How to Adjust Swift Animation Speed?

Hi all,

I'm new to programming, so please excuse any lack of clarity. I'm trying to make one of my buttons have a "blinking effect" using the animateWithDuration method. Currently, it works as a "fade," where the button gradually shows up and disappears every 1 second (I set the duration to be 1.0). I'm hoping to reduce the speed of the animation (not the duration, but the speed), so that the animation effect would occur more abruptly. The interval of the animation needs to stay at every 1 second. Is this possible to accomplish? I've been researching, and it seems like animateWithDuration doesn't allow this sort of specification... Do I need to approach this via another method? I'm including my code below. Thanks for your help! Btw, this is all under UIViewController in UIKit.

    override func viewDidLoad() {
        super.viewDidLoad()

        self.tapButton.alpha = 0
    }

    override func viewDidAppear(animated: Bool) {
        super.viewDidAppear(true)

        UIView.animateWithDuration(1.0, delay: 0, options: .Repeat | .AllowUserInteraction | .Autoreverse, animations: { () -> Void in self.tapButton.alpha = 1.0
            }, completion: nil )
    }