Yes you can. While holding the Alt (option for Mac) key down, position the pointer over the line that separates the adjustment layer and the layer directly below it (the one you want it to effect). You'll see something that looks like two dark circles (one overlapping the other). Click there, and you'll see your adjustment layer move a little to the right and it will add a down-pointing arrow. This is a "clipping mask" and it will restrict your adjustment layer to just the layer below it.