Display real name instead of user name in invite.php email

I'd like to modify the email template for invite.php to display the user's real name instead of their username, but I can't figure out what variable to use.

This is the original code:

<?php echo JText::sprintf('COM_EASYSOCIAL_EMAILS_FRIENDS_INVITE_CONTENT', $senderName);?>

						</p>

I need to know what to use instead of $senderName to display the Name instead of the Username

Thanks