”…centuries of human habitation have nibbled away not only at the earth but our perception of what constitutes nature. When we do not miss what is absent because we have never known it to be there, we will have lost our baseline for recognizing what is truly wild. In its domestication, nature will have become just another human fabrication6, 13.”
We can’t measure darkness. Darkness is the absence of something. Light, however, can vary in intensity, from low to high or dim to bright. It’s when light isn’t there that you have darkness. But the light gradient that we can imagine is limited to the light that we’ve already experienced. Given the brightest light we’ve ever seen, we can imagine dimmer light, and even no light—but brighter light than the brightest? In the same vein, when we think about what constitutes a diverse, natural setting, we often fall into the same problem with referencing. The baselines we use, to scale a lush, beautiful, natural environment against an grave, polluted one, are biased by the ‘nature’ that we’ve experienced. One person’s green could be indiscernible to another’s, like distinguishing objects in a dark room when you’ve just come in from outside. It’s possible that if the people living during the slightly younger earth could see us now, they’d need a lamp to cut through the darkness we’ve enshrouded ourselves in.
With every passing year, more people are living on the planet, using more resources in turn. The water gets dirtier; the air is more polluted; the soil becomes less fertile; more toxic waste is produced and displaced; and deforestation and other means lead to the extinction of more than 27,000 species annually13. What’s additionally problematic is that what is ‘normal’, in terms of these finite, natural resources, changes with each passing generation. Peter Kahn, Jr.14,15,13 called this phenomenon environmental generational amnesia, or “the shifting baseline problem.” An example of this is suggested by interviews in one study of African American children living in inner city Houston. Essentially, the kids understood the concept of air pollution, but not that Houston might have a problem with it (it’s one of the most polluted cities in the country)12,13. Long-term residents in Los Angeles experienced a similar referencing dilemma with smog and their health4,5,13. Sure, smog is bad; dirty is worse than clean, and more resources is better than less. But who’s to say that less ‘nature’ is bad? Can’t we function well without nature, or even find a substitute? After all, we have technology!
Well, to say less nature is bad, we’d first have to show that nature is good. There’s great evidence to suggest that interacting with nature (e.g., plants, animals, water bodies, sun, sky, etc.) is beneficial to peoples’ well being2, 8, 14, 22, 13. Still, children are increasingly coming to understand nature more through T.V. and the Internet than through the real thing15,13. You might say that perhaps nature via technology is just as good. Have you ever tended a real garden9,11,13 or shot a real bird19,13 over the internet? Additionally, there is certainly evidence that points to the psychological benefits (e.g., stress recovery, stress prevention) of pictures10, 16, 17, 13 and videotapes18,13 of nature. One group of researchers streamed nature scenes on plasma TV’s installed in an office building, and people reported increased psychological well being, cognitive functioning, and connection to the community and to nature7, 13. They called these T.V.’s “windows to the outside.” Alas, though self-reported feelings are useful (we can often rely on people to portray their own subjectivity), good scientists try to tease out how these feelings map onto other measures of psychological and physiological states. We can ask, “Can nature T.V. benefit people in ways similar to real nature? What can we manipulate and what can we measure to explore a difference if it’s there?”
Some really clever researchers at the University of Washington in Seattle asked these same questions. They brought in 90 undergraduate students (half male, half female) to complete a series of cognitive tasks. Participants entered an office and waited for 5 minutes. They then completed a proofreading task, a “name-a-droodle” task (what would you call this ambiguous figure?), an “invent-a-droodle” task (Hey, make your own ambiguous figure!), and a “tin can unusual uses” task (what could you use this can for?). Finally, they waited again for another 5 minutes.
What’s clever about it? One-third of the participants completed the tasks in a room with a blank wall, and another third did so with the window open, overlooking a nature scene with a fountain area that “extended to include stands of deciduous trees on one side, and a grassy expanse that allowed a visual ‘exit’ on the other13.” Here’s the interesting condition: the last third of the participants could view the same nature scene, but on a 50-inch plasma television. What did they measure? Heart rate, looking behavior, weather conditions and lighting. Every new task was preceded by a researcher’s personal instructions, a social interaction which provided a low-level stressor (heart rate increases slightly) that could be used to assess heart-rate recovery. There was also a camera, time synchronized with the heart-rate monitor, that was focused on the participants’ faces (how often do they look, and for how long?). They controlled for the outside weather conditions, the lighting on the work surface, and even the distance between the participant and the “window”, glass or plasma. However, because it took so long to install and uninstall the television in the window, the conditions were less than perfectly randomly assigned.
The researchers hypothesized that the rate of heart-rate recovery (after the social interaction) would be greater in the glass window condition compared to the blank wall. They also hypothesized that the longer participants looked at the glass window, the greater the rate of heart-rate recovery. Whether the plasma television effected heart-rate recovery differently than the wall, or differently relative to the time spent looking at it compared to the glass window, was essentially up for grabs.
What did they find? First, heart rate recovery was significantly more rapid in the glass window condition compared to the blank wall, whereas there was no such difference comparing the plasma T.V. condition to the blank wall. Surprisingly, participants looked at the glass window just as often as the T.V., but they looked at the glass window longer. The longer they looked at the glass window, the more rapid the participants’ heart-decreased. This was not the case for duration of looking at the plasma T.V. What’s more is that these findings are significant when controlling for the light on the desktop and the weather conditions outside.
What’s happening at the levels of brain and body when our heart-rate changes? I think that first we should understand how neurons can help communicate information between brain and body. The nervous system is a closed loop of neurons involved in sensation, decision and reaction20. When any kind of receptor organ is stimulated, information is carried via afferent neurons (mediated by interneurons) from that organ to the brain for decision processing, and then back again via efferent neurons to the receptor organ20. How that organ reacts depends on the brain’s ‘decision.’ Afferent neurons are also called sensory neurons, and efferent neurons are also called motor neurons. It’s efferent (motor) control of the cardiovascular system that we’re interested in. Specifically, we want to know about what is responsible for increasing and decreasing heart rate.
The “pace” of our heart rate is modulated by the sinoatrial node (S-A node) in the right ventricle of the heart1. This node is a specialized clump of cells that initiates action potentials for rhythmic beating. The S-A node is our receptor organ of interest. The sympathetic nervous system (SNS), a division of the autonomic nervous system, is responsible for increasing our heart rate (think fight or flight), whereas the parasympathetic nervous system (PNS), the other division, is responsible for maintaining it and decreasing it (think rest and digest). Heart rate is actually kept at a baseline rhythm by the PNS, which innervates the S-A node by the vagus nerve. It is when PNS activity increases that heart rate slows, and when it decreases that heart rate will speed up21. The SNS also innervates the S-A node and increases heart rate through the b1 adrenergic receptors1.
Where is all of this activity originating? Well, the medulla oblongata is like the “cardiac center” of the brain3. If I were to say that the medulla is a ‘center’ making ‘decisions’, I mean that certain parts of the brain (like the medulla) specialize in specific functions (like regulating heart rate), and these specialized areas generate output information based on information that they have received from a multitude of sources (e.g., other brain areas, sensory nerves). The neurons for the vagus nerve efferents (motor, leaving the brain) are found in the dorsal motor nuclei of the vagus in the dorsal aspects of the medulla. Some sympathetic activity comes from the spinal cord, but those efferent neurons are controlled by neurons originating in the dorsolateral reticular formation of the medulla3. When activity increases in them (action potentials), adrenergic activity increases, increasing arterial pressure. These are known as pressor areas, whereas the opposite, depressor areas, are located medially (toward the center) and ventrally (toward the bottom) from the pressor areas. Exciting these areas decreases adrenergic activity, decreasing arterial pressure. The pressor area and the dorsal motor nuclei of the vagus nerve together make up the cardiovascular ‘center3.’ As you can see, even the center’s ‘decisions’ are the product of other inputs.
What this research I’ve described suggests is that something about viewing natural settings can slow down our heart rate. I don’t think that it’s too far-fetched to say that this something is providing input to the cardiovascular center in the medulla that, in turn, ‘decides’ to pump the breaks on our heart rate. Contrary to past claims, it doesn’t look like nature on the tube can provide the same physiologically restorative effect.
The authors noted that their findings speak to a larger problem: the world’s natural resources are quickly disappearing, and new generations are using a degraded version of the world to form their standards of what’s natural, and what’s deplete. We’re forced to keep asking ourselves, “Can we substitute, and is the substitute just as good?” Yes, as population bourgeons, and we’re faced with new problems (i.e., space, food, water), sometimes we have to make due with what is good enough. We’ll adapt, right? Absolutely, but as the authors somberly suggest, “it is important to address the issue of whether such adaptations are not just different but impoverished from the standpoint of human functioning and flourishing…13.” How can we understand the refreshing benefits of a healthy and diverse ecosystem, when we’re walled in by steel and concrete? How can we understand the broad illumination of light, when we’re surrounded by darkness?
- Basics of Cardiac Arrythmias. (n.d.). http://sprojects.mmi.mcgill.ca/. Retrieved April 19, 2012, from sprojects.mmi.mcgill.ca/cardiophysio/AnatomySAnode.htm
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- Chapter 4. (n.d.). Columbia University in the City of New York. Retrieved April 19, 2012, from http://www.columbia.edu/~kj3/Chapter4.htm
- Evans, G. W., Jacobs, S. V., & Frager, N. B. (1982). Behavioral responses to air pollution. Advances in Environmental Psychology (pp. 237-269). Hillsdale, NJ: Earlbaum.
- Evans, G. W., Jacob, S. V., & Frager, N. B. (1982). Human adaptation to smog. Journal of the Air Pollution Control Agency, 32, 1054-1057.
- Fredston, J. A. (2001). Rowing to latitude: journeys along the Arctic’s edge. New York: North Point Press.
- Friedman, B., Freier, N. G., & Kahn Jr., P. H. (2004). Office window of the future?–Two case studies of an augmented window. Extended abstracts of SIGCHI conference on human factors in computing systems (p. 1559). New York, NY: ACM Press.
- Frumpkin, H. (2001). Beyond toxicity: Human health and the natural environment. American Journal of Preventative Medicine, 20, 234-240.
- Goldberg, K. (2000). The robot in the garden telerobotics and telepistemology in the age of the Internet. Cambridge, Mass.: MIT Press.
- Heerwagen, J. H., Orians, G. H., Kellert, S. R., & Wilson, E. O. (1995). Human habitats and aesthetics. The Biophila Hypothesis (pp. 138-172). Washington, DC: Island Press.
- Kahn Jr., P. H., Friedman, B., Alexander, I. S., Freier, N. G., & Collett, S. L. (2005). The distant gardner: What conversations in a telegarden reveal about user experience of telepresence. Proceedings of the 14th international workshop on robot and human interactive communication (pp. 13-18). Piscataway, NJ: Institute of Electrical and Electronics Engineers (IEEE).
- Kahn Jr., P. H., & Friedman, B. (1995). Environmental views and values of children in an inner-city black community. Child Development, 66, 1403-1417.
- Kahn Jr., P. H., Freidman, B., Brian, G., Hagman, J., Severson, R. L., Freier, N. G., et al. (2008). A plasma display window?–The shifting baseline problem in a technologically mediated natural world. Journal of Environmental Psychology, 28, 192-199.
- Kahn, P. H. (2001). The human relationship with nature: development and culture. Cambridge, Mass.: MIT Press.
- Kahn, P. H., & Kellert, S. R. (2002). Children and nature: psychological, sociocultural, and evolutionary investigations. Cambridge, Mass.: MIT Press.
- Kaplan, R., & Kaplan, S. (1989). The experience of nature: a psychological perspective. Cambridge: Cambridge University Press.
- Orians, G. H., Heerwagen, J. H., Barkow, J. H., Cosmides, L., & Tooby, J. (1992). Evolved responses to landscapes. The Adapted mind: evolutionary psychology and the generation of culture (pp. 555-579). New York: Oxford University Press.
- Parsons, R., Tassinary, L. G., Ulrich, R. S., Hebl, M. R., & Grossman-Alexander, M. (1998). The view from the road: Implications for stress recovery and immunization. Journal of Environmental Psychology, 18, 113-139.
- Root, J. (2005, March 20). Just point, click … and kill: Hunt game in the wild from the comfort of home. The Wenatchee World. Retrieved April 19, 2012, from http://www.wenatcheeworld.com/news/2005/mar/20/just-point-click-and-kill-hunt-game-in-the-wild/
- Sule, A. K. (n.d.). Afferent vs Efferent. Buzzle. Retrieved April 19, 2012, from http://www.buzzle.com/articles/afferent-vs-efferent.html
- Tamarkin, D. A. (n.d.). Heart Rate Regulation. STCC Faculty Webpages. Retrieved April 19, 2012, from http://faculty.stcc.edu/AandP/AP/AP2pages/Units18to20/heart/heart2.htm
- Wilson, E. O. (1984). Biophilia. Cambridge, Mass.: Harvard University Press.