What do you think when you hear the word memory? As Steemit is largely inhabited by computer freaks, I assume several of you associate it with computers first, with humans second. In this case, I’m talking about human memory, the topic of the lectures I’m currently attending.
As an introduction, I want to present you the first experiments connected to this, because we didn’t always know what we think is common knowledge today.
Remember, remember …
Herman Ebbinghaus, born in 1850, was told that human memory couldn’t be studied through experiments. That there was just no way that the results would have any significance.
Ebbinghaus said fuck you (showing Wilhelm Wundt, the guy who said that, the mental middle finger) and did it anyway, being experimenter and test subject at once. He made a list with meaningless syllables (bok, lef, taz, and so on) and tried to remember them. 2,300 of them, to be exact. This was repeated several times, with up to 744 hours between attempts. Each time, the time he needed to remember the list perfectly was recorded.
And what did he find out?
The time needed to learn the syllables reduced dramatically between the first few attempts to memorize it, which then reduced in a curve. At one point, repeating the information didn’t result in a decline in the time needed.
And just like this, he had experimentally studied something about human memory!
Take that, Wundt!
Trial and Error
How does learning work? How does our brain connect something we do with something that happens?
That was the question Edward Thorndike (1874 - 1949) asked. And what does a scientist do when they have a question?
They put a poor animal in a box and see what happens.
Watson’s puzzle box already existed and was created for monkeys. The monkey could reach outside the cage to open it and free itself. Thorndike adjusted this experiment for cats by putting a foot-pedal inside the cage that would open the door.
The cat would wander around in the cage, trying to get out, until it found the pedal. This process was repeated several times and the time was recorded. And the time the cat needed dropped, as expected.
Later, Thorndike repeated the experiment with fish, chickens, and dogs. I will leave the question how he made that work to your imagination.
Classic Conditioning
Pavlov … does that name ring a bell?
It shouldn’t! Instead, it should evoke the sound of a metronome.
Pavlov didn’t plan on doing psychological research. He was actually performing a digestion study, for which he was using dogs. He was interested in the link between digestion and salivation and wanted to know if he could cause salivation, and thus digestive activity, by creating an external stimulus.
But that stimulus needed to be regular, controlled. A bell can’t be that perfect, a metronome can. So each time before he fed the dogs, he would turn on the metronome.
This part is really important. If you want to condition something (or someone), you need to first provide the stimulus the subject is supposed to react to (the metronome) and then the stimulus the subject already reacts to automatically (the food). Otherwise, there won’t be any effect.
Oh, and Pavlov didn’t just use a metronome. In addition to several other kinds of regular sounds, he also used … electric shocks.
Aren’t scientists just such sweethearts!
Anyway. After some time of turning on the metronome and then feeding the dogs, the dogs started producing saliva any time they heard the metronome, even if there was no food.
This works on humans too. Just saying.
Sources:
Lecture “Lernen und Gedächtnis - Zelluläre und molekulare Grundlagen“ by Prof. Uli Müller
Pictures taken from pixabay.com
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