Faced with a dauntingly complex problem, scientists typically do the logical thing. They break it into component parts, to simplify and focus their efforts. After all, grappling with smaller facets lets you try to conquer, one piece at a time, a larger problem. But the brain’s very nature resists this technique. In effect, it refuses to be compartmentalized. The more researchers may attempt to look at a single processing question, the more it turns out to be interrelated with many other things going on in the brain.

Take memory. It’s tempting to think of recall as a video recording or some simple device. Far from existing in one discrete module, however, recollections develop from thousands of connections among neurons. In the first article of this issue’s special report on memory, “Making Connections,” by Anthony J. Greene, you will learn that neural connections underlie everything we know. As neurons light up together, they create links within which our memories lie. As Greene puts it, memories are “a web of connections between people and things.” Events that have high emotional value are particularly crisp in our minds. The second article of our special report, “Yearning for Yesterday,” by Jochen Gebauer and Constantine Sedikides, explains how nostalgia, where we bask in the past, can actually be good for you.

Likewise, speech and music at first seem separate in nature. We talk to convey information. Music seems to come from a more emotional place. But perhaps you will not be surprised at this point to learn that, in fact, the brain areas responsible for these functions communicate with one another a great deal—and they develop together as well. Music and language turn out to be partners in the brain. “Indeed, in many respects, music and speech seem to be mirror images, with both playing integral roles in the development of the other—in the way we, as people, bond and communicate, in how we perceive the sounds around us, in our understanding of language and in the workings of our minds,” writes Diana Deutsch in her feature, “Speaking in Tones.” Check out the article to find out why a song in your heart means you can talk the talk.