Is memory unchanging, or ever-changing?
Regardless of the handiness of our smartphones, we still rely on our memories to recall certain images and events that we did not record. We'd like to think that those memories are, as much as possible, "true."
But here's the thing: The way you encode memories depends on the state of your brain at that moment and the environmental context. That means neural network changes forever, and will never return to that exact state, Tranquillo and Hunter said. And when you recall something, that changes your brain, too! The very act of remembering uses brain processes, so you can never go back to the self that you were in the moment you're thinking about. Pretty trippy, right?
Technologies are emerging to help people document their lives digitally as never before. For instance, Microsoft developed a camera called SenseCam, which captures photos of your visual experience all day, every day. Gordon Bell, a Microsoft researcher, wrote a book called "Total Recall" in 2009 after recording every aspect of his life for a decade.
You might think that digital memory is more stable -- at its core, it's just a collection of 0s and 1s after all.
But, like the brain, technology is a constantly evolving, open system, subject to environmental influences. On a small scale, think about how files must be filtered to change formats. With compression, images and videos lose resolution and quality. But programs can alter photos in ways that enhance them, too. The computer is reassembling and reprocessing the files in each of these cases.
And, your computer may eventually break down, purging your files (which is why hard-drive backups are recommended).
Social media also gives new meaning to digital storage. Where you share a photo, how it gets tagged and what its caption says all create a memory around the image that wouldn't exist otherwise, Tranquillo said.
And your digital memory becomes influenced in even stranger ways now that there are social networking tools that update content without your direct intervention -- for instance, posting on Facebook or Twitter when you arrive at a location. With Facebook's Timeline feature, other people can contribute to your online life history by posting photos, videos and comments.
"This is the crowdsourced self," Tranquillo said. "As the viewer changes, so does the collective construction of 'you.'"
Aiding the aging brain
You may have, at one point or another, struggled with multitasking. That's because when you move from one task to another, your brain shuts down one neural circuit in order to move on to the next. That's inefficient, and studies have shown that it's harder for older adults to re-establish that initial circuit and return to the first activity.
But if you use the Internet in ways that make your life more efficient, it could theoretically reduce the multitasking that you do. You don't have to fumble through an address book frantically, or find your way out of an unfamiliar neighborhood unguided, while thinking about other things.
That's important as the number of Americans with Alzheimer's disease -- currently 5.5 million -- continues to climb. As people get older and their memory begins to decline, they are still able to access information through search, helping to compensate for their own memory deficits.
Small is working with computer scientists at UCLA on games that can help older people improve their ability to remember names and faces. Plenty of research is in the works to find brain-boosting pharmaceuticals, supplements and foods (most recently, berries), although nothing is a certain supplement.
The dark side
The downside of technology is that it can make us less thoughtful and less creative. And we may spend less time communicating face to face, which can reduce the quality of relationships. A 2012 survey of American girls found that spending time multitasking with various digital devices, watching video or communicating online is associated with abnormal social tendencies.
It's also not certain that freeing our memory from addresses and phone numbers frees up room to be more creative, Tranquillo said.
What's more, a lot of creative thinking depends on having ideas accessible in a way that preserves their context, so merely writing them down to keep externally -- whether on a computer or a notebook -- doesn't necessarily allow you to do novel things with them.
Tapping storage potential
It's not hard to appreciate how, in terms of sheer volume, computer memory has outpaced humans. Google's Gmail offers 10 gigabytes of storage. Tom Landauer, professor of psychology at the University of Colorado at Boulder, estimated in 1986 that the human brain holds 200 megabytes of information.
And what if we stored all of an individual's experience? Landauer calculated that if a person only takes in one byte per second, and lives about 25,000 days, that's still only 2 gigabytes.
But that's just a tiny fraction of estimates for the brain's total storage capacity, which is as high as 2.5 petabytes (2.6 million gigabytes), based on the number of neurons (1 billion) and connections to other neurons.
That sounds like a lot, but McKinsey Global Institute estimated that consumers stored 7 exabytes (7.5 billion gigabytes) of new data on PCs, laptops and other devices in 2010.
Obviously, there is too much information out there to hope to compete with our minds against machines. But there are certain things you can do to help your brain live a long, healthy life so that you are using it to its fullest potential.