I'm confused as to how you're going to measure how well the priming was because you did not test how quickly I responded to the images BEFORE playing the game. Where is your control sample?
Also by stating it was a maze, I spent most of my time not really sure what I was doing or looking for and it never really sunk in that the trucks were taking away my health.

This is not a game - it but tricks the player into thinking it is.

That being said, some considerations regarding the interaction:

"Maze"
- The maze instance is not only confusing but also unfair: NPC vehicles display erratic patterns, making collisions almost unavoidable
- The 'maze' is nothing but a twisting of narrow roads, and the tires have no other purpose than to give scorepoints to the subject - but then again, what are those scorepoints for? Nothing.
- Three hearts for the player means a short run, reducing interest on 'playing'

Although I understand the study you are undertaking (my major's on Psychoanalisis and Languages), my guess is that your attempt was poorly executed. In my case, while at the maze instance, I was just driving aimlessly, trying to see if there was some kind of exit to the maze (there was none, which frustrated me); then, coming to the pictures' instance, the only thing that kept me guessing (regardless of answertime delay) was to see where it would lead (to nothing, as one may notice).

Regardless of the result you collect from other players, my bet is that the results will all vary so much that you'll have to set a couple model answers to fit to the data you gathered. Due to the poorly-implemented gameplay and truly deceiving character of this flass application, probably none of the result should fit to the survey you meant to collect.

Wow I actually did something productive today huh? I feel good.

Thanks Newgrounds!

15/10 would try again the maze

Guine pigs are for sale not volunteers! I'm sorry I can play only if you pay

I'm delighted to know that I helped with something, specially with science. It was entertaining.