A reader writes:
Jonah Lehrer makes a valid point, but it seems a bit too myopic to carry his assertion that access and mobility do not hamper our memories, or at the very least, encourage the habit of bad memory. On Lehrer's side of the debate, there is the fact that the more one runs across a fact, the more likely one is to remember it. But, on the other side of that line there is a psychological tendency pushing in the direction of forgetfulness: knowing (assuming) that one will always and anywhere have quick access to the solution of every whimsical curiosity fosters a reliance on that access rather than on remembering. One is not encouraged to remember what one expects will always be at one's finger tips. Memory isn't a passive tool, clinging to whatever crosses the mind's field of vision. One must work to remember.
This is why I was so surprised at how well my generally terrible memory improved by forming a simple habit of memorizing a poem a night. I noticeably improved my general comprehension and retention in everyday reading. Living each day as if it's the last may or may not lead one to live a fuller, richer life, but treating each notable thing one reads or hears as if one will never come upon it again will lead one to take remembering more seriously. The omnipresent web fosters, all secondary benefits aside, a very different kind of relationship with information.
"N-back" exercises that you can download as an app can also help build memory.