How Plastic is Your Memory?

In today’s class, students learned how memories are formed and stored in the brain by strengthening connections between brain cells. They learned a new task that requires both visual and motor processing in the brain: how to hit a target with beanbags while wearing prism goggles. Students first learned how to toss beanbags at a target on the ground and to hit the target consistently. With the goggles, the target appears shifted relative to its real position. Humans are able to adapt quickly to this new information, however, and learn to hit the target while wearing the goggles. They also quickly unlearn the shift, and go back to hitting the target normally, when the goggles are removed. Ask your student how easy it was for him or her to learn the task and return to normal!

These changes in skill are due to changes in connections between the brain cells (called neurons) that govern vision and the brain cells that control movement. Neurons connect with each other at small gaps called synapses, and they send chemical signals called neurotransmitters across these gaps. Synapses that are used during repeated, successful practice get stronger, and send a stronger signal, with more neurotransmitter. Synapses that are not used are weakened and send a weaker signal.

Although all parts of the brain contain neurons, and can learn, different parts of the brain are needed to learn different things. To learn our beanbag throwing procedure today required making connections between neurons in visual areas of the brain and neurons in motor areas of the brain. These connections are made in the cerebellum. This type of learning can often take place without conscious thought, and remembering how to do this skill is called procedural memory. Another kind of memory, called declarative memory, takes place in another part of the brain called the hippocampus. Declarative memory is needed to remember experiences and facts.

Additional Information

Read about an amnesia patient, H.M. After surgery to treat severe and debilitating epilepsy, H.M. lost his ability to form new memories about events or experiences, but was still able to learn new motor skills:

And practice your declarative memory skills by coming up with new ways to remember a list of words in our Follow-up Activity, “Your Incredible Memory.”