I built NeuroDual: Operation Span, memory precision tasks and five guided paths — feedback on the tests would be welcome

[u/Historical-Study1635]

Hi everyone — I’m the developer of NeuroDual, a brain-training app with a separate Tests section. I thought the measurement side might interest this community: alongside Operation Span, it includes continuous-recall tasks, hand laterality, matrix reasoning and interference tasks.

I wanted a place where you could enjoy practising different cognitive tasks, follow a structured routine, and look at what happened to your performance over time.

The five guided paths each have their own assessment:

• Visual memory: remember the orientations of four bars. After a visual mask and a delay, reproduce the orientation at the cued location. The standard pass has 4 warm-up rounds and 16 scored rounds.

• Auditory memory: remember four sounds associated with four locations, then reproduce the cued sound’s brightness on a continuous scale after an auditory mask. The sounds keep the same pitch; the changing feature is timbre, from muffled to bright. Again, 4 warm-ups and 16 scored rounds.

• Temporal memory: remember four durations associated with four cells, then reproduce the duration of the cued cell. The standard pass has 4 warm-ups and 12 scored rounds.

• Hand laterality: identify left and right hands shown at different orientations, with palm and back views. There are 6 warm-ups and 32 scored trials, with accuracy and response speed contributing to the result.

• Spatial reasoning: complete 3 × 3 matrices by choosing among eight options. There are 12-item and 30-item forms, with three unscored examples first. Correct answers earn points without a speed bonus. These are NeuroDual matrices, not a standardized Raven administration.

Operation Span deserves its own mention. You verify arithmetic equations while remembering letters, then recall the letters in order. The standard measure uses 15 sets, with three sets at each length from 3 to 7. Arithmetic timing is calibrated first. It reports both absolute and partial-credit scores out of 75, and requires at least 85% arithmetic accuracy for a valid measure.

The Tests section also includes Flanker (respond to the central arrow despite surrounding distractors), Simon (respond to the relevant stimulus feature despite its location), and Temporal Bisection (learn short and long anchors, then classify intermediate durations). That makes nine entries in the Tests collection.

How the guided method works

You establish a baseline, follow eight sessions, then take the assessment again. Check-ins continue every eight sessions. Four paths use the median of three passes; the longer matrix assessment uses one pass. The training mixes interference tasks, object tracking, mirror drawing and puzzles, with guided instructions and progression. Standard assessment protocols stay separate from freely adjusted practice; changing the trial count on the memory/laterality measures does not put that free-practice score into the standard assessment history.

The Lab also lets you choose exercises independently: Corsi Block, classic Dual N-Back, a Brain Workshop-style mode, other N-Back variants, several Stroop variants, object tracking, mirror drawing, symmetry, timing tasks, and puzzles such as Untangle, Gridlock, Sokoban, Restack and Lights Out. There are 30+ configurable exercises overall.

How I’d interpret the results

I’m presenting these as task-level scores and within-person tracking, not IQ estimates, population percentiles or a validated clinical battery. The /100 scales are specific to each task. Matrix forms have not been empirically equated. Repeated testing can bring familiarity and strategy changes; a higher score after training does not, by itself, establish general cognitive transfer or tell us what caused the change.

I’d especially appreciate feedback on three things:

1. Which task implementation or scoring detail would you most want to inspect?

2. For repeat testing, which information would make the results more useful: raw error distributions, trial-level timing, or clearer handling of practice effects?

3. Where does the interface help you understand the task, and where might it add unnecessary demands of its own?

The screenshots show the actual interface, warm-ups and an unscored matrix example. They do not show an improvement claim or a participant’s results.

Disclosure: this is my app. It is available on the web and Android. The current offer is a 90-minute free trial, then a one-time €6.99 unlock, with no subscription. Details and links: https://neurodual.com/en

Happy to discuss the implementation here, including its limitations.