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Why We Dream: Biological Theory Roundup

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We've all had strange dreams: as a kid I was not in the least frightened by the Count Chocula character while awake, but I suffered through many a nightmare about him, his fangs dripping chocolate blood as he stalked me, Bela Lugosi-style, through the eerily empty halls of my school. God knows why. Other dreams make even less sense: I'm packing for a trip when there's a knock at the door. It's Fedex. For some reason, supreme court nominee Sandra Sotomayor has overnighted me a kitten.

So why does the brain produce this narrative junk? We still don't know why for certain, but the last few decades have produced a number of interesting evolutionary theories that move beyond old-hat Jungian archetypes or Freudian "wish fulfillment," and Scientific American's Jesse Bering recently laid out the Darwinian contenders.

Brain conditioning

If your brain went completely dark all night, the theory goes, it would begin to lose function just as rarely-used muscles will atrophy.

Several researchers, including the psychophysiologist Fred Snyder, argued that the adaptive purpose of dreaming may therefore be primarily to stimulate the brain or to keep it "in shape" during prolonged periods of inactivity. Later research offered support for this general idea. For example, specific categories of neurotransmitters were shown to be highly active during this period, while others seemingly "rested."

In other words, as psychologist Steven Pinker puts it, "Dreaming might be a kind of screen saver in which it doesn't really matter what the content is as long as certain parts of the brain are active."

External vigilance

Most dreams are notably lacking in olfactory and auditory content, and one theory holds that that's because if they were, the dreamer would be particularly susceptible to real-world threats like fire or noisy predators.

Being a "light sleeper" in relation to these other sensory domains had adaptive benefits, and since we're in the dark anyway and our eyes are closed, there's less of a risk in hallucinating in our secret visual worlds while our brains are being recharged.

Threat Simulation

This theory holds that dreams function as practice run-throughs for dangerous situations that may occur in the real world; they're drills. (Of course, this theory doesn't explain my kitten-in-the-mail dream; what was that preparing me for?)

"By giving rise to a full-scale hallucinatory world of subjective experience during sleep, the dream production mechanism provides an ideal and safe environment for such sustained practice by selecting threatening waking events and simulating them repeatedly in various combinations." What we should see in contemporary dreams, argues Revonsuo, are "threat scripts" depicting primitive themes of danger that would likely have been relevant in the ancestral environment, such as being chased, falling and so on.

Dreaming as problem solving

According to Harvard University psychologist Deirdre Barrett, "sleeping on it" really works in terms of real-world problem solving, and may actually be the evolutionary purpose of dreaming (even if those dreams don't always make sense to us.) In other words --

-- dreamscapes provided our ancestors (and therefore us) with a sort of creative canvas for solving real-world problems. In support of this, Barrett describes the work of Stanford University psychologist William Dement, who in the early 1970s instructed hundreds of undergraduate students to work on a set of challenging brainteasers before bedtime, so that they'd fall asleep with the problems still on their mind.

What do you think?

Painting by Jamal Vrno.

You can follow my weird dreamlife via Twitter.

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Health
8 Potential Signs of a Panic Attack
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It's not just fear or worry. In fact, many panic attacks don’t look like panic at all. Panic attacks come on rapidly, and often at times that don't seem to make sense. The symptoms of panic disorder vary from person to person and even from attack to attack for the same person. The problems listed below are not unique to panic attacks, but if you're experiencing more than one, it's a good idea to talk to your doctor either way.

1. YOU'RE DIZZY.

Doctors sometimes call the autonomic nervous system (ANS) the "automatic nervous system" because it regulates many vital bodily functions like pumping blood all on its own, without our having to think about it. Panic attacks often manifest through the ANS, leading to increased heart rate or decreased blood pressure, which can in turn lead to feeling lightheaded or faint.

2. YOU'RE LOSING YOURSELF.

Feeling detached from yourself is called depersonalization. Feeling detached from the world, or like it's fake or somehow unreal, is called derealization. Both forms of dissociation are unsettling but common signs that a panic attack has begun.

3. YOU'RE QUEASY.

Our digestive system is often the first body part to realize that something is wrong. Panic sends stress hormones and tension to the gut and disrupts digestion, causing nausea, upset stomach, or heartburn.

4. YOU FEEL NUMB OR TINGLY.

Panic attacks can manifest in truly surprising ways, including pins and needles or numbness in a person's hands or face.

5. YOU'RE SWEATY OR SHIVERING.

The symptoms of a panic attack can look a lot like the flu. But if you don't have a fever and no one else has chattering teeth, it might be your ANS in distress.

6. YOU KNOW THE WORST IS COMING.

While it may sound prophetic or at least bizarre, a sense of impending doom is a very common symptom of panic attacks (and several other conditions). 

7. BREATHING IS DIFFICULT.

The ANS strikes again. In addition to the well-known problems of hyperventilation or shortness of breath, panic attacks can also cause dyspnea, in which a person feels like they can't fill their lungs, and feelings of choking or being smothered.

8. YOU'RE AFRAID OF HAVING A PANIC ATTACK. 

Oddly enough, anxiety about anxiety is itself a symptom of anxiety and panic attacks. Fear of losing control or getting upset can cause people to avoid situations that could be triggering, which can in turn limit their lives. 

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Live Smarter
You Can Be a "Nonresponder" to Some Types of Exercise
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If you’re working out but don’t feel like you’re in any better shape, you might be a “nonresponder.” A study from Queen’s University in Canada finds that how people respond to exercise regimens varies substantially, and what works for one person may not help another person improve at all.

But that doesn’t mean those nonresponders will never get into shape. They just may need to change up their exercise routine for one that is better suited to their body. The study tested two exercise regimes on 21 active adults. Each of them spent three weeks doing endurance training (like running for an extended period of time) or interval training (doing quick bursts of strenuous exercise, like in CrossFit). After a few months of rest between workout periods, they then switched one routine for the other. Endurance trainees rode a stationary bike four times a week for 30 minutes, while high-intensity interval trainees did 20 seconds of hard pedaling on the bike with a 10 second rest after each interval.

Some of the participants showed improvements in physiological markers of fitness like heart rate and oxygen capacity after one of the workout periods, but others didn’t improve at all. Some were even in worse shape than before they began their assigned regimen. However, each individual responded to one of the workouts, even if they didn’t see results in the other.

To figure out which workout works for you, you’ll need to measure your fitness levels, using your pulse as your baseline number, at the beginning of a new workout routine. Then, after a month of either endurance or interval training, you should check to see if you've made improvements in your heart rate, according to the Times. If you haven't, you should switch to another routine.

[h/t The New York Times]

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