The Stroop test measures interference in your reaction time to stimuli. You are offered matched (congruent), neutral, and unmatched (incongruent) stimuli.
The classic example of this is the color word/color test (“Red” written in yellow). Another would be number/number of words (when counting words, “three words” interferes with the correct response of 2). You could also do word/spatial location of word (“bottom” in the top of the screen).
These tests look at your automatic associations. Are some more powerful than others? What might get processed first, basic features or semantic content?
Stroop tests get more interesting when expanded to look at associations to emotional content. This is the premise of the bias tests – your reaction time slows when you see an incongruent association (race, positive word vs race, negative word).
I started writing a Processing sketch for reaction bias, but most of them are available online already, such as the Stroop color test.
Something I would like to study in the future is the relationship between meditative states and trance/hypnotic states. The same priming words and tones can be used to induce both, so what makes them different? One paper says there is virtually no difference. Another agrees, except to note heartrate tends to be slower in meditators. One looks carefully at pre-frontal cortex regulation. The systems for attention and consciousness are tied together so we should expect these altered conscious states share a basis.
Over the weekend I attended a Hack the Brain event at the New School. I tried using the MindFlex to measure my attention, but did not get readings that made sense.
Taken while “focusing” the exact same way. Readings fluctuated almost randomly. When I visualized something very specific, attention did go up a little, but the other readings had no clear correlates. I then tried not focusing on anything at all, and also meditating. Nothing seemed to have a clear correlate.
I experimented with it over the course of an hour and finally gave up. This is not a good device for reliable EEG!