This year’s Nobel Prize in Physiology or Medicine has an indirect but significant connection to dream research. For those of us who believe the scientific study of dreaming needs to be grounded in the evolutionary biology of sleep, the news of the 2017 Nobel should be a cause for celebration.
The prize was awarded to three Americans—Michael W. Young, Michael Rosbash, and Jeffrey C. Hall—in recognition of “their discoveries of molecular mechanisms controlling the circadian rhythm” (quoted from the Nobel committee’s public statement). The key point, from a dream research perspective, is that these three investigators have shown we have a genetically hard-wired need to sleep.
All life on earth is fundamentally oriented toward the cyclical presence and absence of the sun. Every kind of living being has evolved internal clocks of approximately 24 hours in length that guide and regulate their biological processes and behaviors. These internal clocks are known as circadian rhythms, and they have long been observed as powerful factors in plant and animal life. But only recently have the details of how these clocks work become known, thanks to the work of this year’s trio of prize winners. Their studies, going back to the 1980’s, explain how circadian rhythms are programmed into the genetic activities of each cell at the molecular level.
The researchers focused on the circadian rhythms of the fruit fly (Drosophila melanogaster), as a model for understanding similar rhythms in the cells of other organisms. They identified a specific gene in each cell whose activities oscillated in a 24-hour rhythm. During the night, this gene encodes a specific kind of protein that accumulates in the cell. It reaches a high point at the beginning of day, after which the gene shuts itself off and the protein slowly dissolves, reaching a low point at the beginning of night when the process repeats itself. According to this year’s prize winners, the feedback loop involving this specific gene is a key part of the self-sustaining internal chronometer that shapes the functioning of all biological organisms, from flies to humans.
The committee that decides each year’s award made it clear in its statement that the work of Hall, Rosbash, and Young has important relevance for medical practice and social welfare:
“Our wellbeing is affected when there is a temporary mismatch between our external environment and this internal biological clock, for example when we travel across several time zones and experience ‘jet lag.’ There are also indications that chronic misalignment between our lifestyle and the rhythm dictated by our inner timekeeper is associated with increased risk for various diseases.”
Most commentators on the 2017 prize have highlighted this last point, about the diagnosis and treatment of illness. Circadian rhythms influence the human body in numerous ways: via hormone levels, metabolism, temperature, and of course the sleep/wake cycle. Disruptions to the biological clock, whether through behavior (e.g., traveling across several time zones) or internal malfunctioning (e.g., a genetic mutation), can lead to a variety of serious health problems, including diabetes, obesity, cancer, cardiovascular disease, depression, bipolar disorder, memory defects, Alzheimers, and attention-deficit disorders.
The hope is that the more we learn about the elemental mechanisms of circadian rhythms, the better we can treat these problems, and prevent them from occurring in the first place. Further research in chronobiology may show us there are better and worse times of the day for undergoing surgery, taking a medication, or participating in a psychotherapy session.
It may also give us new insights into the rhythms, cycles, and recurrent patterns in human dreaming. Anything that gives a new understanding of sleep has the potential to provide a new understanding of dreams, since dreaming naturally emerges out of the state of sleep. The ubiquity of dreaming in human experience throughout recorded history, in cultures all over the world, strongly suggests it is a phenomenon deeply rooted in our evolutionary heritage. It strengthens the argument in favor of this idea to show, as this year’s Nobel winners have done, that the circadian rhythms guiding our waking and sleeping behaviors are encoded in every cell in our bodies. There can no longer be any question that sleep is an absolutely vital feature of healthy human life. The study of dreams can build on this solid foundation in evolutionary biology to explore in more detail what exactly is happening in the mind and body during sleep that contributes so powerfully to human health.
Note: this was originally published in Psychology Today on October 23, 2017.