Baseline and dual-task comparison
What happens when two simple tasks compete for your attention? First complete each one alone, then try them together and compare how accuracy and response time change.
Complete each visual task alone before the matched dual-task block.
Classify the central shape: C = circle; S = square.
Accuracy change = dual-task accuracy − baseline accuracy; RT cost = dual-task median correct RT − baseline median correct RT. Read the signed values together with both speed and accuracy.
Baseline Accuracy
0%
Dual task Accuracy
0%
Baseline Median RT
—
Dual task Median RT
—
Accuracy change
Not enough trials
RT dual-task cost
Not enough trials
Misses
0
False alarms
0
Baseline Accuracy
0%
Dual task Accuracy
0%
Baseline Median RT
—
Dual task Median RT
—
Accuracy change
Not enough trials
RT dual-task cost
Not enough trials
Misses
0
False alarms
0
No validity flags were detected
This session first presents central shape decisions and peripheral target monitoring as separate baseline blocks. A final block combines them while preserving the event interval and response deadline. Baseline order is counterbalanced and saved with the result.
The browser stores completed summaries locally and uploads no responses. Signed accuracy changes and response-time costs describe this session only. They are not a multitasking score and do not predict driving, workplace, classroom, or medical performance.
Complete both single-task baseline blocks before the combined block. Follow the displayed visual and secondary-task mappings; the combined block keeps the matching timing parameters so each task has its own reference.
If task A is 90% accurate alone and 80% during the combined block, its accuracy change is −10 percentage points. If its correct-response median rises from 500 to 650 ms, its RT cost is +150 ms. Neither change substitutes for task B’s result, and costs remain unavailable with insufficient trials.
A dual-task result has little meaning without knowing how each component looked on its own. The baseline blocks estimate accuracy and response timing for the same person, device, keys, and session before both response streams are combined.
The page alternates whether task A or task B comes first based on the session seed. That counterbalancing does not remove every order or practice effect, but it avoids forcing all users through one fixed baseline order. The saved settings identify the actual order.
Task A is a central choice: press C for a circle or S for a square. Task B is peripheral monitoring: respond to a solid diamond in one corner and withhold the response for an outlined circle. The final block presents both at the same event rhythm.
The default is visual plus visual so it works without audio permission, headphones, or hearing assumptions. The page does not request microphone access, autoplay sound, or treat an audio task as the only route through the session.
For each task, accuracy change equals dual-task accuracy minus baseline accuracy. RT dual-task cost equals dual-task median correct RT minus baseline median correct RT. Misses and false alarms are shown separately.
A result is calculated only when the baseline and dual condition each contain at least three observations. No combined multitasking score is produced. Keeping A and B separate shows whether the two response streams changed in different ways.
When two decisions compete for response time, a person can slow one response, miss an event, or make a faster incorrect choice. A positive RT cost with steady accuracy describes a different pattern from unchanged RT with more misses.
Median RT includes correct responses only, while accuracy includes all expected decisions. This separation prevents an error-heavy fast block from looking better merely because incorrect responses were quick.
Driving, work, and health decisions involve different sensory inputs, training, consequences, and time scales. A short central-shape and corner-target task cannot simulate those environments or certify safe performance.
Browser scheduling, keyboard or touch latency, screen size, interruptions, fatigue, and baseline order all affect this session. Page hiding pauses the task and adds a validity flag; compare personal sessions only with the same mode and event interval.
Multiple Object Tracking asks you to maintain the identities of several moving targets in one continuous display. This page instead combines two response rules: a central classification and intermittent peripheral target detection.
Both can feel busy, but their measurements are not interchangeable. Tracking selection accuracy does not provide a baseline-versus-dual change, and this task does not estimate how many moving objects can be followed.
Pashler, H. (1994). “Dual-task interference in simple tasks: Data and theory.” Psychological Bulletin, 116(2), 220–244. https://doi.org/10.1037/0033-2909.116.2.220
These questions stay tied to the visible content on this page.
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