Attention
Face Aftereffect Task
Also called: face distortion aftereffect, figural face adaptation, normality judgments
Measure how viewing a distorted face shifts which faces look normal. Compare judgments before and after adaptation.
8-12 minTimed: desktop or laptop with a mouse or trackpad
Free to start: 10 free participants per account, then $0.99 per participant for academic research, or any yearly plan. Try it here first, with no account.
- Papers, 2021 to 2025
- 74
- Evidence grade
- D
- Registered clinical studies
- 0
What it measures
Measures how viewing a distorted face shifts what looks normal. Participants judge faces before and after looking at an expanded or contracted face. Scores show the shift toward the adapting distortion.
Constructs
- Face adaptation
- Perceived facial normality
- Visual aftereffects
Research uses
- Face perception research
- Visual adaptation research
How the paradigm works
Viewing an expanded or contracted face can change which distortions look normal. This version compares fixed levels before and after adaptation. One London Set person is selected from a pool of four; two other people appear in practice. Each of seven distortion levels appears four times per block by default, or six times. The seed shuffles levels and chooses the adapting direction unless the study fixes it.
More about the paradigm
Both blocks start with a 30-second exposure, followed by five-second exposures between judgments. Baseline exposures show a cross on gray; adapted exposures show the distorted face. After a 500 ms blank, a test face appears for 1,000 ms. The face disappears before the five-second F/J answer window. Actual display durations are saved. Practice explains the controls without labeling a subjective answer right or wrong.
The primary score is the shift in the rate-weighted center of distortions judged normal, signed toward the adapter. Choices under 100 ms are excluded. A center is blank when any level has fewer than two usable answers or the normal-response profile is flat. This is a short, fixed-level adaptation with our own warps, rather than the source’s two-dimensional staircase. Judgments describe visual impressions, not the people pictured. Norms are off.
Scores
- Aftereffect shiftpoints
- Adapted minus baseline normality center, multiplied by adapter direction. Positive means a shift toward the adapting distortion. Units are Gaussian warp amplitude times 100.
- Informational
- Signed distortion shiftpoints
- Adapted minus baseline center; positive means expansion.
- Informational
- Baseline normality centerpoints
- Rate-weighted center of fixed distortions judged normal before adaptation. At least two usable answers per level and a non-flat profile are required.
- Informational
- Adapted normality centerpoints
- Rate-weighted center after adaptation, on the same distortion scale.
- Informational
- Normal judgments before adaptation%
- Percentage of usable baseline judgments answered normal.
- Informational
- Normal judgments after adaptation%
- Percentage of usable adapted judgments answered normal.
- Informational
- Usable judgmentscount
- Answered test judgments excluding choices under 100 ms.
- Informational
- Planned judgmentscount
- 56 or 84 judgments, excluding practice.
- Informational
- Median answer timems
- Median time from disappearance of the test face to a usable answer.
- Informational
- Anticipationscount
- Answers under 100 ms, excluded from the shift.
- Informational
- Missed judgmentscount
- Test faces with no valid answer within five seconds.
- Informational
Use and evidence
74 papers from 2021 to 2025 name this task in their title or abstract, up 3% compared with 2016 to 2020. That ranks it 292 of 582 test families in our census. See the counts for every test.
Show the numbers
| Year | Papers |
|---|---|
| 2025 | 29 |
| 2024 | 12 |
| 2023 | 10 |
| 2022 | 10 |
| 2021 | 13 |
| 2020 | 12 |
| 2019 | 7 |
| 2018 | 11 |
| 2017 | 14 |
| 2016 | 28 |
| 2015 | 19 |
| 2014 | 30 |
| 2013 | 30 |
| 2012 | 33 |
| 2011 | 38 |
| 2010 | 65 |
| 2009 | 17 |
| 2008 | 17 |
| 2007 | 13 |
| 2006 | 7 |
| 2005 | 11 |
| 2004 | 4 |
| 2003 | 3 |
| 2002 | 1 |
| 2001 | 1 |
| 2000 | 1 |
Use grade D
30 to 99 papers from 2021 to 2025.
Evidence grade D
Little published measurement evidence found.
- Papers on test-retest reliability
- 1
- Papers on reliability or validity
- 12
- Registered clinical studies using it as an outcome
- 0
Measured on ConductCognition
Pooled across the studies that feed our platform norms, by device group. A figure needs 50 or more people.
No pooled figure yet.
Note on the counts: Fixed one-axis normality judgments; impressions, not traits. Norms off..
How the grades work
Use: A is 1,000 or more papers from 2021 to 2025, B 300 to 999, C 100 to 299, D 30 to 99 and E fewer than 30. Evidence: A means at least 25 papers report its test-retest reliability and at least 25 registered clinical studies use it as an outcome; B, at least 8 test-retest papers, and either 5 registered clinical studies or 150 reliability or validity papers; C, at least 2 test-retest papers, 30 reliability or validity papers or 3 registered clinical studies; D, little published measurement evidence found. The counts measure use. They include every paper that names the task in its title or abstract. Grades describe the published research on this task, not ConductCognition's version of it.
Source: ConductCognition test census 0.39.0, counted 10 November 2026 from OpenAlex and ClinicalTrials.gov.
Task design
The trial sequence as the test runs in ConductCognition.
- Faces
- One person selected by the session seed from four London Set neutral front photographs. Two separate people appear in practice. Our code expands or contracts central features while keeping the outer head almost unchanged.
- Levels
- Seven fixed distortion levels: -60, -40, -20, 0, 20, 40 and 60 in warp-amplitude points. The adapter is -80 or +80. These are image-warp settings, not percentages of face size.
- Judgments
- 56 test judgments by default: 4 repeats per level in each of two blocks. The longer setting uses 6 repeats, for 84 judgments. Baseline always precedes adaptation; the seed shuffles each pass.
- Timing
- Each block starts with 30 seconds of gray or the adapting face, then uses 5-second exposures before later tests. A 500 ms blank precedes each 1,000 ms test face. Answer with F or J after it disappears, within 5 seconds. Frame durations are recorded.
- Scoring
- Aftereffect shift is the adapted minus baseline rate-weighted center of normal judgments, signed toward the adapter. A center needs two usable answers at every level and a non-flat profile. Responses under 100 ms are excluded.
These judgments describe visual impressions, not the people pictured. This version uses London Set photographs, one distortion axis, fixed levels and shorter adaptation than the published method. Norms are off. The pool of four test and two practice people overlaps with Face Memory Test (3), Face-Name Memory Task (3), Face Matching Task (6), Chimeric Faces Task (2), Part-Whole Face Task (2), Thatcher Illusion Task (1), Two-Tone Pictures Task (2), Verbal Overshadowing Task (4), Face Impressions Task (6), Real or AI Face Task (6), Uncanny Valley Task (3). One test person is selected per session. Counts include practice and foils in the other tasks. Separate sessions or counterbalance task order when combining face tasks. All 6 people in this pool also appear in the Group Faces Task's stimulus pool.
Quality checks
Each session is marked valid, needs review or invalid, with the reason, before you see its scores.
Scored rows: face_aftereffect_test from the run with the most unique judgments. Normality has no correct answer. Incomplete runs or an undefined normality center are flagged. Missed responses and responses under 100 ms follow the timed-test rule.
Why these rules
There is no correct option to compare with chance, so accuracy is not judged against chance. The shift describes judgments within this session. Missed responses and responses under 100 ms keep the platform's timed-test rule: more than max(3, 25%) missed responses or more than max(2, 20%) responses under 100 ms invalidate, and any is flagged. A response under 100 ms cannot be a reaction to the stimulus.
No percentile. Scores and quality flags only.
Running this test
Settings you can change
| Setting | Standard | Allowed |
|---|---|---|
| Repeats per distortion | 4 (56 judgments, standard) | 4 (56 judgments, standard), 6 (84 judgments) |
| Adapting distortion | Chosen by session seed | Chosen by session seed, Expanded, Contracted |
Yearly plans can change settings within these limits. Free and pay-as-you-go studies use the standard settings.
Need a setting this test does not have?
Devices and languages
- Timed test: participants need a desktop or laptop with a mouse or trackpad. Participant devices
- Languages: English, Spanish, French, German, Italian, Portuguese (Brazil), Chinese (Simplified) and Japanese.
- Available on: Every plan, including the free plan.
- No percentile. Scores and quality flags only. How norms work
- Recruiting online? See the setup guides for Prolific, Sona Systems, CloudResearch Connect and Qualtrics.
Cite and describe
Participants completed the Face Aftereffect Task in a web browser (ConductCognition task version 1.0.0, scoring version 1.0.0; Webster and MacLin, 1999), with the standard settings (repeats per distortion: 4 (56 judgments, standard); adapting distortion: Chosen by session seed). The main score was aftereffect shift (adapted minus baseline normality center, multiplied by adapter direction).
ConductCognition versions: task version 1.0.0, scoring version 1.0.0. Every export records the versions each session used, for a methods section.
- Webster, M. A., & MacLin, O. H. (1999). Figural aftereffects in the perception of faces. Psychonomic Bulletin & Review, 6(4), 647-653. https://doi.org/10.3758/BF03212974Gaussian distortion and normal-or-distorted judgments before and after adaptation.
Source papers
Questions
How long does the Face Aftereffect Task take?
About 8 to 12 minutes, as listed in the test library.
What device does a participant need?
Timed test: participants need a desktop or laptop with a mouse or trackpad. The browser must be Chrome, Edge, Firefox or Safari.
What scores does it produce?
Aftereffect shift, Signed distortion shift, Baseline normality center, Adapted normality center, Normal judgments before adaptation, Normal judgments after adaptation, Usable judgments, Planned judgments, Median answer time, Anticipations and Missed judgments. Each session is also marked valid, needs review or invalid, with the reason.
How widely is the Face Aftereffect Task used in research?
74 papers from 2021 to 2025 name it in their title or abstract, up 3% compared with 2016 to 2020. That ranks it 292 of 582 test families in the ConductCognition test census (use grade D). Source: ConductCognition test census 0.39.0, counted 10 November 2026 from OpenAlex and ClinicalTrials.gov.
How much reliability evidence does the Face Aftereffect Task have?
In the published research, 1 paper reports its test-retest reliability and 0 registered clinical studies use it as an outcome (evidence grade D in the ConductCognition test census).
Does it report a percentile?
No. Scores and quality flags only.
Which settings can a researcher change?
Repeats per distortion (4 (56 judgments, standard), 6 (84 judgments)) and adapting distortion (Chosen by session seed, Expanded, Contracted). Settings can be changed on yearly plans; free and pay-as-you-go studies use the standard settings.
Which languages can participants use?
Participants can take this test in English, Spanish, French, German, Italian, Portuguese (Brazil), Chinese (Simplified) and Japanese. English is on every plan, and the other languages come with yearly plans. Have a native speaker read the machine-translated text before launch.
Is this a clinical test?
No. ConductCognition is for research use only. It runs, scores and exports the test; clinical interpretation is outside the platform.
Every test: the full test list.
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