Working Memory — Visual Digit Span

The digit span task asks you to hold a string of digits in mind and reproduce it. Performance indexes verbal working-memory capacity: the limited store that keeps a small amount of verbal material active — the phonological loop in Baddeley's model (Baddeley, 1992) and, more generally, the few items that can be held in the focus of attention at once (Cowan, 2001). The variants differ in how much they tax the central executive. Forward span is closest to simple storage and rehearsal. Backward span and sequencing additionally require you to manipulate the held material — reversing or reordering it — so they lean more on attentional control and mental manipulation, not just storage. The gap between forward and the manipulation variants is the part most sensitive to executive load. Working-memory capacity is a domain-general bottleneck: it bounds how much information you can keep available while reasoning, following instructions, or reading, and it correlates broadly with attentional control and fluid reasoning (Engle, 2002). Because capacity here is read as a raw maximum span measured under this specific presentation timing, it is a research-grade marker of working-memory capacity — not a diagnostic test for ADHD, a learning disability, or any other condition.

These figures describe this respondent's own within-session performance — reaction-time differences and accuracy across conditions. Where a published reference distribution exists, a percentile within that sample is shown alongside the raw value; otherwise only the raw effect is reported.

• Baddeley, A. (1992). Working memory. Science, 255(5044), 556–559.
• Cowan, N. (2001). The magical number 4 in short-term memory: A reconsideration of mental storage capacity. Behavioral and Brain Sciences, 24(1), 87–114.
• Engle, R. W. (2002). Working memory capacity as executive attention. Current Directions in Psychological Science, 11(1), 19–23.