Interactive Grid First Row Not Selected Default

For Apex Version 19.1 and Above 

1. Goto Region Attributes >> Advance > JavaScript Initialization Code
Copy-Pest the below code :

function(options) {
  options.initialSelection = false;
  return options;
}

OR

For Apex Version 18.2 and Below Version 

Step 1 .  Create a Interactive Grid form. Then assign static id as 'emp' of the Interactive Grid region.

Step 2. Goto Page properties >>Execute When Page Load >>
copy pest the below code.

var ig$ = apex.region("emp").widget();
ig$.interactiveGrid("getViews", ig$.interactiveGrid("getCurrentViewId")).setSelection($());

Thank You