Not exactly. You can't manifest with it only if you've already manifested during the round. As there aren't many other useful purely mental actions you can take, it's best to use Multitask to manifest, and use your move+standard to do something else (examples as per my post.)
You can also use it for knowledge checks, Supernaturals and SLAs, which are all also purely mental actions.
You still get the action, you just can't manifest with it in that instance. But as above - SLAs, PLAs, Su and Knowledge checks are all fair game, as is directing something mentally.