Hi Sarah,
Thanks for this question! I did some digging on this question this morning (and have been deep diving into motor learning over the past couple weeks as I prepare for my MOSC exam and am revamping the NCS Advantage content!). Believe it or not, there isn’t much new literature pertaining to the inverse-U curve (performance relative to arousal) since the 1970s.
My best advice in this patient’s case would be to try to bring her level of arousal back to a therapeutic level in whatever way you can. Learning will be severely impaired in high arousal states. This article is for managing staff in the business world, but I think it has some good takeaways: https://www.mindtools.com/ax20nkm/the-inverted-u-theory.
This article explains that pressure is good up to a point but that performance declines when a person becomes overwhelmed by too much pressure/stress. The author outlines four influencers of pressure: skill level, personality, trait anxiety, and task complexity. Of these, we can most reasonably control skill level and task complexity with our interventions. If we select simple tasks with which the patient is proficient, for example, we may be able to relieve some of their pressure to bring their arousal back to a more therapeutic range, at least temporarily. Encouraging positive self-talk and discouraging negative self-talk during PT sessions can also reduce the impact of the patient’s stress.
It sounds like this patient definitely required an interdisciplinary approach with coordination with pharm and psych, which your team provided. If you are able to successfully lower her level of arousal with simple tasks the patient is comfortable with and positive self-talk, you may have the opportunity to offer more challenges to drive motor learning and help the patient achieve her goals.
Hope this helps!
Chrissy