Attentional Blink Test: Catch Two Rapid Targets

Rapid serial visual presentation places successive items in the same location rather than arranging them across the screen. Letters act as distractors, while two non-repeating digits are the targets. Stable position and size reduce spatial search demands.

Demo mode uses a slower 180 ms frame and one trial at each lag. Standard mode uses 100 ms frames and six trials per lag. Extended and Custom modes change repetition or frame duration, so their results should not be pooled with another setting.

T1 is the first digit and T2 is the second digit in a stream. The response form always asks for T1 first, then T2. Because answers are collected after the complete sequence, motor reaction time is not mixed into target presentation timing.

Every generated sequence contains exactly two targets, and T2 is never the same digit as T1. Distractor letters omit visually ambiguous characters where practical. A fresh seed randomizes target values, distractors, and lag order.

Lag is the position difference between T1 and T2. At lag 1, T2 immediately follows T1; at lag 2, one stream position separates their indexes. This implementation covers lags 1, 2, 3, 4, 5, 6, and 8.

Standard and Extended modes balance the number of trials at every lag before shuffling their order. The chart reports the actual completed trial count for each point rather than drawing a reference curve or a supposed normal range.

T2|T1 means T2 accuracy among trials where T1 was reported correctly. Conditioning on T1 separates second-target reports from trials where the first target was not successfully identified at all.

The page also shows overall T1 and T2 accuracy so the conditional percentage is not read alone. If very few T1-correct trials remain at a lag, the point has a weak denominator; the table displays counts and warns against a stable interpretation.

Presentation is scheduled in the browser and checked against performance.now(). If an actual frame interval differs substantially from the requested interval, that trial is marked timing-invalid and the session receives a timing-drift flag.

Refresh rate, power saving, background work, browser scheduling, and display hardware can all alter timing. The page therefore does not claim millisecond laboratory precision. Hiding the tab pauses the task and invalidates timing for the affected trial.

The graph is a descriptive profile of T2|T1 across the seven lags completed now. It can show uneven accuracy across target spacings in this session, but it does not fit a normal curve, compare you with a population, or diagnose a deficit.

Attentional blink is a temporal two-target phenomenon. It is not the same task as sustained attention over minutes or simultaneous visual-memory recall. One short RSVP run cannot determine health or attention ability as a whole, and practice does not guarantee broad improvement.

Raymond, J. E., Shapiro, K. L., & Arnell, K. M. (1992). “Temporary suppression of visual processing in an RSVP task: An attentional blink?” Journal of Experimental Psychology: Human Perception and Performance, 18(3), 849–860. https://doi.org/10.1037/0096-1523.18.3.849