Your Brain Doesn't Contain Memories. It Is Memories
Recall your favorite memory: getting a top grade in school; the moment you first saw your child's face; the day you realized you had fallen in love. It's not a single memory, though, is it? Reconstructing it, you remember the smells, the colours, the funny thing some other person said, and the way it all made you feel.
Your brain's ability to collect, connect, and create mosaics from these milliseconds-long impressions is the basis of every memory. By extension, it is the basis of you. Every sensory experience triggers changes in the molecules of your neurons, reshaping the way they connect to one another. That means your brain is literally made of memories, and memories constantly remake your brain. This framework for memory dates back decades, which is why you remember things from years ago.
Defining memory is about as difficult as defining time. In general terms, memory is a change to a system that alters the way that system works in the future. A typical memory is really just a reactivation of connections between different parts of your brain that were active at some previous time. All animals—along with many single-celled organisms—possess some sort of ability to learn from the past, they have memories.
Obviously, no memory exists all by itself. Brains break down experience into multiple time scales experienced simultaneously, like sound is broken down into different frequencies perceived simultaneously. This is a nested system, with individual memories existing within multiple time windows of varying lengths.
Confused? You should be, because this is very hard for neuroscientists to understand too. Which means it's going to be a long time before they understand the nuts and bolts of memory formation.
▍生词好句
it's not..., though, is it? : it's used when you want to emphasize some contrasting information about sth., to give some balance to a situation you are describing.
mosaic /mə(ʊ)ˈzeɪɪk/ : n. tiles decorated with in a room. (引申含义: a combination of different elements which together form one thing.) (常用搭配: a clever / rich mosaic)
by extension: connected to what you have just mentioned; taking an earlier idea or point and then to take it one step further. (常用于写作中)
literally /ˈlɪt(ə)rəli/ : adv. to emphasize an exaggeration; to emphasize how large sth. is, especially how large an amount of sth. is; to emphasize a statement and suggest that it is surprising.
in general terms: if you describe sth. in general terms, you describe it without giving details.
all by itself: not near any others; without help from others; without being made to do sth. by others; to show that only one thing is involved in a process or an event.
the nuts and bolts of sth.: the practical workings of sth. and not the theoretical ideas behind sth.; the basic facts or practical things that we need to understand.
