In this situation, response time has to do with the time it takes for the TV's pixels to change from, for example, black to white then back to black again. Say you have an LCD monitor with a white mouse cursor in the middle of a completely black screen. Now move that white cursor around. The smearing, or "ghosting" that appears behind the cursor as it moves is the result of response time. A longer response time results in more ghosting. In a case of zero response time, there would be no ghosting behind the cursor.
Input lag is the time it takes for your video/controller inputs to be shown on the screen. In the case of the black screen and mouse cursor, input lag would be the amount of time it takes between you actually moving the mouse and the cursor moving on the screen.
Response time has nothing to do with the delay you experience in shooters. This is all related to input lag. Just like where you have to calibrate your system for input lag on the rock band games.
Hermolicious84 is correct. Manufacturers never give out input lag specs. It is always response times.