checkerboard
element objects
A checkerboard pattern, including option for flicker.
▸ Object ends on its own?
"Ends on its own" means ends automatically at that point. If an element can end on its own, you don't need to set end conditions for it in property end (unless you want it to maybe end earlier).
No—runs until any condition you set in property end.
size
numChecks
phase
meanIntensity
amplitude
contrast
color
flickerFrequency
All visual elements
position
depth
nn_eyes
rotation
flipHorz
flipVert
colorMask
alpha
intensity
contrastMult
convolution
shader
filterOrder
filterGrayscale
filterResolutionMult
filterGamma
channelResolution
backColor
addDisplay
All visual elements
position
All adjuster elements have
adjust
All response handler elements
translateResponse
scoreResponse
correctResponse
scoreResponseForStaircase
maxNumResponses
recordDefaultResponse
registerTrigger
autoResponse
autoResponseLatency
All elements
start
end
startBuffer
endBuffer
vary
staircase
All objects
report
info
size
Default: square with sides 10 deg
A number that is side length for a square checkerboard, or a vector [width height] for a rectangle (deg).
numChecks
Default: 20 square checks across checkerboard width
Number of checks across the width of the checkerboard. Number of checks across its height is then automatic to give square checks.
Or a vector [n_w n_h] setting number of checks across width and height independently. You can use this if you want non-square checks.
phase
Default: immediate check in quadrant 1 = light
0/1 setting the initial pattern: 0 = check immediately right and below element display center = dark, 1 = light. Note currently the checkerboard is always centered at element position, with the corners of four checks at that point. Element position can be set in property position.
meanIntensity
amplitude
contrast
Defaults: meanIntensity = 0.5, amplitude = 0.5
meanIntensity is a number between 0–1 (black–maximum) setting the mean pixel intensity of dark and light checks.
Also set one of:
amplitude is intensity of light checks − intensity of dark checks.
OR
contrast is Michelson contrast, amplitude / mean intensity. If you set contrast, mean intensity must be > 0.
It's possible to set a combination of these properties that causes the checkerboard to clip at intensity 0 or 1. See record properties maxAmplitude and maxContrast below.
color
Default: white
A 1×3 RGB vector with numbers between 0–1. This defines the color at pixel intensity = 1. Color at intensity = 0 is <cd>[0 0 0]<cd>. Color at all other intensities is linearly interpolated between the two.
flickerFrequency
Default: no flicker
Frequency of switching between dark–light (cycles/sec). 0 = no flicker.
Adjustable properties
You can vary or allow the subject to adjust the following properties of an object of this type when it's running. If you need to make other properties adjustable, you can edit the element type code—see Element Type Programming Manual.
Adjustable properties
Adjustable properties
position
nn_eyes
rotation
colorMask
alpha
intensity
contrastMult
drawCodeVars
(None)
(None)
PsychBench uses record properties to record information during experiments. You can't set record properties but you can see them in experiment results using input property report.
maxAmplitude
maxContrast
All response handler elements
response
responseScore
responseTime
responseLatency
d_responseTime
numResponses
All elements
startTime
endTime
duration
n_startFrame
n_endFrame
startLatencyBufferable
endLatencyBufferable
All elements
startTime
endTime
duration
n_startFrame
n_endFrame
startLatencyBufferable
endLatencyBufferable
trigger
triggerTime
d_triggerTime
numTriggers
syncTime
maxAmplitude
maxContrast
Maximum amplitude and contrast where intensity would clip at 0 or 1, whichever is reached first, given the set mean intensity.