The HED Task Catalog is under development. IDs are not stable until formal release. Comments are welcome at github.com/hed-standard/hed-task/issues.

Digit Span Task

HED task ID: hedtsk_digit_span

Family: Short-term and working memory tasks

Also known as: DS, Forward/Backward Span, Digit Span

Auditory or visual digit sequences reproduced in forward or backward order; longest correctly reproduced length indexes verbal short-term and working memory span.

Description

The Digit Span task measures verbal short-term and working memory capacity. In the Forward condition, participants listen to sequences of digits presented at a rate of one per second and immediately repeat them in the same order; sequence length increases until recall fails. In the Backward condition, participants repeat digits in reverse order, adding a manipulation component. The Sequencing condition (from WAIS-IV) requires reordering digits numerically. Digit Span is one of the oldest and most widely administered neuropsychological measures, embedded in the Wechsler intelligence and memory scales. Forward span primarily indexes the phonological loop, while backward span engages central executive processes.

Inclusion test

An experiment is an instance of this task when its procedure matches, it manipulates at least one of the listed variables, and it records at least one of the listed measures.

Procedure

Sequences of digits are presented at a rate of one per second; participants reproduce the sequence in forward, backward, or sequencing order. Length increases until two consecutive failures.

Manipulation

Direction (forward, backward, sequencing); sequence length; presentation modality (auditory vs. visual).

Measurement

Span (longest correct sequence); total score; forward-backward difference as index of executive load.

Variations

Named versions that change what the participant experiences or does. The identifier of a variation is hedvar_<task>__<variation>.

Variation

Description

Justification

Forward Digit Span

hedvar_digit_span__forward_digit_span

Repeat digits in presentation order; primarily measures phonological loop capacity.

Reproduce digits in order; canonical phonological span measure

Backward Digit Span

hedvar_digit_span__backward_digit_span

Repeat digits in reverse; adds manipulation and executive demand.

Reproduce in reverse; requires mental transformation

Digit Span Sequencing (WAIS-IV)

hedvar_digit_span__digit_span_sequencing_wais_iv

Reorder digits from lowest to highest; requires sequencing operations.

Reorder digits from smallest to largest; different transformation requirement

Letter-Number Sequencing

hedvar_digit_span__letter_number_sequencing

Mixed sequences of letters and digits; reorder numbers first, then letters alphabetically.

Alternating letters and numbers reordered separately; dual sequencing demand

Auditory vs. Visual Presentation

hedvar_digit_span__auditory_vs_visual_presentation

Digits spoken aloud vs. presented visually on screen; modality effects on span.

Visual digit presentation vs. auditory; different input modality

Adaptive Staircase Versions

hedvar_digit_span__adaptive_staircase_versions

Computerized versions adjusting sequence length based on accuracy; more precise span estimates.

Adaptive difficulty tracking; different trial-generation procedure

Spatial Digit Span

hedvar_digit_span__spatial_digit_span

Digits presented at spatial locations; combines verbal and spatial demands.

Digits at spatial locations; adds spatial component

Running Digit Span

hedvar_digit_span__running_digit_span

Unpredictable sequence lengths; recall the last N items; measures updating.

Recall last N digits of unknown-length list; different task structure

Grouped/Chunked Presentation

hedvar_digit_span__grouped_chunked_presentation

Digits presented in rhythmic groups; examines effects of chunking.

Digits presented in groups; tests chunking facilitation

Matrix Span

hedvar_digit_span__matrix_span

Memory for spatial locations within a matrix; visuospatial analog.

Spatial matrix locations instead of digits; different stimulus type

Supra-Span Lists

hedvar_digit_span__supra_span_lists

Lists exceeding span; number of trials to criterion measures learning rate.

Lists exceed span; tests learning over trials

Cognitive processes

This task is designed to engage the following processes:

Key references

  • Baddeley, A. D. (1986). Working Memory. Oxford University Press. (DOI)

  • Miller, G. A. (1956). The magical number seven, plus or minus two: Some limits on our capacity for processing information. Psychological Review, 63(2), 81–97. (DOI, PubMed)

Further references

  • Woods, D. L., Kishiyama, M. M., Yund, E. W., Herron, T. J., Edwards, B., Poliva, O., … & Reed, B. (2011). Improving digit span assessment of short-term verbal memory. Journal of Clinical and Experimental Neuropsychology, 33(1), 101–111. (DOI)