hi,
it's hard to say what you'll need in the future, as it will depend a lot on the direction you take. but i'd say that R would be a better second string to your bow, than spss. spss can certainly do more than jamovi ... but i'm not sure how relevant that stuff would be to neuroscience. R on the other hand, does a lot of very useful stuff to just about any field.
so if you want to develop some really useful skills, i'd encourage you to learn R.
i don't know if spss has much of a future.
cheers
jonathon