setinterval not working to change image src

Wondering why the following code will not change my img src. The commented out example works just fine. And the alert triggers every 4 seconds. Replacing the src just wont work inside the set interval function.

$(document).ready(function(){
    $(".samples_1_1").on("click", function(){
        alert('asdf');
        //$(this).attr("src", "../../static/results/samples_1_2.png");
        setInterval(function() {
          alert('alert 1');
          $(this).src("src", "../../static/results/samples_1_2.png");        
        }, 4000);
      });
    });