I think the brain is most interesting when it doesn't work the way you expect it should. Psychology often confirms our intuitions about how our minds work, but it offers quite a few surprises as well. Although some psychology buff's will have heard a few of these before, here's a list of quirks in your brain you probably didn't realize you had:
1) Your short-term memory has a max capacity of seven.
Humans have three forms of memory: sensory, long-term and short-term. Long-term memory is like hard-drive space, while short-term memory works like a very small RAM. This short-term memory can hold only about five to nine (average is seven) items at a time.
Remembering information longer than this requires you to either compress it down into seven units or store it in long-term memory. Most phone numbers are only seven digits.
2) Chartreuse is the most visible color.
Yellow-green, chartreuse, sits right in the middle of the frequencies of visible light. Your eyes have receptors for blue, green and red. Being in the middle, yellow-green triggers the most of these receptors to fire, making it easy to spot. In some cities, firetrucks have been changed from red to a yellow-green color to make them more visible.
3) Your subconscious is smarter than you are.
Or at least more powerful. In one study, a square was assigned to a location on a computer screen through a complex pattern. After watching it, people began to get results better than chance of picking out where the square would pop up next. But when asked to consciously determine the pattern, even given a few hours, nobody could do it.
4) You have two nervous systems.
One set controls excitation and the other controls inhibition. If you hold out your hand, you might notice minor tremors. This is caused by slight, random differences in the amount each of the two systems are firing.
5) Your brain is awful at probability.
Okay, so maybe your high-school math teacher could have told you this one. But, what's interesting isn't that your brain is bad at probability, but how. In one study recipients were asked:
Linda is 31 years old, single, outspoken, and very bright. She majored in philosophy. As a student, she was deeply concerned with issues of discrimination and social justice, and also participated in anti-nuclear demonstrations.
Rank the following statements from most probable to least probable:Linda is a teacher in an elementary school.
- Linda works in a bookstore and takes Yoga classes.
- Linda is active in the feminist movement.
- Linda is a psychiatric social worker.
- Linda is a member of the League of Women Voters.
- Linda is a bank teller.
- Linda is an insurance salesperson.
- Linda is a bank teller and is active in the feminist movement.
Almost 90% of students responded that #7 was more probable than #5. This is despite the fact that to be a bank teller and in the feminist movement is completely contained within the set of #5 (just being a bank teller). It seems our minds like to think more details make events more probable, not less.
6) Your memory isn't great either.
Studies have shown that people are highly likely to misremember past events. Even worse, it is incredibly easy to suggest a memory that never happened. This is why so-called "repressed" memories should be given a lot of thought. It is far easier to suggest a memory of an event never happened, then it is to recover one that actually did.
7) You can perceive depth with one eye.
It's a myth that depth perception is entirely the result of having two eyes. Binocular vision does assist in making a three-dimensional picture. However, most of your ability to perceive depth comes from inside your brain. It has been wired to look at angles and proportions to judge distance.
If you required two eyes to perceive depth then most optical illusions wouldn't work and it would be incredibly difficult to gather information from flat photographs. Not to mention a lot more one-eyed pirates walking overboard.
8 ) Long-term memory shuts down during sleep.
The parts of the brain that transfer information to long-term memory shut down while sleeping. This is why dreams quickly fade away after you wake up. Although you may have several dreams in a night, they aren't being recorded into long-term memory. Generally only the fragments of a dream left in short-term memory have a chance to be encoded after you wake up.
9) You have an instant playback feature.
At the beginning I mentioned that humans have three forms of memory, short-term, long-term and sensory. Sensory memory is your brain's equivalent to an instant playback feature. Working for both your vision and hearing, your thalamus can resend signals a few seconds after they were originally sent.
Imagine being at a party and overhearing someone say your name. Often you can recall what they said even though you were focused on another conversation. This is because your sensory memory re-sends the signals when it finds something important, such as your name. If you lacked this form of memory, activities such as multitasking or taking notes from a speaker would be impossible.
If you're asked to repeat something you just said because the other person wasn't listening, just wait a few seconds. Often they can replay the message in their head and give a response.