Battery guide
Visual Perception Battery guide
Three tests of contrast sensitivity, finding hidden shapes and judging the upright, for visual perception research.
- Guide version
- 1.2.0
- Battery version
- 1.0.0
What it measures
Who it is for: Visual perception research.
It measures Contrast sensitivity, Finding shapes hidden in a pattern and Visual field dependence.
Attention: Keeping attention on a task and picking out what matters.
Scores describe how a person performs on these tasks. Research use only.
Tests in order
The tests run in this order. A study started from the battery keeps the order and the settings.
1. Contrast Sensitivity Test. A research measure of contrast sensitivity on the participant's own screen. After a short screen calibration, faint striped patches tilt left or right at five stripe widths, and participants press an arrow key for the tilt. A staircase for each stripe width finds the faintest patch the person sees.
2. Hidden Shapes Test. A measure of finding a simple shape hidden in a complex drawing, after the embedded figures paradigm. Each screen shows a shape above three line drawings, and participants choose the drawing that hides it at the same size and turn. The drawings get busier in three levels. The main score is the number of shapes found, with the median time to find them.
3. Rod and Frame Task. Measures how much a tilted square frame pulls a person's sense of upright. Participants turn a rod, shown as two dots in a round window on a dark screen, until it looks upright, with no frame, an upright frame or a frame tilted 10, 20 or 30 degrees to either side.
| Order | Test | Domain | Time |
|---|---|---|---|
| 1 | Contrast Sensitivity Test | Attention | 8 to 10 minutes |
| 2 | Hidden Shapes Test | Attention | 5 to 8 minutes |
| 3 | Rod and Frame Task | Attention | 6 to 9 minutes |
Time and devices
Allow about 27 minutes for the whole battery. The table gives each test's time.
Participants can use a desktop or laptop.
On a desktop or laptop the screen must be at least 1024 by 700 pixels.
Participants need Chrome, Edge, Firefox or Safari.
| Test | Timing | Devices |
|---|---|---|
| Contrast Sensitivity Test | Untimed | Desktop or laptop |
| Hidden Shapes Test | Untimed | Desktop or laptop or tablet |
| Rod and Frame Task | Untimed | Desktop or laptop |
Languages
Runs in all eight participant languages.
How to give it
Start a study from the battery in the app. The tests, their order and their settings are already set and stay fixed. If you change, reorder or customize a test, the study becomes a custom study and no longer carries the battery.
Each test opens with its instructions. Participants see these:
Contrast Sensitivity Test: Press the left or right arrow for the way the stripes tilt.
Hidden Shapes Test: Choose the drawing that has the shape hidden in it, by click, tap or the 1, 2 and 3 keys.
Rod and Frame Task: Turn the rod with the left and right arrow keys until it is exactly upright, ignoring the frame, then press the spacebar.
| Step | Before you invite participants |
|---|---|
| 1 | Ask participants to use a desktop or laptop in a room with steady light and no glare on the display. |
| 2 | Ask participants to wear the glasses or contact lenses they use for a computer. |
| 3 | Ask participants not to change the display's brightness after the contrast task's calibration. |
| 4 | Pilot the battery yourself on a desktop or laptop. |
How each test is scored
The server scores each test when the participant finishes it. The primary score is the one the app compares with a norm. The other scores are reported with it.
Every result records its scoring version. For this battery they are Contrast Sensitivity Test 1.0.0, Hidden Shapes Test 1.0.0 and Rod and Frame Task 1.0.0.
| Test | Score | What it is | Better |
|---|---|---|---|
| Contrast Sensitivity Test | Log Contrast Sensitivity at 3 c/deg (primary) | Log10 of one over the Michelson contrast seen at 81.6% correct at 3 cycles per degree, from that frequency's answers by maximum likelihood. | Higher means fainter patches were seen |
| Contrast Sensitivity Test | Area Under the Log CSF | Area under log contrast sensitivity over log10 spatial frequency from 0.75 to 6 cycles per degree, by the trapezoid rule. Null unless all four frequencies have a threshold. | Higher means better sensitivity across frequencies |
| Contrast Sensitivity Test | Log Contrast Sensitivity at 0.75 c/deg | Log contrast sensitivity at 0.75 cycles per degree. | Higher means fainter patches were seen |
| Contrast Sensitivity Test | Log Contrast Sensitivity at 1.5 c/deg | Log contrast sensitivity at 1.5 cycles per degree. | Higher means fainter patches were seen |
| Contrast Sensitivity Test | Log Contrast Sensitivity at 6 c/deg | Log contrast sensitivity at 6 cycles per degree. | Higher means fainter patches were seen |
| Contrast Sensitivity Test | Log Contrast Sensitivity at 12 c/deg | Log contrast sensitivity at 12 cycles per degree. Null when the screen cannot draw that frequency with 4 pixels per cycle. | Higher means fainter patches were seen |
| Contrast Sensitivity Test | Peak Log Contrast Sensitivity | Highest log contrast sensitivity measured at any frequency. | Higher means fainter patches were seen |
| Contrast Sensitivity Test | Peak Frequency (c/deg) | Spatial frequency of the highest log contrast sensitivity. | Informational |
| Contrast Sensitivity Test | Staircase Reversals by Frequency | Changes of direction in each staircase's contrasts, keyed by cycles per degree. | Informational |
| Contrast Sensitivity Test | Frequencies Shown | Spatial frequencies the screen drew with at least 4 pixels per cycle. | Five on fine screens |
| Contrast Sensitivity Test | Frequencies Dropped | Spatial frequencies left out because the screen could not draw them with 4 pixels per cycle. | Informational |
| Contrast Sensitivity Test | Accuracy (proportion) | Share correct over answers at or after 100 ms. | The staircases keep it high |
| Contrast Sensitivity Test | Viewing Distance (cm) | Distance from the eyes to the screen, from the blind spot or the set distance. | Informational |
| Contrast Sensitivity Test | Blind-spot Presses | Blind-spot presses accepted for the viewing distance. Null with a set distance. | Five are planned |
| Contrast Sensitivity Test | Blind-spot Spread | Standard deviation of the blind-spot distances over their mean. | Above 0.2 is flagged for review |
| Contrast Sensitivity Test | Screen Pixels per mm (px/mm) | Screen pixels per millimeter from the card match. | Outside 2.5 to 15 is flagged for review |
| Contrast Sensitivity Test | Screen Pixels per Degree (px/degree) | Screen pixels in one degree of visual angle at the viewing distance. | Informational |
| Contrast Sensitivity Test | Device Pixel Ratio | Screen pixels per CSS pixel, as the browser reported it. | Informational |
| Contrast Sensitivity Test | Dropped Frame Rate (proportion) | Share of display frames the browser dropped while the patches showed. | Above 0.05 is flagged for review |
| Hidden Shapes Test | Shapes Found (primary) | Items answered with the drawing that hides the shape. | Higher is better |
| Hidden Shapes Test | Accuracy (proportion) | Share of items answered correctly. | Higher is better; chance is 0.33 |
| Hidden Shapes Test | Median Time to Find (ms) | Median time from the screen's onset to a correct answer. | Lower is faster |
| Hidden Shapes Test | Accuracy, Easy Drawings (proportion) | Share correct at the level with the fewest lines. | Higher is better |
| Hidden Shapes Test | Accuracy, Medium Drawings (proportion) | Share correct at the middle level. | Higher is better |
| Hidden Shapes Test | Accuracy, Hard Drawings (proportion) | Share correct at the level with the most lines. | Higher is better |
| Hidden Shapes Test | Median Response Time (ms) | Median time to answer, right or wrong. | Informational; the test has no time limit |
| Hidden Shapes Test | Anticipations | Presses under 100 ms from the screen's onset. They are not taken as answers. | Lower is better |
| Hidden Shapes Test | Planned Items (trials) | Items the session planned to show. | Informational |
| Hidden Shapes Test | Total Items (trials) | Items answered in the scored run. | Fewer than planned is flagged for review |
| Rod and Frame Task | Mean Error, Tilted Frame (degrees, primary) | Mean distance from upright of the settings made with a tilted frame. | Lower is closer to upright |
| Rod and Frame Task | Frame Pull (degrees) | Mean pull toward the frame's tilt over tilts of 10, 20 and 30 degrees. Each tilt's pull is half the difference between the settings with the frame tilted clockwise and counterclockwise. | Larger means more reliance on the frame |
| Rod and Frame Task | Frame Pull at 20 Degrees (degrees) | The pull at a tilt of 20 degrees, near its usual peak; the pulls at 10 and 30 degrees are also reported. | Larger means more reliance on the frame |
| Rod and Frame Task | Rod Alone Setting (degrees) | Mean signed setting with no frame, the subjective visual vertical; positive leans clockwise. | Near 0 is upright |
| Rod and Frame Task | Upright Frame Error (degrees) | Mean distance from upright of the settings inside an upright frame. | Lower is closer to upright |
| Rod and Frame Task | Setting Spread (degrees) | Mean spread of the settings within each frame condition. | Lower is more consistent |
| Rod and Frame Task | Median Setting Time (ms) | Median time from the rod appearing to the spacebar. | Informational |
| Rod and Frame Task | Unturned Settings | Settings made without turning the rod from where it started. | Lower is better |
Session quality rules
The app checks every session when it scores it and records one of four states.
An Invalid session stays in the study's results, labelled with its reason, and does not count toward norms.
A session can carry warnings and still be valid. The results list the warnings next to the scores.
| State | What it means |
|---|---|
| Norm-ready | The session passed every check and a norm exists for it, so the app can show a percentile. |
| Raw-only | The scores are usable, but the app shows no percentile. Typical reasons are no norm for the test, changed settings, or a warning that makes a comparison unfair, such as a restart or a screen too short for the display. |
| Invalid technical | The setup broke the timing or the task. Examples are leaving full screen, a browser tab that lost focus during a timed test, and long pauses. |
| Invalid behavioral | The responses suggest the task was not done as asked. Examples are a failed attention check, repeated switching away from the task, and accuracy at or below chance on a choice task. |
Published norms used
No published norm is used for any test in this battery.
ConductCognition also builds norms from its own participants. An age band of a test uses them once it holds at least 50 valid sessions on the same device and input type, run with standard settings and scored with the current scoring version. Sessions from paying customers' studies and from clinical or patient samples do not count.
A report shows a percentile only when the app has stored one for that session. Otherwise it shows the raw scores.
Every reference group covers ages 18 and over. No reference group covers a participant under 18, so their report shows raw scores only, and their sessions do not count toward norms.
How to cite
ConductScience, Inc. Visual Perception Battery guide, version 1.2.0. ConductCognition. https://conductcognition.com/batteries/visual-perception/guide
Cite the guide version you used. Name the battery version (1.0.0) and the scoring versions listed in this guide.