Change Detection Task¶
HED Task ID: hedtsk_change_detection
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¶
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¶
Variation |
Description |
Justification |
|---|---|---|
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 |
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 |
Oriented bars instead of colors; probes non-color feature binding. |
Orientation feature instead of color; different perceptual dimension |
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 |
Irrelevant items present alongside targets; measures filtering efficiency. |
Some items task-relevant, others to be ignored; adds selective attention demand |
Continuous Report / Precision Task |
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 |
Items encoded one at a time; changes encoding from parallel to serial. |
Items presented serially before test; different encoding structure |
Cognitive processes¶
This task engages the following cognitive processes:
Key references¶
{‘authors’: ‘Luck, S. J., & Vogel, E. K.’, ‘year’: 1997, ‘title’: ‘The capacity of visual working memory for features and conjunctions’, ‘venue’: ‘Nature’, ‘venue_type’: ‘journal’, ‘journal’: ‘Nature’, ‘volume’: ‘390’, ‘issue’: ‘6657’, ‘pages’: ‘279-281’, ‘doi’: ‘10.1038/36846’, ‘openalex_id’: None, ‘pmid’: None, ‘citation_string’: ‘Luck, S. J., & Vogel, E. K. (1997). The capacity of visual working memory for features and conjunctions. Nature, 390(6657), 279–281.’, ‘url’: ‘https://doi.org/10.1038/36846’, ‘source’: ‘crossref’, ‘confidence’: ‘high’, ‘verified_on’: ‘2026-04-20’}
{‘authors’: ‘Cowan, N.’, ‘year’: 2001, ‘title’: ‘The magical number 4 in short-term memory: A reconsideration of mental storage capacity’, ‘venue’: ‘Behavioral and Brain Sciences’, ‘venue_type’: ‘journal’, ‘journal’: ‘Behavioral and Brain Sciences’, ‘volume’: ‘24’, ‘issue’: ‘1’, ‘pages’: ‘87-114’, ‘doi’: ‘10.1017/s0140525x01003922’, ‘openalex_id’: None, ‘pmid’: None, ‘citation_string’: ‘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.’, ‘url’: ‘https://doi.org/10.1017/s0140525x01003922’, ‘source’: ‘crossref’, ‘confidence’: ‘high’, ‘verified_on’: ‘2026-04-20’}
{‘authors’: ‘Vogel, E. K., & Machizawa, M. G.’, ‘year’: 2004, ‘title’: ‘Neural activity predicts individual differences in visual working memory capacity’, ‘venue’: ‘Nature’, ‘venue_type’: ‘journal’, ‘journal’: ‘Nature’, ‘volume’: ‘428’, ‘issue’: ‘6984’, ‘pages’: ‘748-751’, ‘doi’: ‘10.1038/nature02447’, ‘openalex_id’: None, ‘pmid’: None, ‘citation_string’: ‘Vogel, E. K., & Machizawa, M. G. (2004). Neural activity predicts individual differences in visual working memory capacity. Nature, 428(6984), 748–751.’, ‘url’: ‘https://doi.org/10.1038/nature02447’, ‘source’: ‘crossref’, ‘confidence’: ‘high’, ‘verified_on’: ‘2026-04-20’}
Recent references¶
{‘authors’: ‘Luck, S. J., & Vogel, E. K.’, ‘year’: 2013, ‘title’: ‘Visual working memory capacity: from psychophysics and neurobiology to individual differences’, ‘venue’: ‘Trends in Cognitive Sciences’, ‘venue_type’: ‘journal’, ‘journal’: ‘Trends in Cognitive Sciences’, ‘volume’: ‘17’, ‘issue’: ‘8’, ‘pages’: ‘391-400’, ‘doi’: ‘10.1016/j.tics.2013.06.006’, ‘openalex_id’: None, ‘pmid’: None, ‘citation_string’: ‘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.’, ‘url’: ‘https://doi.org/10.1016/j.tics.2013.06.006’, ‘source’: ‘crossref’, ‘confidence’: ‘high’, ‘verified_on’: ‘2026-04-20’}
{‘authors’: ‘Adam, K. C. S., Mance, I., Fukuda, K., & Vogel, E. K.’, ‘year’: 2015, ‘title’: ‘The Contribution of Attentional Lapses to Individual Differences in Visual Working Memory Capacity’, ‘venue’: ‘Journal of Cognitive Neuroscience’, ‘venue_type’: ‘journal’, ‘journal’: ‘Journal of Cognitive Neuroscience’, ‘volume’: ‘27’, ‘issue’: ‘8’, ‘pages’: ‘1601-1616’, ‘doi’: ‘10.1162/jocn_a_00811’, ‘openalex_id’: None, ‘pmid’: None, ‘citation_string’: ‘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.’, ‘url’: ‘https://doi.org/10.1162/jocn_a_00811’, ‘source’: ‘crossref’, ‘confidence’: ‘high’, ‘verified_on’: ‘2026-04-20’}
{‘authors’: ‘Luria, R., Balaban, H., Awh, E., & Vogel, E. K.’, ‘year’: 2016, ‘title’: ‘The contralateral delay activity as a neural measure of visual working memory’, ‘venue’: ‘Neuroscience & Biobehavioral Reviews’, ‘venue_type’: ‘journal’, ‘journal’: ‘Neuroscience & Biobehavioral Reviews’, ‘volume’: ‘62’, ‘issue’: None, ‘pages’: ‘100-108’, ‘doi’: ‘10.1016/j.neubiorev.2016.01.003’, ‘openalex_id’: None, ‘pmid’: None, ‘citation_string’: ‘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.’, ‘url’: ‘https://doi.org/10.1016/j.neubiorev.2016.01.003’, ‘source’: ‘crossref’, ‘confidence’: ‘high’, ‘verified_on’: ‘2026-04-20’}
{‘authors’: ‘Ma, W. J., Husain, M., & Bays, P. M.’, ‘year’: 2014, ‘title’: ‘Changing concepts of working memory’, ‘venue’: ‘Nature Neuroscience’, ‘venue_type’: ‘journal’, ‘journal’: ‘Nature Neuroscience’, ‘volume’: ‘17’, ‘issue’: ‘3’, ‘pages’: ‘347-356’, ‘doi’: ‘10.1038/nn.3655’, ‘openalex_id’: None, ‘pmid’: None, ‘citation_string’: ‘Ma, W. J., Husain, M., & Bays, P. M. (2014). Changing concepts of working memory. Nature Neuroscience, 17(3), 347–356.’, ‘url’: ‘https://doi.org/10.1038/nn.3655’, ‘source’: ‘crossref’, ‘confidence’: ‘high’, ‘verified_on’: ‘2026-04-20’}