Two things that the Bible says.
1. the dead know nothing – Ecclesiastes 9:5
2. there is going to be a resurrection – acts 24:15
Add those two together and it is evident that a dead person will have no awareness of the time that passes between his death and his resurrection: dying and being resurrected to the dead person will happen in an instant.
So a person dying under even the most horrendous circumstances will pass instantaneously back to life. Whatever they were experiencing when they died will be gone and they will wake up surrounded by friends and family welcoming them back to life.
What will that person feel? Will they feel resentful and angry about the means of their death or will they feel a whoosh of relief that the means of their death is gone and that they are still alive in a new world?
The apostle Paul wrote: death, where is thy sting? Because the resurrection means that death has no sting. Every victim of the world of men will find relief and healing by means of the resurrection.
Why then did Jesus tell us about the rich man and Lazarus, and described the rich man as being fully aware of his state, and surroundings?
Luk 16:19-31 WEB
19 “Now there was a certain rich man, and he was clothed in purple and fine linen, living in luxury every day. 20 A certain beggar, named Lazarus, was taken to his gate, full of sores, 21 and desiring to be fed with the crumbs that fell from the rich man’s table. Yes, even the dogs came and licked his sores. 22 The beggar died, and he was carried away by the angels to Abraham’s bosom. The rich man also died, and was buried. 23 In Hades, he lifted up his eyes, being in torment, and saw Abraham far off, and Lazarus at his bosom. 24 He cried and said, ‘Father Abraham, have mercy on me, and send Lazarus, that he may dip the tip of his finger in water, and cool my tongue! For I am in anguish in this flame.
’ 25 “But Abraham said, ‘Son, remember that you, in your lifetime, received your good things, and Lazarus, in the same way, bad things. But here he is now comforted, and you are in anguish. 26 Besides all this, between us and you there is a great gulf fixed, that those who want to pass from here to you are not able, and that no one may cross over from there to us.’ 27 “He said, ‘I ask you therefore, father, that you would send him to my father’s house; 28 for I have five brothers, that he may testify to them, so they won’t also come into this place of torment.’ 29 “But Abraham said to him, ‘They have Moses and the prophets. Let them listen to them.’ 30 “He said, ‘No, father Abraham, but if one goes to them from the dead, they will repent.’ 31 “He said to him, ‘If they don’t listen to Moses and the prophets, neither will they be persuaded if one rises from the dead.’”
Looks pretty clear that Abraham and the rich man were quite aware, and very cognizant of their surroundings, the surroundings of each other, and were pleading for relief of others who were not yet dead.
We then see in John 11 that Jesus told Mary that the dead who believe in him are actually quite alive.
Joh 11:25-26 WEB
25 Jesus said to her, “I am the resurrection and the life. He who believes in me will still live, even if he dies. 26 Whoever lives and believes in me will never die. Do you believe this?”
It's also curious that Paul told the Corinthians in 2 Corinthians 5 that once they left their bodies, they would immediately be in the presence of the Lord, and would be better off.
2Co 5:1-9 WEB
1 For we know that if the earthly house of our tent is dissolved, we have a building from God, a house not made with hands, eternal, in the heavens. 2 For most certainly in this we groan, longing to be clothed with our habitation which is from heaven, 3 if indeed being clothed, we will not be found naked. 4 For indeed we who are in this tent do groan, being burdened, not that we desire to be unclothed, but that we desire to be clothed, that what is mortal may be swallowed up by life. 5 Now he who made us for this very thing is God, who also gave to us the down payment of the Spirit. 6 Therefore we are always confident and know that while we are at home in the body, we are absent from the Lord; 7 for we walk by faith, not by sight. 8 We are courageous, I say, and are willing rather to be absent from the body and to be at home with the Lord. 9 Therefore also we make it our aim, whether at home or absent, to be well pleasing to him.
We then read in Philippians 1, how Paul describes he'd prefer to be with Jesus, instead of in this life, but that he'll stick around to benefit the people of philippi.
Phi 1:20-25 WEB 20 according to my earnest expectation and hope, that I will in no way be disappointed, but with all boldness, as always, now also Christ will be magnified in my body, whether by life or by death. 21 For to me to live is Christ, and to die is gain. 22 But if I live on in the flesh, this will bring fruit from my work; yet I don’t know what I will choose. 23 But I am hard pressed between the two, having the desire to depart and be with Christ, which is far better. 24 Yet to remain in the flesh is more needful for your sake. 25 Having this confidence, I know that I will remain, yes, and remain with you all for your progress and joy in the faith,
Based on these, I'm not seeing anything that would show humans are not cognizant of their surroundings, during this life or the next.