The+environment+and+physiological+processes

=** Learning outcome **=
 * ** Discuss two effects of the environment on physiological processes //(for example, effects of jet lag on bodily rhythms, effects of deprivation on neuroplasticity, effects of environmental stressors on reproductive// mechanisms)//.// **


 * Discuss ** Offer a considered and balanced review that includes a range of arguments, factors or hypotheses. Opinions or conclusions should be presented clearly and supported by appropriate evidence.

toc


 * IF this learning outcome appears as an __ essay __, you must be able to discuss TWO of the following **
 * neuroplasticity AND/ OR
 * mirror neurons AND/ OR
 * seasonal affective disorder (connected to hormones - this study could also be used for the learning outcome on hormones)

Keep in mind that if you are only required to explain one study, you will have to provide a detailed summary of the study, as opposed to only giving a brief overview and using the results in conjunction with other studies as part of a body of evidence to support a point of view.
 * If an __ SAQ __ asks you to address this learning outcome through explaining ONE study, I suggest you use either Rosenzweig or Maguire. **

=Effect 1: Brain plasticity=

**Example 1: Brain plasticity and Spatial Memory**

 * Use class notes
 * Look also at further research done by [|Maguire on brain plasticity, the hippocampus and memory]

Example 2: Increased synaptic connections as a result of enriched environments

 * Rosenzweig [[file:Rosenzweig's study.pdf]]**
 * Study summaries should be made from this original.**

Supporting studies

 * [|An overview of enrichment studies]
 * Mice placed in enriched environments can recover lost memories, giving hope to those who study Alzheimer's. []

Variables involved in enrichment studies
[|A discussion of variables that should be taken into account when assessing enrichment studies]

Harnessing neuroplasticity

=Effect 2: The impact of light on hormonal levels= (Just remember - this learning outcome is not the same as the one on hormones even though it discusses a hormone. This is because it is not the impact of hormones on behavior BUT the impact of the environment on physiology. Think of it as looking at the context from a different angle)
 * One outcome - Seasonal Affective Disorder**

Crane & Hadad, page 50
 * Source:**

[|Gooley et al. 2011] "//exposure to electrical light between dusk and bedtime strongly suppresses melatonin levels and may impact physiologic processes regulated by melatonin signaling, such as sleepiness...//"
 * **Study 1**:


 * Procedure **
 * 116 participants divided into 2 groups exposed to different levels of light in the 8 hours prior to bedtime for five consecutive days.
 * Group 1 exposed to room light
 * Group 2 exposed to dim light
 * Melatonin measured through continuous collection of blood plasma every 30-60 minutes


 * Results **
 * Group 1 (exposure to room light) - melatonin duration reduced by about 90 minutes when compared to dim light exposure.
 * Exposure to room light during the usual hours of sleep suppressed melatonin by greater than 50 percent.
 * **Significance** - changing levels of light are correlated with change in levels of melatonin - this in turn appears to impact the sleep/wake cycle which in turn has been connected to mood disorders such as SAD ||

Rosenthal 1987 - findings suggest that higher levels of melatonin contribute to seasonal affective disorder (SAD) Keep in mind that the evidence is inconclusive - SAD cannot yet be fully explained by any one single cause [|Impact of light treatment] Rosenthal explains SAD and provides data on the efficacy of light treatment ||
 * **Study 2**:

An evaluation of the melatonin hypothesis and SAD
Studies suggest that melatonin (as part of a physiological process) is inhibited by bright light (the environment) During winter months, therefore, levels of melatonin rise - Studies indicate that this could be connected to a depressive state known as Seasonal Affective disorder (SAD) If this hypothesis holds, then suppression of melatonin by light should induce an antidepressant effect.

//"The results of several studies have argued against this hypothesis.// //These and other results suggest that the suppression of pineal melatonin secretion may account for some symptoms that resolve during light therapy, but there is no convincing evidence that it is __**central**__ to the disorder.//" (Source: [])
 * ** Point 1: Not all studies agree **
 * //Firstly, administration of melatonin to successfully treated SAD patients did not induce them to relapse.//
 * //Secondly, SAD patients treated with atenolol (beta-adrenergic blocker) that// **reduces** //night-time melatonin levels failed to improve their condition.//


 * Significance**: light (as an environmental factor) and its impact on melatonin secretion may not be the most important factor in causing SAD ||

Treatment must be tailored to the patient
 * ** Point 2: the success of light treatment varies **

//"Sixty to 80 percent of SAD sufferers benefit from light therapy. The amount of light varies from person to person. ... Most people respond to light therapy within 2 to 4 days of initiating treatment. Although the amount of time needed varies, most people need between 30 and 90 minutes of light therapy per day//." ([|Targun and Rosenthal 2008])
 * **Significance** - if light therapy is not successful with at least 20 percent of SAD patients, then it cannot be argued that light (as an environmental factor) will have the same impact on physiological processes in all subjects (human or animal) ||

[|Connection between light and depression]
 * Extension reading **

=Effect 3: Mirror Neurons=

Introduction
We have looked at brain plasticity and how the brain can change as a result of an enriched environment. For those of you who have investigated melatonin, you have also looked at how light can change melatonin levels and thus impact on mood (in this case depression and seasonal affective disorder – SAD). Another topic for this learning outcome is mirror neurons, which appear to play a role in our ability to learn from, and empathize with, other people. Research indicates that mirror neurons appear to help us experience what others are experiencing, simply from watching them.

**Summary of the role played by mirror neurons**

 * __I: READ__:**
 * ** Crane and Hadad, pages 48 – 49 ( **//The textbooks are on the shelves behind the whiteboard - return them when you are finished//** ) **
 * Winerman, L. (2005). The mind's mirror. []
 * [|Association for Psychological Science (2007, May 6). Mirror Neurons: How We Reflect On Behavior. //Science Daily//.]
 * [|Society For Neuroscience (2007, November 7). Mirror, Mirror In The Brain: Mirror Neurons, Self-understanding And Autism Research. //ScienceDaily//.]
 * [|(2010) First direct recording of mirror neurons in human brain]

__**II: CHECK YOUR UNDERSTANDING:**__
 * Your notes should contain your answers to the following questions:**
 * 1) Define the meaning of a) //mirror neuron//; b) //empathy//; c) //neural message d) firing//
 * 2) In the context of the learning outcome a) What is the environmental factor? b) What is the effect on physiological processes
 * 3) **From the above readings, choose and summarize** 2 studies that support the impact of observation on the physiological process of mirror neurons firing. Make sure you expand on the significance of the findings in the context of the learning outcome.

__**III: WATCH**__
 * Ramachandran on TedTalk**

media type="custom" key="5789809" []


 * Question:** What is Ramachandran’s key point in this presentation? Support your answer with evidence from the transcript (remember you can access the transcript from the tedtalk site)

=Effect 4: The effect of environmental stressors on metabolism=

media type="custom" key="24915552"

=Further reading=

[|Environment, hormones, stress and problem-solving] [|Reflections on mirror neurons] [|Monkey see, monkey do] [|Mirror, Mirror In The Brain: Mirror Neurons, Self-Understanding And Autism Research] [|The Mirror Neuron Revolution: Explaining What Makes Humans Social]