Visual Psychophysics Engine

Neil Parry

The Visual Psychophysics Engine is a versatile software tool for ViSaGe that was developed by Dr Neil Parry (Clinical Vision Scientist, The University of Manchester). It is supplied with a suite of pre programmed experimental paradigms which allow you to measure luminance and chromatic Contrast Sensitivity Functions, increment thresholds and De Lange curves. You can also create your own bespoke protocols and present standard visual stimuli like sinewave gratings and Gabor patches using the easy-to-use, menu-driven interface.

Guide Price: £1500

SKU: N2800

Flexibility to design your own experiments

VPE offers great flexibility over your experimental protocols, and includes an interactive demonstration on how to design your own experiment from scratch.


Stimulus types include:

  • Grating
  • Gabor
  • Checkerboard
  • Spot
  • Compound (average of 2 gratings)
  • Cross (for fixation)
  • Campbell-Robson grating
  • Bitmap

With control of options and parameters including:

  • Shape, size, position, orientation, profile
  • Spatial & temporal modulation, sinusoidal, square, frequency, phase, drift, pulse, ramp, delay, attack, plateau, decay
  • Contrast (Michealson, LogDeltaL), modulation
  • Colour, CIE, RGB, RGBLC, rotation, purity

Experimental design

Options include:

  • Free running
  • Method of adjustment
  • Yes/No
  • 2 Alternate Forced Choice (spatial or temporal)
  • Staircase


Results can be displayed as spreadsheet data, and graphically.

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