I don't think it's that unreasonable to speculate that a level of brain activity below that of an NDE would still be a conscious sort of awareness. Have you seen the recent research suggesting that NDE's correspond to supercharged brain states? if that is the case, its a long way from this level of activity to unconsciousness and that leaves plenty of intermediate levels of awareness, including groggy, foggy, indeterminate, incoherent, disoriented, apathetic, etc..

Have you seen many scientific studies that support notion that NDEs result from the process of the brain shutting down and are seen as a sudden spike in brain activity just prior to death?

This is where I found a study.
https://www.washingtonpost.com/national/health-science/surge-of-brain-activity-may-explain-near-death-experience-study-says/2013/08/12/47026016-0105-11e3-9a3e-916de805f65d_story.html?utm_term=.6a7c7895aaa4

My point was that a sudden spike just prior to death is not the same as a spike followed by a gradual decrease in brain activity representing "intermediate levels of awareness, including groggy, foggy, indeterminate, incoherent, disoriented, apathetic, etc."