https://ai.meta.com/blog/brain-ai-image-decoding-meg-magneto... [2023] https://ai.meta.com/blog/brain-ai-research-human-communicati... [last year, focuses on decoding text]
^ There's a research team at Meta that studies this. You need an MEG -- thats $2-5M + the shielded room it lives in and the experts that can operate it.
EEG doesn't work due to low spatial resolution and how finicky it is to place the electrodes to get a good signal
The signals from neurons are just unbelievably tiny and are in an absolute sea of noisy trash. No one is ever going to read your thoughts without your consent (or by wrestling you into a big MEG, in which case you have bigger things to worry about). No one is going to be reading your dreams with any sort of accuracy either.