Scientists use Flashes of Light to Investigate Memory

If you’ve seen the Men in Black movies, you might remember the neuralyzer – the flashy thing the agents use to wipe memories? Well this might make you remember. Researchers at the University of California have just used flashes of light to find new evidence about how the brain stores memories.

What were they looking for?

Dr. Brian Wiltgen and Kazumasa Tanaka – a graduate student – were trying to investigate how the brain stores memories. It’s thought that one specific region of the brain – the hippocampus – is what triggers memory recall.

What did they find?

Their study supported their hypothesis. “Our study demonstrates that memory is retrieved when the hippocampus reinstates patterns of cortical activity that were observed during learning,” said Dr. Wiltgen in an email.

How did they do it?

To do this study, the researchers created genetically modified mice that did two specific things. First, their brain cells would light up like Christmas lights when activated by a memory. Secondly, the scientists could also temporarily de-activate cells.

The researchers then tested their hypothesis. If the mice were stimulated to remember a scary event in their past (in this case, an electric shock) they normally froze and their brain cells would light up. However, if the researchers turned off hippocampus cells, the brain cells never lit up and the mice didn’t freeze.

So?

It means that the mice didn’t recall that memory.

They forgot?

Not quite. The memory was still there – the brain cells were still there, after all – they just weren’t able to access it. Without the hippocampus to act like a key, the memory was locked away.

What does this mean?

In an email, Dr. Wiltgen said, “The hope is that once we figure out how these processes work we will be better able to understand (and treat) human disorders that affect memory.”

One caveat of this study is that the research was specifically looking at what’s known as episodic memories – memories of people, places, and events. It’s thought that other types of memory – such as skills or languages – might be controlled differently.