My trackpad and keyboard stop working every few minutes

My comp: 2012 Macbook Pro, (not retina) 15-inch display, 2.6GHz i7, 8 GB 1600 MHz DDR3, less than half storage used out of 750GB, running OS X Yosemite 10.10.4

Basically, every 5-10 minutes or so, my trackpad freezes and i can't move the pointer. I try to scroll with the arrow keys, and that doesn't work either so there seems to be intermittent lapses between the communication of my comp and screen or maybe it's not going through at all. If If move/click/hit the trackpad for a few seconds, it seems to come back working, but it is obviously very annoying.

Any ideas? Thank you!