Yes, it is possible by calling the method setPingInterval . By default, an update is sent every 5 seconds. Sending the ping more frequently can be useful to get a bit more accurate statistics, sending it less frequently can be useful to reduce the amount of traffic your server has to handle.
var intervalInSeconds = 2;
_paq.push(['MediaAnalytics::setPingInterval', intervalInSeconds]);
Make sure to call this method as early as possible, for example just after _paq.push(['setSiteId', 'X']);