NDE
My family had a summer tradition to meet at the lake with my cousins, aunts and uncles. We had a larger, tractor tire, innertube and a smaller, care tire, innertube so we would fit the smaller tube in the middle of the big tube to make a kind of inner tube raft. My cousins and I would cut about 20-30 feet of twine rope, tie it to the larger tube and take it out on the water. We would jump on the tubes and creat large waves until we would fall in the water, then we would swim to the middle of the smaller tube and climb back up on the innertube raft. It was a whole lot of fun and I would always look forward to those summer days.
One summer day I submerged, as I had done hundreds of times before, to make the 2' swim to the center of the tubes. Little did I know that as I went underwater one of my cousins jumped off the raft, which shifted it's position. As I tried to emerge in the center of the tubes I noticed the raft had shifted because my head bounced off the bottom of the tubes. I swam down a little looked up, adjusted my trajectory, closed my eyes because the water was murky and tried to emerge in the center again. Something shifted the tube again as my head got semi-stuck between the two tubes. I panicked a little, swam down a little more and checked where the tube shifted again.
This time I decided to swim to the outside of the raft, catch my breath and see what was going on. I swam a few feet and tried to surface, but my head met the bottom of the tubes again. Panic slowly began to fill my mind. I was almost out of breath and the only thing I could thing to do was to swim down. Swim down and push off the bottom of the bottom of the lake so I could finally take a breath of fresh air. I hadn't really paid attention to where we were exactly on the lake but I knew we didn't venture out too deep and assumed that I would be fine. Deeper and deeper I swam, all the while looking up, until I could feel my lungs screaming in pain and began to shake uncontrollably. I began to think that I was going to drown, just then my foot made contact with a rock just as my lungs were at their limit. I glanced up to see where the tube was then launched myself away from it with all my might. My lungs couldn't take it anymore and the air exploded out of my mouth which caused me to involuntarily gasp, inhaling the lake water.
Suddenly I was somewhere else, somewhere extremely dark where I couldn't feel anything. As I looked around at the emptiness I saw a speck of light in the distance and as soon as I saw the speck of light, I was engulfed. Suddenly I was surrounded by a warm golden light that seemed to stretch in every direction forever. As I looked towards the direction I was floating I saw three golden orbs somewhat close to me. As I gawked at these orbs, they began pouring into me slowly filling me with amazing sensations. After a few seconds I was full of whatever energy the orbs were made of and I began to feel sleepy. I began to assume a fetal positin as the light slowly began to fade past me but before I could fall asleep I felt a sharp cold spot on the end of my nose. The very next second was emerging from the lake directly beside the tubes. My arm reached up and grabbed hold of the tubes as I began purging the lake water from my lungs, screaming wildly at my cousins while they sat there staring at me in disbelief. I climbed on the tubes from the outside, which was much harder than from the center, and began tieing the twine rope around my waist. As I tied the twine I noticed that I felt different, as though I was now completely empty inside. After tieing the rope to my waist I jumped back into the water and pulled us back to our camp site and got out of the water.
I have felt that emptiness from that day onwards.

Honestly, I think that NDE experiences as evidenced by many researchers are actually not a good material to make a final conclusions - which the authors of such researches almost always do.
I didn't find a really reliable research on NDE in fact.
Perhaps you found any reliable research in this subject?