Cognitive Psychology
Posner Spatial Cueing
Keep your eyes on the cross. A box brightens, then a target appears — sometimes where the cue was, sometimes not. Press as soon as you see it.
Illustrative timing — a browser demonstration, not laboratory measurement
Learning objective
By the end you should be able to split a cueing effect into a benefit and a cost using a neutral baseline, and say why neither shows covert orienting on its own.
About 20 minutes. Nothing you do here is saved or sent anywhere.
What this browser cannot do
Your eye position is not measured. This page has no access to a camera or an eye tracker, and it cannot tell whether you kept fixation or simply looked at the cue. Asking you to hold fixation is an instruction, not a control. Every result here is compatible with covert orienting and with small eye movements you did not notice making.
Browser timing is approximate. Display refresh, keyboard latency and background processes add tens of milliseconds. Treat the numbers as illustrative.
- Answer the prediction below — it unlocks the experiment.
- Run the untimed practice trials first. They give feedback and are not scored.
- Run a scored block. Keep looking at the central cross throughout.
- Read your three condition means, then work out where the benefit and the cost are.
- If you would rather not do a speeded task, load the worked example instead: it is a documented simulated dataset and reaches every conclusion on this page.
First, a prediction
In the experiment below, a cue brightens one of two boxes and then a target appears in one of them. On valid trials the target appears in the cued box; on invalid trials it appears in the other one; on neutral trials both boxes are cued, so the cue points nowhere. The cue is correct on three out of every four cued trials, so it is worth using.
The experiment
Look at the central cross and keep looking at it. When the target — a filled disc — appears, say which box it is in: press Left arrow or Right arrow, or use the two buttons. No trial is timed out; the target waits for you.
Key terms
- Covert orienting
- Shifting attention to a place without moving your eyes. It is why the task asks you to keep looking at the central cross.
- Cue-to-target interval
- The gap between the cue appearing and the target appearing. Often written SOA, for stimulus onset asynchrony.
- Neutral trial
- A trial whose cue points nowhere in particular. It is the baseline the valid and invalid conditions are each measured against.
- Benefit and cost
- The two halves of a cueing effect, each measured from the neutral baseline: what a valid cue was worth, and what an invalid one cost.
Which box is the target in?
Six untimed practice trials with feedback, then a scored block with no feedback until it ends.
Status Not started.
Answer the question above to unlock the experiment.
Three conditions
| Cue type | Trials | Correct | Mean RT | Median RT | Spread (SD) |
|---|
Benefit, cost, and what they are not
Reading your pattern
Challenge — benefit, cost, or neither?
Three fictional studies report mean reaction times for the same three conditions. For each, decide what the pattern supports. The neutral condition is the baseline: a cue can only be said to help if valid beats neutral, and can only be said to hurt if invalid is worse than neutral.
What this demonstrates
Attention can move while the eyes do not
The cueing paradigm was designed to show that the place you are attending to and the place you are looking at can come apart. A cue you are told to ignore, at a location your eyes never visit, still changes how quickly you respond to what appears there. That dissociation is the reason the word covert is used at all: overt orienting is the eye movement, covert orienting is the shift of attention that can happen without one.
A neutral baseline is what makes the effect readable
Valid trials minus invalid trials gives one number, and that number hides two different things. Subtract the neutral baseline instead and you get two: a benefit (neutral minus valid) when attention is already in the right place, and a cost (invalid minus neutral) when it has to be disengaged from the wrong one. Studies that report only valid against invalid cannot tell you which of the two produced their effect, and the two have different theoretical consequences.
Cost is usually the larger half
In the published literature the cost of an invalid cue is typically bigger than the benefit of a valid one, which is part of why disengagement became a topic in its own right. Whether your own block shows that depends heavily on how many invalid trials you ran — eight is not many.
Endogenous and exogenous cues are not the same thing
A peripheral flash, like the one used here, pulls attention whether or not it is informative and does so within roughly a tenth of a second. A central symbolic cue — an arrow at fixation that you have to interpret — works more slowly and only when it is worth using. This tool uses a peripheral cue that is also predictive, so it mixes the two, which is a simplification made for the sake of getting a visible effect in a classroom block.
For teaching elsewhere: take this activity as one self-contained block of HTML, on the clipboard or as a file. Either way it is styled so that it will not disturb the page you put it into.