Bar the alterations made to the login screen, the most immediate substantial change you’re aware of when booting up OS X Lion for the first time is the reversal of trackpad scrolling direction. Whereas previously a two-fingered slide down the pad would scroll a page down, now a two-fingered slide up the pad is required.

My initial reaction was that this seemed counter-intuitive. The move is obviously a part of Apple’s strategy to make their desktop / laptop OS mirror their wildly successful iOS for iPhone, iPod Touch and iPad. The swipe-up-to-move-down gesture on iOS is perfectly intuitive: you are moving the page directly with your fingers as though it was a physical document – as though pushing a piece of paper away from you.

After getting the gesture wrong a few times within my first couple of minutes with Lion I realised that the cognitive disconnection for me was that I’m not touching my MacBook’s screen, I’m touching the trackpad or the surface of my Magic Mouse. This single remove from the content on the screen proved enough for my brain to stumble at the page-as-physical-document analogy.

I’ve had no problem adopting Lion’s other gesture inputs: the three-fingered swipe between applications is on its way to replacing Cmd+Tab for instance, and if I ever spend the hour it’s going to take to sort Launchpad into something usable I’ll rely on the multi-finger pinch gesture to get there (I removed the ugly chrome icon from my Dock pretty quickly, along with the uninspring one for Mission Control).

But the more I thought about it, the more difficult I found the mental leap to seeing my trackpad gestures as directly controlling the screen. And I think I know why: decades of controlling a mouse cursor have firmly established in my mind that that is my presence on the screen. I pull the mouse down and the onscreen arrow moves down. I click the mouse button, move the mouse away from me and I begin highlighting text upwards on the page. With an OS that employs the convention of the mouse, as opposed to a direct touchscreen interface, it’s the cursor that I control, not the content on the screen.

The reason I was having a problem making the mental leap, it seems to me now, is that I was using a single finger in a downward gesture on the trackpad to move my cursor downwards, but the same gesture with two fingers moved the contents of my screen upwards.

So I decided to revert to the old style of scrolling. If you were being oversensitive about things you could choose to feel a little slighted by the fact that making this change involves unchecking a box marked ‘Scroll direction: natural’; that essentially makes my choice ‘Scroll direction: freakish’. It’s OK though, I have a thick skin developed over years of going into videogame option menus to invert my Y axis. But that’s another topic.