Digit Span (Forward)

The Digit Span Forward task is the most widely used measure of verbal short-term memory capacity. On each trial, a sequence of digits is presented one at a time in the centre of the screen. Immediately after the last digit disappears, the participant types the sequence in the same order they heard it and presses Enter.

The task begins with spans of 3 digits and increases through 4, 5, 6, 7, 8, and 9. Two trials are presented at each span level. Performance is assessed as the longest span at which the participant recalls correctly on at least one of two trials — the forward digit span score. The task ends automatically after both trials at a given span level are failed.

This implementation uses 2 practice trials (span 3, with feedback) followed by the main task (14 trials: 2 per span level from 3 to 9). Each digit is displayed for 1000 ms, separated by a 500 ms blank inter-stimulus interval. After each practice trial, participants receive feedback showing whether they were correct and the correct sequence, so they understand the response format before data collection begins.