Blurry Images (PHP)

In section 3.0.7 we gave an example how to show a stimulus only a limited amount of time. Now we look at another example, where we measure time that participants need to solve a problem.

We assume that abc.gif is a layered image that starts with some blurry spots which gradually evolve into letters. Participants have to find which of the spots becomes the letter A.

<HTML>
<?
    $sec=explode(" ",microtime());
    $sec=$sec[0]+$sec[1];
    echo "<BODY BGCOLOR=white>
        <FORM METHOD=POST ACTION=$SCRIPT_NAME>\n";
    if (! $SEC) {
        echo "<CENTER>Click on the letter A!<BR>
        <INPUT TYPE=IMAGE NAME=ABC ALT='.' SRC=abc.gif></CENTER><BR>
        <INPUT TYPE=HIDDEN NAME=SEC VALUE=$sec>";
    }
    else {
        $diff = $sec-$SEC;
        echo "This took $diff seconds<BR>
        Your coordinates were $ABC_x,$ABC_y";
    }
?>
</FORM>
</BODY>
</HTML>



Oliver Kirchkamp 2013-04-15