Another glider crash?

A few people have mentioned 'tunnel vision'.

I've heard of 'tunnel vision' associated with hypoxia, and also with the 'fight or flight adrenaline response' where vision is literally narrowed to the center of the visual field. Tunnel vision is like you're looking through a tube. The field of vision is narrowed to a few degrees.

But in this case, are people actually suggesting 'mental fixation' where the mind is unable to switch to an alternate course of action or alternate explanation for what is happening? For example, pilot becomes fixated on the idea that the spoilers are malfunctioning and fails to realize that he is holding the gear lever? This metaphoric, but not literal 'tunnel vision'.

My reason for asking is that I'm wondering whether 'mental fixation' is more likely during the 'fight or flight adrenaline response'? Is there any training or habits of mind that will reduce the tendency to mental fixation. Is a tendency to 'mentally fixate' a part of the normal aging process? Does fatigue increase the tendency to mentally fixate?

These questions have general medical/technical answers, but it would be useful hear anecdotes of how individuals have been tripped up by mental fixation in the context of soaring. I'd like to think about how I might find myself fixating while piloting and how I might spot that when it is happening and 'snap out of it'. Knowing about the case of 'grabbing the gear handle and thinking it is the spoiler handle' might pop into my mind if I'm ever in that situation. It would be useful to know of other common cases of fixation in piloting gliders.