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.

Change Detection Task

HED task ID: hedtsk_change_detection

Family: Short-term and working memory tasks

Also known as: Luck-Vogel Task, VWM Capacity Task

Brief sample array followed after a blank delay by a probe array; participant reports whether any item changed. Yields visual working memory capacity (K).

Description

The Change Detection Task, developed by Luck and Vogel (1997), is the standard paradigm for measuring visual working memory capacity. Participants briefly view a memory array of colored squares (typically 100–500 ms), followed by a blank retention interval (~900 ms), then a test array. On half the trials, one item changes color; participants report whether a change occurred. Performance is converted to a capacity estimate (K) using Cowan’s formula: K = set size × (hit rate − false alarm rate). The task established that visual WM capacity is approximately 3–4 items in healthy adults and has been instrumental in research linking WM capacity to attention, intelligence, and neural oscillations.

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

A brief memory array of colored squares (or oriented bars) is followed by a retention interval and a test array; participants indicate whether a change occurred.

Manipulation

Set size (number of items); retention interval; number of changes; feature complexity.

Measurement

Accuracy converted to capacity estimate K (Cowan’s K or Pashler’s K); RT.

Variations

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

Variation

Description

Justification

Standard Color Change Detection

hedvar_change_detection__standard_color_change_detection

Colored squares; whole-array test (same/different judgment).

Canonical flicker paradigm: colored squares change across blank; whole/partial report

Single-Probe Change Detection

hedvar_change_detection__single_probe_change_detection

Only one item presented at test; reduces spatial comparison demands.

Post-array probe tests one item; different response structure from whole-display report

Orientation Change Detection

hedvar_change_detection__orientation_change_detection

Oriented bars instead of colors; probes non-color feature binding.

Orientation feature instead of color; different perceptual dimension

Conjunction Change Detection

hedvar_change_detection__conjunction_change_detection

Stimuli defined by feature conjunctions (color+orientation); tests feature binding.

Conjunctions of features can change; higher-order binding demand

Change Detection with Filtering

hedvar_change_detection__change_detection_with_filtering

Irrelevant items present alongside targets; measures filtering efficiency.

Some items task-relevant, others to be ignored; adds selective attention demand

Continuous Report / Precision Task

hedvar_change_detection__continuous_report_precision

Report the feature value (color angle) of a probed item on a continuous scale; measures precision vs. capacity.

Participant reports exact remembered value on continuous wheel; different response format

Sequential Presentation

hedvar_change_detection__sequential_presentation

Items encoded one at a time; changes encoding from parallel to serial.

Items presented serially before test; different encoding structure

Cognitive processes

This task is designed to engage the following processes:

Key references

  • Luck, S. J., & Vogel, E. K. (1997). The capacity of visual working memory for features and conjunctions. Nature, 390(6657), 279–281. (DOI, PubMed)

  • 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. (DOI, PubMed)

  • Vogel, E. K., & Machizawa, M. G. (2004). Neural activity predicts individual differences in visual working memory capacity. Nature, 428(6984), 748–751. (DOI, PubMed)

Further references

  • Luck, S. J., & Vogel, E. K. (2013). Visual working memory capacity: From psychophysics and neurobiology to individual differences. Trends in Cognitive Sciences, 17(8), 391–400. (DOI, PubMed)

  • Adam, K. C. S., Mance, I., Fukuda, K., & Vogel, E. K. (2015). The contribution of attentional lapses to individual differences in visual working memory capacity. Journal of Cognitive Neuroscience, 27(8), 1601–1616. (DOI, PubMed)

  • Luria, R., Balaban, H., Awh, E., & Vogel, E. K. (2016). The contralateral delay activity as a neural measure of visual working memory. Neuroscience & Biobehavioral Reviews, 62, 100–108. (DOI, PubMed)

  • Ma, W. J., Husain, M., & Bays, P. M. (2014). Changing concepts of working memory. Nature Neuroscience, 17(3), 347–356. (DOI, PubMed)