Again, this makes logical sense; the primitive human who runs from something that might be a tiger was more likely to survive and reproduce than the one who said, “Let’s just wait so we can be sure.” The first human arrives back at the tribe intact, whereas the second is the tiger’s breakfast.
This is a useful survival strategy in the wild, but for the modern human it’s quite disruptive. The fight-or-flight response involves many real and demanding physical processes, and it takes time for the effects of these to wear off. The adrenalin surge alone takes a while to leave the bloodstream, so having our whole bodies enter combat mode whenever a balloon pops unexpectedly is rather inconvenient.25 We can experience all the tension and build-up required for a fight-or-flight response, only to realize quickly that it’s not required. But we still have tense muscles and a rapid heartbeat and so on, and not relieving this with a frantic sprint or wrestling session with an intruder can cause cramps, knots in muscles, trembling and many other unpleasant consequences as the tension becomes too much.
There’s also the increased emotional sensation. Someone primed to be terrified or angry can’t just switch it off in an instant, so it often ends up being directed at less deserving targets. Tell an incredibly tense person to “relax” and see what happens.
The demanding physical aspect of the fight-or-flight response is only part of the issue. The brain being so attuned to seek out and focus on danger and threats is increasingly problematic. Firstly, the brain can take account of the present situation and become more alert to danger. If we’re in a darkened bedroom, the brain is aware that we can’t see as much, so is attuned for any suspicious noise, and we know it should be quiet at night, so any noises that do occur get far more attention and are more likely to trigger our alarm systems. Also, our brain’s complexity means humans now have the ability to anticipate, rationalize and imagine, meaning we can now be scared of things that haven’t happened or aren’t there such as the axe-murderer bathrobe.
Chapter 3 is dedicated to the weird ways in which the brain uses and processes fear in our daily lives. When not overseeing (and often disrupting) the fundamental processes we need to keep ourselves alive, our conscious brains are exceptionally good at thinking up ways in which we might come to harm. And it doesn’t even have to be physical harm; it can be intangible things such as embarrassment or sadness, things that are physically harmless but that we still really want to avoid, so the mere possibility is enough to set off our fight-or-flight response.
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* It’s not exactly a one-way relationship either. The brain doesn’t just influence the food we eat; it seems the food we eat does (or did) have considerable influence over how our brains work.4 There’s evidence to suggest that the discovery of cooking meant humans could suddenly obtain a great deal more nourishment from food. Perhaps an early human tripped and dropped his mammoth steak into the communal campfire. The determined primitive maybe got a stick and hooked his steak out, only to find it was suddenly more palatable and appetising. Raw food being cooked means it’s easier to eat and digest. The long and dense molecules in it are broken down or denatured, allowing our teeth, stomachs and intestines to get better nourishment from our food. This seemingly led to a rapid expansion in brain development. The human brain is an incredibly demanding organ when it comes to bodily resources, but cooking food allowed us to meet its needs. Enhanced brain development meant we got smarter, and invented better ways of hunting, and methods of farming and agriculture and so on. Food gave us bigger brains, and bigger brains gave us more food, forming a literal feedback.
? This is a joke. For now.
2
The gift of memory (keep the receipt)
The human memory system, and its strange features
The word “memory” is often heard these days, but in the technological sense. Computer “memory” is an everyday concept that we all understand—a storage space for information. Phone memory, iPod memory, even a USB flash drive is referred to as a “memory stick.” There’s not much simpler than a stick. So you could forgive people for thinking that computer memory and human memory are roughly the same in terms of how they work. Information goes in, the brain records it, and you access it when you need it. Right?
Wrong. Data and info are put into the memory of a computer, where they remain until needed, at which point they are retrieved, barring some technical fault, in exactly the same state in which they were first stored. So far, so logical.
But imagine a computer that decided some information in its memory was more important than other information, for reasons that were never made clear. Or a computer that filed information in a manner that didn’t make any logical sense, meaning you had to search through random folders and drives trying to find the most basic data. Or a computer that kept opening your more personal and embarrassing files, like the ones containing all your erotic Care Bears fan fiction, without being asked, and at random times. Or a computer that decided it didn’t really like the information you’d stored, so altered it for you to suit its preferences.
Imagine a computer that did all these things, all the time. Such a device would be flung out of your office window less than half an hour after being switched on, for an urgent and terminal meeting with the concrete parking lot three stories below.
But your brain does all these things with your memory, and all the time. Whereas with computers you can buy a newer model or take a malfunctioning one back to the store and scream at the salesperson who recommended it, you’re basically stuck with your brain. You can’t even turn it off and on again to reboot the system (sleep doesn’t count, as we saw earlier).
This is just one example of why “the brain is like a computer” is something you should say to many modern neuroscientists, if you enjoy watching people twitch due to barely suppressed frustration. This is because it’s a very simplistic and misleading comparison, and the memory system is a perfect illustration of this. This chapter looks at some of the more baffling and intriguing properties of the brain’s memory system. I would have described them as “memorable,” but there’s no way to guarantee that, given how convoluted the memory system can be.
Why did I just come in here?
(The divide between long-term and short-term memory)