The Tools

Stimulus Drawing

New algorithms are all implemented in MATLAB to enhance the VSG's drawing capabilities.

• Commonly used stimuli including: gratings, checkerboards, Gabors, Gaussian derivatives
• Noise drawing, with wide range of statistical properties
• Drawn to sub-pixel accuracy
• Can be used with Colour Tools, to directly draw chromatic stimuli in any supported colour space
• Multiple moving regions: easily specify motion between multiple stimuli (ViSaGe only)

Psychophysics

A completely new set of functions implement many commonly used psychophysical techniques.

• Bayesian Statistics
• Classical methods: Method of Adjustment, Method of Constant Stimuli, Method of Limits
• Adaptive methods: Log/Linear ascending/descending staircases, PEST, QUEST, ZEST and more

Calibration, Photometry & Colour

As well as support for standard colorimetric colour specification, the new Colour Tool allows you to define stimuli in terms of actual cone stimulation. Underlying the new Colour Tool are spectroradiometric display calibration routines.

• Monitor calibration using the new CRS SpectroCAL photospectrometer and third-party photometers and spectroradiometers
• Standard colorimetric spaces: CIE 1931, CIE 1976 etc.
• Cone fundamental based colour spaces: SML, DKL etc, using Judd/Vos, or Stockman/Sharpe matching functions
• Photopic and Scotopic Luminance, V_M(λ), V₂^*(λ)
• Stimulus specification colour contrast, LMS and cone quantum catch

Eye Movements

The CRS Video Eyetracker Toolbox system can be easily integrated for gaze tracking and gaze contingent displays.

Dot Plotting

• Dot plotting sequences specified by matrices
• Random dot stereograms using Z buffer to specify disparity

Electrophysiogy

Popular stimuli for pattern ERG/VEPs, all with configurable output trigger.

• Checkerboards
• Gratings
• Isoluminant colour
• Motion onset

Real Demonstrations

The CRS Toolbox includes a collection of real demonstrations, which implement classic vision science experiments. These can be used as the basis of your own experiments, to understand VSG technical and programming concepts, and as teaching tools. All the demos have an easy to use GUI interface. Developing this Toolbox is an on-going project and new demonstrations will be constantly added. Currently we are working on:

• Contrast Sensitivity
• Cone isolating stimuli
• Retinotopic mapping stimuli for functional imaging
• Coherent and incoherent motion thresholds
• M-sequences
• Biological motion
• Tachistoscopic displays
• Common visual illusions
• Pupillometry
• Electrophysiology

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