
Both studies here have this feature, where the 'direction of causality' is unclear. |
Triangulating evidenceThere is lots of useful triangulating evidence for this section. We already saw that both of the studies on the Hormones page could also both be used to support the idea that the environment can have an effect on physiological processes.
Brain damage caused by accidents (such as to K.F. from the Cognition and Physiology section) could also be used to support this conclusion. The Bremner et al study used PET and MRI scanning techniques, so this will be relevant to the Brain Imaging Technologies section. Assignment 4 - Section A questionRe-read the information above and then answer the following question from memory:
Explain one effect of the environment on physiology (8) |
Introducing the 22 mark essay question
All sections with a Level 3 command term can be assessed in a 22 mark essay (remember that a learning objective with a 22 mark command term could also come up as an 8 mark question, but not vice versa).
Although any Level 3 command term could be asked, we'll concentrate on the one given in the learning objective, so the question is "Discuss two effects of the environment on physiological processes" You will need to plan an essay which will be about 2-3 sides of A4 long, including a detailed focus on the command term. The marking criteria are below. ALWAYS refer to these before you begin to plan your essay. It is crucial that you know what the examiners are looking for so that you can write exactly what is needed for top marks! |
Planning a great 22 mark questionKNOW THE COMMAND TERM! This is absolutely crucial! A different command term requires a different style of essay, so you need to tailor what you write to the question. You will still be able to use the same pieces of information, but how you use them may vary.
PLAN PLAN PLAN! Every year the examiners' comments mention that essays which are clearly planned score the best marks. FOLLOW THEIR ADVICE! Don't be afraid to spend up to 10 minutes in an exam planning your essay (and longer earlier in the year when are learning and practising). USE EVIDENCE! You have 2 detailed studies here to use, but you should also look to find triangulating evidence using other experimental methods or from other areas of the syllabus EVALUATE! You must evaluate the studies you present. Evaluating means talking about the strengths and weaknesses of the study as well as the strengths and weaknesses of the level of analysis as a whole with reference to the question (e.g. reductionist explanation of genetics in some behaviour) |
Revision |
Extension |