What this test measures
A set of squares lights up simultaneously, holds for a moment, and vanishes. Your job is to click every square that was lit, in any order you like. Clear the pattern and the next level adds one more square; the grid itself grows from 3×3 to 6×6 as you climb. A wrong click costs one of your three lives, and clicking a square you have already found costs nothing. Your score is the last level you completed.
What you are exercising is visual-spatial short-term memory: the ability to hold a spatial layout in mind for a few seconds without any external record of it. The moment the squares disappear, the only copy of that pattern is the one in your head, and everything you do next depends on how faithfully it survived the two or three seconds it takes you to start clicking. Psychologists call the amount you can hold your span, and the striking thing about span is how small it is compared with what the eye takes in. Your visual system handles millions of pixels at once. What it can carry forward past the moment of disappearance is a handful of items.
This is not the same as Sequence Memory
The two tests look similar and measure different things, which is exactly why both are here. In Sequence Memory the squares light one after another and you must reproduce the order. Order is the whole task: knowing which four squares were involved earns you nothing if you tap them in the wrong sequence. That is sequential span, and it leans on the machinery that keeps things in temporal order — the same machinery that lets you repeat a phone number back.
Here everything appears at once and order is irrelevant. There is no sequence to rehearse, so the strategies that carry you through a sequence test do not transfer. Instead you encode a shape: a diagonal, a cluster in one corner, three along the top edge. People often score quite differently on the two, and a large gap between them is informative rather than contradictory. It usually means one of the two encoding strategies is doing most of your work.
Why there is no percentile here
Most sites would tell you that your result beats some percentage of players. We do not, because no published normative distribution matches this task, and inventing one would make the number worse than useless.
There is a well-established clinical relative: the Corsi block-tapping task, in which an examiner touches wooden blocks and the patient reproduces the pattern. Normative data exists for it — Kessels and colleagues (2000) published standardisation data for exactly that purpose. But the Corsi task is sequential, administered by a person, with physical blocks. Grading a self-paced browser game with simultaneous stimuli against those tables would be comparing two different tasks and calling the difference a score.
The research that does speak to simultaneous patterns points somewhere interesting. Luck and Vogel (1997) found that visual working memory holds roughly four objects, and Cowan (2001) argued across a wide body of evidence that about four chunks is the general limit once rehearsal and grouping are controlled for. Those experiments used brief, precisely timed displays under laboratory conditions. This game shows the pattern for one to two and a half seconds on whatever screen you happen to be holding. If most people reach level eight or ten here — well past four squares — that is not a refutation of the research. It is evidence that you are grouping, which is the next section.
Why you can beat the four-item limit
The capacity limit is measured in chunks, not squares, and a chunk is whatever your brain has learned to treat as one thing. Three squares in a row are one chunk if you see them as a line. Four squares at the corners of a rectangle are one chunk if you see the rectangle. This is why players who describe patterns as shapes climb further than players who try to remember individual positions: they are spending one slot where the other person spends four.
Practical versions of the same trick:
- Look for lines and edges. Rows, columns and diagonals are already familiar objects and cost almost nothing to store.
- Split the grid into quadrants and count within each. "Two top-left, three bottom-right" is two chunks and a pair of small numbers, which is far cheaper than six coordinates.
- Name the shape. A silent verbal label — "L", "arrow", "staircase" — recruits a second memory system alongside the visual one, and two weak copies of a pattern beat one.
- Remember the gaps on dense boards. When most of the grid is lit, the unlit squares are the smaller set. Memorising four holes is easier than memorising fourteen tiles.
- Keep your eyes still. Sweeping around during the display costs you time and fragments the layout. A steady gaze near the centre lets peripheral vision take the whole board as one image.
- Click the ones you are sure about first. The pattern decays while you deliberate, so spending your confidence early leaves fewer squares to reconstruct from a fading trace.
What moves your score between runs
Expect variation. Span measures are noisy in individuals, and a single run tells you less than the shape of five runs. Screen size matters more than people expect: a 6×6 grid on a phone puts the whole board inside a small visual angle, which helps encoding, while the same grid on a large monitor forces eye movements that break it into pieces. Interruptions are brutal here — a notification arriving during the display does not distract you so much as overwrite you, because whatever occupies visual working memory next takes the slots your pattern was using.
Fatigue shows up as a specific failure: you still see the pattern clearly but lose it in the second or two between the squares vanishing and your first click. That gap is where maintenance happens, and maintenance is the first thing tiredness takes.
Frequently asked questions
Does order matter?
No. Click the lit squares in whatever order you like. Only the set matters, which is what separates this test from Sequence Memory, where the order is the entire task.
What is a good level?
We will not hand you a number dressed up as a norm, because none exists for this format. Use your own history instead: play several runs on the same device, take your typical level as your baseline, and treat movement against that baseline as real. Comparing a phone run with a desktop run is comparing two different viewing conditions.
Does practice actually help?
Your raw capacity is fairly stable, but your encoding strategy is not, and strategy is where most improvement comes from. Players who start chunking gain several levels quickly and then plateau. That plateau is closer to your real capacity than your first-ever run was.
Why does the grid keep growing?
Because a fixed grid stops testing memory once the pattern covers most of it. On a full board, remembering the few dark squares becomes easier than remembering the lit ones, and the task quietly turns into something else. Growing the grid keeps the lit squares sparse and keeps the measurement honest.
Is this a test for any medical condition?
No. It is a browser game, not a clinical instrument, and it cannot detect or rule out anything. Real assessment of visual-spatial memory uses standardised tasks administered by a professional under controlled conditions. If you are worried about your memory, that is a conversation for a doctor, not a web page.