Apparatus and calibration.

Display.

Stimuli were displayed on a $[DISPLAYNAME?Yes]{$[DISPLAYNAME]}$[DISPLAYNAME?No]{$[CalibrationName]} monitor driven by a $[GRAPHICSBOARD] with $[VIDEORAM] MB of video RAM, housed in an Apple $[MACTYPE] computer. The display measures $[DisplayWidthMM] x $[DisplayHeightMM] mm and its resolution was set to $[DisplayWidth] x $[DisplayHeight] pixels in $[DisplayBitsPerPixel]-bit color mode at a frame rate of $[DisplayFrameRate] Hz. The monitor was viewed in a blacked out room from a distance of $[DisplayViewingDistance] mm, corresponding to a field of view of $[FOVWidthDeg] x $[FOVHeightDeg] deg of visual angle (i.e. a pixel size of $[PIXEL_ARCSEC] arcseconds or a Nyquist frequency of $[NyquistSF] cpd).

Stimuli Appearance.

Stimuli were generated in the $[DisplayChromaticMode] space and presented in $[DisplayRendering] mode $[DisplayChromaticMode=Mono 9.6 bits Bit-Stealing]{(Tyler, 1997)} $[DisplayChromaticMode=Mono 10.8 bits Bit-Stealing]{(Tyler, 1997)} with a $[DisplayChromaticMode=RGB]{8}$[DisplayChromaticMode=Achromatic]{8}$[DisplayChromaticMode=Mono 9.6 bits Bit-Stealing]{9.6}$[DisplayChromaticMode=Mono 10.8 bits Bit-Stealing]{10.8}$[DisplayChromaticMode=Mono Bits++]{14}$[DisplayChromaticMode=Color Bits++]{14} bits resolution using the Psykinematix software (from KyberVision, Montreal QC, Canada, psykinematix.com) (Beaudot, 2009). Background was set to $[DisplayBackgroundColor] with a luminance of $[MEAN_LUMINANCE] cd/m2. $[FixationMark<>]{A $[FixationColor] '$[FixationMark]' fixation mark was presented during stimulus presentation.} $[PreFixationMark<>]{A $[PreFixationColor] '$[PreFixationMark]' fixation mark was presented before stimulus presentation.} $[PostFixationMark<>]{A $[PostFixationColor] '$[PostFixationMark]' fixation mark was presented after stimulus presentation.} If presented, fixation marks were displayed at the Cartesian location ($[FixationXPos], $[FixationYPos]) relative to the display center. If auditory feedback was provided, a '$[SndIndicator]' sound was emitted before each stimulus presentation and a '$[SndCorrect]' or '$[SndIncorrect]' sound was emitted after a correct or incorrect response, respectively. Trial progress was set to a $[NextTrialTrigger] mode. New stimuli were generated on-line for each trial or presentation.

Calibration.

$[COLORCALIBRATION=Radiometric] { The spectral emissions of the red, green and blue phosphors of the monitor were calibrated using a $[SPECTROMETER_DEVICE] device. $[Fundamentals=SmithPokorny75]{The Smith & Pokorny fundamentals (Smith & Pokorny, 1975)} $[Fundamentals=StockmanSharpe2000 2deg]{The Stockman & Sharpe 2 deg fundamentals (Stockman & Sharpe, 2000)} $[Fundamentals=StockmanSharpe2000 10deg]{The Stockman & Sharpe 10 deg fundamentals (Stockman & Sharpe, 2000)} were used for the spectral absorption of the L, M and S cones. From these data a linear transform was calculated to specify the phosphor contrasts required for given cone contrasts (Cole & Hine, 1992). } $[COLORCALIBRATION=Colorimetric] { The xy chromatic coordinates (based on the CIE 1931 standard) of the red, green and blue phosphors of the monitor were measured using a $[SPECTROMETER_DEVICE] colorimeter (from manufacturer). } $[PHOTOMETER_DEVICE?1] { The monitor was gamma corrected in software with lookup tables using luminance measurements obtained from a $[PHOTOMETER_DEVICE] device (from manufacturer) interfaced with the Psykinematix software. }