An object of type fixedStepStaircase is an “n-down/m-up” (i.e. n correct responses → step harder, m incorrect responses → step easier) staircase with fixed step sizes. Subject threshold is calculated as the average staircase value across reversals.
You can add columns setting properties for one or more fixedStepStaircase objects in the optional table for objects not specific to trial (experiment, device, staircase objects). [Or in the coding method: Make a fixedStepStaircase object outside trials using function fixedStepStaircaseObject, set properties, and input it to addToExperiment.]
No default
Initial staircase value (a number).
Default: step on 2 correct / 1 incorrect responses in a row
A 1×2 vector setting how many [correct incorrect] response trials in a row are needed to step the staircase value in the respective direction. e.g. <cd>[2 1]<cd> gives a 2-harder/1-easier staircase.
No default
A 1×2 vector setting staircase value step sizes for [correct incorrect]. One number must be positive (increase staircase value), the other negative (decrease). Which one you make positive or negative depends on whether it’s an increasing or decreasing psychometric function.
Default: numFastReversals = no fast reversals
Default: fastStepSizes = stepSizes above
numFastReversals is number of reversals to do fast. 0 = none.
fastStepSizes is like stepSizes above. <cd>[]<cd> = same as stepSizes.
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.